UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Genetic effects on wood shrinkage, relative density, grain angle, tracheid length, and fibril angle in… Koshy, Mathew P. 1993

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-UBC_1993 A1 K67.pdf [ 5.82MB ]
Metadata
JSON: 831-1.0106811.json
JSON-LD: 831-1.0106811-ld.json
RDF/XML (Pretty): 831-1.0106811-rdf.xml
RDF/JSON: 831-1.0106811-rdf.json
Turtle: 831-1.0106811-turtle.txt
N-Triples: 831-1.0106811-rdf-ntriples.txt
Original Record: 831-1.0106811-source.json
Full Text
831-1.0106811-fulltext.txt
Citation
831-1.0106811.ris

Full Text

GENETIC EFFECTS ON WOOD SHRINKAGE, RELATIVE DENSITY, GRAIN ANGLE, TRACHEID LENGTH, AND FIBRIL ANGLE IN DOUGLAS-FIR (PSEUDOTSUGA MENZIESII VAR. MENZIESII (MIRB.) FRANCO) by MATHEW P. KOSHY B. Sc., U n i v e r s i t y of Kerala, 1969 M. Sc., U n i v e r s i t y o f Kerala, 1971 M. Sc., U n i v e r s i t y of Wales, 1987 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN THE FACULTY OF GRADUATE STUDIES (Department of Forest Sciences) We accept t h i s t h e s i s as conforming >fcp ^ h e^required standard THE UNIVERSITY OF BRITISH COLUMBIA March, 1993 © Mathew P. Koshy, 1993 In presenting t h i s t h e s i s i n p a r t i a l f u l f i l l m e n t of the requirements f o r an advanced degree at the U n i v e r s i t y of B r i t i s h Columbia, I agree t h a t the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r reference and study. I f u r t h e r agree t h a t permission f o r extensive copying of t h i s t h e s i s f o r s c h o l a r l y purposes may be granted by the head of my department or by h i s or her r e p r e s e n t a t i v e s . I t i s understood that copying or p u b l i c a t i o n of t h i s t h e s i s f o r f i n a n c i a l gain s h a l l not be allowed without my w r i t t e n permission. (Signature) Department of The U n i v e r s i t y of B r i t i s h Columbia Vancouver, Canada ABSTRACT Seven wood t r a i t s : shrinkage ( l o n g i t u d i n a l , t a n g e n t i a l , and r a d i a l ) , r e l a t i v e d ensity, g r a i n angle, t r a c h e i d length, and f i b r i l angle, and two growth t r a i t s , height and diameter at breast height were analyzed i n 413 t r e e s belonging t o 48 f u l l - s i b f a m i l i e s (4 p o l l e n and 12 seed parents) from an 18-yea r - o l d c o a s t a l D o u g l a s - f i r (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) progeny t e s t . Clones from s i x of the parents a l s o were sampled. Six samples per age l e v e l (age l e v e l s 0 to 4 along stem r a d i i ) , with two r i n g s i n each age l e v e l , were examined i n a b o l t taken at breast height of the t r e e f o r shrinkage and r e l a t i v e d e n s i t y . Smaller sample s i z e s were used f o r the other t r a i t s . Trends with age from the p i t h were decreasing l o n g i t u d i n a l shrinkage and f i b r i l angle and i n c r e a s i n g r a d i a l and t a n g e n t i a l shrinkage, g r a i n angle, and t r a c h e i d length. R e l a t i v e d e n s i t y f i r s t decreased and then increased beyond age l e v e l 2. Genetic e f f e c t s were minimal f o r wood q u a l i t y t r a i t s except f o r r e l a t i v e d e n sity. Most of the v a r i a t i o n f o r wood q u a l i t y t r a i t s was w i t h i n t r e e and between i n d i v i d u a l t r e e s w i t h i n f a m i l i e s . Genetic c o r r e l a t i o n s between wood q u a l i t y t r a i t s were minimal except between r e l a t i v e d e n s i t y and r a d i a l shrinkage, which was p o s i t i v e . Genetic c o r r e l a t i o n s between growth characters l i k e height and diameter a t breast height and wood q u a l i t y t r a i t s were a l s o minimal except f o r r e l a t i v e density and l o n g i t u d i n a l shrinkage a t e a r l y age l e v e l s . S e l e c t i o n f o r increased height can be expected to i i i reduce longitudinal shrinkage and re la t i ve density at early age leve ls , and have v i r t u a l l y no e f fect on the other t r a i t s studied. The resu l ts support current e f fo r t s to increase wood production through genetic improvement in growth rate by showing that current programs of se lect ion for rapid early height growth w i l l not (with the exception of r e l a t i ve density) resu l t in substant ia l reductions in several wood qual i ty t r a i t s beyond the f i r s t few years of tree growth. The demonstrated lack of substantial genetic e f fects for several t r a i t s indicated that genetic improvement can progress more rapid ly by concentrating on a much smaller number of t r a i t s . i v CONTENTS Page TITLE PAGE 1 ABSTRACT i i CONTENTS i v LIST OF TABLES v i LIST OF FIGURES x i LIST OF APPENDICES X V ACKNOWLEDGEMENTS X V i i INTRODUCTION 1 LITERATURE REVIEW 6 MATERIALS AND METHODS 17 Sampling of t r e e s 20 Measurement of shrinkage 23 Measurement of r e l a t i v e d e n s i t y 24 Measurement of g r a i n angle 24 Measurement of t r a c h e i d length 25 Measurement of f i b r i l angle 25 S t a t i s t i c a l a n a l y s i s of data 26 An a l y s i s of variance 2 6 A n a l y s i s of covariance 30 Prel i m i n a r y study 35 Number of samples w i t h i n t r e e and number of tr e e s w i t h i n p l o t - 35 Number of t r e e s w i t h i n f a m i l y 37 Number of blocks per l o c a t i o n 40 Estimation of genetic parameters 42 Estimation of h e r i t a b i l i t y 42 V Estimation of c l o n a l h e r i t a b i l i t y 47 Estimation of phenotypic and ge n e t i c c o r r e l a t i o n 48 RESULTS AND DISCUSSION 49 I. Eighteen-year-old f u l l - s i b progeny 49 A. General l e v e l s and o v e r a l l phenotypic trends at the d i f f e r e n t age l e v e l s 49 B. Means and phenotypic trends f o r h a l f - s i b f a m i l i e s a t d i f f e r e n t age l e v e l s 65 C. H e r i t a b i l i t y 103 D. Phenotypic c o r r e l a t i o n s between shrinkage and other wood t r a i t s 116 E. Genetic c o r r e l a t i o n s between shrinkage and other wood t r a i t s 121 F. Phenotypic c o r r e l a t i o n s between wood t r a i t s and growth characters 124 G. Genetic c o r r e l a t i o n s between wood t r a i t s and growth characters 127 I I . P a r e n t a l clones 130 A. General l e v e l s and o v e r a l l phenotypic trends at the d i f f e r e n t age l e v e l s 130 B. Means and phenotypic trends f o r clones at d i f f e r e n t age l e v e l s 137 C. Estimation of c l o n a l h e r i t a b i l i t y 154 CONCLUSIONS 157 LITERATURE CITED 162 APPENDICES 170 v i LIST O F TABLES No. Page 1. Parent t r e e numbers and l o c a t i o n s 18 2a. Sources of v a r i a t i o n , degrees of freedom (DF), expected mean squares ( E M S ), and denominators ( i n brackets) f o r F t e s t s f o r l o n g i t u d i n a l shrinkage (%) , t a n g e n t i a l shrinkage (%), r a d i a l shrinkage (%), r e l a t i v e density, and g r a i n angle (•) i n the f i r s t stage a n a l y s i s ( S - s i t e , B-block, M-male, F-female, T-tree, C-side, A-age l e v e l ; C and A are f i x e d e f f e c t s ) 27 2b. Sources of v a r i a t i o n , degrees of freedom (DF), expected mean squares ( E M S ), and denominators ( i n brackets) f o r F t e s t s f o r t r a c h e i d length i n the f i r s t stage of a n a l y s i s (M-male, T-tree, S-side, A-age l e v e l ; A i s a f i x e d e f f e c t ) 28 2c. Sources of v a r i a t i o n , degrees of freedom (DF), expected mean squares ( E M S ), and denominators ( i n brackets) f o r F t e s t s f o r f i b r i l angle (°) i n the f i r s t stage a n a l y s i s (M-male, F-female, T-tree, W-wood type, A-age l e v e l ; W and A are f i x e d e f f e c t s ) 29 3a. Sources of v a r i a t i o n , degrees of freedom (DF), expected mean squares (EMS) and denominators ( i n brackets) f o r F t e s t s f o r l o n g i t u d i n a l shrinkage (%), t a n g e n t i a l shrinkage (%), r a d i a l shrinkage (%), r e l a t i v e d e n s i t y and g r a i n angle (°) i n the second stage a n a l y s i s ( S - s i t e , B-block, M-male, F-female, T-tree) 31 3b. Sources of v a r i a t i o n , degrees of freedom (DF), expected mean squares ( E M S ), and denominators ( i n brackets) f o r F t e s t s f o r t r a c h e i d length (mm) and f i b r i l angle (°) f o r second stage a n a l y s i s 32 3c. Sources of v a r i a t i o n , degrees of freedom (DF), expected mean squares ( E M S ), and denominators ( i n brackets) f o r F t e s t s f o r height (m) and diameter at breast height (cm) ( S - s i t e , B-block, M-male, F-female, T-tree) 33 4 . Sources of v a r i a t i o n , degrees of freedom (DF), expected mean squares ( E M S ), and denominators ( i n brackets) f o r F t e s t s f o r l o n g i t u d i n a l shrinkage (%), t a n g e n t i a l shrinkage (%), r a d i a l shrinkage (%), and r e l a t i v e d e n s i t y i n the pa r e n t a l clones i n the f i r s t stage v i i a n a l y s i s (C-clone, T-tree, S-side, A-age l e v e l ; A i s a f i x e d e f f e c t ) 34 5. Sources of v a r i a t i o n , degrees of freedom (DF), expected mean squares (EMS) and denominators ( i n brackets) f o r F t e s t s f o r l o n g i t u d i n a l shrinkage (%), t a n g e n t i a l shrinkage (%), r a d i a l shrinkage (%), and r e l a t i v e d e n s i t y i n the p a r e n t a l clones i n second stage a n a l y s i s (C-clone, T-tree, S-side) 34 6. Components of variance used i n d e r i v i n g the phenotypic variance f o r the d i f f e r e n t kinds of h e r i t a b i l i t i e s f o r l o n g i t u d i n a l shrinkage, t a n g e n t i a l shrinkage, r a d i a l shrinkage, and r e l a t i v e d e n s i t y 45 7. Components of variance used f o r d e r i v i n g the phenotypic variance f o r the d i f f e r e n t kinds of h e r i t a b i l i t i e s f o r height and diameter at breast height 46 8. Components of variance used f o r d e r i v i n g phenotypic variance f o r c l o n a l h e r i t a b i l i t y 47 9. Means f o r shrinkage (%) r e l a t i v e d e n s i t y , g r a i n angle ( 8 ) , t r a c h e i d length (mm), and f i b r i l angle (°) at f i v e age l e v e l s 51 10. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r l o n g i t u d i n a l shrinkage (LS) (%), t a n g e n t i a l shrinkage (T S ) ( % ) , and r a d i a l shrinkage (RS) (%) i n the three sub-samples (XI, X2, and X3) ( S - s i t e , B-block, M-male, F-female, T-tree, C-side, A-age l e v e l ; C and A are f i x e d e f f e c t s ) 53 11. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r r e l a t i v e d e n s i t y i n the three sub-samples (XI, X2, and X3) and f o r g r a i n angle (°) i n two sub-samples (XI and X2) used f o r the a n a l y s i s ( S - s i t e , B-block, M-male, F-female, T-tree, C-side; A-age l e v e l ; C and A are f i x e d e f f e c t s ) 57 12. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r t r a c h e i d length (mm) (M-male, F-female, T-tree, C-side, A-age l e v e l ; C and A are f i x e d e f f e c t s ) 61 13. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r f i b r i l angle (°) (M-male, F-female, T-tree, W-wood type, T-tree, A-age; A and W are f i x e d e f f e c t s ) 64 A V l l l 1 4 . Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r l o n g i t u d i n a l shrinkage (%) at d i f f e r e n t age l e v e l s ( S - s i t e , B-block, M-male, F-female, T-tree) 68 15. Estimates of components of variance and components as percentage of t o t a l v a r i a n c e , f o r l o n g i t u d i n a l shrinkage (%) at d i f f e r e n t age l e v e l s ( S - s i t e , B-block, M-male, F-female, T-tree) 69 16. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r t a n g e n t i a l shrinkage (%) at d i f f e r e n t age l e v e l s ( S - s i t e , M-male, F-female, T-tree) 75 17. Estimates of components of variance and components as percentage of t o t a l variance f o r t a n g e n t i a l shrinkage (%) at d i f f e r e n t age l e v e l s ( S - s i t e , B-block, M-male, F-female, T-tree) 76 18. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r r a d i a l shrinkage (%) a t d i f f e r e n t age l e v e l s ( S - s i t e , B-block, M-male, T-tree) 81 19. Estimates of components of variance and components as percentage of t o t a l variance f o r r a d i a l shrinkage (%) at d i f f e r e n t age l e v e l s ( S - s i t e , B-block, M-male, F-female, T-tree) 82 20. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r r e l a t i v e d e n s i t y a t d i f f e r e n t age l e v e l s ( S - s i t e , B-block, M-male, F-female, T-tree) 87 21. Estimates of components of variance and components as percentage of the t o t a l variance f o r r e l a t i v e d e n s i t y at the d i f f e r e n t age l e v e l s ( S - s i t e , B-block, M-male, F-female, T-tree) 88 22. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r g r a i n angle (°) at d i f f e r e n t age l e v e l s ( S - s i t , B-block, M-male, F-female, T-tree) 92 23. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r t r a c h e i d length (mm) at d i f f e r e n t age l e v e l s (M-male, F-female, T-tree) 94 S o u r c e s o f v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r e a r l y - w o o d and l a t e - w o o d f i b r i l a n g l e (°) a t d i f f e r e n t age l e v e l s (M-male, F - f e m a l e , T - t r e e ) S o u r c e s o f v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r h e i g h t (m) and d i a m e t e r a t b r e a s t h e i g h t (DBH) o f t h e p r o g e n y ( S - s i t e , B - b l o c k , M-male, F-female) E s t i m a t e s o f components o f v a r i a n c e f o r h e i g h t and d i a m e t e r a t b r e a s t h e i g h t (DBH) and components as p e r c e n t a g e o f t o t a l v a r i a n c e ( S - s i t e , B - b l o c k , M-male, F - f e m a l e ) E s t i m a t e s o f h e r i t a b i l i t y f o r l o n g i t u d i n a l s h r i n k a g e (%), t a n g e n t i a l s h r i n k a g e (%), r a d i a l s h r i n k a g e (%), and r e l a t i v e d e n s i t y ( S t a n d a r d e r r o r s a r e g i v e n i n b r a c k e t s ) E s t i m a t e s o f h e r i t a b i l i t y f o r h e i g h t (m) and d i a m e t e r a t b r e a s t h e i g h t (DBH) (cm) ( S t a n d a r d e r r o r s a r e g i v e n i n b r a c k e t s ) P h e n o t y p i c and g e n e t i c c o r r e l a t i o n c o e f f i c i e n t s ( b o l d ) between wood t r a i t s ( S t a n d a r d e r r o r s a r e g i v e n below each) S h r i n k a g e : l o n g i t u d i n a l ( L S ) , t a n g e n t i a l ( T S ) , r a d i a l (RS); R e l a t i v e d e n s i t y (RD), G r a i n a n g l e (GA), T r a c h e i d l e n g t h ( T L ) , F i b r i l a n g l e : E a r l y - w o o d (FAE), Late-wood ( F A L ) ; 0-4 Age l e v e l s ) P h e n o t y p i c and g e n e t i c c o r r e l a t i o n c o e f f i c i e n t s f o r wood t r a i t s w i t h growth c h a r a c t e r s h e i g h t (HT) and d i a m e t e r a t b r e a s t h e i g h t (DBH) ( S h r i n k a g e : l o n g i t u d i n a l ( L S ) , t a n g e n t i a l ( T S ) , r a d i a l (RS); R e l a t i v e d e n s i t y (RD); G r a i n a n g l e (GA); T r a c h e i d l e n g t h ( T L ) ; F i b r i l a n g l e : e a r l y -wood (FAE), l a t e - w o o d ( F A L ) ; 0-4-age l e v e l s ) O v e r a l l mean f o r s h r i n k a g e (%) and r e l a t i v e d e n s i t y a t t h e d i f f e r e n t age l e v e l s i n t h e p a r e n t a l c l o n e s S o u r c e s o f v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r l o n g i t u d i n a l s h r i n k a g e (%), t a n g e n t i a l s h r i n k a g e (%), r a d i a l s h r i n k a g e (%), and r e l a t i v e d e n s i t y (RD) i n t h e p a r e n t a l c l o n e s ( C - c l o n e , T - t r e e , S - s i d e , A-age l e v e l ) S o u r c e s o f v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r s h r i n k a g e (%) a t d i f f e r e n t age l e v e l s i n the p a r e n t a l clones (C-clone, T-tree, S-side) 139 34. Estimates of components of vari a n c e f o r l o n g i t u d i n a l shrinkage (%) a t d i f f e r e n t age l e v e l s i n the p a r e n t a l clones (Components expressed as percent of t o t a l v a r i a n c e given i n brackets) (C- clone, T- t r e e , S- side) 140 35. Estimates of components of variance f o r t a n g e n t i a l shrinkage (%) a t d i f f e r e n t age l e v e l s i n the p a r e n t a l clones (Components expressed as percentage of t o t a l variance given i n brackets) (C-clone, T-tree, S-side) 144 36. Estimates of components of variance f o r r a d i a l shrinkage (%) at d i f f e r e n t age l e v e l s i n the p a r e n t a l clones (Components expressed as percentage of t o t a l variance given i n brackets) (C- clone, T- t r e e , S- side) 147 37. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r r e l a t i v e d e n s i t y at d i f f e r e n t age l e v e l s i n the p a r e n t a l clones (C-clone, T-tree, S-side) 151 38. Estimates of components of variance f o r r e l a t i v e d e n s i t y at d i f f e r e n t age l e v e l s f o r the p a r e n t a l clones (Components expressed as percentage of t o t a l variance given i n brackets; C-clone, T-tree, S-side) 152 39. Estimates of c l o n a l h e r i t a b i l i t y f o r shrinkage (%) and r e l a t i v e d e n s i t y at d i f f e r e n t age l e v e l s f o r p a r e n t a l clones (Standard e r r o r given i n brackets) 155 x i LIST OF FIGURES No. Page 1. Geographical l o c a t i o n of parent t r e e s and t e s t s i t e s 19 2. Sampling scheme w i t h i n b o l t 22 3. Comparative e f f i c i e n c y of sampling 6 samples w i t h i n t r e e and 3 t r e e s w i t h i n p l o t (6S3T) with other options (9S2T-9 samples w i t h i n t r e e and 2 t r e e s w i t h i n p l o t , 3S6T-3 samples w i t h i n t r e e and 6 t r e e s w i t h i n p l o t , 2S9T-2 samples w i t h i n t r e e and 9 t r e e s w i t h i n p l o t ; L S - l o n g i t u d i n a l shrinkage, GA-grain angle; 1-3-age l e v e l s ) 36 4. E f f e c t of number of t r e e s sampled per h a l f - s i b f a m i l y on magnitude of d i f f e r e n c e between f a m i l i e s t h a t can be detected i n standard d e v i a t i o n u n i t s (N-number of t r e e s , L S - l o n g i t u d i n a l shrinkage, GA-grain angle, 1-3-age l e v e l s ) 39 5. Mean percent l o n g i t u d i n a l , t a n g e n t i a l , and r a d i a l wood shrinkage (%) a t age l e v e l s 0, 1, 2, 3, and 4 i n the progeny 52 6. Mean r e l a t i v e d e n s i t y of wood at age l e v e l s 0, 1, 2, 3, and 4 i n the progeny 56 7. Mean g r a i n angle (°) of wood at age l e v e l s 0, 1, 2, 3, and 4 i n the progeny 59 8. Mean t r a c h e i d length (mm) a t age l e v e l s 0, 1, 2, 3, and 4 i n the progeny 60 9. Mean f i b r i l angle (°) at age l e v e l s 0, 1, 2, 3, and 4 i n the early-wood (EW) and late-wood (LW) i n the progeny 63 10a. Mean l o n g i t u d i n a l shrinkage (%) of wood at age l e v e l s 0, 1, 2, 3, and 4 f o r 12 maternal h a l f - s i b f a m i l i e s 66 10b. Mean l o n g i t u d i n a l shrinkage (%) of wood at age l e v e l s 0, 1, 2, 3, and 4 f o r 4 pa t e r n a l h a l f - s i b f a m i l i e s 67 11. Comparison of major components of variance f o r l o n g i t u d i n a l shrinkage (%) of wood at age l e v e l s 0, 1, 2, 3, and 4 i n the progeny ( S - s i t e , B-block, M-male, F-female, T-tree) 71 x i i 12a. Mean t a n g e n t i a l shrinkage (%) of wood at age l e v e l s 0, 1, 2, 3, and 4 f o r 12 maternal h a l f - s i b f a m i l i e s 73 12b. Mean t a n g e n t i a l shrinkage (%) of wood at age l e v e l s 0, 1, 2, 3, and 4 f o r 4 p a t e r n a l h a l f - s i b f a m i l i e s 74 13. Comparison of major components of varia n c e f o r t a n g e n t i a l shrinkage (%) of wood a t age l e v e l s 0, 1, 2, 3, and 4 i n the progeny ( S - s i t e , B-block, M-male, F- female, T-tree) 77 14a. Mean r a d i a l shrinkage (%) of wood a t age l e v e l s 0, 1, 2, 3, and 4 f o r 12 maternal h a l f - s i b f a m i l i e s 79 14b. Mean r a d i a l shrinkage (%) of wood at age l e v e l s 0, 1, 2, 3, and 4 f o r 4 pa t e r n a l h a l f - s i b f a m i l i e s 80 15. Comparison of major components of variance f o r r a d i a l shrinkage (%) of wood a t age l e v e l s 0, 1, 2, 3, and 4 i n the progeny ( S - s i t e , B-block, M-male, F-female, T-tree) 83 16a. Mean r e l a t i v e d e n s i t y of wood at age l e v e l s 0, 1, 2, 3, and 4 f o r 12 maternal h a l f - s i b f a m i l i e s 85 16b. Mean r e l a t i v e d e n s i t y of wood at age l e v e l s 0, 1, 2, 3, and 4 f o r 4 pa t e r n a l h a l f - s i b f a m i l i e s 86 17. Comparison of major components of variance f o r r e l a t i v e d e n s i t y of wood at age l e v e l s 0, 1, 2, 3, and 4 i n the progeny ( S - s i t e , B-block, M-male, F-female, T - tree) 89 18. Mean g r a i n angle (°) of wood a t age l e v e l s 0, 1, 2, and 3 f o r 4 maternal and 2 pa t e r n a l h a l f - s i b f a m i l i e s 91 19. Mean t r a c h e i d length (mm) of wood at age l e v e l s 0, 1, 2, 3, and 4 f o r 4 maternal and 2 pa t e r n a l h a l f - s i b f a m i l i e s 93 2 0a. Mean f i b r i l angle (°) of early-wood at age l e v e l s 0, 1, 2, 3, and 4 f o r 4 maternal and 2 pat e r n a l h a l f - s i b f a m i l i e s 96 xiii 20b. Mean f i b r i l angle (°) of late-wood a t age l e v e l s 0 , 1, 2, 3 , and 4 f o r 4 maternal and 2 pa t e r n a l h a l f - s i b f a m i l i e s 97 21. Comparison of major components of varia n c e f o r height and diameter at breast height (OBH) i n the progeny ( S - s i t e , B-block, M-male, F-female, T-tree) 102 22. Narrow sense i n d i v i d u a l h e r i t a b i l i t y f o r l o n g i t u d i n a l shrinkage (%) (LS), t a n g e n t i a l shrinkage (%) (TS), r a d i a l shrinkage (%) (RS), and r e l a t i v e d e n s i t y (RD) of wood a t age l e v e l s 0, 1, 2, 3, and 4 i n the progeny 107 23. Narrow sense f a m i l y h e r i t a b i l i t y f o r l o n g i t u d i n a l shrinkage (%) (LS), t a n g e n t i a l shrinkage (%) (TS), r a d i a l shrinkage (%) (RS), and r e l a t i v e d e n s i t y (RD) of wood at age l e v e l s 0, 1, 2, 3, and 4 i n the progeny 108 24. Broad sense i n d i v i d u a l h e r i t a b i l i t y f o r l o n g i t u d i n a l shrinkage (%) (LS), t a n g e n t i a l shrinkage (%) (TS), r a d i a l shrinkage (%) (RS), and r e l a t i v e d e n s i t y (RD) of wood a t age l e v e l s 0, 1, 2, 3, and 4 i n the progeny 109 25. Broad sense f a m i l y h e r i t a b i l i t y f o r l o n g i t u d i n a l shrinkage (%) (LS), t a n g e n t i a l shrinkage (%) (TS), r a d i a l shrinkage (%) (RS), and r e l a t i v e d e n s i t y (RD) of wood at age l e v e l s 0, 1, 2, 3, and 4 i n the progeny 110 26. Mean wood shrinkage (%) at age l e v e l s 1-8 i n s i x par e n t a l clones (28, 49, 60, 62, 72, and 73) ( L S - l o n g i t u d i n a l shrinkage (%), T S - t a n g e n t i a l shrinkage (%), RS- r a d i a l shrinkage (%)) 132 27. Mean r e l a t i v e density at age l e v e l s 1 t o 8 i n s i x par e n t a l clones (28, 49, 60, 62, 72, and 73) 133 28. Mean l o n g i t u d i n a l shrinkage (%) at age l e v e l s 1 t o 8 f o r s i x par e n t a l clones (28, 49, 60, 62, 72, and 73) 138 29. Comparison of components of variance f o r l o n g i t u d i n a l shrinkage (%) at age l e v e l s 1 t o 8 i n s i x pa r e n t a l clones (C-clone, T-tree, S-side) 141 30. Mean t a n g e n t i a l shrinkage (%) at age i n t e r v a l s 1 t o 8 f o r s i x par e n t a l clones )28, 49, 60, 62, 72, and 73) 143 31. Comparison of components of variance f o r x i v t a n g e n t i a l shrinkage (%) a t age l e v e l s 1 t o 8 i n s i x p a r e n t a l clones (C-clone, T-tree, S-side) 145 32. Mean r a d i a l shrinkage (%) a t age i n t e r v a l s 1 t o 8 f o r s i x p a r e n t a l clones (28, 49, 60, 62, 72, and 73) 146 33. Comparison of components of varia n c e f o r r a d i a l shrinkage (%) at age l e v e l s 1 t o 8 i n s i x p a r e n t a l clones (C-clone, T-tree, S-side) 148 34. Mean r e l a t i v e d e n s i t y a t age i n t e r v a l s 1 t o 8 f o r s i x p a r e n t a l clones (28, 49, 60, 62, 72, and 73) 150 35. Comparison of components of variance f o r r e l a t i v e d e n s i t y at age l e v e l s 1 t o 8 i n s i x pa r e n t a l clones (C-clone, T-tree, S-side) 153 36. C l o n a l h e r i t a b i l i t y f o r l o n g i t u d i n a l shrinkage (%) (LS), t a n g e n t i a l shrinkage (%)(TS), r a d i a l shrinkage (%)(RS), and r e l a t i v e d e n s i t y (RD) at age l e v e l s 1 t o 8 156 XV LIST OF APPENDICES No Page 1. H a l f - s i b and f u l l - s i b f a m i l y means f o r l o n g i t u d i n a l shrinkage (%) a t d i f f e r e n t age l e v e l s (Males 1-4, Females 1-12, Age l e v e l s 0-4; h a l f - s i b f a m i l y means given i n bold face) 170 2. H a l f - s i b and f u l l - s i b f a m i l y means f o r t a n g e n t i a l shrinkage (%) at d i f f e r e n t age l e v e l s (Males 1-4, Females 1-12, Age l e v e l s 0-4; h a l f - s i b f a m i l y means given i n bold face) 172 3. H a l f - s i b and f u l l - s i b f a m i l y means f o r r a d i a l shrinkage (%) at d i f f e r e n t age l e v e l s (Males 1-4, Females 1-12, Age l e v e l s 0-4; h a l f - s i b family means given i n bold face) 174 4. H a l f - s i b and f u l l - s i b f a m i l y means f o r r e l a t i v e d e n s i t y at d i f f e r e n t age l e v e l s (Males 1-4, Females 1-12, Age l e v e l s 0-4; h a l f - s i b f a m i l y means given i n bold face) 176 5. H a l f - s i b and f u l l - s i b f a m i l y means f o r g r a i n angle (°) a t d i f f e r e n t age l e v e l s (Males 1,3, Females 1-4, Age l e v e l s 0-4; h a l f - s i b family means given i n bold face) 178 6. H a l f - s i b and f u l l - s i b f amily means f o r t r a c h e i d length (mm) at d i f f e r e n t age l e v e l s (Males 1,3, Females 1-4, Age l e v e l s 0-4; h a l f - s i b family means given i n bold face) 179 7. H a l f - s i b and f u l l - s i b f amily means f o r f i b r i l angle (°) i n early-wood at d i f f e r e n t age l e v e l s (Males 1,3, Females 1-4, Age l e v e l s 0-4; h a l f - s i b family means given i n bold face) 180 8. H a l f - s i b and f u l l - s i b family means f o r f i b r i l angle (°) i n late-wood at d i f f e r e n t age l e v e l s (Males 1,3, Females 1-4, Age l e v e l s 0-4; h a l f - s i b family means given i n bold face) 181 9. H a l f - s i b and f u l l - s i b family means f o r x v i height ( i n meters) f o r the progeny (Males 1-4, Females 1-12; h a l f - s i b f a m i l y means given i n bold face) 182 10. H a l f - s i b and f u l l - s i b f a m i l y means f o r diameter a t breast height ( i n cm) f o r the progeny (Males 1-4, Females 1-12; h a l f - s i b f a m i l y means given i n bold face) 183 11. Mean l o n g i t u d i n a l shrinkage (%) a t d i f f e r e n t age l e v e l s f o r the p a r e n t a l clones 184 12. Mean t a n g e n t i a l shrinkage (%) a t d i f f e r e n t age l e v e l s f o r the p a r e n t a l clones 185 13. Mean r a d i a l shrinkage (%) at d i f f e r e n t age l e v e l s f o r the p a r e n t a l clones 186 14. Mean r e l a t i v e d e n s i t y at d i f f e r e n t age l e v e l s f o r the p a r e n t a l clones 187 A x v i i ACKNOWLEDGEMENTS The author acknowledges, with deep g r a t i t u d e , Dr. Donald T. Les t e r , F a c u l t y of For e s t r y , The U n i v e r s i t y of B r i t i s h Columbia, under whose guidance and s u p e r v i s i o n t h i s p r o j e c t was accomplished. The author a l s o acknowledges, Dr. Raymond G. Peterson, F a c u l t y of A g r i c u l t u r a l Science, The U n i v e r s i t y of B r i t i s h Columbia, Dr. R. M. Kellogg, F o r i n t e k Canada Corporation, Dr. L a s z l o Paszner, F a c u l t y of Forestry, The U n i v e r s i t y of B r i t i s h Columbia, and Dr. J . G. Worall, f o r t h e i r v a l u a b l e support and guidance i n t h i s study. G r a t e f u l acknowledgement i s given t o Mr. C h r i s Heaman and Mr. Jack Woods, B.C. M i n i s t r y of Forests and Lands, f o r t h e i r v aluable help and support i n the c o l l e c t i o n of the experimental m a t e r i a l s and to Dr. Judy Loo-Dinkins, F o r e s t r y Canada, Dr. An t a l Kozak and Dr. V a l e r i e LeMay, F a c u l t y of Forestry, The U n i v e r s i t y of B r i t i s h Columbia, f o r t h e i r advice on the s t a t i s t i c a l a n a l y s i s of the data. S p e c i a l thanks are due t o Mr. A. A. Karim and Mr. Shudao N i , Fac u l t y of Forestry, and Mr. N e i l Jackson and Mr. Jurgen Pehlke, Faculty of A g r i c u l t u r e f o r t h e i r valuable a s s i s t a n c e during the experimental phase of the study. The f a c i l i t i e s and s e r v i c e s rendered by Fa c u l t y of Forestry, The U n i v e r s i t y of B r i t i s h Columbia, Forintek Canada Corporation, and B.C. M i n i s t r y of Forests and Lands are a l s o g r a t e f u l l y acknowledged. x v i i i Deep g r a t i t u d e i s expressed t o my mother, Sosamma, my wife, Kumari, and my c h i l d r e n Susan, Annie, and J e r r y f o r t h e i r patience and encouragement. F i n a l l y , the author i s a p p r e c i a t i v e of the f i n a n c i a l support provided f o r t h i s study by B.C. Science C o u n c i l and P o l d i Bentley NSERC/Industrial Chair i n Forest Genetics and Tree Improvement. 1 INTRODUCTION D o u g l a s - f i r , Pseudotsuga menziesii (Mirb.) Franco belongs t o the f a m i l y Pinaceae. The genus Pseudotsuga i s c h a r a c t e r i z e d by i t s woody cones with p e r s i s t e n t s c a l e s and t r i d e n t - l i k e b r a cts protruding from the cone. Though e i g h t species are i d e n t i f i e d under t h i s genus, only two, P. macrocarpa Mayr and P. m e n z i e s i i are found i n North America (Issac and Dimock, 1965). P. macrocarpa has a l i m i t e d range of d i s t r i b u t i o n confined w i t h i n C a l i f o r n i a while P. menziesii has a wide north-south range of over 5000 km from the P a c i f i c Northwest ( l a t . 55°) to Mexico ( l a t . 19°). I t extends from the P a c i f i c coast t o the eastern slope of the Rocky Mountains ( S i l e n , 1978). Over i t s wide range, two v a r i e t i e s are u s u a l l y recognized. P. menziesii var. menziesii (Mirb.) Franco i s growing i n the c o a s t a l region, while P. menziesii var. glauca (Beissn.) Franco grows i n the i n t e r i o r . I t s f a s t growth r a t e and the demand f o r i t s high q u a l i t y s t r u c t u r a l timber i n both domestic and i n t e r n a t i o n a l markets has brought high prominence t o D o u g l a s - f i r i n the P a c i f i c Northwest. In 1990-91, 7,312,000 m3 of D o u g l a s - f i r logs were harvested i n B r i t i s h Columbia. A l s o over 2 0 m i l l i o n D o u g l a s - f i r seedlings were "planted during t h i s p e r i o d ( M i n i s t r y of Forests and Lands, 1991) . One of the major causes of lowering of lumber grade and value i s the increased percentage of j u v e n i l e wood (MacKay, 1989). The harvest of younger t r e e s due to a l i m i t e d supply 2 of o l d e r t r e e s and a v a i l a b i l i t y of younger t r e e s of merchantable s i z e produced by genetic improvement programs i n f u t u r e , w i l l increase the amount of j u v e n i l e wood i n the wood harvest. Increased amount of j u v e n i l e wood causes problems i n processing and a l s o i n product q u a l i t y (Senft and Bendtsen, 1984). Lumber c o n t a i n i n g l a r g e amounts of j u v e n i l e wood warps due t o unbalanced shrinkage and such lumber w i l l be degraded during d r y i n g and storage. When a 2" x 6" board i s degraded from grade 2 t o grade 3, i t causes about 30 % p r i c e r e d u c t i o n . When i t i s degraded t o economy grade, there i s about 70% p r i c e r e d u c t i o n . J o i s t and beam strength are reduced and v a r i a b i l i t y among boards i n strength i s increased with increased j u v e n i l e wood. A j o i s t c o n t a i n i n g s i g n i f i c a n t amounts of j u v e n i l e wood w i l l have about 4 0 % l e s s strength than one cut from mature wood (Senft and Bendtsen, 1984). Large l o n g i t u d i n a l shrinkage i n j u v e n i l e wood can a l s o cause s t r e s s imbalance i n panels, beams, frames, e t c . (Gorman, 1985). Pulp from j u v e n i l e wood has lower t e a r strength and opac i t y than pulp from mature wood. The lower densit y of j u v e n i l e wood can a l s o reduce d i g e s t e r output per cubic meter of input. Though t e c h n o l o g i c a l s o l u t i o n s can a l l e v i a t e some of the problems i n the raw m a t e r i a l , a s o l u t i o n at the resource regeneration l e v e l would be more appropriate. A genetic s o l u t i o n t o decrease the amount of j u v e n i l e wood and increase i t s q u a l i t y i s f e a s i b l e , i f s u f f i c i e n t genetic v a r i a b i l i t y f o r wood q u a l i t y t r a i t s i s a v a i l a b l e f o r 3 s e l e c t i o n i n the s p e c i e s . V a r i a t i o n i n wood p r o p e r t i e s between t r e e s and between provenances w i t h i n s p e c i e s i s common and wood c h a r a c t e r i s t i c s are responsive t o improvement through g e n e t i c manipulation (van Buijtenen, 1962; Zobel, 1984). B r i t i s h Columbia has an extensive breeding program i n c o a s t a l D o u g l a s - f i r , which began i n 1957 with phenotypic s e l e c t i o n of p l u s - t r e e s (Orr-Ewing, 1969). I n i t i a l l y , s e l e c t i o n s were based on growth and form. These s e l e c t i o n s were from a broadly defined seed zone of c o a s t a l B r i t i s h Columbia and Northern Washington (Heaman, 1967). F i r s t generation orchards were e s t a b l i s h e d and they are c u r r e n t l y p r o v i d i n g much of the seed f o r r e f o r e s t a t i o n programs. Over the next s e v e r a l years, f i r s t generation seed orchards w i l l be replaced by second generation orchards. The breeding program i n D o u g l a s - f i r c u r r e n t l y encompasses establishment of breeding populations f o r recu r r e n t s e l e c t i o n , estimation of genetic parameters and breeding values of s e l e c t e d parent t r e e s . The information and m a t e r i a l from t h i s process w i l l provide the b a s i s f o r futu r e breeding programs. Various genetic i n v e s t i g a t i o n s on growth, form, r e l a t i v e d e n s i t y e t c . are i n progress. Among these, an 18-year-old progeny t e s t , which was at a stage where i t re q u i r e d t h i n n i n g , provided a good opportunity f o r d e s t r u c t i v e sampling to i n v e s t i g a t e genetic e f f e c t s on wood shrinkage, and to study phenotypic and genetic c o r r e l a t i o n s with other important wood c h a r a c t e r i s t i c s l i k e r e l a t i v e wood 4 densi t y , g r a i n angle, t r a c h e i d length and f i b r i l angle. The pa r e n t a l clones of the same parents being i n v e s t i g a t e d i n the progeny t e s t assembled i n a clone bank a t Cowichan Lake were a l s o being removed from the s i t e and were a v a i l a b l e f o r d e s t r u c t i v e sampling t o study shrinkage and r e l a t i v e d e n s i t y . In t h i s context, the study i n t h i s t h e s i s was undertaken t o i n v e s t i g a t e genetic e f f e c t s on some fundamental aspects of wood q u a l i t y , genetic i n t e r r e l a t i o n s h i p s between wood q u a l i t y t r a i t s , and the r e l a t i o n s h i p s between wood q u a l i t y t r a i t s and stem growth. Primary emphasis of the study was on wood shrinkage i n the 18-year-old t r e e s from progeny t e s t i n g . Other wood t r a i t s l i k e r e l a t i v e density, g r a i n angle, t r a c h e i d length and f i b r i l angle were a l s o studied t o understand the r e l a t i o n s h i p s between shrinkage i n d i f f e r e n t g r a i n d i r e c t i o n s and these characters. The p a r e n t a l clones were i n v e s t i g a t e d i n order t o estimate c l o n a l v a r i a b i l i t y and h e r i t a b i l i t y . Factors i n s i d e and outside the t r e e a f f e c t the bi o l o g y of wood formation. While s i t e , s o i l , c l imate e t c . are some of the e x t e r n a l f a c t o r s , age of the r i n g from the p i t h , which i s g e n e r a l l y r e l a t e d t o the p o s i t i o n of l i v e crown i n r e l a t i o n t o the zone of wood formation, i s one of the major f a c t o r s w i t h i n the t r e e . The e f f e c t of age on the r e l a t i o n between growth r a t e and wood p r o p e r t i e s i s of considerable importance. This study a l s o looked i n t o the e f f e c t of age 5 l e v e l on the p r o p e r t i e s of wood formed and the Influence of age on the r e l a t i o n between growth r a t e and wood p r o p e r t i e s . T h i s study attempts t o answer questions p e r t i n e n t t o the b i o l o g y of wood formation and making management d e c i s i o n s i n D o u g l a s - f i r breeding. The s p e c i f i c questions addressed are: 1. Is there a s i g n i f i c a n t e f f e c t of age l e v e l (from pith) at the time of wood formation on wood shrinkage and other wood c h a r a c t e r i s t i c s ? 2. Is there s i g n i f i c a n t family e f f e c t on shrinkage and other wood q u a l i t y t r a i t s ? 3. What i s the magnitude of the h e r i t a b i l i t i e s of these t r a i t s ? 4. What are the phenotypic and genetic r e l a t i o n s h i p s between shrinkage and other wood t r a i t s ? 5 . What are the phenotypic and genetic r e l a t i o n s h i p s between wood q u a l i t y t r a i t s and growth characters? 6. Based upon the h e r i t a b i l i t i e s and genetic r e l a t i o n s h i p s of these t r a i t s , what are the o p p o r t u n i t i e s f o r t h e i r improvement i n D o u g l a s - f i r breeding program? 6 LITERATURE REVIEW Wood i s a product of the cambium and i t c o n s i s t s of d i f f e r e n t wood elements which have passed through various phases of development. Numerous f a c t o r s both i n s i d e and outside the t r e e lead t o v a r i a t i o n i n wood s t r u c t u r e and p r o p e r t i e s . "Wood q u a l i t y i s t h e r e f o r e a concept - an idea formulated by g e n e r a l i z a t i o n from p a r t i c u l a r s , the p a r t i c u l a r s i n t h i s instance being the wood elements produced i n wood formation" (Larson, 1969). Although a l l the causes of v a r i a b i l i t y i n wood cannot be completely explained, many of them can be r e l a t e d t o t r e e growth which i s a f f e c t e d by various f a c t o r s l i k e environment, s i l v i c u l t u r a l p r a c t i c e , h e r e d i t y e t c . V a r i a t i o n i n wood p r o p e r t i e s has been reviewed exhaustively by Zobel and van Buijtenen (1989). Species adapted to nonshaded h a b i t a t s produce denser wood compared t o shade t o l e r a n t species (Lawton, 1984). S i m i l a r l y , t r e e s growing i n windy s i t e s produce denser wood than t r e e s growing on s h e l t e r e d h a b i t a t s . B e t t e r s i t e c o n d i t i o n s l i k e s u f f i c i e n t moisture, n u t r i e n t s and l i g h t cause high volume production of l e s s dense wood (Knigge, 1961). This can be expressed i n the s i t e index : wood s p e c i f i c g r a v i t y r e l a t i o n s h i p (Gilmore et al., 1966). In Do u g l a s - f i r , permeability of wood has been shown t o d i f f e r due t o s i t e d i f f e r e n c e s . Kennedy (1961) found that d i f f e r e n c e s i n the amount of late-wood were r e l a t e d t o p r e c i p i t a t i o n . Although macro and micro-environment exert 7 strong c o n t r o l over average wood p r o p e r t i e s , genetic c o n t r o l r e s u l t s i n t r e e - t o - t r e e d i f f e r e n c e s w i t h i n the same s p e c i f i c environment. Large d i f f e r e n c e s among i n d i v i d u a l t r e e s w i t h i n a s i t e make i t d i f f i c u l t t o de t e c t d i f f e r e n c e s caused by s i t e or s o i l v a r i a b i l i t y ( Zobel and van Buijtenen, 1989). S i l v i c u l t u r a l treatments a f f e c t t r e e growth r a t e and p a t t e r n which i n tu r n can s i g n i f i c a n t l y a f f e c t wood p r o p e r t i e s . I n t e r a c t i o n s between growth r a t e and wood p r o p e r t i e s are complex and not always p r e d i c t a b l e (Zobel and van Buijtenen, 1989). L i t e r a t u r e regarding the r e l a t i o n s h i p s of growth r a t e and growth c o n d i t i o n s with wood p r o p e r t i e s i s c o n f l i c t i n g . I t i s g e n e r a l l y b e l i e v e d that i n c o n i f e r s with a pronounced late-wood zone, r a p i d growing wood i s i n h e r e n t l y low i n r e l a t i v e d e n s i t y and has short t r a c h e i d s , l a r g e f i b r i l angle, and other mostly undesirable characters. Corriveau et al. (1991) found a s i g n i f i c a n t negative genetic c o r r e l a t i o n between r e l a t i v e d e n s i t y and t r e e diameter i n 19-year-old white spruce (Picea glauca (Moench) Voss), while a p o s i t i v e genetic c o r r e l a t i o n was found between r e l a t i v e d e n s i t y and t r e e height. King (1986) observed negative genetic c o r r e l a t i o n between wood den s i t y and growth t r a i t s i n D o u g l a s - f i r , when wood formed between ages 8 t o 12 years was considered. Various other s t u d i e s on eastern c o n i f e r species found no s i g n i f i c a n t r e l a t i o n s h i p s between growth r a t e and wood s p e c i f i c g r a v i t y , while s t u d i e s on western species showed s i g n i f i c a n t 8 negative r e l a t i o n s h i p s (Zobel and van Buijtenen, 1989 ) . A s i m i l a r negative r e l a t i o n s h i p has been reported i n broad-leaved hard-wood species (Yanchuk, et a l . 1984). Based on st u d i e s i n c o a s t a l D o u g l a s - f i r populations, McKimmy and Campbell (1982) proposed t h a t seed sources r e f l e c t an adaptive response t o environment so t h a t at a given annual r i n g width, some seed sources have lower d e n s i t i e s than others. Some other reviews conclude t h a t r e l a t i v e d e n s i t y and f i b e r characters are mostly r e l a t e d t o age of wood from the p i t h and not growth r a t e ( Dadswell, 1958; Spurr and Hsiung, 1954, Bendtsen, 1978). These s t u d i e s i n d i c a t e t h a t a t the same age or number of r i n g s from p i t h , t r e e s of the same species tend t o have s i m i l a r r e l a t i v e d e n s i t y independent of growth r a t e , although there may be la r g e d i f f e r e n c e s r e l a t e d t o v a r i a t i o n among t r e e s . The m a t e r i a l r e f e r r e d t o i n these r e p o r t s was comprised of r i n g s beyond 30 years from the p i t h . V a r i a t i o n i n r i n g width a t these age l e v e l s may not be q u i t e s u f f i c i e n t t o demonstrate r e l a t e d change i n s p e c i f i c g r a v i t y . E r i c k s o n and Arima (1974) found immediate production of lower d e n s i t y wood with f e r t i l i z a t i o n and t h i n n i n g i n 21-year o l d D o u g l a s - f i r t r e e s . The e f f e c t , however was mainly f o r the f i r s t 3 t o 4 years a f t e r treatment, and l a t e r , normal wood production was resumed. I t might be reasonable t o assume that such change i n s p e c i f i c g r a v i t y due to f a s t e r growth r a t e i s more pronounced i n wood formed at r i n g s c l o s e r t o p i t h than r i n g s f a r t h e r from the p i t h . 9 The r e l a t i o n s h i p of r e l a t i v e d e n s i t y with age i s confounded with p o s i t i o n of crown i n r e l a t i o n t o the p o s i t i o n of wood formation. Wood formed i n the p a r t of the stem which i s under the prolonged i n f l u e n c e of the a p i c a l meristem i s d i f f e r e n t from that produced at p o s i t i o n s where such e f f e c t i s l e s s (Panshin and de Zeeuw, 1980). Seasonal l e v e l s of auxins, g i b b e r e l l i n s and c y t o k i n i n s , o p e r a t i n g i n the presence of d i f f e r e n t l e v e l s of n a t u r a l i n h i b i t o r s , exert c o n t r o l over the type of xylem produced (Brown, 1980). The wood produced under the a c t i v e c o n t r o l of the a p i c a l meristem i s c a l l e d j u v e n i l e wood. Though j u v e n i l e wood i s produced i n c o n i f e r s and hard-woods, i t i s much l e s s evident i n hard-woods (Zobel and van Buijtenen, 1989) . Compared to mature wood, j u v e n i l e wood of c o n i f e r s i s c h a r a c t e r i z e d by lower r e l a t i v e density, shorter t r a c h e i d s , higher l o n g i t u d i n a l shrinkage, lower strength, lower percent of l a t e wood, more compression wood, higher moisture content, thinner c e l l w a l l s , l a r g e r lumen diameter, lower c e l l u l o s e content and higher l i g n i n content (Bendtsen, 1978). These p r o p e r t i e s are not uniform from the p i t h outwards. In general, wood i n the f i r s t - f o r m e d r i n g s has the lowest r e l a t i v e density, shortest f i b e r s and l a r g e s t f i b r i l angles. In successive r i n g s from the p i t h , the r e l a t i v e d e n s i t y and f i b e r length increases and f i b r i l angle decreases. The change i n these p r o p e r t i e s i s very r a p i d i n the f i r s t few r i n g s and then becomes gradual. In the case of se v e r a l western c o n i f e r s i n c l u d i n g D o u g l a s - f i r , the f i r s t few r i n g s 10 o f t e n show higher r e l a t i v e d e n s i t y followed by a decrease and subsequent increase (Jozsa et a l . , 1989). The d i f f e r e n t i a t i o n of wood i n t o j u v e n i l e and nature depends upon how the j u v e n i l e wood i s def i n e d anatomically, because some c h a r a c t e r i s t i c s l i k e c e l l length may reach maturity before characters l i k e c e l l w a l l thickness (Bendtsen, 1978). Loo at a l . (1985) reported 11.45 years as the mean t r a n s i t i o n age f o r s p e c i f i c g r a v i t y i n l o b l o l l y pine (Pinus taeda) while f o r t r a c h e i d length i t was 10.30 years. I t i s g e n e r a l l y assumed that the j u v e n i l e core i n c l u d e s the f i r s t 5 t o 20 r i n g s from the p i t h depending upon species and l o c a l i t y (Erickson and Arima, 1974; Isebrands and Bensend, 1972) . Genetic v a r i a t i o n i n wood p r o p e r t i e s can be assessed at the species and within-species l e v e l s . V a r i a t i o n at the within - s p e c i e s l e v e l i s important to t r e e breeders. The important elements of within-species v a r i a t i o n are geographic v a r i a t i o n , stand-to-stand v a r i a t i o n , and v a r i a t i o n among i n d i v i d u a l t r e e s w i t h i n stands. There i s s i g n i f i c a n t v a r i a t i o n among species i n the amount and d i s t r i b u t i o n of genetic v a r i a t i o n . Some species l i k e red pine and yellow b i r c h are very uniform, while others l i k e l o b l o l l y pine and D o u g l a s - f i r are h i g h l y v a r i a b l e (Zobel and van Buijtenen, 1989). In D o u g l a s - f i r , although wood p r o p e r t i e s vary phenotypically, the patterns of geographic v a r i a t i o n s are not c l e a r cut (Wahlgren, 1965). A s l i g h t trend of 11 i n c r e a s i n g s p e c i f i c g r a v i t y from north t o south along the coast and west of the Rocky Mountains, and a reverse trend i n the eastern region of the mountains, doesn't seem t o have much p r a c t i c a l importance (Zobel and van Buijtenen, 1989). S p e c i f i c g r a v i t y and strength p r o p e r t i e s were found to be s i g n i f i c a n t l y greater f o r c o a s t a l provenances compared to i n t e r i o r ones (USDA, 1974) . Based on the expression of weakest wood i n the southern i n t e r i o r , Noskowiak and Snodgrass (1961) suggested t h a t i n t e r i o r populations are c l e a r l y d i f f e r e n t populations w i t h i n the species, with regard t o wood p r o p e r t i e s . E l e v a t i o n a l v a r i a t i o n was reported by Lassen and Okkonen (1969). Trees from low e l e v a t i o n s (below 900 f t ) had an average s p e c i f i c g r a v i t y of 0.504 while t r e e s from high e l e v a t i o n s (2000-3000 f t ) had an average of 0.477. Stand to stand genetic v a r i a t i o n i s very small. Tree-to-tree v a r i a b i l i t y w i t h i n a source i s u s u a l l y considerably greater than provenance or stand d i f f e r e n c e s (Zobel and van Buijtenen, 1989). Tree-to-tree v a r i a t i o n i n d i f f e r e n t wood q u a l i t y t r a i t s i s w e l l documented i n d i f f e r e n t t r e e species (Zobel and van Buijtenen, 1989). Tree-to-tree v a r i a b i l i t y i n wood p r o p e r t i e s i n D o u g l a s - f i r has been reported by various authors (McKimmy and Nicholas, 1971 ; Wellwood and Smith, 1962; McKimmy and Campbell, 1982; King, 1986; Bastien, J . C. et al. , 1985; Vargas-Hernandez and Adams, 1991, 1992). Most of these r e p o r t s are on s p e c i f i c g r a v i t y and shows moderate to high h e r i t a b i l i t y . 12 Very few s t u d i e s are a v a i l a b l e i n t r e e s on v a r i a t i o n i n wood shrinkage p r o p e r t i e s . Nepveu and V e i l i n g (1983) reported moderately high t r e e - t o - t r e e v a r i a b i l i t y f o r volumetric shrinkage i n Betula pendula. In a recent unpublished study by Weyerhaeuser Company, Tacoma, Washington, i t was observed t h a t v a r i a t i o n i n l o n g i t u d i n a l shrinkage i s high among f a m i l i e s of l o b l o l l y pine and the h e r i t a b i l i t y of t h i s t r a i t i s s u f f i c i e n t l y high t o allow genetic manipulation (Megraw and T a l b e r t , unpublished). D u f f i e l d (1964) reported t r a c h e i d length v a r i a t i o n i n D o u g l a s - f i r and discussed the p o s s i b i l i t y of s e l e c t i n g extreme v a r i a n t s . Smith (1959) found s i g n i f i c a n t v a r i a t i o n i n f i b r i l angle among t r e e s of Araucaria cunninghamii. S i g n i f i c a n t variance i n f i b r i l angle among f a m i l i e s was a l s o observed i n Pinus elliotti (Smith, 1967) More v a r i a b i l i t y i n wood c h a r a c t e r i s t i c s occurs w i t h i n a s i n g l e t r e e than between t r e e s (Larson, 1969). Within-tree v a r i a b i l i t y of wood p r o p e r t i e s i s manifested i n d i f f e r e n t ways ( N i c h o l l s , 1986; Yanchuk and Micko, 1990; Seth et al., 1987; Loo-Dinkins and Gonzalez, 1991; Gonzalez, 1989). Within an annual r i n g there are considerable d i f f e r e n c e s i n wood p r o p e r t i e s . In a d d i t i o n , there are gradual changes i n wood p r o p e r t i e s from the early-wood to late-wood zone, with d i f f e r e n t p r o p e r t i e s having d i f f e r e n t patterns of change. From p i t h t o bark, each t r a i t may vary i n a d i f f e r e n t way, and the pattern f o r any one t r a i t may d i f f e r i n d i f f e r e n t c o n i f e r species. There i s v a r i a t i o n associated with height 13 i n the t r e e . F i n a l l y , c i r c u m f e r e n t i a l v a r i a t i o n i s also demonstrated (Gonzalez, 1989). Considering the l a r g e amount of v a r i a t i o n w i t h i n the t r e e , i t i s important t o decide how to sample the t r e e t o study wood p r o p e r t i e s . Sampling at breast height i s g e n e r a l l y accepted as r e p r e s e n t a t i v e i n most wood q u a l i t y s t u d i e s . S i g n i f i c a n t c o r r e l a t i o n s between lower stem and whole stem values f o r wood p r o p e r t i e s have been reported (Einspahr et a l . , 1962; Cown, 1976). But i n some cases only a r e l a t i v e l y small p r o p o r t i o n of the v a r i a t i o n i s accounted f o r by breast height v a r i a t i o n . Only 25 % f o r t r a c h e i d length and 50% f o r late-wood percentage were accounted f o r by breast height sampling. S i m i l a r l y s i n g l e - r a d i u s core sampling does not adequately account f o r c i r c u m f e r e n t i a l v a r i a t i o n . But data on samples from opposite r a d i i should y i e l d s u f f i c i e n t information to account f o r t h i s v a r i a t i o n (Einspahr et al., 1962). Magnitudes of h e r i t a b i l i t i e s , c o e f f i c i e n t s of phenotypic v a r i a t i o n , and phenotypic and genetic i n t e r r e l a t i o n s h i p s among d i f f e r e n t wood p r o p e r t i e s are very important i n choosing appropriate breeding s t r a t e g i e s . R e l a t i o n s h i p s of wood t r a i t s with growth t r a i t s l i k e height, diameter, volume e t c . are a l s o very important. Although wood q u a l i t y t r a i t s g e n e r a l l y have higher h e r i t a b i l i t i e s than growth t r a i t s , lower phenotypic v a r i a t i o n causes reduction i n p o t e n t i a l genetic gain through s e l e c t i o n (Bastien et al., 1985). 1 4 I n t e r r e l a t i o n s h i p s between wood q u a l i t y t r a i t s and between wood q u a l i t y t r a i t s and growth t r a i t s are not of t e n fa v o r a b l e . Many s t u d i e s on phenotypic c o r r e l a t i o n s between wood t r a i t s are a v a i l a b l e . Volumetric shrinkage from the green t o the oven-dry s t a t e i s reported t o be p o s i t i v e l y c o r r e l a t e d with b a s i c d e n s i t y (Kelsey, 1963). Karkkainen and Marcus (1985) reported that r e l a t i v e d e n s i t y has a p o s i t i v e phenotypic c o r r e l a t i o n with volumetric shrinkage, but a negative c o r r e l a t i o n with l o n g i t u d i n a l shrinkage. With constant d e n s i t y and increase i n growth r i n g width, there was increased shrinkage. Meylan (1972) reported on shrinkage patterns at d i f f e r e n t moisture l e v e l s f o r d i f f e r e n t f i b r i l angles and found a p o s i t i v e r e l a t i o n s h i p between f i b r i l angle and l o n g i t u d i n a l shrinkage. H a r r i s and Meylan (1972), based on t h e o r e t i c a l modeling and experimental s t u d i e s i n Pinus radiata a l s o reported dependence of l o n g i t u d i n a l shrinkage on f i b r i l angle. T h i s r e l a t i o n s h i p between l o n g i t u d i n a l shrinkage and f i b r i l angle was c u r v i l i n e a r . A dramatic increase i n l o n g i t u d i n a l shrinkage was observed when f i b r i l angle was l a r g e r than 30°. Meylan (1967) reported on the r e l a t i o n s h i p between l o n g i t u d i n a l shrinkage and t a n g e n t i a l shrinkage. While there was a dramatic increase i n l o n g i t u d i n a l shrinkage when f i b r i l angle was l a r g e r than 30°, there was a considerable decrease i n t a n g e n t i a l shrinkage. Voorhies and Groman (1982) a l s o found a strong phenotypic c o r r e l a t i o n between l o n g i t u d i n a l shrinkage and f i b r i l angle i n ponderosa pine. 15 Tracheid characters are oft e n r e l a t e d t o s p e c i f i c g r a v i t y . Goggans (1964) observed s i g n i f i c a n t phenotypic and genotypic c o r r e l a t i o n s between t r a c h e i d cross s e c t i o n a l area and late-wood s p e c i f i c g r a v i t y of Pinus taeda, while c o r r e l a t i o n s between t r a c h e i d length and late-wood s p e c i f i c g r a v i t y were not s i g n i f i c a n t . In s t u d i e s of r a d i a t a pine by H a r r i s (1961) and D o u g l a s - f i r by McKimmy and Nicholas (1971), no c o r r e l a t i o n between t r a c h e i d length and s p e c i f i c g r a v i t y was found. R e l a t i o n s h i p s between wood s p e c i f i c g r a v i t y and growth t r a i t s l i k e height and diameter at breast height have been widely examined i n f o r e s t t r e e s (Zobel and van Buijtenen, 1989). Various st u d i e s i n D o u g l a s - f i r have shown negative phenotypic c o r r e l a t i o n s between growth t r a i t s and s p e c i f i c g r a v i t y (Zobel and van Buijtenen, 1989). A t r e e breeder, however, i s p r i m a r i l y concerned with genetic c o r r e l a t i o n s between t r a i t s . Genetic c o r r e l a t i o n s between s p e c i f i c g r a v i t y and growth t r a i t s are negative i n many c o n i f e r s , i n c l u d i n g D o u g l a s - f i r ( S q u i l l a c e et a l . , 1962; Stonecypher and Zobel, 1966; McKimmy and Campbell, 1982; King, 1986; Vargas-Hernandez and Adams, 1991). Nepveu and V e i l i n g (1983) found a favorable r e l a t i o n s h i p between volumetric shrinkage and growth r a t e i n Betula pendula. No rep o r t s are a v a i l a b l e on genetic c o r r e l a t i o n s between shrinkage and other wood p r o p e r t i e s i n c o n i f e r s . When t r a i t s considered f o r s e l e c t i o n have p o s i t i v e genetic c o r r e l a t i o n s , i t i s p o s s i b l e to s e l e c t f o r one 16 t r a i t and obtain c o r r e l a t e d gain i n the others. McKinley et a l . (1982), f o r example, found t h a t l o b l o l l y pine r e l a t i v e d e n s i t y i s h i g h l y c o r r e l a t e d t o stem s t r a i g h t n e s s , narrow crowns and h o r i z o n t a l branch angle, and suggested the use of these t r a i t s f o r i n d i r e c t s e l e c t i o n f o r r e l a t i v e d e n s i t y . When negative c o r r e l a t i o n s occur between t r a i t s under c o n s i d e r a t i o n , the most e f f i c i e n t method of maximizing gains f o r s e v e r a l t r a i t s i s index s e l e c t i o n (Young, 1961). However, i n s e l e c t i o n index procedure, economic weights of the t r a i t s are needed. For wood q u a l i t y t r a i t s , i t i s often not p o s s i b l e to obtain economic weights. In such s i t u a t i o n s , s e n s i t i v i t y a n a l y s i s of expected gains to changes i n t e c h n i c a l weighting i s suggested by Baradat (1979). He has used t h i s technique i n s e l e c t i n g f o r height and basal curvature i n Pinus pinaster. King (1986) a l s o used the same technique f o r suggesting breeding options f o r Do u g l a s - f i r based on height, diameter at breast height, and r e l a t i v e density. Magnussen and K e i t h (1991) computed s e l e c t i o n i n d i c e s f o r jack pine (Pinus JbanJcsiana Lamb.) under various assumptions about economic values of the t r a i t s under s e l e c t i o n , and with c o n s t r a i n t s on the magnitude and d i r e c t i o n of expected gain f o r volume and wood pr o p e r t i e s . They pr e d i c t e d good progress i n a l l t r a i t s when volume received the highest weight. 17 MATERIALS AND METHODS The m a t e r i a l f o r the study came from D o u g l a s - f i r progeny t r i a l s and clone banks e s t a b l i s h e d by the B.C. M i n i s t r y of For e s t s . Twenty-two t r e e s from a population of f i r s t - g e n e r a t i o n , s e l e c t e d parent t r e e s of c o a s t a l B r i t i s h Columbia were used as seed parents i n these t r i a l s . Four other t r e e s from the same population were used as p o l l e n parents and crossed with the 22 seed parents i n a f a c t o r i a l mating design (North C a r o l i n a design I I , Comstock and Robinson, 1952) . Seeds from a l l f a m i l i e s were spot seeded i n nursery beds. In f a l l , 1972, the seedlings were trans p l a n t e d i n t o s t y r o 8 plugs. In sp r i n g , 1973, a complete s et of crosses was f i e l d planted i n Greater V i c t o r i a Watershed area (GVWS). Another set was planted at Cowichan Lake Experiment S t a t i o n (CLES) i n spr i n g , 1974. The progeny t r i a l s were l a i d out i n a randomized complete block design with three r e p l i c a t i o n s of nine-tree p l o t s at a spacing of 3 m x 3 m. In the GVWS area, the p l o t design was a 9-tree square, while at CLES area i t was a 9-tree l i n e . Out of t h i s progeny t r i a l , progeny of 12 randomly s e l e c t e d seed parents crossed with the four p o l l e n parents were used f o r the present study (Table 1). Locations of the 16 s e l e c t e d p arental t r e e s are shown i n F i g . 1. The GVWS s i t e i s on a uniform slope with a gradient of 20-25% and a SSE exposure. I t supports coarse loamy podzols, very dry to f r e s h . The n u t r i e n t regime i s medium with over 100 cm of r o o t i n g depth. 1 8 Table 1. Parent t r e e numbers and l o c a t i o n s Tree No. a Location E l e v a t i o n Lat. Long. Seed Parents 4 9 b P a r k s v i l l e 685 49°17• 123*33 • 60 b Cambell River 30 50 o15' 125°24 ' 7 2 b K o k s i l a h 550 48°37 • 123°48 1 7 3 b Cowichan 180 48°50' 124°10' 110 Powell River 290 49°52' 124°19' 193 C h i l l i w a c k 625 49°07' 121°36• 300 Howe Sound 370 49°36' 123°19 ' 323 P i t River 370 49°41' 122°43 • 408 C h i l l i w a c k 825 49°07• 121°49• 499 Kelsey Bay 150 50°26' 126°14• 549 Knight I n l e t 150 50°50' 125°50' 623 Powell River 623 49°52• 124°19' Lien Parents 28 b Ladysmith 685 48°56' 123°53' 33 Cowichan 580 48°50' 124°05' 62 b Sproat Lake 60 49°18' 125°13• 448 G a r i b a l d i 625 49°51' 123°08• a B.C. Plus t r e e r e g i s t r a t i o n number b Clones used f o r the c l o n a l study (which are a l s o parents of progenies used i n the preliminary study) 19 Figure 1. Geographical l o c a t i o n of parent t r e e s and t e s t s i t e s 2 0 The CLES s i t e i s loca t e d at an e l e v a t i o n of 165 m. I t i s on undulating topography with humo-feric podzols, sandy loam i n t e x t u r e . The s o i l moisture regime i s from dry to moist. The s o i l n u t r i e n t regime v a r i e s from poor t o r i c h . Rooting depth i s up to 100 cm (Klinka et al., 1984). The c l o n a l study m a t e r i a l came from a clone bank at Cowichan Lake Experiment S t a t i o n , where g r a f t s ranged i n age from 25 to 30 years. S i x of the p a r e n t a l clones, four seed parents and 2 p o l l e n parents (Table. 1) were used f o r the study. Sampling of t r e e s The sampling of t r e e s from these sources was c a r r i e d out i n two phases f o r progeny. In the i n i t i a l phase, a smaller sample was used t o d e r i v e p r e l i m i n a r y estimates of the variances of the d i f f e r e n t t r a i t s . Based on these estimates, an augmented design was derived and sampling c a r r i e d out. The i n i t i a l phase of the study used progeny of four seed parents and two p o l l e n parents (Table 1). Sampling was c a r r i e d out from two r e p l i c a t i o n s at the two s i t e s . Three t r e e s per p l o t were randomly s e l e c t e d . Altogether, 96 t r e e s were sampled f o r the i n i t i a l study. For the c l o n a l study, three ramets each from the s i x clones were sampled. Sampling procedures were s i m i l a r i n both the i n i t i a l and augmented s t u d i e s . A f t e r randomly choosing the tr e e t o be sampled, diameter at breast height (DBH) was measured. Then the t r e e was f e l l e d and t o t a l height was measured. 21 Next a b o l t , 35 cm long, was cut between the branch whorls at breast height. The b o l t was marked f o r c a r d i n a l d i r e c t i o n s and l a b e l l e d , wrapped i n polythene bags, and t i e d a i r - t i g h t . The b o l t s were transported t o a f r e e z e r warehouse a t Vancouver and stored at 0°C. In the case of the c l o n a l study, b o l t s were c o l l e c t e d e a r l i e r at breast height from three ramets per clone and store d i n a f r e e z e r . Each frozen b o l t was taken out on the day t o be processed f o r p r e p a r a t i o n of samples. A diagrammatic r e p r e s e n t a t i o n of the sampling scheme w i t h i n the b o l t i s given i n F i g . 2. Each b o l t was sawn i n h a l f along an east-west d i r e c t i o n . Three boards were sawn l o n g i t u d i n a l l y from each h a l f of the b o l t t o provide s i x r a d i a l samples per t r e e . A length of 5 cm was trimmed from the ends of the boards t o reduce storage e f f e c t . From the remaining board, s t i c k s approximately 1.5 x 1.5 cm and 30 cm long were cut t o provide samples. Each of the s t i c k s had two annual r i n g s . Rings 1-2 were designated as age l e v e l 0 and 3-4 as age l e v e l 1, r i n g s 5-6 as age l e v e l 2, r i n g s 7-8 as age l e v e l 3 and r i n g s 9-10 as age l e v e l 4. Though few samples had age l e v e l 5 (rings 11-12), they were not used i n the study. For clones, where tr e e s were older, up t o 8 age l e v e l s were sampled. A 20-cm piece from the lower p a r t of the s t i c k was used f o r the estimation of shrinkage. Permanent marks were made at the middle p o r t i o n of the s t i c k on the t a n g e n t i a l and r a d i a l planes and a l s o at both the t i p s on late-wood zone to denote the p o s i t i o n s f o r measurements. The upper 10 22 Figure 2. Sampling scheme w i t h i n b o l t Rings 1 to 10 0 to 4 Age l e v e l s A . Cross se c t i o n of a h a l f - b o l t showing p o s i t i o n s of boards and samples f o r age l e v e l s 0 to 4 4 3 2- 1 O 7 4-L 4 — > 7) R e l a t i v e density Grain angle Tracheid length and f i b r i l angle Shrinkage d i r e c t i o n s : L - l o n g i t u d i n a l T - t a n g e n t i a l R - r a d i a l B. One board with f i v e age l e v e l s C. One s t i c k with samples f o r d i f f e r e n t studies 23 cm piece was f u r t h e r d i v i d e d i n t o three p i e c e s . The top piece was used f o r the estimation of r e l a t i v e d e n s i t y , the middle one f o r g r a i n angle, and the lower one f o r f i b e r c h a r a c t e r i s t i c s . The samples prepared f o r the shrinkage and r e l a t i v e d e n s i t y estimations were immediately soaked i n water f o r 24 hours to achieve f i b e r s a t u r a t i o n p o i n t . The samples f o r g r a i n angle, t r a c h e i d length, and f i b r i l angle study were stored i n f r e e z i n g temperatures u n t i l the time of preparation of samples f o r these measurements. Measurement of shrinkage Samples at the f i b e r s a t u r a t i o n p o i n t were measured i n l o n g i t u d i n a l , t a n g e n t i a l and r a d i a l d i r e c t i o n s using a Mitutoyo d i g i m a t i c i n d i c a t o r with a p r e c i s i o n of 1 / 1 0 0 0 mm. The samples were then a i r d r i e d f o r 24 hours and oven d r i e d i n a preheated ( 1 0 6 ° C ) hot a i r oven f o r 24 hours. The d r i e d samples were again measured at the same measurement point s i n l o n g i t u d i n a l , t a n g e n t i a l and r a d i a l d i r e c t i o n s . From the wet and dry measurements, percent shrinkage was estimated as f o l l o w s . % shrinkage = ({H_ - M 2)/ M x ) * 1 0 0 where M^ = Wet measurement M 2 = Dry measurement I f the samples were warped during drying, necessary c o r r e c t i o n s were made f o r the l o n g i t u d i n a l dry measurement using trigonometric functions as follows. C L = ( T T * D * A ) / 3 6 0 where C L = corrected length 24 D - (T / 2 ) 2 / (2 * C) T « chord C * perpendicular distance from the center of chord t o the c i r c l e A - ( ( S i n ( ( T / 2 ) / R)) * (180 / ir) ) * 2 R - D / 2 Measurement of r e l a t i v e d e n s i t y R e l a t i v e d e n s i t y was measured using the g r a v i m e t r i c method (Dadswell and N i c h o l l s , 1959). A f t e r submersion i n water f o r 24 hours, samples were wiped with wet b l o t t i n g paper t o remove any excessive water. Each sample was then dipped i n water i n a beaker placed on a s e n s i t i v e s c a l e , using a pointed metal needle. The s c a l e was tared before the d i p p i n g of the sample. The increase i n weight i n gm r e g i s t e r e d on the balance was numerically equivalent to the volume of the sample i n cubic centimeters. The samples were then a i r d r i e d f o r 24 hours and then d r i e d f o r 24 hours i n a preheated (106°C) hot a i r oven. The sample was then immediately weighed. R e l a t i v e density was estimated as f o l l o w s . R e l a t i v e density = W^  / V w where W<j = Dry weight i n gm V w = Wet volume i n cm 3 Measurement of g r a i n angle Grain angle i n r e s p e c t i v e annual r i n g s was determined by measuring the angle between l i n e s d i s c l o s e d on the t a n g e n t i a l surface and the edge of the sample a f t e r p e e l i n g 25 t h i n s l i v e r s from the t a n g e n t i a l s urface (Dadswell and N i c h o l l s , 1959) . T h i s measurement was made i n the late-wood. Measurement of tracheid length Small p e e l i n g s of wood taken from the late-wood region of the sample t i s s u e were mascerated using a mixture of g l a c i a l a c e t i c a c i d and hydrogen peroxide (50:50) b o i l i n g i n a steam bath. When the peel i n g s were uniformly t r a n s l u c e n t , they were washed with water, teased apart and sta i n e d with 1 % (W/V) Chlora z o l black E f o r 20 minutes. The sta i n e d f i b e r s l u r r y sample mixed with water was s t r a i n e d through a 150-mesh SS screen i n a No. 3 Buchner fun n e l . The f i b e r s were t r a n s f e r r e d t o s l i d e s by l a y i n g the s l i d e on the deposit caught on the screen. The slide-mounted f i b e r s were observed under a microscope and f i b e r length measured u s i n g a computerized d i g i t i z e r device developed a t Forintek Corporation, Vancouver. Measurement of f i b r i l angle F i b r i l angle was measured using the technique described by Senft and Bendtsen (1985). Frozen wood samples were soaked i n water at room temperature and d r i e d i n hot a i r oven a t 106 °C to induce checking i n the c e l l w a l l s . The soaking and drying process was repeated s e v e r a l times to induce maximum checking i n the c e l l w a l l s . S e r i a l r a d i a l s e c t i o n s (15 microns thick) were cut and stored i n 50 % et h y l a l c o h o l . The stored sections were immersed i n 70% al c o h o l f o r 5 minutes and then immersed i n a 2 % s o l u t i o n of iodine potassium iodide f o r 2-10 seconds. The excess 26 s o l u t i o n was b l o t t e d and a few drops of 6 0 % n i t r i c a c i d were added. The s e c t i o n was then put on a s l i d e and covered with a cover s l i p . The m i c r o f i b r i l angles i n early-wood and late-wood were measured using the d i r e c t i o n of elongated dark c r y s t a l s of io d i n e f i l l i n g the cracks i n p a r a l l e l l i n e s . For the measurement, a C a r l Z e i s s Jena Jenamed 2 t r a n s m i t t e d - l i g h t microscope with video p r o j e c t i o n was used. F i b r i l angle measurements were made on the TV screen using a p r o t r a c t o r . S t a t i s t i c a l a n a l y s i s of the data S t a t i s t i c a l a n a l y s i s of the data was c a r r i e d out using the SAS s t a t i s t i c a l package on a mainframe computer at the U n i v e r s i t y of B r i t i s h Columbia Computing Center. Proc Means, Proc GLM and Proc Var comp procedures of SAS (SAS I n s t i t u t e , 1987) were u t i l i z e d f o r the a n a l y s i s at d i f f e r e n t stages. Analysis of variance The a n a l y s i s was c a r r i e d out i n three stages. In the f i r s t stage, f o r each t r a i t , Proc GLM was used t o t e s t a l l the sources of v a r i a t i o n i n the model and t h e i r i n t e r a c t i o n s . The s t r u c t u r e of t h i s a n a l y s i s i s given i n Table 2 a, b, and c . At t h i s stage, i n the case of shrinkage and r e l a t i v e density i n the progeny study, because of the large magnitude of the data s et and the complexity of the model, smaller subsets were taken from the main data set, choosing 2 p o l l e n and 2 seed parents at random and considering t h e i r progeny. Three such subsets Table 2a. Sources of v a r i a t i o n , degrees of freedom (DF), expected mean squares (EMS), and denominators ( i n brackets) f o r F t e s t s f o r l o n g i t u d i n a l shrinkage (%), t a n g e n t i a l shrinkage (%) , r a d i a l shrinkage (%) , r e l a t i v e density, and g r a i n angle (°) i n the f i r s t stage a n a l y s i s ( S - s i t e , B-block, M-male, F-female, T-tree, C-side, A-age l e v e l ; C and A f i x e d e f f e c t s ) Source DF Expected mean squares 27 s 1 0 16 17 18 20 21 23 24 26 27 (26+21-20+24 26 B ( S ) 2 0 16 17 20 23 26 ( 2 3 + 2 0 - 1 7 ) 25 M 1 0 16 17 18 19 23 24 25 ( 2 4 + 1 9 - 1 8 ) 24 S*M 1 0 16 17 18 23 24 ( 2 3 + 1 8 - 1 7 ) 23 B * M ( S ) 2 0 16 17 23 ( 1 7 ) 22 F 1 0 16 17 18 19 20 21 22 ( 2 1 + 1 9 - 1 8 ) 21 S*F 1 0 16 17 18 20 21 ( 2 0 + 1 8 - 1 7 ) 20 B * F ( S ) 2 0 16 17 20 ( 1 7 ) 19 M*F 1 0 16 17 18 19 ( 1 8 ) 18 S * H * F 1 0 16 17 18 ( 1 7 ) 17 B * M * F ( S ) 2 0 16 17 ( 1 6 ) 16 T ( S * B * M * F ) 16 0 16 ( 0 ) 15 C ( S * B * M * F * T ) 32 0 15 ( 0 ) 14 A 4 0 14 ( 0 ) 13 S * A 4 0 13 ( 0 ) 12 B * A ( S ) 8 0 12 ( 0 ) 11 M*A 4 0 11 ( 0 ) 10 S * H * A 4 0 10 ( 0 ) 9 B * H * A ( S ) 8 0 9 ( 0 ) 8 F * A 4 0 8 ( 0 ) 7 S * F * A 4 0 7 ( 0 ) 6 B * F * A ( S ) 8 0 6 ( 0 ) 5 M * F * A 4 0 5 ( 0 ) 4 S * M * F * A 4 0 4 ( 0 ) 3 B * H * F * A ( S ) 8 0 3 ( 0 ) 2 T * A ( S * B * M * F ) 64 0 2 ( 0 ) 1 C * A ( S * B * H * F * T ) 128 0 1 ( 0 ) 0 E r r o r 640 0 Table 2b. Sources of v a r i a t i o n , degrees of freedom (DF), expected mean squares (EMS), and denominators ( i n brackets) f o r F t e s t s f o r t r a c h e i d length i n the f i r s t stage of an a l y s i s (M-male, F-female, T-tree, S-side, A-age l e v e l ; S and A f i x e d e f f e c t s ) Source DF Expected mean squares 11 M 1 0 8 10 F 3 0 8 9 M*F 3 0 8 8 T ( M * F ) 8 0 8 7 S ( M * F * T ) 16 0 7 6 A 4 0 6 ( 0 ) 5 M*A 4 0 5 ( 0 ) 4 F * A 12 0 4 ( 0 ) 3 M * F * A 12 0 3 ( 0 ) 2 T * A ( M * F ) 32 0 2 ( 0 ) 1 S * A ( M * F * T ) 64 0 1 ( 0 ) 0 E r r o r 7840 0 9 11 ( 9 ) 9 10 ( 9 ) 9 ( 8 ) ( 0 ) ( 0 ) Table 2c. Sources of v a r i a t i o n , degrees of freedom (DF), expected mean squares (EMS), and denominators ( i n brackets) f o r F t e s t s f o r f i b r i l angle (°) i n the f i r s t stage a n a l y s i s (M-male, F-female, T - t r e e , W-wood type, A-age l e v e l ; W and A f i x e d ) Source DF Expected mean squares 19 M 1 0 18 F 3 0 17 M*F 3 0 16 T(M*F) 8 0 15 U 1 0 14 M*W 1 0 13 F*W 3 0 12 M*F*W 3 0 11 T * U ( M * F ) 8 0 10 A 4 0 9 M*A 4 0 8 F * A 12 0 7 M * F * A 12 0 6 T * A ( M * F ) 32 0 5 U * A 4 0 4 M*W*A 4 0 3 F * U * A 12 0 2 M * F * W * A 12 0 1 T * W * A ( M * F ) 32 0 0 E r r o r 1440 0 16 17 19 ( 1 7 ) 16 17 18 ( 1 7 ) 16 17 ( 1 6 ) 16 (0) 15 (0) 14 ( 0 ) 13 ( 0 ) 12 ( 0 ) 11 ( 0 ) 10 ( 0 ) 9 ( 0 ) 8 ( 0 ) 7 ( 0 ) 6 ( 0 ) 5 ( 0 ) 4 ( 0 ) 3 ( 0 ) 2 ( 0 ) ( 0 ) 30 were considered. Subsequently, as age e f f e c t was found t o be s i g n i f i c a n t along with i t s i n t e r a c t i o n s , analyses were c a r r i e d out separately by age. At each age l e v e l , Proc GLM was used t o t e s t the s i g n i f i c a n c e of each source of v a r i a t i o n . Structure of t h i s a n a l y s i s i s given i n Table 3 a, b, and c. In the t h i r d stage of analyses, which was c a r r i e d out by age with the same s t r u c t u r e as a n a l y s i s 2, Proc Varcomp was used t o estimate the components of variance f o r the estimation of genetic parameters. Wherever estimated variance components are negative, they are presented as such, though i t i s s t a t i s t i c a l l y u n r e a l i s t i c . The s t r u c t u r e of ANOVA f o r the c l o n a l study i s given i n Tables 4 and 5. Proc Means was used f o r c a l c u l a t i n g the means. Analysis of covariance A n a l y s i s of covariance was done i n d i r e c t l y using a n a l y s i s of variance. The Proc Varcomp f u n c t i o n of the SAS package was u t i l i z e d f o r t h i s . The f o l l o w i n g r e l a t i o n s h i p was used i n the i n d i r e c t method. Variance X + Y = Variance X + Variance Y + 2 * Covariance XY (Ross, 1984) Analyses of variance were c a r r i e d out f o r t r a i t 1 and 2 and f o r 1+2. Based on the r e l a t i o n given above, covariance was estimated. Components of covariance were estimated based on the above r e l a t i o n s h i p using the same method as that of a n a l y s i s of variance. Table 3a. Sources of variation, degrees of freedom (DF), expected mean squares (EMS), and denominators (in brackets) for F tests for longitudinal shrinkage (%) , tangential shrinkage (%) , radial shrinkage (%) , relative density, and grain angle (°) in the second stage analysis (S-site, B-block, M-male, F-female, T-tree); Coefficients for EMS: 0- 1, 1- 6; 2- 12, 3- 24, 4- 48, 5- 48, 6- 96, 7- 192, 8- 144, 9- 288, 10- 576, 11- 576, 12- 1152 Source DF Expected mean squares 12 S 1 0 1 2 3 5 6 8 9 11 12 (11+9-8+6-5 -3+2) 11 B ( S ) 2 0 1 2 5 8 11 ( 8 + 5 - 2 ) 10 M 3 0 1 2 3 4 8 9 10 ( 9 + 4 - 3 ) 9 S*M 3 0 1 2 3 8 9 ( 8 + 3 - 2 ) 8 B * M ( S ) 6 0 1 2 8 ( 2 ) 7 F 11 0 1 2 3 4 5 6 7 ( 6 + 4 - 3 ) 6 S*F 11 0 2 3 5 6 (5+3 - 2 ) 5 B * F ( S ) 22 0 2 5 ( 2 ) 4 M*F 33 0 2 3 4 ( 3 ) 3 S * M * F 33 0 1 2 3 ( 2 ) 2 B * M * F ( S ) 66 0 1 2 ( 1 ) 1 T ( S * B * H * F ) 192 0 ( 0 ) 0 E r r o r 1920 0 32 Table 3b. Sources of v a r i a t i o n , degrees of freedom (DF) , expected mean squares (EMS), and denominators ( i n brackets) f o r F t e s t s f o r t r a c h e i d length (mm) and f i b r i l angle (°) fo r second stage a n a l y s i s (M-male, F-female, T-tree) Source DF Expected mean square 4 M 1 0 1 2 4 (2) 3 F 3 0 1 2 3 (2) 2 M*F 3 0 1 2 (1) 1 T(M*F) 8 0 1 (0) 0 E r r o r 1584 a a Degrees of freedom of e r r o r f o r f i b r i l angle was 144 3 3 Table 3c. Sources of v a r i a t i o n , degrees of freedom ( D F ) , expected mean squares (EMS), and denominators ( i n brackets) f o r F t e s t s f o r height (m) and diameter a t breast height (cm) ( S - s i t e , B-block, M-male, F-female, T-tree); C o e f f i c i e n t s f o r EMS: 0- 1, 1- 2, 2- 4, 3- 8, 4- 8, 5- 16, 6- 32, 7- 24, 8- 48, 9- 96, 10- 96, 11-192 Source D F Expected mean square 11 s 1 0 1 2 4 5 7 8 10 B(S) 2 0 1 4 7 9 M 3 0 1 2 3 7 8 8 S*M 3 0 1 2 7 8 7 B*M(S) 6 0 ' 7 (1) 6 F 11 0 2 3 A 5 6 (5+3-2) 5 S*F 11 0 1 2 A 5 (A+2-1) 4 B*F(S) 22 0 A (1) 3 M*F 33 0 1 2 3 (2) 2 S*M*F 33 0 1 2 (1) 1 B*M*F(S) 66 0 1 (0) 0 Error 192 0 10 11 (10+8-1+5-4-2+1) 10 (7+4-1) 34 Table 4. Sources of v a r i a t i o n , degrees of freedom (DF) , expected mean squares (EMS), and denominators ( i n brackets) f o r F t e s t s f o r l o n g i t u d i n a l shrinkage (%) , t a n g e n t i a l shrinkage (%), r a d i a l shrinkage (%), and r e l a t i v e d e n s i t y i n the p a r e n t a l clones i n f i r s t stage a n a l y s i s (C-clone, T-t r e e , S-side, A-age; A f i x e d e f f e c t ) Source DF Expected mean square 7 C 5 0 5 6 7 6 T(C) 12 0 5 6 (5) 5 S(C*T) 18 0 5 (0) 4 A 7 0 4 (0) 3 C*A 35 0 3 (0) 2 T*A(C) 84 0 2 (0) 1 S*A(C*T) 126 0 1 (0) 0 Er r o r 576 0 Table 5. Sources of v a r i a t i o n , degrees of freedom (DF) , expected mean squares (EMS), and denominators ( i n brackets) f o r F t e s t s f o r l o n g i t u d i n a l shrinkage (%) , t a n g e n t i a l shrinkage (%), r a d i a l shrinkage (%), and r e l a t i v e d e n s i t y i n the p a r e n t a l clones i n second stage a n a l y s i s (C-clone, T-t r e e , S-side); ( C o e f f i c i e n t s f o r EMS: 0- 1, 1- 3, 2- 6, 3-18) Source DF Expected mean square 3 C 5 0 1 2 3 (2) 2 T(C) 12 0 1 2 (1) 1 S(C*T) 18 0 1 (0) 0 Er r o r 72 0 35 P r e l i m i n a r y study Based on the estimates of variance i n the p r e l i m i n a r y study, necessary sample s i z e s required f o r the complete study were c a l c u l a t e d i n c l u d i n g number of samples w i t h i n the t r e e , number of tr e e s w i t h i n p l o t , number of tr e e s w i t h i n family, and number of blocks w i t h i n l o c a t i o n . Number of samples within tree and number of trees within plot Estimation of sample s i z e was based on the variance only. Experimental e r r o r c o n s i s t s of two sources of v a r i a t i o n at t h i s l e v e l , one r e s u l t i n g from variance between samples w i t h i n t r e e and the other between t r e e s w i t h i n the p l o t . The p r e c i s i o n was c a l c u l a t e d f o r the experiment keeping t o t a l degrees of freedom the same and changing the degrees of freedom of samples wit h i n t r e e and tr e e s w i t h i n p l o t . D i f f e r e n t designs were then compared using the e r r o r variance of the designs (Steel and T o r r i e , 1960). Lo n g i t u d i n a l shrinkage and gr a i n angle at three age l e v e l s (1-3) were used f o r t h i s estimation. The r e l a t i v e e f f i c i e n c y of the sampling already c a r r i e d out (6 samples per t r e e and 3 tr e e s per plot) i s compared with other p o s s i b l e samplings ( F i g . 3) . Although 6 tre e s with 3 samples per tr e e and 9 trees with 2 samples per tr e e are expected t o be more e f f i c i e n t , t h i s many t r e e s could not be taken out from the t r i a l as there were only 9 tr e e s i n each p l o t . Increasing the number of samples w i t h i n t r e e t o 9 and tre e s t o two was l e s s e f f i c i e n t . 36 Figure 3. Comparative e f f i c i e n c y of sampling 6 samples w i t h i n t r e e and 3 t r e e s w i t h i n p l o t (6S3T) with other options (9S2T-9samples w i t h i n t r e e and 2 t r e e s w i t h i n p l o t , 3S6T-3 samples w i t h i n t r e e and 6 t r e e s w i t h i n p l o t , 2S9T-2 samples w i t h i n t r e e and 9 t r e e s w i t h i n p l o t ; L S - l o n g i t u d i n a l shrinkage, GA-grain angle; 1-3-age l e v e l s ) 9S2T 6S3T 3S6T 2 S 9 T - » - LS1 - * - L S 2 LS3 —•— GA1 — B — G A 2 -x— G A 3 37 Number of trees within family Robertson (1957) estimated the number of o f f s p r i n g per h a l f - s i b f a m i l y to be t e s t e d when there i s a l i m i t on the t o t a l number of o f f s p r i n g that can be t e s t e d . When the breeder has the opportunity to compromise between number of o f f s p r i n g per family and number of f a m i l i e s , the optimal f a m i l y s i z e with h a l f - s i b f a m i l i e s i s estimated as f o l l o w s . n « 0.56 V T/N h 2 where n = optimal family s i z e T = t o t a l number of i n d i v i d u a l s that can be measured N = number of f a m i l i e s to be s e l e c t e d h 2 = h e r i t a b i l i t y of the character. For g e n e t i c parameter estimation, the number of f a m i l i e s must be s u f f i c i e n t l y high to sample the range of genetic v a r i a b i l i t y and to estimate variance components p r e c i s e l y . A w e l l designed t e s t with 50 or more f a m i l i e s should provide good estimates of genetic parameters (Namkoong and Roberds, 1974). However, commonly a d e f i n i t e number of f a m i l i e s are a v a i l a b l e f o r t e s t i n g and the breeder i s p r i m a r i l y i n t e r e s t e d to know how many o f f s p r i n g need to be t e s t e d i n order to achieve r e l i a b l e evaluations of each family so that best may be chosen. With t h i s purpose i n view, C o t t e r i l l and James (1984) proposed a scheme as f o l l o w s . 6/o = ( Z a + Z B ) 2 V (2-2t)/n where S/o = minimum d i f f e r e n c e between f a m i l i e s i n u n i t s 38 of standard d e v i a t i o n ( Z a + Zfl) « a constant r e f l e c t i n g the p r o b a b i l i t y t h a t the progeny t e s t w i l l show a s t a t i s t i c a l l y s i g n i f i c a n t d i f f e r e n c e between observed means of two f a m i l i e s when minimum d i f f e r e n c e between t h e i r true means i s S (Snedecor and Cochran, 1967). t - \ h 2 f o r h a l f - s i b and % h 2 f o r f u l l - s i b progeny h 2 = h e r i t a b i l i t y n = number of t r e e s per family Preliminary estimates of h e r i t a b i l i t y f o r l o n g i t u d i n a l shrinkage and g r a i n angle a t three age l e v e l s (1-3) from the pr e l i m i n a r y data set were used f o r estimating n using the above equation. The e f f e c t of increase i n number of t r e e s per h a l f - s i b family on the magnitude of the d i f f e r e n c e between f a m i l i e s t h a t can be detected i s given i n F i g . 4. The magnitude of the d i f f e r e n c e was found t o decrease r a p i d l y as sample s i z e increased from 1 to 8. Above that, i t decreased g r a d u a l l y . So a sampling s i z e of 8 t r e e s per h a l f - s i b family was found to be appropriate. 39 Figure 4. E f f e c t of number of tr e e s sampled per h a l f - s i b family on magnitude of d i f f e r e n c e that can be detected between f a m i l i e s i n standard d e v i a t i o n u n i t s (N-number of t r e e s , L S - l o n g i t u d i n a l shrinkage, GA-grain angle, 1-3-age l e v e l s ) ~\ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1— 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 N - » LS1 - » LS2 LS3 —G A 1 GA2 GA3 40 Number of blocks per location Number of blocks needed f o r d e t e c t i n g family d i f f e r e n c e s was c a l c u l a t e d using the equation MINB = (FTAB - 1 ) * VR where MINB = minimum number of blocks r e q u i r e d FTAB = Tabulated F value f o r appropriate degrees of freedom VR = (VE + N * VBF) / (N * VF) VE = E r r o r variance VBF = Variance Block * Family VF = Variance family N = Number of tr e e s per p l o t (Loo-Dinkins, 1989). Variance components estimated f o r l o n g i t u d i n a l shrinkage were used f o r t h i s estimation. Based on estimated variance components, the number of blocks r e q u i r e d v a r i e d from 5 to 14. This estimation was based on 8 f u l l - s i b f a m i l i e s i n the pr e l i m i n a r y study. However, based on the a v a i l a b i l i t y of resources, only two blocks were used f o r the study. Considering the resource a v a i l a b i l i t y f o r the study and the estimations f o r e f f e c t i v e sample s i z e s , the augmented study contained 2 s i t e s , 2 blocks, 4 males, 12 females, 2 tr e e s per p l o t , and 6 samples per t r e e f o r shrinkage and r e l a t i v e d e nsity. Smaller sample s i z e s were used f o r g r a i n angle, t r a c h e i d length, and f i b r i l angle due to l i m i t a t i o n of 41 resource f o r the study. In the case of g r a i n angle, 2 s i t e s , 2 blocks, 2 males and 4 females, 3 t r e e s per p l o t , and 6 samples per t r e e were used a t each age l e v e l . For t r a c h e i d length, one s i t e , one block, 2 males, 4 females, 2 t r e e s per p l o t , 2 samples per age, and 50 f i b e r measurements per sample were made. In the case of f i b r i l angle, one s i t e , one block, 2 males, 4 females, 2 t r e e s per p l o t , 2 samples per t r e e i n each age i n t e r v a l and 10 f i b r i l - a n g l e measurements per sample were used. The reduced sample s i z e , e s p e c i a l l y number of h a l f - s i b f a m i l i e s used f o r some t r a i t s , w i l l a f f e c t the estimations of variance among f a m i l i e s f o r those t r a i t s and a l s o the c o r r e l a t i o n s of these t r a i t s with others. 42 Estimation of genetic parameters Estimation of heritability H e r i t a b i l i t y i n the broad sense i s d e f i n e d as the r a t i o of g e n e t i c variance to the phenotypic variance h 2 B - o 2G/ a 2 P where h 2 g *= broad sense h e r i t a b i l i t y O2Q • genetic variance a 2 p - phenotypic variance H e r i t a b i l i t y i n the broad sense describes what p o r t i o n of the t o t a l v a r i a t i o n i s due to d i f f e r e n c e s among genotypes of i n d i v i d u a l s i n the population. H e r i t a b i l i t y i n the narrow sense i s d e f i n e d as the r a t i o of a d d i t i v e genetic variance ( c r 2 ^ ) to phenotypic variance (a 2p) (Falconer, 1989). h 2 = o 2 k I a 2 P h 2 = narrow sense h e r i t a b i l i t y a 2 ^ = a d d i t i v e genetic variance a 2 p = phenotypic variance Here, h e r i t a b i l i t y i s the proportion of the t o t a l variance that i s due to d i f f e r e n c e s among breeding values of i n d i v i d u a l s i n the population. H e r i t a b i l i t y i s s p e c i f i c to the population and t r a i t under co n s i d e r a t i o n . I t i s one of the most important genetic parameter i n e v a l u a t i n g response to s e l e c t i o n . The magnitude of h e r i t a b i l i t y gives an i n d i c a t i o n as to whether progress through s e l e c t i o n f o r a character i s worthwhile. 43 When i n d i v i d u a l s measured from progeny t e s t are the s e l e c t i o n u n i t , the phenotypic variance can be g e n e r a l l y expressed as ff2P = °2k + °2D + °2G*E + °2E where a 2 p = phenotypic variance cr 2^ * a d d i t i v e variance a 2 n * dominance variance a 2G*£ * genotype environment i n t e r a c t i o n a 2 £ = environmental variance When s e l e c t i o n s are made from the parent generation based on breeding value of the parents derived from the performance of t h e i r progeny, the phenotypic variance of family means i s the phenotypic variance among s i b s d i v i d e d by the number of observations making up the components. The numerator of h e r i t a b i l i t y i s the covariance between the genetic value and the phenotype measured t o estimate that value (Namkoong, 1981). When s e l e c t e d t r e e s are assembled i n seed orchards and allowed to f r e e l y intermate, t h i s covariance i s o 2^, because both parents are s e l e c t e d . The numerator f o r h e r i t a b i l i t y , when s e l e c t i o n s are made i n the parent generation based on progeny t e s t i n g , i s r o2^. The value of r ( c o e f f i c i e n t of variance component) i s *; i n the case of h a l f - s i b f a m i l i e s (Falconer, 1989). In the case of broad sense h e r i t a b i l i t y , the numerator includes a d d i t i v e and non-additive variances. In a f a c t o r i a l mating design, assuming t h a t there i s no inbreeding, the variances among seed parents (cx 2f ) and 44 among p o l l e n parents ( a 2 m ) estimate one-quarter of the a d d i t i v e genetic variance ( a 2 ^ ) (Falconer, 1989). The male x female i n t e r a c t i o n (<*2mf) estimates one-quarter of dominance genetic variance (Falconer, 1989). In t h i s experiment, a d d i t i v e genetic variance (CT2A) w a s estimated based on females as there were 12 females compared t o 4 males. Because there are only four male parents, the p r e c i s i o n f o r the estimation of dominance genetic variance was low. In the case of t r a i t s which express low h e r i t a b i l i t i e s the p r e c i s i o n w i l l be very low. Covariance between two t r a i t s among h a l f - s i b f a m i l i e s estimates one quarter of the a d d i t i v e genetic covariance between those two t r a i t s . Component of covariance among seed parents were used f o r the estimation of a d d i t i v e genetic covariance between t r a i t s i n t h i s study. The components of variance used f o r the estimation of phenotypic variance d i f f e r e d f o r d i f f e r e n t t r a i t s as the model d i f f e r e d f o r the d i f f e r e n t t r a i t s . The components of variance used f o r l o n g i t u d i n a l shrinkage, t a n g e n t i a l shrinkage and r a d i a l shrinkage, and r e l a t i v e d e n s i t y are given i n Table. 6. The components of variance used f o r height and DBH are given i n Table 7. 45 Table 6 . Components of variance used i n d e r i v i n g the phenotypic variance f o r the d i f f e r e n t kinds of h e r i t a b i l i t i e s f o r l o n g i t u d i n a l shrinkage, t a n g e n t i a l shrinkage, r a d i a l shrinkage, and r e l a t i v e d e n s i t y Components f o r Phenotypic variance I n d i v i d u a l Family 2 Narrow sense Broad sense a2S*M a,B*M(S) a2 S * F ff2B*F(S) a2M*F a2S*M*F CT2B*M*F(S) a2T(S*B*M*F) ° E r r o r a2S*M a,B*M(S) °2F °2S*F a2B*F(S) a2M*F a2S*M*F a2B*M*F(S) a2T(S*B*M*F) a E r r o r 2 a 2 F a 2 S * F a2B*F(S) a2M*F a2S*M*F a2B*M*F(S) a2T(S*B*M*F) a E r r o r _2 2 M a2S*M CT,B*M(S) a 2 F a2 S * F a2B*F(S) CT2M*F a2S*M*F a2B*M*F(S) ff2T(S*B*M*F) ° E r r o r a Components are di v i d e d by number of observations making up the mean 46 T a b l e 7. C o m p o n e n t s o f v a r i a n c e u s e d f o r d e r i v i n g t h e p h e n o t y p i c v a r i a n c e f o r t h e d i f f e r e n t k i n d s o f h e r i t a b i l i t i e s f o r h e i g h t a n d d i a m e t e r a t b r e a s t h e i g h t C o m p o n e n t s f o r p h e n o t y p i c v a r i a n c e I n d i v i d u a l F a m i l y a ff,S*M a , B * M ( S ) a2 S * F CT2S*F a2 B * F ( S ) a 2 B * F ( S ) a2 M * F a 2 M * F a2 S * M * F A2 S * M * F a2 B * M * F ( S ) a 2 B * M * F ( S ) a E r r o r a E r r o r a2 S * M CT2S*M a , B * M ( S ) CT5B*M(S) °2F °2S*F A2 S * F a2 B * F ( S ) a 2 B * F ( S ) a2 M * F a 2 M * F A2 S * M * F ( 7 2 S * M * F < 72 B * M * F ( S ) a 2 B * M * F ( S ) ° E r r o r a E r r o r N a r r o w s e n s e B r o a d s e n s e a C o m p o n e n t s a r e d i v i d e d b y number o f o b s e r v a t i o n s m a k i n g u p t h e mean 47 Estimation of clonal heritability From c l o n a l t e s t s , only broad sense h e r i t a b i l i t y can be estimated. The component of variance a 2C was used as the numerator of the equation f o r estimating c l o n a l h e r i t a b i l i t y . The components used f o r d e r i v i n g the denominator i s given i n Table 8. Table 8. Components of variance used f o r d e r i v i n g phenotypic variance f o r c l o n a l h e r i t a b i l i t y H e r i t a b i l i t y Components of v a r i a n c e 3 Broad sense (Clonal) O2Q a 2T(C) a 2S(C*T) 2 ° Er r o r a Components are d i v i d e d by number of observations making up the mean The standard e r r o r s of the h e r i t a b i l i t y estimates were approximated according to Kendall and Stuart ( 1977) as: SE (h 2) = { E [ ( 2 ( M i ) 2 / df) (dh 2/dMi) 2] } 2 where SE (h 2) = standard e r r o r of h e r i t a b i l i t y = i t n mean square df = degrees of freedom 48 Estimation of phenotypic and genetic correlations Phenotypic c o r r e l a t i o n s f o r i n d i v i d u a l and family values were estimated based on the phenotypic variances used f o r the r e s p e c t i v e h e r i t a b i l i t i e s and the corresponding phenotypic covariance derived as described elsewhere. r p - Cov XY p / V ( o 2 X p * a 2Y p) where Cov XYp « phenotypic covariance of v a r i a b l e X and Y (X- t r a i t 1 , Y- t r a i t 2) a 2Xp = phenotypic variance of v a r i a b l e X a 2Yp = phenotypic variance of v a r i a b l e Y Genetic c o r r e l a t i o n (r&) was estimated as f o l l o w s : rA = Cov XY A / V ( c2XA * a2YA) where CovXY^ = a d d i t i v e genetic covariance of t r a i t 1 and t r a i t 2 a2XA = a d d i t i v e variance f o r t r a i t 1 a 2Y^ = a d d i t i v e variance f o r t r a i t 2. Standard e r r o r s f o r the phenotypic and genetic c o r r e l a t i o n s were estimated using the method of Kendall and Stuart (1977). 49 RESULTS AND DISCUSSION In general, the experiment was c l o s e t o balanced with very few missing observations. S u r v i v a l of t r e e s was b e t t e r at the Cowichan Lake s i t e compared to the V i c t o r i a Watershed s i t e . There was a s u f f i c i e n t number of t r e e s a v a i l a b l e f o r sampling at the V i c t o r i a Watershed s i t e , and the e f f e c t of wider spacing due to higher m o r t a l i t y w i t h i n p l o t s i s not expected t o i n f l u e n c e the r e s u l t s s e r i o u s l y . Although warping i n the samples was very minimal, c o r r e c t i o n s were made on warped samples to adjust t h e i r length f o r the l o n g i t u d i n a l shrinkage. Reaction wood was o c c a s i o n a l l y encountered i n the samples, e s p e c i a l l y i n the lower age l e v e l s , but i t s presence was not q u a n t i f i e d . Although d e t a i l e d t e s t s were not conducted to check whether b a s i c assumptions of ANOVA were met, r e s i d u a l p l o t s were checked f o r homogeneity of variance. The Durbin-Watson constant was used to check a u t o c o r r e l a t i o n (Neter et al., 1990). In general, the r e s i d u a l p l o t s d i d not i n d i c a t e d e v i a t i o n from homogeneity of variance. There was a l s o no s i g n i f i c a n t a u t o c o r r e l a t i o n . I. EIGHTEEN-YEAR-OLD FULL-SIB PROGENY A. General l e v e l s and o v e r a l l phenotypic trends a t the d i f f e r e n t age l e v e l s T h i s study considered general l e v e l s of the c h a r a c t e r i s t i c s at d i f f e r e n t age l e v e l s independently. 50 1. Longitudinal shrinkage O v e r a l l mean l o n g i t u d i n a l shrinkage was expressed with-i n a range of 0.315 to 0.152 % between the d i f f e r e n t age l e v e l s . Percent l o n g i t u d i n a l shrinkage was highest a t age l e v e l 0 (Table 9) . As the age l e v e l increased, percent l o n g i t u d i n a l shrinkage decreased ( F i g . 5) . At age l e v e l 4, mean percent l o n g i t u d i n a l shrinkage was reduced t o h a l f the s i z e of t h a t at age l e v e l 0. Age e f f e c t was found t o be s t a t i s t i c a l l y s i g n i f i c a n t at a p r o b a b i l i t y l e v e l of 95 % (Table 10). Lo n g i t u d i n a l shrinkage of normal c o n i f e r wood from green t o oven-dry i s i n the range of 0.1 % to 0.2 % (Panshin and Zeeuw, 1980), but shrinkage up to 5.8 % has been reported (FPL, 1960). Nault (1989) observed shrinkage of nearly 0.4 % at r i n g s c l o s e r t o p i t h with a gradual decrease to 0.1 % at the 50th r i n g i n D o u g l a s - f i r . L o n g i t u d i n a l shrinkage observed i n t h i s study at age l e v e l 4, (0.152 % ) , i s c l o s e t o mature wood l o n g i t u d i n a l shrinkage. The higher shrinkage found at e a r l i e r age l e v e l s may be a t t r i b u t e d to j u v e n i l e wood. D i f f e r e n t studies have shown increased l o n g i t u d i n a l shrinkage i n j u v e n i l e wood ( Bendtsen, 1978; Nault, 1989). This increased shrinkage may be r e l a t e d to various c h a r a c t e r i s t i c s of the j u v e n i l e wood. C o r r e l a t i o n s with these t r a i t s w i l l be examined l a t e r i n the di s c u s s i o n . 51 Table 9. Means f o r shrinkage (%) , r e l a t i v e d e n s i t y , g r a i n angle (•), t r a c h e i d length (mm) and f i b r i l angle (•) a t f i v e age l e v e l s Character Age l e v e l s 0 1 2 3 4 Shrinkage: L o n g i t u d i n a l (%) 0. 315 0. 233 0. 198 0. 171 0. 152 Tangential (%) 4. 798 5. 316 6. 602 7. 802 8. 138 Ra d i a l (%) 3. 198 2. 931 3. 489 4. 175 4 . 532 R e l a t i v e d e n s i t y 0. 398 0. 379 0. 361 0. 372 0. 395 Grain angle (°) 0. 1 0. 8 1. 3 1. 4 1. 6 Tracheid length(mm)1. 40 1. 86 2. 39 2. 69 2. 94 F i b r i l angle (•): Early-wood 29. 4 27. 0 26. 0 25. 5 23 . 0 Late-wood 23 . 4 18. 8 16. 6 13. 4 3. 4 52 Figure 5. Mean percent l o n g i t u d i n a l , t a n g e n t i a l , and r a d i a l wood shrinkage (%) at age l e v e l s 0, 1, 2, 3, and 4 i n the progeny » 53 Table 10. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r l o n g i t u d i n a l shrinkage ( L S ) ( % ) , t a n g e n t i a l shrinkage (TS)(%) and r a d i a l shrinkage (RS)(%) i n the three sub-samples XI, X2, and X3 ( S - s i t e , B-block; M-male, F-female, T-tree, C-side, A-age l e v e l ; C and A f i x e d e f f e c t s ) Source LS TS RS XI X2 X3 XI X2 X3 XI X2 X3 S B(S) M S*M B*M(S) F S*F B*F(S) M*F S*M*F B*M*F(S) T(S*B*M*F) C(S*B*M*F*T) A S*A B*A(S) M*A S*M*A B*M*A(S) F*A S*F*A B*F*A(S) M*F*A S*M*F*A B*M*F*A(S) T*A(S*B*M*F) C*A(S*B*M*F*T) E r r o r * * * * * * * * * * * * * * * * * * * * S i g n i f i c a n c e at 95 % confidence l e v e l 54 2. Tangential shrinkage T a n g e n t i a l shrinkage ranged from 4.8 % t o 8.1 %. Unlik e l o n g i t u d i n a l shrinkage, t a n g e n t i a l shrinkage g r a d u a l l y increased from age l e v e l 0 to age l e v e l 4 (F i g . 5 ) . At age l e v e l 4 t a n g e n t i a l shrinkage almost doubled i n comparison with t h a t a t age l e v e l 0 (Table 9). ANOVA showed s t a t i s t i c a l l y s i g n i f i c a n t d i f f e r e n c e s between age l e v e l s (Table 10). Coastal D o u g l a s - f i r wood i s reported to have around 7.6 % t a n g e n t i a l shrinkage (USDA, 1974). The shrinkage l e v e l at age l e v e l 3, (7.8 % ) , i s c l o s e to t h i s general average. 3. Radial shrinkage At age l e v e l 0 , 3.2 % r a d i a l shrinkage was observed and i t increased to 4.5 % at age l e v e l 4. S i m i l a r t o t a n g e n t i a l shrinkage, r a d i a l shrinkage a l s o increased with age ( F i g . 5) . Amount of shrinkage as w e l l as r a t e of increase was lower i n the case of r a d i a l shrinkage compared to t a n g e n t i a l shrinkage (Table 9) . ANOVA r e s u l t s showed s t a t i s t i c a l l y s i g n i f i c a n t d i f f e r e n c e s between age l e v e l s (Table 10). Average r a d i a l shrinkage i n c o a s t a l D o u g l a s - f i r i s reported t o be around 4.8 % (USDA, 1974). A r a d i a l shrinkage of 4.5 % observed at age l e v e l 4 i s almost comparable to that. Radial shrinkage i n mature wood i s ge n e r a l l y expressed at h a l f the magnitude of t a n g e n t i a l shrinkage. A t a n g e n t i a l shrinkage of 8.1 % and 4.5 % r a d i a l 55 shrinkage expressed at age l e v e l 4 c l o s e l y approximates t h i s r e l a t i o n s h i p . 4. Relative density R e l a t i v e d e n s i t y ranged from 0.361 at age l e v e l 2 to 0.398 at age l e v e l 0. R e l a t i v e d e n s i t y at age l e v e l 4 was a l s o c l o s e t o t h a t at age l e v e l 0. Change i n r e l a t i v e d e n s i t y with age shoved a d i f f e r e n t p a t t e r n compared with the shrinkage. R e l a t i v e density was highest at age l e v e l 0 (Table 9) . I t decreased u n t i l age l e v e l 2 and reached values as low as 0.36. At subsequent age l e v e l s , r e l a t i v e d e n s i t y increased s t e a d i l y ( F i g . 6). ANOVA showed s t a t i s t i c a l l y s i g n i f i c a n t d i f f e r e n c e s between mean r e l a t i v e d e n s i t i e s at the d i f f e r e n t age l e v e l s (Table 11) Numerous s t u d i e s on s p e c i f i c g r a v i t y of D o u g l a s - f i r wood have shown s i g n i f i c a n t change i n s p e c i f i c g r a v i t y with age from p i t h (Zobel and van Buijtenen, 1989; King, 1986; Vargas-Hernandez and Adams, 1991). Jozsa et al. (1989) observed a d e c l i n e i n s p e c i f i c g r a v i t y of D o u g l a s - f i r at breast height from 0.52 at the p i t h to about 0.44 at age 7, the l a t t e r which i s about 15 % l e s s than the average d i s c s p e c i f i c g r a v i t y (0.53). From age 10 to 30, a r a p i d increase was noted from 0.46 to 0.56. Observations at 20, 40 and 60 percent sampling height a l s o gave comparable observations. Average s p e c i f i c g r a v i t y of mature Douglas-f i r wood i s reported to be 0.44 (USDA, 1974). The r e l a t i v e d ensity value of 0.394, reached at age l e v e l 4, has not reached the species average f o r mature wood. Loo et al. « - R e l a t i v e d e n s i t y 5 7 Table 11. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r r e l a t i v e d e n s i t y i n the three sub-samples (XI, X2, and X3) and f o r g r a i n angle(°) i n two sub-samples (SI and S2) used f o r the a n a l y s i s (C and A f i x e d e f f e c t s ) ( S - s i t e , B-block, M-aale, r-female, T-tree C-side, A-age l e v e l ) Source R e l a t i v e d e n s i t y Grain angle XI X2 X3 XI X2 S B(S) M S*M B*M(S) F S*F B*F(S) M*F * S*M*F B*M*F(S) * T(S*B*M*F) * * * * * C(S*B*M*F*T) * * * * * A * * * * * S*A * * * * B*A(S) * * * M*A * * * * * S*M*A * B*M*A(S) * * F*A * * S*F*A * B*F*A(S) * * M*F*A * S*M*F*A B*M*F*A(S) T*A(S*B*M*F) C*A(S*B*M*F*T) E r r o r * S i g n i f i c a n c e at 9 5 % confidence l e v e l 5 8 (1985) reported 11.45 years as the t r a n s i t i o n age f o r mature wood i n l o b l o l l y pine. The r e l a t i v e d e n s i t y p r o f i l e over age i n D o u g l a s - f i r has shown gradual increase i n r e l a t i v e d e n s i t y t o over 40 years (Megraw, 1985). 5. Grain angle Very minimal g r a i n angle was expressed i n the t r e e s studied. Maximum g r a i n angle, 1.6°, was expressed a t age l e v e l 4. Grain angle was lowest at age l e v e l 0 (Table 9). As age increased, a left- h a n d g r a i n angle increased ( F i g 7). ANOVA showed a s t a t i s t i c a l l y s i g n i f i c a n t age e f f e c t (Table 11) . In soft-woods, ge n e r a l l y , wood adjacent t o p i t h i s s t r a i g h t grained and then g r a i n angle increases g r a d u a l l y reaching a maximum value w i t h i n the f i r s t ten annual growth r i n g s . Thereafter g r a i n angle decreases and reaches zero. Then a right-handed g r a i n angle may slowly develop and increase as the age advances (Harris, 1989). In the present study, the tr e e s are i n the i n i t i a l phase where the l e f t handed s p i r a l develops and increases from p i t h t o bark. However, the angle expressed i s very low compared with population averages reported. 6. Tracheid length Tracheids i n r i n g s c l o s e t o the p i t h were very short. But as age l e v e l increased, t r a c h e i d length a l s o increased (Fi g . 8) . Age e f f e c t was s t a t i s t i c a l l y s i g n i f i c a n t i n the ANOVA (Table 12). At age l e v e l 0, average t r a c h e i d length Figure 7. Mean g r a i n angle (*) of wood at age l e v e l s 0, 1 2, 3, and 4 i n the progeny i 1 1 1 r 0 1 2 3 4 Age levels Grain angle Figure 8. Mean t r a c h e i d length (mm) at age l e v e l s 0, 1, 2 3, and 4 i n the progeny Age levels *— Tracheid length 61 Table 1 2 . Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r t r a c h e i d length (mm) (M-male, F-female, T-t r e e , C-side, A-age l e v e l ; C and A f i x e d e f f e c t s ) Source Tracheid length M F M*F T (M*F) C(M*F*T) * A * M*A * F*A * M*F*A * T*A(M*F) * C*A(M*F*T) * Er r o r * S i g n i f i c a n c e at 95 % confidence l e v e l 62 was 1.39 mm while at age l e v e l 4, t r a c h e i d length was 2.94 mm (Table 9). S i m i l a r increase i n t r a c h e i d length from p i t h t o bark was observed i n D o u g l a s - f i r by Wellwood and Smith (1962). They a t t r i b u t e d 65 % of the v a r i a t i o n t o the age l e v e l from the p i t h . E r ickson and Arima (1974) a l s o found s i m i l a r trends i n D o u g l a s - f i r , with t r a c h e i d length having an r 2 of 83% with the l o g of age. Most other c o n i f e r s a l s o express such a trend. Loo et al. (1985) reported 10.3 years as the t r a n s i t i o n age f o r t r a c h e i d length, from j u v e n i l e wood to mature wood i n Pinus taeda. Average t r a c h e i d length f o r D o u g l a s - f i r i s around 4 mm. The maximum t r a c h e i d length of 2.94 mm observed at age l e v e l 4 i n t h i s study was not c l o s e t o mature wood values. An increase i n late-wood with age i s reported f o r up to 30-40 years a f t e r which t r a c h e i d length l e v e l s o f f (Megraw, 1985). D u f f i e l d (1964) found a r a p i d r i s e during the f i r s t decade, and a reduced r a t e a f t e r t h a t . 7. Fibril angle F i b r i l angle i n early-wood was higher than that i n late-wood at a l l age l e v e l s (Table 9). F i b r i l angle at age l e v e l 4 was 23° i n the case of early-wood while i t was 3° i n the case of late-wood. Both i n early-wood and late-wood, f i b r i l angle decreased as age l e v e l increased ( F i g . 9) . Both age and type of wood ( e a r l y - and late-wood) showed s t a t i s t i c a l l y s i g n i f i c a n t d i f f e r e n c e s i n the ANOVA (Table 13) . 63 Figure 9. Mean f i b r i l angle (") at age l e v e l s 0, 1, 2, 3, and 4 i n the early-wood (EW) and late-wood (LW) i n the progeny 64 Table 13. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r f i b r i l angle (°) (M-male, F-female, T-tree, W-wood type ( e a r l y - or late-wood), T-tree, A-age; A and W f i x e d e f f e c t s ) Source F i b r i l angle M F M*F T(M*F) * w * M*W F*W M*F*W * T*W(M*F) * A M*A * F*A * M*F*A * T*A(M*F) * W*A * M*W*A * F*W*A * M*F*W*A * T*W*A(M*F) * E r r o r * S i g n i f i c a n c e at 95 % confidence l e v e l 65 E r i c k s o n and Arima (1974) found a decrease from 32° at r i n g s c l o s e t o p i t h t o 7° at 30 years of age i n the l a t e -wood of D o u g l a s - f i r . The average value 23.4* observed i n the present study i s lower than that observed by Erickson and Arima (1974). The m a t e r i a l f o r t h e i r study was from a thinned and f e r t i l i z e d t r i a l compared t o the unthinned and n o n - f e r t i l i z e d t r i a l used f o r the present study. The f a s t e r growth r a t e r e s u l t i n g from the s i l v i c u l t u r a l treatments could lead t o such changes i n wood p r o p e r t i e s (Bendtsen, 1978) . For a l l of the wood characters included i n t h i s study, along with the age e f f e c t , various i n t e r a c t i o n s of age with other sources were s t a t i s t i c a l l y s i g n i f i c a n t . P l o t s of the d i f f e r e n t t r a i t s at the d i f f e r e n t age l e v e l s f o r the two s i t e s d i d not show considerable d i f f e r e n c e i n the p r a c t i c a l sense. However, because of the s i g n i f i c a n t age e f f e c t and i t s i n t e r a c t i o n s , f u r t h e r analyses were c a r r i e d out by age l e v e l . B. Means and phenotypic trends f o r h a l f - s i b f a m i l i e s at d i f f e r e n t age l e v e l s 2. Longitudinal shrinkage A l l the maternal and paternal f a m i l i e s showed a s i m i l a r decreasing trend i n l o n g i t u d i n a l shrinkage with age as observed f o r o v e r a l l means ( F i g . 10 a, b) . The v a r i a t i o n among f a m i l i e s was highest at the lower age l e v e l s . Age l e v e l s 0, 1 and 2 showed considerable v a r i a t i o n while at age l e v e l s 3 and 4 there was l i t t l e v a r i a t i o n (Table 14, 15). 6 6 Figure 10a. Mean l o n g i t u d i n a l shrinkage (%) of wood at age l e v e l s 0, 1, 2, 3, and 4 f o r 12 maternal h a l f - s i b f a m i l i e s 0 . 1 J 1 1 . . r 0 1 2 3 4 Age levels Figure 10b. Mean l o n g i t u d i n a l shrinkage (%) of wood at age l e v e l s 0, 1, 2, 3, and 4 f o r 4 paternal h a l f - s i b f a m i l i e s 6 8 Table 14. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r l o n g i t u d i n a l shrinkage (%) at d i f f e r e n t age l e v e l s ( S - s i t e , B-block, M-male, F-female, T-tree) Age l e v e l Source 0 1 2 3 4 S B(S) * * * M S*M B*M(S) * F * S*F B*F(S) M*F S*M*F * * * B*M*F(S) T(S*B*M*F) * * * * * E r r o r * S i g n i f i c a n c e at 95 % confidence l e v e l Table 15. Estimates of components of variance and components as percentage of the t o t a l variance f o r l o n g i t u d i n a l shrinkage (%) at the d i f f e r e n t age l e v e l s ( S - s i t e , B-block, M-male, F-female, T-tree) Age l e v e l Source 0 1 2 3 4 Var % Var % Var % Var % Var % Var(S) -0. 002288 -5. 9 0. 000094 0. 3 0. 000048 0. 2 -0. 000033 -0. 2 -0. 000075 -0. 8 Var(B(S)) 0. 003836 9. 9 0. 002098 5. 6 0. 000176 0. 8 0. 000048 0. 3 0. 000098 1. 0 Var ( M ) -0. 000113 -0. 3 0. 000355 1. 0 0. 000219 1. 0 0. 000034 0. 2 -0. 000059 -0. 6 Var(S*M) 0. 000766 2 . 0 0. 000102 0. 3 -0. 000084 -0. 4 -0. 000087 -0. 6 0. 000216 2. 2 Var(B*M*(S)) 0. 000193 0. 5 0. 000138 0. 4 0. 000063 0. 3 0. 000135 0. 9 -0. 000152 -1. 6 Var(F) 0. 003602 9. 3 0. 001518 4. 1 0. 000378 1. 7 0. 000009 0. 1 -0. 000015 -0. 2 Var(S*F) 0. 001122 2. 9 0. 000285 0. 8 -0. 000047 -0. 2 -0. 000189 -1. 3 0. 000012 0. 1 Var(B*F(S)) -0. 000133 -0. 3 -0. 000054 -0. 1 -0. 000080 -0. 4 0. 000035 0. 2 -0. 000032 -0. 3 Var (M*F) 0. 000676 1. 8 -0. 000625 -1. 7 -0. 000479 -2 . 2 0. 000049 0. 3 0. 000138 1. 4 Var(S*M*F) 0. 002177 5. 6 0. 002149 5. 8 0. 001741 8. 0 0. 001127 7. 6 -0. 000183 -1. 9 Var(B*M*F(S)) -0. 001633 -4. 2 0. 000397 1. 1 0. 000180 0. 8 -0. 001078 -7. 3 0. 000407 4. 2 Var(T(S*B*M*F) )0. 013247 34. 3 0. 005019 13. 5 0. 002806 12. 9 0. 003006 20. 4 0. 001218 12. 7 Var(Error) 0. 017144 44 . 4 0. 025685 69. 1 0. 016878 77. 4 0. 011701 79. 3 0. 008058 83. 7 70 Some of the i n t e r a c t i o n s were a l s o s i g n i f i c a n t . E s p e c i a l l y s i t e * male * female source was s i g n i f i c a n t a t age l e v e l s 1, 2 and 3. Though s i t e e f f e c t was not s i g n i f i c a n t , block-w i t h i n - s i t e was s i g n i f i c a n t a t 0, 1, and 4 age l e v e l s . Mean l o n g i t u d i n a l shrinkage (%) f o r the 12 maternal and four p a t e r n a l h a l f - s i b f a m i l i e s a t the f i v e age l e v e l s i s given i n Appendix 1. There were s t a t i s t i c a l l y s i g n i f i c a n t d i f f e r e n c e s between maternal f a m i l i e s a t age l e v e l 0 while there was no s t a t i s t i c a l d i f f e r e n c e between the p a t e r n a l f a m i l i e s (Table 14) . V a r i a t i o n between t r e e s w i t h i n p l o t was s t a t i s t i c a l l y s i g n i f i c a n t at a l l age l e v e l s . Estimates of components of variance are given i n Table 15. At a l l age l e v e l s , e r r o r was the highest component. Comparison of other p r i n c i p a l sources of variance are given i n F i g . 11. Tree-t o - t r e e v a r i a t i o n was greater than other components. The high l o n g i t u d i n a l shrinkage at age l e v e l 0 and i t s gradual decrease with increase i n age shows t h a t i t i s a matter of concern at e a r l y age l e v e l s only. Though presence of s i g n i f i c a n t family v a r i a t i o n f o r l o n g i t u d i n a l shrinkage at age l e v e l 0 i n d i c a t e s that there i s scope f o r improving the t r a i t by breeding methods, i t may not be of much p r a c t i c a l importance as that part i s r e l a t i v e l y very small compared to the whole diameter of the stem. Though there are various reports on higher l o n g i t u d i n a l shrinkage at r i n g s c l o s e r to p i t h , very few family e f f e c t s have been reported i n c o n i f e r s . In a recent unpublished study, Megraw and T a l b e r t (Weyerhaeuser Company, Tacoma) observed a high Figure 11. Comparison of major components of variance f o r l o n g i t u d i n a l shrinkage (%) of wood at age l e v e l s 0, 1, 2, 3, and 4 i n the progeny ( S - s i t e , B-block, M-male, F-female, T-tree) 72 degree of v a r i a b i l i t y between f a m i l i e s i n l o b l o l l y pine f o r l o n g i t u d i n a l shrinkage and a h e r i t a b i l i t y s u f f i c i e n t l y high to allow g e n e t i c manipulation. A c l o n a l study i n Ouercus spp. by Nepveu (1984), however, showed very l i t t l e v a r i a t i o n between c l o n a l f a m i l i e s f o r l o n g i t u d i n a l shrinkage. Another study i n Be tula pendula by Nepveu and V e i l i n g (1983) a l s o showed very l i t t l e f a m i l y v a r i a t i o n f o r l o n g i t u d i n a l shrinkage. However, when volumetric shrinkage was considered, s t a t i s t i c a l l y s i g n i f i c a n t family v a r i a t i o n was observed. 2. Tangential shrinkage Unlike l o n g i t u d i n a l shrinkage, t a n g e n t i a l shrinkage showed very l i t t l e v a r i a t i o n between fam i l y means at age l e v e l s 0 and 1 (Appendix 2). At higher age l e v e l s there was comparatively more variance between f a m i l i e s . A l l the f a m i l i e s showed a s i m i l a r trend of i n c r e a s i n g t a n g e n t i a l shrinkage with i n c r e a s i n g age (Fig 12 a, b). Between-tree v a r i a t i o n w i t h i n p l o t was s t a t i s t i c a l l y s i g n i f i c a n t at a l l age l e v e l s . Maternal and paternal family means were not s t a t i s t i c a l l y d i f f e r e n t (Table 16) . The e r r o r component was the highest source of v a r i a t i o n followed by between-tree source (Table 17) . Comparison of the major components of variance other than e r r o r i s given i n F i g . 13. Studies i n Betula pendula by Nepveu and V e i l i n g (1983) showed s i g n i f i c a n t v a r i a t i o n between f a m i l i e s f o r t a n g e n t i a l shrinkage. No reports are a v a i l a b l e f o r s i m i l a r s tudies i n c o n i f e r s to compare with the present study. Figure 12a. Mean t a n g e n t i a l shrinkage (%) of wood at age l e v e l s 0, 1, 2, 3, and 4 f o r 12 maternal h a l f - s i b f a m i l i e s Figure 12b. Mean t a n g e n t i a l shrinkage (%) of wood at ag l e v e l s 0, 1, 2, 3, and 4 f o r 4 paternal h a l f - s i b f a m i l i e s Table 16. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r t a n g e n t i a l shrinkage (%) a t d i f f e r e n t age l e v e l s ( S - s i t e , B-block, M-male, F-female, T-tree) Age l e v e l Source 0 1 2 3 4 S B(S) * M S*M B*M(S) F S*F B*F(S) * M*F S*M*F * B*M*F(S) T(S*B*M*F) * * * * * Er r o r * S i g n i f i c a n c e at 95 % confidence l e v e l Table 17. Estimates of components of variance and components as percentage of t o t a l variance f o r t a n g e n t i a l shrinkage (%) at d i f f e r e n t age l e v e l s ( S - s i t e , B-block, M-male, F-female, T-tree) Age l e v e l Source 0 1 2 3 4 Var % Var % Var % Var % Var % Var (S) 0. 102046 9. 9 -0. 027625 -1. 9 0. 320751 8. 1 0. 175381 6. 1 0. 016095 0. 8 Var (B (S) ) 0. 013607 1. 3 0. 046772 3. 2 0. 105207 2. 7 -0. 004332 -0. 2 0. 000018 0. 0 Var (M) 0. 009565 0. 9 0. 053805 3. 7 0. 143686 3 . 6 0. 017387 0. 6 0. 039530 1. 9 Var (S*M) -0. 004120 -0. 4 0. 011368 0. 8 -0. 015501 -0. 4 -0. 011512 -0. 4 0. 009599 0. 5 Var (B*M(S)) -0. 011463 -1. 1 -0. 003089 -0. 2 0. 004102 0. 1 -0. 024019 -0. 8 -0. 033490 -1. 6 Var (F) 0. 053027 5. 1 0. 014335 1. 0 0. 107139 2 . 7 0. 114024 4. 0 0. 080706 3 . 9 Var (S*F) -0. 022133 -2 . 1 0. 010925 0. 8 -0. 151352 -3 . 8 -0. 040273 -1. 4 0. 004142 0. 2 Var (B*F(S)) -0. 007221 -0. 7 0. 012708 0. 9 0. 104642 2 . 6 0. 011333 0. 4 -0. 024088 -1. 2 Var (M*F) 0. 011026 1. 1 0. 031439 2. 2 -0. 068671 -1. 7 -0. 015995 -0. 6 -0. 018303 -0. 9 Var (S*M*F) 0. 017280 1. 7 0. 022144 1. 5 0. 347327 8. 8 0. 081475 2. 9 0. 021767 1. 1 Var (B*M*F(S)) -0. 010633 -1. 0 -0. 037279 -2 . 6 -0. 176224 -4 . 4 0. 003908 0. 1 0. 145381 7 . 1 Var (T(S*B*M*F))0. 257650 24 . 9 0. 330019 22. 8 1. 103579 27. 9 0. 787252 27. 6 0. 462934 22 . 5 Var (Error) 0. 625214 60. 5 0. 983716 67. 9 2. 135450 53. 9 1. 761849 61. 7 1. 352332 65. 8 77 Figure 13. Comparison of major components of variance f o r t a n g e n t i a l shrinkage (%) of wood at age l e v e l s 0, 1, 2, 3, and 4 i n the progeny ( S - s i t e , B-block, M-male, F- female, T-tree) ^ Var (S) H Var (S*F) Var (B(S)) Var (M*F) Var (F) Var (T(S*B*M*F)) 78 3. Radial shrinkage R a d i a l shrinkage showed a patte r n of change s i m i l a r to tha t of r e l a t i v e d e n s i t y ( F i g . 14 a, b) . At age l e v e l 1 there was a decrease i n r a d i a l shrinkage f o r a l l the f a m i l i e s , a f t e r which i t increased with age. Compared to t a n g e n t i a l shrinkage, there was more v a r i a t i o n between f a m i l i e s at a l l age l e v e l s f o r r a d i a l shrinkage (Appendix 3) . However, family v a r i a t i o n was not s t a t i s t i c a l l y s i g n i f i c a n t at any age l e v e l , while between-tree v a r i a t i o n was s i g n i f i c a n t at a l l age l e v e l s (Table 18). Estimates of variance components are given i n Table 19. E r r o r variance was the biggest source of v a r i a t i o n . Comparison of other major components of variance are given i n F i g . 15. Among the sources other than e r r o r , between-tree v a r i a t i o n was highest. Reports on studies of family v a r i a t i o n f o r r a d i a l shrinkage i n c o n i f e r s are not a v a i l a b l e . Studies i n Betula pendula by Nepveu and V e i l i n g (1983) showed s t a t i s t i c a l l y s i g n i f i c a n t v a r i a t i o n between f a m i l i e s f o r t h i s t r a i t . The high l e v e l of v a r i a b i l i t y w i t h i n t r e e and between-trees w i t h i n p l o t i n t h i s study may be masking family d i f f e r e n c e s 4. Relative density A l l maternal and paternal f a m i l i e s showed a gradual decrease i n r e l a t i v e density from age l e v e l 0 t o age l e v e l 2, followed by a gradual increase i n l a t e r age l e v e l s . Unlike shrinkage, r e l a t i v e density showed s i g n i f i c a n t v a r i a t i o n between maternal f a m i l i e s at a l l age l e v e l s (Table 79 Figure 14a. Mean r a d i a l shrinkage (%) of wood at age l e v e l s 0, 1, 2, 3, and 4 f o r 12 maternal h a l f - s i b f a m i l i e s 6 5.5 Age levels Figure 14b. Mean r a d i a l shrinkage (%) of wood at age l e v e l s 0, 1, 2, 3, and 4 f o r 4 paternal h a l f - s i b f a m i l i e s Table 18. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r r a d i a l shrinkage (%) a t d i f f e r e n t age l e v e l s ( S - s i t e , B-block, M-male, F-female, T-tree) Age l e v e l Source 0 1 2 3 4 S B(S) * * M S*M B*M(S) F S*F B*F(S) M*F S*M*F B*M*F(S) T(S*B*M*F) * * * * * Er r o r * S i g n i f i c a n c e at 95 % confidence l e v e l Table 19. Estimates of components of variance and components as percentage of t o t a l variance f o r r a d i a l shrinkage (%) at d i f f e r e n t age l e v e l s ( S - s i t e , B-block, M-male, F-female, T-tree) Age l e v e l Source 0 1 2 3 4 Var % Var % Var % Var % Var % Var (S) -0. 015287 -1. 1 -0. 022599 -1. 6 0. 126438 8. 3 0. 184192 13. 2 0. 190335 10. 9 Var (B(S)) 0. 026199 1. 9 0. 059225 4. 2 0. 100310 6. 6 0. 099310 7. 1 0. 038722 2. 2 Var (M) 0. 011325 0. 8 0. 011693 0. 8 0. 015379 1. 0 -0. 013294 -1. 0 -0. 002261 -0. 1 Var (S*M) -0. 001539 -0. 1 0. 002450 0. 2 -0. 001481 -0. 1 0. 012693 0. 9 -0. 012713 -0. 7 Var (B*M(S)) -0. 004915 -0. 4 -0. 002554 -0. 2 -0. 008237 -0. 5 0. 002222 0. 2 0. 006355 0. 4 Var (F) 0. 038441 2. 8 0. 037653 2. 7 0. 042851 2. 8 0. 031852 2. 3 0. 001125 0. 1 Var (S*F) -0. 000154 -0. 0 0. 017272 1. 2 -0. 006103 -0. 4 0. 009700 0. 7 0. 043246 2 . 5 Var (B*F(S)) -0. 039500 -2 . 9 -0. 004680 -0. 3 -0. 012329 -0. 8 -0. 027797 -2 . 0 -0. 015984 -0. 9 Var (M*F) -0. 025502 -1. 9 -0. 007791 -0. 6 -0. 003874 -0. 3 0. 020493 1. 5 0. 027811 1. 6 Var (S*M*F) 0. 063437 4 . 7 -0. 010797 -0. 8 0. 029319 1. 9 0. 000686 0. 0 -0. 053059 -3. 1 Var (B*M*F(S)) 0. 072483 5. 3 0. 027236 1. 9 0. 042502 2. 8 0. 016649 1. 2 0. 057720 3 . 3 Var (T(S*B*M*F))0. 147365 10. 9 0. 173864 12. 4 0. 374270 24. 5 0. 451743 32. 3 0. 443474 25. 5 Var (Error) 1. 085213 79. 9 1. 126780 80. 0 0. 829476 54. 3 0. 610414 43. 6 1. 014198 58. 3 03 Figure 15. Comparison of major components of variance f o r r a d i a l shrinkage (%) of wood at age l e v e l s 0, 1, 2, 3, and 4 i n the progeny ( S - s i t e , B-block, M-male, F-female, T-tree) 84 20). At age l e v e l 0, p a t e r n a l family source of v a r i a t i o n was a l s o s t a t i s t i c a l l y s i g n i f i c a n t . The range of v a r i a t i o n among f a m i l i e s was not much d i f f e r e n t at the d i f f e r e n t age l e v e l s (Appendix 4) . Between-tree v a r i a t i o n was a l s o s i g n i f i c a n t a t a l l age l e v e l s . The patte r n of change i n r e l a t i v e density from p i t h t o bark f o r a l l the f a m i l i e s was almost the same (Fi g . 16 a, b) . Estimates of components of variance are given i n Table 21. E r r o r variance was the highest source of v a r i a t i o n followed by between-trees w i t h i n p l o t . Comparison of the major components of variance other than e r r o r i s given i n F i g . 17. Studies i n c o n i f e r s on family v a r i a t i o n i n r e l a t i v e d e n s i t y are numerous. Various studies i n D o u g l a s - f i r a l s o have shown s t a t i s t i c a l l y s i g n i f i c a n t d i f f e r e n c e s between f a m i l i e s (Vargas-Hernandez and Adams, 1991, 1992). In a study i n v o l v i n g open p o l l i n a t e d f a m i l i e s from d i f f e r e n t sources, McKimmy and Campbell (1982) found s i g n i f i c a n t v a r i a t i o n between the sources but not between f a m i l i e s w i t h i n populations. King et al. (1989) a l s o studied t r e e s i n the p l a n t a t i o n s sampled i n t h i s study using increment cores. Mean wood density of l a s t 4 r i n g s (8-12 years) showed s i g n i f i c a n t v a r i a t i o n among h a l f - s i b f a m i l i e s . 5. Grain angle Mean g r a i n angle increased from age l e v e l 0 t o age l e v e l 4 i n a l l the maternal and paternal f a m i l i e s . The trend with age was s i m i l a r i n a l l f a m i l i e s . V a r i a t i o n between family means f o r gr a i n angle increased with age 85 Figure 16a. Mean r e l a t i v e density of wood at age l e v e l s o, 1, 2, 3, and 4 f o r 12 maternal h a l f - s i b f a m i l i e s 0.42 0.33 0.32-1 , , , , r 0 1 2 3 4 Age levels Figure 16b. Mean r e l a t i v e d e n s i t y of wood at age l e v e l s 0 1, 2, 3, and 4 f o r 4 paternal h a l f - s i b f a m i l i e s 87 Table 2 0 . Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r r e l a t i v e d e n s i t y at d i f f e r e n t age l e v e l s ( S - s i t e , B-block, M-male, F-female, T-tree) Age l e v e l Source S B(S) M S*M B*M(S) F S*F B*F(S) M*F S*M*F B*M*F(S) T(S*B*M*F) Er r o r ** * S i g n i f i c a n c e at 95 % confidence l e v e l ** S i g n i f i c a n c e at 99 % confidence l e v e l Table 21. Estimates of components of variance and components as percentage of the t o t a l variance f o r r e l a t i v e density at the d i f f e r e n t age l e v e l s ( S - s i t e , B-block, M-male, F-female, T-tree) Age l e v e l Source 0 1 2 3 4 Var % Var % Var % Var % Var % Var (S) -0. 000015 -1. 5 -0. 000012 -0. 8 0. 000056 3. 6 0. 000189 9. 6 0. 000066 4. 2 Var (B(S)) 0. 000028 2. 8 0. 000082 5. 4 0. 000116 7. 3 0. 000254 12. 9 0. 000076 4. 9 Var (M) 0. 000055 5. 5 0. 000033 2. 2 0. 000031 2. 0 0. 000025 1. 3 0. 000009 0. 6 Var (S*M) -0. 000004 -0. 4 0. 000012 0. 8 0. 000001 0. 0 0. 000011 0. 6 -0. 000016 -1. 0 Var (B*M(S)) -0. 000003 -0. 3 -0. 000015 -1. 0 -0. 000022 -1. 4 -0. 000011 -0. 5 0. 000006 0. 4 Var (F) 0. 000159 15. 9 0. 000117 7. 7 0. 000145 9. 1 0. 000142 7. 2 0. 000136 8. 7 Var (S*F) 0. 000004 0. 4 0. 000025 1. 6 0. 000003 0. 2 0. 000006 0. 3 0. 000045 2 . 9 Var (B*F(S)) 0. 000022 2. 2 0. 000005 0. 3 -0. 000032 -2. 0 -0. 000041 -2. 1 -0. 000051 -3. 2 Var (M*F) 0. 000028 2. 8 0. 000015 1. 0 -0. 000009 -0. 6 0. 000036 1. 8 -0. 000079 -5. 1 Var (S*M*F) -0. 000040 -4. 1 0. 000026 1. 7 -0. 000006 -0. 4 0. 000002 0. 1 0. 000174 11. 1 Var (B*M*F(S)) 0. 000028 2. 8 0. 000081 5. 3 0. 000099 6. 2 0. 000070 3 . 5 0. 000096 6. 1 Var (T(S*B*M*F))0. 000311 31. 2 0. 000522 34. 1 0. 000529 33 . 4 0. 000547 27. 7 0. 000413 26. 4 Var (Error) 0. 000426 42. 7 0. 000639 41. 7 0. 000673 42 . 5 0. 000740 37. 6 0. 000691 44. 1 CO CO 89 Figure 17. Comparison of major components of variance f o r r e l a t i v e d e n s i t y of wood at age l e v e l s 0, 1, 2, 3, and 4 i n the progeny ( S - s i t e , B-block, M-male, F-female, T- tree) I H Var (S*F) g§8 V a r W*^ V a r 0" (S*B*M*F)) 90 l e v e l ( F i g . 18; Appendix 5). However, the v a r i a t i o n due to family e f f e c t was not s i g n i f i c a n t at any age l e v e l (Table 22). Male * Female i n t e r a c t i o n was s i g n i f i c a n t a t age l e v e l 0. V a r i a t i o n between t r e e s w i t h i n p l o t s was a l s o s t a t i s t i c a l l y s i g n i f i c a n t at age l e v e l s 1, 2 and 3. Family v a r i a t i o n f o r g r a i n angle was demonstrated f i r s t by Champion (1929) i n Pinus roxbhurghii. Studying open-pollinated progeny of 33 t r e e s i n Pinus radiata, N i c h o l l s et al. (1964) have a l s o shown s i g n i f i c a n t v a r i a t i o n among f a m i l i e s . Zobel et al. (1968) found s i g n i f i c a n t d i f f e r e n c e s among f u l l - s i b f a m i l i e s of l o b l o l l y pine, but not among h a l f - s i b f a m i l i e s . Zobel et al. (1968) a l s o observed v a r i a t i o n i n g r a i n angle among tr e e s w i t h i n p l o t s . Considerable c l o n a l v a r i a t i o n was reported i n Pinus radiata (Harris, 1989) . 6. Tracheid length The i n c r e a s i n g trend i n t r a c h e i d length with age l e v e l was s i m i l a r i n a l l the maternal and pat e r n a l f a m i l i e s (Appendix 6). Tracheid length showed very l i t t l e v a r i a t i o n between f a m i l i e s at lower age l e v e l s ( F i g . 19) . At age l e v e l 4, however, both paternal and maternal family e f f e c t s were s i g n i f i c a n t . V a r i a t i o n between trees was s i g n i f i c a n t at a l l age l e v e l s (Table 23). There i s considerable evidence i n c o n i f e r s f o r s i g n i f i c a n t v a r i a t i o n among f a m i l i e s i n t r a c h e i d length (Smith, 1967) . McKimmy and Nicholas (1971) reported s i g n i f i c a n t v a r i a t i o n between f a m i l i e s f o r t r a c h e i d length Figure 18. Mean g r a i n angle (°) of wood at age l e v e l s 0, 1, 2, and 3 f o r 4 maternal and 2 paternal h a l f - s i b f a m i l i e s 92 Table 22. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r g r a i n angle (*) at d i f f e r e n t age l e v e l s ( S - s i t e ; B-block, M-male; F-female, T-tree) Age l e v e l Source S B(S) M S*M B*M(S) F S*F B*F(S) M*F S*M*F B*M*F(S) T(S*B*M*F) E r r o r * S i g n i f i c a n c e at 95 % confidence l e v e l 93 Figure 19. Mean t r a c h e i d length (nun) of wood at age l e v e l s 0, 1, 2, 3, and 4 f o r 4 maternal and 2 pa t e r n a l h a l f - s i b f a m i l i e s 94 Table 23. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r t r a c h e i d length (mm) at d i f f e r e n t age l e v e l s (M-male, F-female, T-tree) Age l e v e l Source M F M*F T (M*F) E r r o r * S i g n i f i c a n c e at 95 % confidence l e v e l 95 i n a study i n v o l v i n g 47-year-old D o u g l a s - f i r t r e e s . The three outermost r i n g s from mature wood were used f o r that study. 7. Fibril angle F i b r i l angle i n early-wood and late-wood g r a d u a l l y decreased from age l e v e l 0 to age l e v e l 4 i n a l l the f a m i l i e s (Appendices 7, 8; F i g . 20 a, b) . Family v a r i a t i o n was s t a t i s t i c a l l y s i g n i f i c a n t only at age l e v e l 3 i n l a t e -wood. Between-tree-variation was s u b s t a n t i a l and was s t a t i s t i c a l l y s i g n i f i c a n t at a l l age l e v e l s (Tables 24). Reports of family v a r i a t i o n f o r f i b r i l angle are few. Studies i n Pinus sp. have shown presence and absence of v a r i a t i o n i n f i b r i l angle among f a m i l i e s (Mergen and F u r n i v a l , 1960; K e l l e r , 1973). The lack s i g n i f i c a n t family v a r i a t i o n observed f o r shrinkage i n t h i s study could be a lack of r e a l genetic d i f f e r e n c e or low p r e c i s i o n of the experiment. Consistent s i g n i f i c a n t family v a r i a t i o n f o r r e l a t i v e d e n s i t y i n t h i s study, a r e s u l t which i s comparable t o other s t u d i e s , suggests that the r e s u l t s represent a lack of r e a l d i f f e r e n c e rather than low p r e c i s i o n of the experiment. However, the very small number of f a m i l i e s used i n the case of g r a i n angle, t r a c h e i d length, and f i b r i l angle i s not s u f f i c i e n t t o assess the family e f f e c t s . Figure 20a. Mean f i b r i l angle (*) of early-wood at age l e v e l s 0, 1, 2, 3, and 4 f o r 4 maternal and 2 p a t e r n a l h a l f -s i b f a m i l i e s 97 Figure 20b. Mean f i b r i l angle (") of late-wood at age l e v e l s 0, 1, 2, 3, and 4 f o r 4 maternal and 2 paternal h a l f - s i b f a m i l i e s 0 1 2 3 4 Age levels 98 Table 24. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r early-wood and late-wood f i b r i l angle (°) at d i f f e r e n t age l e v e l s (M-male, F-female, T-tree) Age l e v e l Source 0 1 2 3 4 Early-wood: M F M*F T(M*F) * * * * * E r r o r Late-wood: M F M*F T(M*F) * Er r o r * S i g n i f i c a n c e at 95 % confidence l e v e l 1 * * * * * 99 8. Tree height Mean t r e e height f o r the maternal f a m i l i e s v a r i e d from 10.8 m t o 13.4 m and f o r the p a t e r n a l f a m i l i e s from 11.8 m to 13.3 m (Appendix 9). S i t e and maternal f a m i l y e f f e c t s were s t a t i s t i c a l l y s i g n i f i c a n t . S i t e x Male x Female and Block x Male x Female w i t h i n s i t e e f f e c t s were a l s o s t a t i s t i c a l l y s i g n i f i c a n t (Table 25) . Estimates of components of variance showed s i t e as the highest c o n t r i b u t o r t o variance i n height followed by e r r o r (Table 26). Comparison of the major components of variance i s given i n F i g . 21. S i t e and e r r o r were the l a r g e s t sources of variance f o r both height and DBH. The female component was considerably l a r g e r f o r height than f o r DBH. E a r l i e r s t u d i e s with the same experimental m a t e r i a l found s t a t i s t i c a l l y s i g n i f i c a n t maternal and p a t e r n a l f a m i l y e f f e c t s f o r height at an age of s i x years (Yeh and Heaman, 1982). Tenth-year and 12th-year heights studied by King (1986) a l s o showed a s i g n i f i c a n t maternal family e f f e c t i n t h i s m a t e r i a l . 9. Diameter at breast height Diameter at breast height (DBH) v a r i e d from 15.09 cm to 18.07 cm i n maternal f a m i l i e s and from 16.12 cm to 17.60 cm i n p a t e r n a l f a m i l i e s (Appendix 10). DBH d i d not show s i g n i f i c a n t v a r i a t i o n among family means and s i t e means. However, b l o c k - w i t h i n - s i t e and Block * Male * Female with-i n - s i t e showed s t a t i s t i c a l s i g n i f i c a n c e (Table 25) . Estimates of components of variance f o r DBH are given i n 100 Table 25. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r height (m) and diameter a t breast height (DBH) (cm) of the progeny ( S - s i t e , B-block, M-male, F-female) Source Height DBH S * B(S) * M S*M B*M(S) F * S*F B*F(S) M*F S*M*F * B*M*F(S) * * Er r o r * S i g n i f i c a n c e at 95 % confidence l e v e l 101 Table 26. Estimates of components of variance f o r height and diameter at breast height (DBH) and components as percentage of t o t a l variance ( S - s i t e , B-block, M-male, F-female) Source Height DBH Var % Var % Var (S) 1.690666 37.9 1.468825 18. 8 Var (B(S)) -0.010333 -0.2 0.436801 5. 6 Var (M) 0.325557 7.3 0.381470 4. 9 Var (S*M) 0.051434 1.2 0.257099 3. 3 Var (B*M(S)) 0.013946 0.3 -0.107807 -1. 4 Var (F) 0.516479 11. 6 0.265421 3. 4 Var (S*F) -0.003677 -0.1 0.538155 6. 9 Var (B*F(S)) 0.035765 0.8 0.097812 1. 3 Var (M*F) 0.207189 4.6 -0.020103 -0. 3 Var (S*M*F) 0.307669 6.9 0.399883 5. 1 Var (B*M*F(S))0.400618 9.0 0.869445 11. 1 Var (Error) 0.927771 20.8 3.237388 41. 4 F i g u r e 2 1 . C o m p a r i s o n o f m a j o r c o m p o n e n t s o f v a r i a n c e f o r h e i g h t a n d d i a m e t e r a t b r e a s t h e i g h t (DBH) i n t h e p r o g e n y ( S - s i t e , B - b l o c k , M - m a l e , F - f e m a l e , T - t r e e ) 1 0 3 Table 26. Comparison of the components of variance i s shown i n F i g . 21. S i t e and e r r o r sources were the major c o n t r i b u t o r s t o variance. Yeh and Heaman (1982) and King (1986) found s i g n i f i c a n t maternal f a m i l y e f f e c t s f o r DBH a t ages 6 and 12 years, r e s p e c t i v e l y , i n t h i s m a t e r i a l when both s i t e s were used i n the a n a l y s i s . However, when a n a l y s i s was c a r r i e d out se p a r a t e l y f o r the s i t e s by King (1986), Greater V i c t o r i a s i t e d i d not show any s i g n i f i c a n t p a t e r n a l family e f f e c t s at age 12. C. H e r i t a b i l i t y Narrow-sense h e r i t a b i l i t i e s were based on a d d i t i v e variance estimated from variance f o r maternal f a m i l i e s . Broad-sense h e r i t a b i l i t i e s were based on a d d i t i v e variance estimation based on variance of maternal f a m i l i e s and p a t e r n a l f a m i l i e s and dominance v a r i a t i o n based on male x female i n t e r a c t i o n . In most of the characters studied, p a t e r n a l family variances were very low. T h i s could be a t t r i b u t e d t o chance of s e l e c t i n g paternal parents with very l i t t l e variance between them i n the small sample s i z e (4) used i n the study. This may have a f f e c t e d the estimation of a d d i t i v e variance f o r the c a l c u l a t i o n of broad-sense h e r i t a b i l i t i e s . Though t h e o r e t i c a l l y broad-sense h e r i t a b i l i t y i s greater than narrow-sense h e r i t a b i l i t y , estimates of broad-sense h e r i t a b i l i t i e s were lower i n t h i s study due to the above reason. 1 0 4 The estimates of i n d i v i d u a l and fami l y h e r i t a b i l i t i e s , both narrow-sense and broad-sense and t h e i r standard e r r o r s f o r l o n g i t u d i n a l shrinkage, t a n g e n t i a l shrinkage, r a d i a l shrinkage and r e l a t i v e d e n s i t y are given i n Table 27. As the number of f a m i l i e s used were very low i n the case of g r a i n angle, t r a c h e i d length and f i b r i l angle, no estimations of h e r i t a b i l i t i e s were made f o r these t r a i t s . Estimates of h e r i t a b i l i t i e s f o r height and diameter at breast height are given i n Table 28. 1. Longitudinal shrinkage Narrow-sense i n d i v i d u a l h e r i t a b i l i t y f o r l o n g i t u d i n a l shrinkage ranged from 0.389 at age l e v e l 0 t o 0 at age l e v e l 4. As the age l e v e l increased, h e r i t a b i l i t y g r a d u a l l y decreased and reached zero at age l e v e l 4 ( F i g . 22). Narrow-sense f a m i l y h e r i t a b i l i t y ranged from 0.732 to 0. Family h e r i t a b i l i t y was highest at age l e v e l 1 , but decreased with i n c r e a s i n g age and reached zero at age l e v e l 4 ( F i g . 23) . I n d i v i d u a l and family broad-sense h e r i t a b i l i t i e s decreased with increase i n age l e v e l up to age l e v e l 2. Thereafter they increased s l i g h t l y (Figs. 24, 25). Considering the standard e r r o r s , narrow-sense i n d i v i d u a l h e r i t a b i l i t y was considerable only at age l e v e l 0 whereas narrow-sense family h e r i t a b i l i t y was considerable at age l e v e l s 0-2. Dominance variance was not s i g n i f i c a n t at any age l e v e l and hence broad-sense i n d i v i d u a l and family h e r i t a b i l i t i e s d i d not show appreciable increase over narrow-sense h e r i t a b i l i t i e s . 105 Table 27. Estimates of h e r i t a b i l i t y f o r l o n g i t u d i n a l shrinkage (%) , t a n g e n t i a l shrinkage (%) , r a d i a l shrinkage (%) and r e l a t i v e d e n s i t y (Standard e r r o r s are given i n brackets) Age l e v e l s H e r i t a b i l i t y 0 1 2 Lo n g i t u d i n a l shrinkage: Narrow sense: I n d i v i d u a l 0. 389 0. 174 0. 070 0. 003 0. 000 (0. 222) (0. 103) (0. 059) (0. 032) Family 0. 699 0. 732 0. 611 0. 058 0. 000 (0. 180) (0. 203) (0. 351) (0. 690) Broad sense: I n d i v i d u a l 0. 261 0. 036 0. 000 0. 019 0. 042 (0. 163) (0. 090) (0. 074) (0. 067) Family 0. 488 0. 329 0. 071 0. 101 0. 139 (0. 181) (0. 229) (0. 287) (0. 255) (0. 339) Tangential shrinkage: Narrow sense: I n d i v i d u a l 0. (0. 231 111) 0. (0. 040 640) 0. (0. 121 061) 0. (0. 170 086) 0. (0. 158 096) Family 0. (0. 852 132) 0. (0. 307 386) 0. (0. 904 220) 0. (0. 833 149) 0. (0. 765 211) Broad sense: I n d i v i d u a l 0. (0. 184 116) 0. (0. 183 098) 0. (0. 064 117) 0. (0. 074 084) 0. (0. 082 109) Family 0. (0. 553 141) 0. (0. 564 174) 0. (0. 416 224) 0. (0. 439 181) 0. (0. 448 212) Rad i a l shrinkage: Narrow sense: I n d i v i d u a l 0. (0. 114 079) 0. (0. 110 070) 0. (0. 132 078) 0. (0. 114 085) 0. (0. 003 070) Family 0. (0. 685 289) 0. (0. 687 206) 0. (0. 738 202) 0. (0. 598 248) 0. (0. 027 582) Broad sense: I n d i v i d u a l 0. 000 0. (0. 049 053) 0. (0. 078 088) 0. (0. 107 097) 0. (0. 072 086) Family 0. (0. 164 252) 0. (0. 432 199) 0. (0. 403 187) 0. (0. 332 212) 0. (0. 256 301) Contd. 106 Table 27. contd. R e l a t i v e d e n s i t y : Narrow sense: I n d i v i d u a l 0. 644 0. 321 0. 410 0. 371 0. 381 (0. 274) (0. 178) (0. 176) (0. 173) (0 200) Family 0. 853 0. 722 0. 896 0. 838 0 798 (0. 082) (0. 148) (0. 082) (0. 102) (0 184) Broad sense: I n d i v i d u a l 0. 546 0 247 0. 224 0. 313 0 000 (0 158) (0 122) (0. 123) (0 127) Family 0 809 0 .564 0. 649 0 675 0 265 (0 072) (0 .136) (0. 125) (0 112) (0 262) Figure 22. Narrow sense i n d i v i d u a l h e r i t a b i l i t y f o r l o n g i t u d i n a l shrinkage (%) (LS), t a n g e n t i a l shrinkage (%) (TS) , r a d i a l shrinkage (%) (RS), and r e l a t i v e d e n s i t y (RD) of wood at age l e v e l s 0, 1, 2, 3, and 4 i n the progeny 0.7 Age levels • LS — T S RS - B - RD Figure 23. Narrow sense family h e r i t a b i l i t y f o r l o n g i t u d i n a l shrinkage (%) ( L S ), t a n g e n t i a l shrinkage (%) (TS) , r a d i a l shrinkage (%) (RS), and r e l a t i v e d e n s i t y (RD) of wood at age l e v e l s 0, 1, 2, 3, and 4 i n the progeny 109 Figure 24. Broad sense i n d i v i d u a l h e r i t a b i l i t y f o r l o n g i t u d i n a l shrinkage (%) ( L S ) , t a n g e n t i a l shrinkage (%) ( T S ) , r a d i a l shrinkage (%) ( R S ) , and r e l a t i v e d e n s i t y (RD) of wood at age l e v e l s 0, 1, 2, 3, and 4 i n the progeny 0.9 Age levels - LS —•— TS RS - B - RD Figure 25. Broad sense family h e r i t a b i l i t y f o r l o n g i t u d i n a l shrinkage (%) (LS), t a n g e n t i a l shrinkage (%) (TS), r a d i a l shrinkage (%) (RS), and r e l a t i v e d e n s i t y (RD) of wood at age l e v e l s 0, 1, 2, 3, and 4 i n the progeny 0.9 0 J 1 1 1 1 r 0 1 2 3 4 Age levels • LS —»— TS -*- RS - e - RD Very few re p o r t s are a v a i l a b l e on estimates of h e r i t a b i l i t y f o r l o n g i t u d i n a l shrinkage. Studies by Megraw and T a l b e r t (unpublished) found ' s u f f i c i e n t l y high' l e v e l s of h e r i t a b i l i t y f o r l o n g i t u d i n a l shrinkage i n j u v e n i l e wood of l o b l o l l y pine t o allow genetic manipulation. Studies i n Quercus species (Nepveu, 1984) and Betula pendula (Nepveu and V e i l i n g , 1983), however, found only n o n s i g n i f i c a n t estimates of h e r i t a b i l i t y . H e r i t a b i l i t y of l o n g i t u d i n a l shrinkage i n wood formed at about 10 years age was a l s o found t o be ' n o n - s i g n i f i c a n t 1 in Pinus radiata ( N i c h o l l s et a l . , 1964) 2. Tangential shrinkage Narrow-sense i n d i v i d u a l h e r i t a b i l i t i e s f o r t a n g e n t i a l shrinkage v a r i e d from 0.231 to 0.04 0. Compared t o l o n g i t u d i n a l shrinkage, t a n g e n t i a l shrinkage had lower i n d i v i d u a l narrow-sense h e r i t a b i l i t y at age l e v e l 0, but h e r i t a b i l i t y tended to remain r e l a t i v e l y s t a b l e over the d i f f e r e n t age l e v e l s , except at age l e v e l 2 ( F i g . 22) . Family h e r i t a b i l i t y values were high at a l l age l e v e l s and remained s t a b l e over the d i f f e r e n t age l e v e l s except at age l e v e l 2 ( F i g . 23). Broad-sense h e r i t a b i l i t i e s d i d not show any increase over narrow-sense h e r i t a b i l i t i e s (Figs. 24, 25) . Reports on narrow-sense h e r i t a b i l i t y are not a v a i l a b l e f o r t a n g e n t i a l shrinkage i n c o n i f e r s . However, c l o n a l h e r i t a b i l i t y estimates i n Quercus spp. by Nepveu (1984) were around 0.322 which was ' s i g n i f i c a n t ' . Studies i n Betula 112 pendula by Nepveu and V e i l i n g (1983) obtained ' s i g n i f i c a n t ' i n d i v i d u a l narrow-sense (0.321) and broad-sense (0.380) h e r i t a b i l i t i e s f o r t h i s t r a i t . 3. Radial shrinkage Narrow-sense i n d i v i d u a l h e r i t a b i l i t y estimates though low (< 0.132), v a r i e d l i t t l e from age l e v e l 0 t o 3. At age l e v e l 4, however, i t was nearly zero ( F i g . 22). Family h e r i t a b i l i t i e s were f a i r l y l a r g e and expressed the same trend with age as i n d i v i d u a l h e r i t a b i l i t i e s ( F i g . 23). I n d i v i d u a l and fa m i l y broad-sense h e r i t a b i l i t i e s were very low (F i g s . 24, 25) Estimates of h e r i t a b i l i t i e s f o r r a d i a l shrinkage were not a v a i l a b l e f o r c o n i f e r s . Studies i n Betula pendula by Nepveu and V e i l i n g (1983) d i d not show s i g n i f i c a n t h e r i t a b i l i t i e s f o r r a d i a l shrinkage. Clonal h e r i t a b i l i t y f o r r a d i a l shrinkage i n Quercus spp. was found t o be • s i g n i f i c a n t ' (Nepveu, 1984). 4. Relative density R e l a t i v e density had a f a i r l y high narrow-sense i n d i v i d u a l h e r i t a b i l i t y (0.644) at age l e v e l 0, but i t was only about 60 % of t h i s value i n the remaining age l e v e l s ( F i g . 22) . Narrow-sense family h e r i t a b i l i t y remained high at a l l age l e v e l s ( F i g . 23) . Broad-sense h e r i t a b i l i t y estimates were not greater than of narrow-sense h e r i t a b i l i t i e s (Figs. 24, 25). Wood density has c o n s i s t e n t l y been shown to be under strong genetic c o n t r o l i n f o r e s t t r e e s , as i n d i c a t e d by 1 1 3 moderate t o high h e r i t a b i l i t y estimates (Zobel and van Buijtenen, 1989). King et a l . (1988) reported a narrow-sense i n d i v i d u a l h e r i t a b i l i t y of 0.90 and a narrow-sense fa m i l y h e r i t a b i l i t y of 0.93 i n the same genetic m a t e r i a l as i n the present study. T h e i r estimations were based on 5 mm core samples at age 8-12 years taken a t breast height at one of the two t e s t s i t e s (Cowichan Lake) . The age l e v e l of t h e i r m a t e r i a l i s nearly equivalent to age l e v e l 4 i n the present study. However, t h e i r estimates are q u i t e a b i t greater than that of the present study. The Cowichan Lake s i t e was more uniform compared to V i c t o r i a Watershed s i t e and e r r o r variance i s smaller when Cowichan Lake s i t e alone i s considered. T h i s may be one of the major reasons f o r the d i f f e r e n c e i n the estimates of h e r i t a b i l i t y between the two s t u d i e s . The use of bigger wood samples f o r estimating r e l a t i v e d e n s i t y i n the present study a l s o may be a c o n t r i b u t i n g f a c t o r f o r the d i f f e r e n c e . 5. Height and diameter at breast height Estimated h e r i t a b i l i t i e s of height and DBH are given i n Table 28. Both i n d i v i d u a l and family narrow-sense h e r i t a b i l i t i e s f o r height were considerably g r e a t e r than those f o r DBH. Broad-sense h e r i t a b i l i t y showed an increase i n the case of i n d i v i d u a l h e r i t a b i l i t y . Estimates of h e r i t a b i l i t i e s f o r height and DBH i n the same t r i a l a t 6 years of age were 0.10 and 0.12, r e s p e c t i v e l y (Yeh and Heaman, 1982) . King (1986) estimated h e r i t a b i l i t i e s of 0.140 and 0.164, r e s p e c t i v e l y , at age 12. Table 28. Estimates of h e r i t a b i l i t y f o r height (m) and diameter at breast height (DBH)(cm) (Standard e r r o r s are given i n brackets) H e r i t a b i l i t y Height DBH Narrow sense: I n d i v i d u a l 0.741 0.179 (0.349) (0.251) Family 0.771 0.350 (0.131) (0.400) Broad sense: I n d i v i d u a l 0.902 0.214 (0.264) (0.246) Family 0.720 0.342 (0.105) (0.254) 115 The present estimates show a s u b s t a n t i a l increase over that at ages 6 and 12 years. Studies on height growth at v a r i o u s growth stages i n s e v e r a l f a m i l i e s of D o u g l a s - f i r by Namkoong mt al. (1972) i n d i c a t e d t h a t g e n e t i c c o n t r o l of a p i c a l growth changes during the t r e e ' s l i f e t i m e . I t was found to be strongest i n the j u v e n i l e and e a r l y reproductive years and then d e c l i n e d . At i n i t i a l establishment stage, moderate l e v e l s of genetic variance, as a response to requirement of populations to adapt to v a r i a b l e s o i l s and climates, i s expressed. But as the t r e e s emerge from t h i s stage and an e c o l o g i c a l dominance i s e s t a b l i s h e d , genotypic d i f f e r e n c e between t r e e s decrease. Then as t r e e s enter i n t o an a c t i v e reproductive phase at ages 15 through 20, height growth may be r e s t r i c t e d t o a l l o c a t e s u f f i c i e n t energy f o r reproductive needs. During t h i s stage, e r r o r variance decreases. However, t r e e growth i s cumulative and e a r l y d i f f e r e n c e i n heights may be c a p i t a l i z e d . Hence an increased h e r i t a b i l i t y at t h i s period i s p o s s i b l e . T h i s could be the reason why higher h e r i t a b i l i t i e s were observed during t h i s study (18-year-old) compared to t h a t of King (1986) and Yeh and Heaman (1982). I n t r a - c l a s s c o r r e l a t i o n , which i s \ h e r i t a b i l i t y i n the case of h a l f - s i b f a m i l i e s , was found to decrease from 0.126 to 0.058 from age 5 years t o 12 years and then increase to 0.141 at age 23 years and then decrease beyond that age i n D o u g l a s - f i r (Namkoong et al., 1972). There i s evidence t o suggest t h a t the e r r o r v a r i a t i o n may increase again a f t e r 40 years without increase 116 i n g e n e t i c variance leading to lower h e r i t a b i l i t y f o r height beyond t h a t age (Namkoong et al., 1972). The d i f f e r e n c e i n sample s i z e could a l s o be the cause f o r the increase i n h e r i t a b i l i t y i n t h i s study compared t o t h a t of King. While King examined 22 h a l f - s i b f a m i l i e s , t h i s study considered only 12 f a m i l i e s s e l e c t e d at random from those 22 f a m i l i e s . A f u r t h e r study i n v o l v i n g the 22 f a m i l i e s included i n the study by King would probably i n d i c a t e whether the change i n h e r i t a b i l i t y i s an outcome of d i f f e r e n c e i n sample s i z e . D. Phenotypic c o r r e l a t i o n s between shrinkage and other wood t r a i t s Phenotypic c o r r e l a t i o n c o e f f i c i e n t s (rp) ( i n d i v i d u a l basis) between shrinkage and other d i f f e r e n t wood q u a l i t y t r a i t s are given i n Table 29. 1. Longitudinal shrinkage L o n g i t u d i n a l shrinkage was negatively c o r r e l a t e d with t a n g e n t i a l shrinkage and r a d i a l shrinkage. The negative c o r r e l a t i o n was g e n e r a l l y higher with t a n g e n t i a l shrinkage than with r a d i a l shrinkage. The c o r r e l a t i o n decreased with i n c r e a s i n g age l e v e l s i n the case of t a n g e n t i a l shrinkage. C o r r e l a t i o n s of l o n g i t u d i n a l shrinkage with r e l a t i v e d ensity were very low. Although small at age l e v e l 0, the c o r r e l a t i o n s were nearly zero a t the o l d e r age l e v e l s . C o r r e l a t i o n with g r a i n angle and t r a c h e i d length were a l s o g e n e r a l l y low. C o r r e l a t i o n with early-wood and late-wood f i b r i l angle were weak. 117 Table 29. Phenotypic and genetic c o r r e l a t i o n c o e f f i c i e n t s (bold) between wood t r a i t s (Standard e r r o r s are given below each) Shrinkage: l o n g i t u d i n a l (LS), t a n g e n t i a l (TS), r a d i a l (RS), r e l a t i v e d e n s i t y (RD), g r a i n angle (GA), t r a c h e i d length (TL), f i b r i l angle:early-wood (FAE), late-wood (FAL); 0-4- age l e v e l s ) LS TS RS RD GA TL FAE FAL LS 0 - 0 . 2 9 8 0.209 - 0 . 2 9 7 0.213 0.532 0.641 - - - -1 - 0 . 2 9 8 0.533 0.305 0.282 0.318 0.239 - - - -2 3 0.172 0.510 0.121 0.327 - 0 . 0 9 5 0.104 TS 4 -0.389 0.030 -0.254 0.718 0.187 0.078 - - - --0.315 0.018 0.003 2.138 0.828 0.959 - - - --0.208 0.019 0.641 3.295 0.688 0.361 - - - --0.229 0.019 0.287 2.610 0.299 0.170 - - - --0.193 0.022 - 0 . 7 6 5 3.692 -0 . 1 2 0 0.110 - - - -RS -0.074 0.035 0.010 0.035 0.480 0.275 - - - --0.345 0.018 0.297 0.018 0.991 0.680 - - - --0.160 0.020 0.414 0.017 0.934 0.568 - - - --0.177 0.020 0.356 0.018 1.195 0.973 - - - --0.121 0.022 0.245 0.021 1.180 2.030 - -Contd. -118 Table 29. contd. LS TS RS RD GA TL F A E FAL RD 0.198 -0.037 0.105 0.034 0.035 0.035 0.091 0.161 0.175 0.020 0.020 0.020 0.051 0.007 0.239 0.020 0.020 0.019 -0.063 0.073 0.285 0.020 0.020 0.019 -0.060 -0.037 0.270 0.022 0.022 0.021 GA -0.087 0.046 0.065 0.065 0.073 0.073 0.073 0.073 •0.109 0.041 0.182 0.040 0.006 0.042 •0.025 0.042 •0.043 0.042 0.211 0.040 -0.028 0.042 •0.020 0.041 •0.763 0.018 0.028 0.043 -0.197 0.041 -0.031 0.043 TL 0.160 -0.157 0.173 -0.100 0.074 0.175 0.175 0.174 0.178 0.178 -0.049 0.179 0.272 0.166 -0.239 0.169 •0.280 0.166 0.192 0.173 0.292 0.164 0.154 0.175 -0.129 0.177 -0.165 0.175 0.265 0.167 -0.107 0.178 0.313 0.162 0.037 0.179 0.303 0.163 0.507 0.134 0.105 0.178 0.201 0.172 0.080 0.178 0.018 0.180 0.168 0.175 Contd. 119 Table 29. contd. L S TS RS RD GA TL FAE FAL FAE 0.128 0.030 0.032 0.151 -0.422 0.220 0.273 0.277 0.258 0.271 0.212 0.264 0.019 -0.307 0.317 0.258 0.234 0.232 •0.020 -0.249 -0.686 0.258 0.242 0.137 -0.315 -0.199 0.488 0.250 0.266 0.211 0.487 0.258 -0.640 0.212 0.259 0.164 •0.284 0.455 0.782 0.159 -0.137 0.141 0.277 0.239 0.117 0.294 0.296 0.296 0.068 0.002 0.418 -0.029 0.110 -0.352 0.300 0.302 0.249 0.301 0.298 0.264 FAL 0.157 -0.040 -0.208 0.252 0.258 0.247 -0.206 -0.241 -0.413 -0.103 0.247 0.243 0.214 0.274 -0.242 -0.283 0.363 0.243 0.238 0.224 -0.422 -0.573 -0.639 0.673 0.212 0.173 0.153 0.141 -0.161 -0.223 0.347 0.252 0.245 0.227 0.065 -0.396 -0.536 0.365 0.257 0.218 0.184 0.240 0.083 0.036 -0.099 -0.055 -0.261 -0.656 -0.070 0.256 0.258 0.256 0.257 0.241 0.147 0.300 0.185 0.034 0.158 -0.376 -0.288 -0.382 0.702 0.249 0.258 0.252 0.222 0.237 0.220 0.153 120 2. Tangential shrinkage C o r r e l a t i o n s between t a n g e n t i a l and r a d i a l shrinkage were p o s i t i v e , though low, except a t age l e v e l 0. C o r r e l a t i o n s of t a n g e n t i a l shrinkage with r e l a t i v e d e n s i t y and with g r a i n angle were very low or e s s e n t i a l l y zero. Low p o s i t i v e c o r r e l a t i o n s were observed with t r a c h e i d length at age l e v e l s 1 t o 4 . At age l e v e l 0 there was a s l i g h t negative c o r r e l a t i o n . Early-wood f i b r i l angle shoved very l i t t l e c o r r e l a t i o n except at age l e v e l 3. At age l e v e l 3, a p o s i t i v e c o r r e l a t i o n vas observed. Late-vood f i b r i l angle had no s u b s t a n t i a l c o r r e l a t i o n v i t h t a n g e n t i a l shrinkage. 3. Radial shrinkage R a d i a l shrinkage had veak p o s i t i v e c o r r e l a t i o n s v i t h r e l a t i v e d e n s i t y and c o r r e l a t i o n increased v i t h age l e v e l . Grain angle had no c o r r e l a t i o n v i t h r a d i a l shrinkage. Tracheid length a l s o had only very veak c o r r e l a t i o n v i t h r a d i a l shrinkage. Early-vood f i b r i l angle vas p o s i t i v e l y c o r r e l a t e d v i t h r a d i a l shrinkage at age l e v e l s 1 to 4. The c o r r e l a t i o n increased v i t h i n c r e a s i n g age up to age l e v e l 3. But i n the case of late-vood f i b r i l angle, b e t t e r c o r r e l a t i o n vas found at age l e v e l s 1 t o 2. 121 E. Oenetio c o r r e l a t i o n * between shrinkage and other wood t r a i t s Genetic c o r r e l a t i o n s between shrinkage and other wood t r a i t s are given i n Table 29. Where the a d d i t i v e genetic variance f o r one of the t r a i t s was zero or very low, the c o r r e l a t i o n c o e f f i c i e n t was not estimated. 1. Long!tudinal shrinkage Negative genetic c o r r e l a t i o n with t a n g e n t i a l shrinkage was observed at age l e v e l s 0 and 1 though minimal. At age l e v e l 2, a p o s i t i v e c o r r e l a t i o n was observed. Standard e r r o r s of c o r r e l a t i o n s were very high. In the case of r a d i a l shrinkage, a negative c o r r e l a t i o n was observed at age l e v e l 0, while at age l e v e l s 1 and 2 p o s i t i v e c o r r e l a t i o n s were observed. R e l a t i v e d e n s i t y showed p o s i t i v e g e n e t i c c o r r e l a t i o n with l o n g i t u d i n a l shrinkage at age l e v e l s 0 and 1. 2. Tangential shrinkage There was no s i g n i f i c a n t genetic c o r r e l a t i o n between t a n g e n t i a l and r a d i a l shrinkage a t any age l e v e l . Genetic c o r r e l a t i o n with r e l a t i v e density was low a t age l e v e l 0. But at age l e v e l 1 i t reached a higher value and then gradually decreased. At age l e v e l 4 i t showed a s l i g h t negative c o r r e l a t i o n . 3. .Radial shrinkage R a d i a l shrinkage showed considerable genetic c o r r e l a t i o n with r e l a t i v e density. Although the c o r r e l a t i o n 122 c o e f f i c i e n t s increased v i t h age, t h e i r standard e r r o r s vere a l s o greater. The c e l l v a i l can be considered as a f i b e r composite of c e l l u l o s e m i c r o f i b r i l embedded i n a matrix bonded sidevays by veak hydrogen bonds and l o n g i t u d i n a l l y by strong covalent bonds (Kelsey, 1963). When a c e l l v a i l i s soaked, va t e r molecules are e a s i l y attached a t the hydrogen bond s i t e s . On drying, v a t e r i s removed from the hydrogen bond s i t e s f a s t e r and hence greater shrinkage occurs sidevays than i n the l o n g i t u d i n a l d i r e c t i o n (Kelsey, 1963). When the f i b r i l s are o r i e n t e d i n a greater angle, l o n g i t u d i n a l shrinkage i s increased, v h i l e shrinkage i n the t a n g e n t i a l and r a d i a l d i r e c t i o n s decreases. As the c e l l v a i l s are wider i n the t a n g e n t i a l d i r e c t i o n the increase i n shrinkage i s more pronounced i n the t a n g e n t i a l d i r e c t i o n than i n the r a d i a l d i r e c t i o n . These negative c o r r e l a t i o n s between l o n g i t u d i n a l shrinkage and t a n g e n t i a l shrinkage and between l o n g i t u d i n a l shrinkage and r a d i a l shrinkage are expressed i n the present study at a l l age l e v e l s . The stronger negative c o r r e l a t i o n expected between l o n g i t u d i n a l shrinkage and t a n g e n t i a l shrinkage a l s o i s demonstrated. However, t h i s negative c o r r e l a t i o n was observed at age l e v e l s 0 and 1 only i n the case of l o n g i t u d i n a l shrinkage and t a n g e n t i a l shrinkage. L o n g i t u d i n a l shrinkage at higher age l e v e l s are too low to express any c o r r e l a t i o n with t a n g e n t i a l shrinkage. 123 The lack of c o r r e l a t i o n between l o n g i t u d i n a l shrinkage and f i b r i l angle i n t h i s study d i f f e r s from the observation of H a r r i s and Meylan (1972), who found a c u r v i l i n e a r r e l a t i o n s h i p between these t r a i t s . However, i n t h e i r s t u d i e s the r e l a t i o n s h i p was more pronounced a t f i b r i l angles above 30°. In the present study, a l l the observations of f i b r i l angle were below t h i s l e v e l . R e l a t i o n s h i p s of r e l a t i v e d e n s i t y with t a n g e n t i a l and r a d i a l shrinkage are w e l l e s t a b l i s h e d . When r e l a t i v e d e n s i t y increases, t a n g e n t i a l and r a d i a l shrinkage increase, while l o n g i t u d i n a l shrinkage decreases (Karkkainen and Marcus, 1985). This r e l a t i o n , however, has been shown to be very weak i n the case of t r e e s with high e x t r a c t i v e contents (Kelsey, 1963). In the present study, r e l a t i v e density was found to be p o s i t i v e l y c o r r e l a t e d with r a d i a l shrinkage, but was e s s e n t i a l l y unrelated with both t a n g e n t i a l and l o n g i t u d i n a l shrinkage. Even though the r e l a t i o n s h i p between l o n g i t u d i n a l shrinkage and r e l a t i v e d e n s i t y i s very low, the c o r r e l a t i o n c o e f f i c i e n t s were p o s i t i v e at age l e v e l s 0 and 1 and negative at higher age l e v e l s . T h i s i n d i c a t e s t h at there are other f a c t o r s involved i n higher r e l a t i v e d e n s i t y and higher shrinkage a t lower age l e v e l s . C o c k r e l l (1974) has found such behavior i n sequoia wood with higher l e v e l s of compression wood. I t i s i n f e r r e d from many observations that the formation of r e a c t i o n wood i s r e l a t e d to the process of s t r a i g h t e n i n g of leaning stems. While the shoot i s t h i n at e a r l y age l e v e l s , 124 there w i l l be higher l e v e l s of such e f f e c t s on the t r e e and hence higher l e v e l s of r e a c t i o n wood a t e a r l y age l e v e l s . Greater m i c r o f i b r i l angle i s u s u a l l y a s s o c i a t e d with r e a c t i o n wood. L i g n i n content i s increased from 20 to 30 % i n r e a c t i o n wood, while c e l l u l o s e l e v e l s are reduced by about 20 %. Th i s causes a major s h i f t i n c e l l u l o s e : l i g n i n r a t i o i n the c e l l w a l l . The considerable increase i n s p e c i f i c g r a v i t y i n the r e a c t i o n wood c e l l w a l l i s due to t h i c k e r w a l l s . Though l e v e l s of r e a c t i o n wood were not q u a n t i f i e d i n t h i s study, higher l e v e l s of r e a c t i o n wood were observed i n the samples i n e a r l y age l e v e l s . F. Phenotypic c o r r e l a t i o n between wood t r a i t s and growth characters Phenotypic c o r r e l a t i o n s (rp) ( i n d i v i d u a l basis) between wood q u a l i t y t r a i t s and t r e e growth characters, t o t a l t r e e height and DBH are given i n Table 30. 1. Longitudinal shrinkage The c o r r e l a t i o n between l o n g i t u d i n a l shrinkage and t o t a l height at age 18 years was weakly negative, ranging from -0.307 at age l e v e l 0 t o nea r l y zero a t age l e v e l 4. C o r r e l a t i o n at d i f f e r e n t age l e v e l s showed a decreasing trend with age l e v e l increase. C o r r e l a t i o n with diameter at breast height was al s o weakly negative at the f i r s t 3 age l e v e l s and nearly zero at l a t e r age l e v e l s . 125 Table 30. Phenotypic and genetic c o r r e l a t i o n c o e f f i c i e n t s f o r wood t r a i t s with growth characters height (HT) and diameter at breast height (DBH)(Shrinkage:longitudinal (LS), t a n g e n t i a l (TS), r a d i a l (RS); R e l a t i v e d e n s i t y (RD); Grain angle (GA); Tracheid length (TL); F i b r i l angle: early-wood (FAE), late-wood (FAL); 0-4 Age l e v e l s ) LS TS RS RD GA TL FAE FAL Phenotypic c o r r e l a t i o n s : Height 0 -0.307 0. 032 0.244 0.033 -0.054 0.035 -0.176 0.034 0. 0. 091 072 0. 0. 399 151 -0.085 0.275 0. 0. 103 255 1 -0.174 0. 020 -0.034 0.020 -0.129 0.020 -0.179 0.020 0. 0. 022 039 0. 0. 235 170 -0.145 0.253 0. 0. 150 252 2 -0.094 0.020 -0.105 0.020 -0.024 0.020 -0.124 0.020 0. 0. 015 042 0. 0. 323 161 -0.314 0.250 0. 0. 066 257 3 -0.090 0.020 0.011 0.020 -0.175 0.020 -0.146 0.020 -0. 0. 003 043 0. 0. 054 179 -0.084 0.300 -0. 0. 219 246 4 -0.031 0.022 0.157 0.022 -0.019 0. 022 -0.133 0.022 0. 0. 229 170 0.005 0.302 -0. 0. 024 258 DBH 0 -0.198 0.034 0.200 0.033 -0.013 0.035 -0.180 0.034 0. 0. 010 073 0. 0. 125 177 -0.038 0.277 0. 0. 275 239 1 -0.097 0.020 -0.080 0.020 -0.149 0.020 -0.272 0.019 0. 0. 025 042 0. 0. 013 180 0.010 0.258 0. 0. 224 245 2 -0.029 0.020 -0.187 0.020 -0.220 0. 019 -0.309 0.018 0. 0. 059 042 0. 0. 252 168 -0.127 0.273 0. 0. 130 254 3 0.002 0. 020 -0.039 0.020 -0.112 0.020 -0.320 0.020 0. 0. 083 043 -0. 0. 215 171 0.319 0.271 0. 0. 108 255 4 0.058 0.022 0.105 0. 022 -0.111 0.022 -0.366 0.019 0. 0. 006 180 -0.056 0.301 0. 0. 253 242 Contd. 126 Table 30. contd. LS TS RS RD GA TL FAE FAL Genetic c o r r e l a t i o n s : Height 0 -0.506 0.453 -0.763 -0.356 0.389 1.154 1.751 0.187 1 -0.540 0.020 -0.814 -0.565 0.710 5.680 3.000 0.296 2 -0.425 -0.336 -0.685 -0.353 0.658 6.672 3.987 0.205 3 -0.097 0.528 -0.740 -0.326 1.870 5.046 3.907 0.176 4 0.000 0.646 -1.231 -0.382 4.167 5.149 0.201 DBH 0 -0.584 0.115 -0.922 -1.073 0.909 2.841 4.578 1.022 1 -0.378 -1.536 -1.567 -1.452 1.723 15.882 7.741 1.124 2 -0.066 -1.351 -1.506 -1.157 1.620 16.920 10.255 0.898 4 0.000 - - -1.111 0.656 127 2. Tangential shrinkage At age l e v e l 0 , a p o s i t i v e c o r r e l a t i o n vas observed v i t h 18-year height, but at other age l e v e l s , c o r r e l a t i o n s vere not s i g n i f i c a n t . With diameter at breast height a l s o , t a n g e n t i a l shrinkage shoved p o s i t i v e c o r r e l a t i o n at age l e v e l 0 . At age l e v e l s 1, 2 and 3, negative c o r r e l a t i o n vas observed. 3. Radial shrinkage R a d i a l shrinkage showed c o n s i s t e n t l y negative, but very veak c o r r e l a t i o n s with height and DBH. 4. Relative density R e l a t i v e d e n s i t y showed a weak negative c o r r e l a t i o n with 18-year height at a l l age l e v e l s . Compared to age l e v e l s 2-4, age l e v e l s 0-1 showed higher values of the c o r r e l a t i o n c o e f f i c i e n t . C o r r e l a t i o n s between r e l a t i v e d e n s i t y and DBH were a l s o negative, but higher compared to those between r e l a t i v e density and height. The c o r r e l a t i o n c o e f f i c i e n t increased with increase i n age l e v e l . 0. Genetic c o r r e l a t i o n between wood t r a i t s and growth characters Genetic c o r r e l a t i o n s (r^) between wood t r a i t s and growth characters are given i n Table 30. 1. Longitudinal shrinkage Moderately negative genetic c o r r e l a t i o n s between l o n g i t u d i n a l shrinkage and t o t a l t r e e height were observed at age l e v e l s 0-2, but were nearly zero at l a t e r stages. 1 2 8 G e n e t i c c o r r e l a t i o n v a l u e s f o r d i a m e t e r were n e g a t i v e a t age l e v e l s 0-2. But s t a n d a r d e r r o r s were v e r y h i g h . 2. Tangential shrinkage T a n g e n t i a l s h r i n k a g e had a p o s i t i v e c o r r e l a t i o n w i t h h e i g h t e x c e p t a t age l e v e l 2. Though r v a l u e s were h i g h e r a t age l e v e l s 3 and 4, s t a n d a r d e r r o r s were a l s o v e r y h i g h . DBH showed v e r y l i t t l e c o r r e l a t i o n . 3. Radial shrinkage R a d i a l s h r i n k a g e showed n e g a t i v e g e n e t i c c o r r e l a t i o n w i t h h e i g h t . The c o r r e l a t i o n e s t i m a t e s r e m a ined s t a b l e t h r o u g h a l l age l e v e l s . However, t h e s t a n d a r d e r r o r s e s t i m a t e d were v e r y h i g h . G e n e t i c c o r r e l a t i o n s w i t h d i a m e t e r a t b r e a s t h e i g h t were a l s o s i m i l a r . 4. Relative density G e n e t i c c o r r e l a t i o n s between r e l a t i v e d e n s i t y a t a l l age l e v e l s and 18-year h e i g h t were n e g a t i v e , and somewhat s i m i l a r . E s t i m a t e s o f g e n e t i c c o r r e l a t i o n s were g r e a t e r t h a n t h a t o f p h e n o t y p i c c o r r e l a t i o n s . E s t i m a t e s o f g e n e t i c c o r r e l a t i o n s between r e l a t i v e d e n s i t y a t a l l age l e v e l s and DBH were n o t e s t i m a t e d as DBH d i d n ' t show s i g n i f i c a n t f a m i l y d i f f e r e n c e s . Moderate n e g a t i v e c o r r e l a t i o n s between growth t r a i t s and wood d e n s i t y have been r e p o r t e d i n D o u g l a s - f i r ( B a s t i e n e t a l . , 1985, K i n g , 1986, Vargas-Hernandez, 1991, 1992). S i m i l a r r e s u l t s were o b t a i n e d i n t h e p r e s e n t s t u d y . I t has been a r g u e d t h a t t h i s n e g a t i v e r e l a t i o n i s seen when t h e age f a c t o r i s n o t c o n s i d e r e d (Bendtsen, 1978) . But i n t h e 129 present study, when the r e l a t i o n s h i p was explored at d i f f e r e n t age l e v e l s , the negative r e l a t i o n s h i p was observed at a l l age l e v e l s f o r height and DBH. So i t can be assumed th a t though age i s an important f a c t o r , growth r a t e a l s o i s a f f e c t i n g the wood t r a i t s . S i m i l a r negative phenotypic and genetic c o r r e l a t i o n s were observed a l s o between height and l o n g i t u d i n a l shrinkage. T h i s i n d i c a t e s t h at increased growth r a t e i n height would decrease l o n g i t u d i n a l shrinkage at age l e v e l 0. However, t h i s negative c o r r e l a t i o n i s not observed at higher age l e v e l s . Hence, the f a c t o r s i n f l u e n c i n g the r e l a t i o n s h i p between l o n g i t u d i n a l shrinkage and growth r a t e at age l e v e l s 0 and 4 may not be the same. The decrease i n l o n g i t u d i n a l shrinkage at the higher growth r a t e s could be a t t r i b u t e d t o reduction i n r e a c t i o n wood which reduces l o n g i t u d i n a l shrinkage. Greater v e r t i c a l growth could reduce the amount of r e a c t i o n wood i n t r e e s ( C o c k r e l l , 1974) . Sequoia t r e e s which have r a p i d v e r t i c a l growth have l e s s r e a c t i o n wood compared with other c o n i f e r s . However, i n cases where there was an increase i n r e a c t i o n wood , i t was accompanied by higher r e l a t i v e density and higher l o n g i t u d i n a l shrinkage ( C o c k r e l l , 1974). 130 I I . PARENTAL CLONES Wood shrinkage and r e l a t i v e d e n s i t y only were studied i n the p a r e n t a l clones. As the t r e e s were o l d e r compared to the progeny, 8 age l e v e l s were included i n the study. The experiment was balanced. Occurrence of warping i n the samples f o r l o n g i t u d i n a l shrinkage was r a r e . Necessary c o r r e c t i o n s were made wherever needed. A. General l e v e l s and o v e r a l l phenotypic trends a t the d i f f e r e n t age l e v e l s L o n g i t u d i n a l shrinkage (%) , t a n g e n t i a l shrinkage (%) , r a d i a l shrinkage (%) and r e l a t i v e d e n s i t y (%) at d i f f e r e n t age l e v e l s i n the clones are given i n Table 31. Tangential and r a d i a l shrinkage gradually increased with age l e v e l while l o n g i t u d i n a l shrinkage decreased ( F i g . 26) . R e l a t i v e d e n s i t y decreased at age l e v e l 2 and then increased ( F i g . 27). The trends observed i n the parental clones were s i m i l a r t o those observed i n the progeny. However, the r a t e of increase i n t a n g e n t i a l and r a d i a l shrinkage and r e l a t i v e d e n s i t y from age l e v e l 2 to 4 was lower i n the case of clones, than i n the progeny m a t e r i a l . Table 31. Overall mean for shrinkage (%) and relative density at the different age levels in the parental clones Age level Characters 1 2 3 4 5 6 7 8 Shrinkage (%): Longitudinal 0. 227 0. 177 0. 184 0. 187 0.190 0. 181 0.178 0.175 Tangential 5. 195 5. 701 5. 792 5. 769 5.996 6. 316 6.900 7.438 Radial 3. 141 3 . 229 3. 212 3 . 179 3.369 3 . 583 4.054 4.473 Relative 0. 391 0. 381 0. 382 0. 384 0.384 0. 387 0.394 0.402 Density 132 Figure 26. Mean wood shrinkage (%) at age l e v e l s 1-8 i n s i x pare n t a l clones (28, 49, 60, 62, 72, and 73) ( LS-l o n g i t u d i n a l shrinkage (%), T S - t a n g e n t i a l shrinkage (%), RS-r a d i a l shrinkage (%)) 133 Figure 2 7 . Mean r e l a t i v e d e n s i t y at age l e v e l s 1 to 8 i n s i x p a r e n t a l clones (28, 49, 60, 62, 72, and 73) 0.405 1 2 3 4 5 6 7 8 A g e levels 134 1. Longitudinal shrinkage L o n g i t u d i n a l shrinkage (%) was highest a t age l e v e l 1 (0.227 \ ) . As the age l e v e l increased l o n g i t u d i n a l shrinkage g r a d u a l l y decreased ( F i g . 26). L o n g i t u d i n a l shrinkage at age l e v e l 8 was 0.175 %. A n a l y s i s of variance revealed s i g n i f i c a n t d i f f e r e n c e s between age l e v e l s . D i f f e r e n c e s between sides w i t h i n a t r e e were a l s o s i g n i f i c a n t (Table 32) . I n t e r a c t i o n of clone with age was a l s o found to be a s i g n i f i c a n t e f f e c t . Compared t o the progeny m a t e r i a l s studied, l o n g i t u d i n a l shrinkage was lower at age l e v e l s 1 and 2. But at age l e v e l s 3 and 4, i t was higher. 2. Tangential shrinkage Tangential shrinkage (%) ranged from 5.2 % at age l e v e l 1 t o 7.4 % at age l e v e l 8 ( F i g . 26). A n a l y s i s of variance showed s i g n i f i c a n t v a r i a t i o n due to clones, sides w i t h i n a tr e e , and age. I n t e r a c t i o n of age with clone was al s o s i g n i f i c a n t (Table 32). Tangential shrinkage (%) at age l e v e l 1 was comparable i n the progeny and parental clones. However, at age l e v e l s 2, 3, and 4, parental clones showed considerably l e s s t a n g e n t i a l shrinkage. Tangential shrinkage at age l e v e l 4 was 5.8 % while i n the progeny mat e r i a l i t was 8.1 %. Table 32. Sources of v a r i a t i o n and t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r l o n g i t u d i n a l shrinkage (%), t a n g e n t i a l shrinkage (%), r a d i a l shrinkage (%), and r e l a t i v e density i n the pa r e n t a l clones (Cy-clone, T-tree, S-side, A-age l e v e l ) Source LS TS RS RD C * * * T(C) S(C*T) * * * * A * * * * C*A * * * * T*A(C) * S*A(C*T) * S i g n i f i c a n c e at 95 % confidence l e v e l 136 3. Radial shrinkage R a d i a l shrinkage (%) ranged from 3.1 % at age l e v e l 1 to 4.5 % a t age l e v e l 8. R a d i a l shrinkage was lower than t a n g e n t i a l shrinkage, but r a d i a l shrinkage and t a n g e n t i a l shrinkage showed s i m i l a r patterns of change from age l e v e l 1 t o age l e v e l 8 ( F i g . 26) . A n a l y s i s of variance showed s i g n i f i c a n t d i f f e r e n c e between clones, s i d e s w i t h i n t r e e s and age l e v e l s . Age * Clone i n t e r a c t i o n was a l s o s i g n i f i c a n t (Table 32) . Compared to progeny m a t e r i a l , there wasn't much d i f f e r e n c e i n r a d i a l shrinkage of the clones at the d i f f e r e n t age l e v e l s . However, the t a n g e n t i a l shrinkage ; r a d i a l shrinkage r a t i o was much lower i n p a r e n t a l clones. T h i s can be a t t r i b u t e d to the lower t a n g e n t i a l shrinkage i n the p a r e n t a l clones. 4. Relative density Mean r e l a t i v e density was 0.39 at age l e v e l 1. I t decreased at age l e v e l 2, but from age l e v e l 3 onwards, gra d u a l l y increased and reached 0.40 at age l e v e l 8 ( F i g . 27) . A n a l y s i s of variance showed s i g n i f i c a n t d i f f e r e n c e between c l o n a l means, sides and ages. I n t e r a c t i o n of age with clone was a l s o s i g n i f i c a n t (Table 33). Mean r e l a t i v e density values at the d i f f e r e n t age l e v e l s were s i m i l a r i n the progeny and pa r e n t a l clones. Trends i n the change of r e l a t i v e density with i n c r e a s i n g age were a l s o s i m i l a r i n the two types of ma t e r i a l s . 137 B. Means and phenotypic trends i n the d i f f e r e n t clones at d i f f e r e n t age l e v e l s As age l e v e l s and most i n t e r a c t i o n s with age were s i g n i f i c a n t , the analyses were c a r r i e d out f o r each age separately. 1. L o n g i t u d i n a l shrinkage Mean l o n g i t u d i n a l shrinkage (%) f o r the d i f f e r e n t clones at d i f f e r e n t age l e v e l s are given i n Appendix 11. Most of the clones showed highest shrinkage at age l e v e l 1, with decreasing values as age l e v e l increased. However, i n clones 60 and 62 , the trend was reversed, with shrinkage at age l e v e l 1 among the lowest observed. Clone 73 showed higher shrinkage at a l l age l e v e l s . Maximum v a r i a t i o n between clones was observed at age l e v e l 1 and as age l e v e l increased, v a r i a t i o n between clones decreased ( F i g . 28). Analyses of variance showed a s i g n i f i c a n t clone e f f e c t at age l e v e l 1 and 3. Sides within t r e e s was s i g n i f i c a n t at a l l age l e v e l s except 2 and 3 (Table 43) . Estimates of variance components f o r l o n g i t u d i n a l shrinkage at d i f f e r e n t age l e v e l s are given i n Table 44. A comparative representation of the d i f f e r e n t components i s given i n F i g . 29. The c l o n a l component was highest at age l e v e l 0 and then i t gradually decreased t o zero by age l e v e l 8. E r r o r variance was the highest at a l l age l e v e l s . Sides w i t h i n t r e e was s i g n i f i c a n t while the between-tree component was very low at a l l age l e v e l s . Figure 28. Mean l o n g i t u d i n a l shrinkage (%) at age l e v e l s t o 8 f o r s i x parental clones (28, 49, 60, 62, 72, and 73) 1 2 3 4 5 6 7 8 Age levels 28 —•— 49 60 - B - 62 - * - 72 -dk- 73 Table 33. Sources of variation and their s t a t i s t i c a l significance for shrinkage (%) at different age levels in the parental clones (C-clone, T-tree, S-side) Ag e level Source 1 2 3 4 5 6 7 8 Longitudinal shrinkage (W) C * * T(C) S(C*T) * * * * * * Error Tangential shrinkage (%) : C * T(C) S (C*T) * * * * * * * * Error Radial shrinkage (%): C * * T(C) S(C*T) * * * Error * Significance at 95% confidence level Table 34. Estimates of components of variance f o r l o n g i t u d i n a l shrinkage (%)at d i f f e r e n t age l e v e l s i n the parental clones (Components expressed as percent of t o t a l variance given i n brackets)(C-clone, T-tree, S-side) Source Age l e v e l 1 2 3 4 5 6 7 8 c 0 .006043 0 .001479 0 .002105 0 .000497 0 .001696 0 .000887 0 .000314 -0.000058 (17.8) (17.8) (13.0) ( 2.8) ( 9.2) ( 7.7) ( 3.9) (-0.64) T(C) -0 .000248 0 .000970 0 .000512 -0 .001212 -0 .001002 -0 .000894 -0 .001219 -0.000181 (-0.7) (11.7) ( 3.2) (-6.8) (-5.4) (-7.8) (-15.0) (-2.0) S(C*T) 0 .008822 0 .001088 -0 .000219 0 .005397 0 .005634 0 .004266 0 .004123 0.002946 (26.0) (13.1) (-1.4) (30.1) (30.4) (37.2) (51.3) (32.44) Error 0 .019264 0 .004761 0 .013794 0 .013248 0 .012209 0 .007202 0 .004825 0.006374 (56.9) (57.4) (85.2) (73.9) (65.9) (62.8) (60.0) (70.2) 141 Figure 29. Comparison of components of variance f o r l o n g i t u d i n a l shrinkage (%) at age l e v e l s 1 t o 8 i n s i x p a r e n t a l clones (C-clone, T-tree, S-side) 142 2. Tangential shrinkage Mean t a n g e n t i a l shrinkage (%) a t d i f f e r e n t age l e v e l s f o r the 6 clones i s shown i n Appendix 12. In most of the clones, t a n g e n t i a l shrinkage slowly increased from age l e v e l 1 t o age l e v e l 5 (Fig 30) . Thereafter, the increase was more r a p i d . V a r i a t i o n between clones was maximum at age l e v e l 8 . A n a l y s i s of variance showed s i g n i f i c a n c e between c l o n a l means at age l e v e l 8 only. Side-within-tree was s i g n i f i c a n t at a l l age l e v e l s (Table 33) . The d i f f e r e n t components of variance f o r t a n g e n t i a l shrinkage at d i f f e r e n t age l e v e l s are given i n Table 35. The c l o n a l component increased with age l e v e l . While s i d e - w i t h i n - t r e e and e r r o r components were s u b s t a n t i a l , the between-tree component was very low ( F i g . 31) . 3. Radial shrinkage Mean r a d i a l shrinkage (%) at the d i f f e r e n t age l e v e l s i s given i n Appendix 13. V a r i a t i o n between clones was s i g n i f i c a n t at age l e v e l s 1 and 2 (Table 43) . Patterns of change with i n c r e a s i n g age were s i m i l a r t o those f o r t a n g e n t i a l shrinkage ( F i g . 32) . Components of variance f o r . r a d i a l shrinkage at d i f f e r e n t age l e v e l s are given i n Table 36. The c l o n a l component was r e l a t i v e l y s u b s t a n t i a l only at age l e v e l s 1 and 2 ( F i g . 33). Err o r variance was the highest component and the si d e - w i t h i n - t r e e component a l s o was s u b s t a n t i a l . 143 Figure 30. Mean t a n g e n t i a l shrinkage (%) at age i n t e r v a l s 1 t o 8 f o r s i x parental clones )28, 49, 60, 62, 72, and 73) A g e l e v e l » - 28 —+— 49 60 •e- 6 2 7 2 -A 7 3 Table 35. Estimates of components of variance f o r t a n g e n t i a l shrinkage (%) at d i f f e r e n t age l e v e l s i n the parental clones (Components expressed as percentage of t o t a l variance given i n brackets) (C-clone, T-tree, S-side) Source Age l e v e l 1 2 3 4 5 6 7 8 c 0 .067221 0 .097197 0 .120688 0 .121374 -0 .012507 0 .206478 0 .242044 0 .308082 (5.68) (8.19) (15.2) (12.1) (-1.0) (13.5) (12.7) (14.3) T(C) -0 .043860 0 .061067 -0 .018062 -0 .072397 -0 .121730 -0 .065175 -0 .235755 -0 .464804 (-3.7) (5.14) (-2.3) (-7.2) (-10.0) (-4.3) (-12.0) (-22.0) S(C*T) 0 .379014 0 .301181 0 .232361 0 .381390 0 .503579 0 .552651 0 .949816 1 .244645 (32.0) (25.4) (29.3) (37.9) (42.0) (36.1) (49.9) (57.8) Error 0 .780538 0 .727888 0 .458443 0 .575657 0 .830787 0 .837086 0 .948609 1 .064505 (66.0) (61.3) (57.8) (57.2) (69.2) (54.7) (49.8) (49.5) Figure 31. Comparison of components of variance f o r t a n g e n t i a l shrinkage (%) at age l e v e l s 1 to 8 i n s i x p a r e n t a l clones (C-clone, T-tree, S-side) Figure 32. Mean r a d i a l shrinkage (%) at age i n t e r v a l s 1 to 8 f o r s i x p a r e n t a l clones (28, 49, 60, 62, 72, and 73) Age levels - • - 28 —<— 49 60 —E3— 62 72 -*r- 73 Table 36. Estimates of components of variance for radial shrinkage (%) at different age levels in the parental clones (Components expressed as percentage of t o t a l variance given in brackets) (C-clone, T-tree, S-side) Source Age level 1 2 3 4 5 6 7 8 c 0 .112214 0 .139717 0 .050716 0 .060970 0 .062604 0.032910 0.005116 0 .187394 (14.5) (14.3) (8.33) (10.1) ( 8.9) ( 4.6) ( 0.6) (8.4) T(C) -0 .027139 0 .017588 -0 .037620 -0 .088183 -0 .053022 -0.069629 -0.024403 -0 .135896 (-3.5) ( 1.8) (-6.2) (-15.0) (-7.6) (-9.7) (-2.6) (-6.1) S(C*T) -0 .020308 0 .051754 0 .240461 0 .225273 0 .220446 0.122195 0.208080 0 .418129 (-2.6) ( 5.28) (39.5) (37.5) (31.4) (17.1) (22.3) (18.8) Error 0 .707258 0 .770641 0 .355495 0 .403337 0 .471537 0.629876 0.742448 1 .749099 (91.6) (78.7) (58.4) (67.1) (67.2) (88.1) (79.7) (78.8) Figure 33. Comparison of components of variance f o r r a d i a l shrinkage (%) at age l e v e l s 1 to 8 i n s i x parental clones (C-clone, T-tree, S-side) 149 4. Relative density Mean r e l a t i v e d e n s i t y f o r the d i f f e r e n t clones at 8 age i n t e r v a l s i s given i n Appendix 14. V a r i a t i o n between c l o n a l means was s i g n i f i c a n t at a l l age l e v e l s . Side-within-tree a l s o showed s i g n i f i c a n c e at most of the age l e v e l s (Table 37) . While most clones showed a decrease i n r e l a t i v e d e n s i t y a t age l e v e l s 2 or 3 compared to age l e v e l 1, one clone showed an i n c r e a s i n g trend over the f i r s t three age l e v e l s , with a subsequent decrease from age l e v e l 3 to 6 ( F i g . 34). Except i n clone 73, maximum r e l a t i v e density was expressed at age l e v e l 8. Estimates of components of variance f o r r e l a t i v e d e n s i t y are given i n Table 38. The c l o n a l component was s u b s t a n t i a l at a l l age l e v e l s . Comparison of the d i f f e r e n t components are shown i n F i g . 35. Between-tree variance was very low at a l l age l e v e l s as would be expected i n a c l o n a l t r i a l . The s i d e - w i t h i n - t r e e component was s u b s t a n t i a l except at age l e v e l 6. 150 Figure 34. Mean r e l a t i v e density at age i n t e r v a l s 1 t o 8 f o r s i x p a r e n t a l clones (28, 49, 60, 62, 72, and 73) 4 5 Age levels -m- 28 —•— 49 60 - B - 62 - * - 72 —A— 73 Table 37. Sources of density at d i f f e r e n t v a r i a t i o n and age l e v e l s i n t h e i r s t a t i s t i c a l s i g n i f i c a n c e f o r r e l a t i v e the parental clones (C-clone, T-tree, S-side) Source Age l e v e l 1 2 3 4 5 6 7 8 c * T(C) S(C*T) * * * * * * * * * * * * * Error * S i g n i f i c a n c e at 9 5 % confidence l e v e l Table 38. Estimates of components of variance f o r r e l a t i v e density at d i f f e r e n t age l e v e l s f o r the parental clones (Components expressed as percentage of t o t a l variance given i n brackets; C-clone, T-tree, S-side) Source Age l e v e l 1 2 3 4 5 6 7 8 c 0 .000910 0 .000734 0 .001087 0 .001150 0 .000913 0 .001265 0 .000993 0 .001177 (27.0) (29.6) (30.8) (36.4) (37.3) (38.2) (37.9) (38.4) T(C) -0 .000468 0 .000065 0 .000109 0 .000071 0 .000244 0 .000261 0 .000410 0 .000053 (-14.0) (2.64) (3.08) (2.25) (9.97) (7.88) (15.7) (1.72) S(C*T) 0 .001755 0 .000543 0 .000868 0 .000957 0 .000214 -0 .000122 0 .000122 0 .000512 (52.1) (21.9) (24.6) (30.3) (8.74) (-3.7) (4.66) (43.2) Err o r 0 .001172 0 .001134 0 .001464 0 .000982 0 .001076 0 .001908 0 .001094 0 .001327 (34.8) (45.8) (41.5) (31.1) (44.0) (57.6) (41.8) (43.2) (Jl Figure 3 5 . Comparison of components of variance f o r r e l a t i v e d e n s i t y a t age l e v e l s 1 to 8 i n s i x parental clones (C-clone, T-tree, S-side) 154 C. Estimation of c l o n a l h e r i t a b i l i t y 1. Longitudinal shrinkage C l o n a l h e r i t a b i l i t y f o r l o n g i t u d i n a l shrinkage i s given i n Table 39. H e r i t a b i l i t y was high (0.711) at age l e v e l l . But i t g r a d u a l l y decreased and reached 0 by age l e v e l 8 (F i g . 36). 2. Tangential shrinkage C l o n a l h e r i t a b i l i t y f o r t a n g e n t i a l shrinkage increased from 0.422 at age l e v e l 1 to 0.734 at age l e v e l 8 ( F i g . 36). At age l e v e l 5 h e r i t a b i l i t y was 0 (Table 39). 3. Radial shrinkage C l o n a l h e r i t a b i l i t y estimates f o r r a d i a l shrinkage showed a gradual decrease with increase i n age l e v e l ( F i g . 36). At age l e v e l 7, a low h e r i t a b i l i t y (0.070) was observed (Table 39). 4. Relative density C l o n a l h e r i t a b i l i t y estimates f o r r e l a t i v e d e n s i t y at age l e v e l s 1 t o 8 ranged from 0.806 to 0.880. The v a r i a t i o n i n h e r i t a b i l i t y between age l e v e l s i s very low ( F i g . 36) . Maximum h e r i t a b i l i t y was observed at age l e v e l 6 (Table 39). Table 39. Estimates of c l o n a l h e r i t a b i l i t y f o r shrinkage (%) and r e l a t i v e density at d i f f e r e n t age l e v e l s f o r the parental clones (Standard e r r o r given i n brackets) Age l e v e l Character 1 2 3 4 5 6 7 8 Longitudinal shrinkage 0. ,711 0. ,658 0. .700 0. . 288 0. .569 0. .522 0. ,364 0. .000 (0. ,218) (0. .258) (0. .226) (0, .539) (0. .324) (0. .360) (0. .479) Tangential shrinkage 0. .422 0. .467 0. , 675 0. .630 0. ,000 0. .639 0. .646 0. .734 (0. .436) (0. .402) (0, . 245) (0. .279) (0. ,875) (0. .272) (0. ,266) (0. .205) Radial shrinkage 0. .807 0. .709 0, . 517 0, .666 0. .580 0. .506 0. . 070 0. .607 (0. . 146) (0, .219) (0, , 363) (0. , 251) (0. .316) (0. .372) (0. .700) (0. .302) Re l a t i v e density 0.819 0.807 0.806 0.829 0.838 0.880 0.820 0.870 (0.137) (0.146) (0.146) (0.129) (0.122) (0.090) (0.135) (0.098) 156 Figure 36 . C l o n a l h e r i t a b i l i t y f o r l o n g i t u d i n a l shrinkage (%) (LS), t a n g e n t i a l shrinkage (%)(TS), r a d i a l shrinkage (%)(RS), and r e l a t i v e density (RD) at age l e v e l s 1-8 A g e l e v e l s * L S — I — T S R S - a - R D 157 CONCLUSIONS Based on the r e s u l t s , the questions r a i s e d at the beginning of the study can be answered as f o l l o w s : 1. Is there s i g n i f i c a n t e f f e c t of age l e v e l (from pith) at the time of wood formation on wood shrinkage and other wood c h a r a c t e r i s t i c s ? Age l e v e l of the r i n g from p i t h at the time of wood formation i s s i g n i f i c a n t f o r shrinkage, r e l a t i v e d e n s i t y , g r a i n angle, t r a c h e i d length, and f i b r i l angle. As age increases, l o n g i t u d i n a l shrinkage and f i b r i l angle decrease, while transverse and r a d i a l shrinkage, g r a i n angle and t r a c h e i d length increase. R e l a t i v e density decreases up to age l e v e l 2 and then increases. The r a t e of change decreases beyond age l e v e l 3 f o r shrinkage while t h a t of r e l a t i v e d e n s i t y does not show that trend at age l e v e l s 3 and 4. The olde r p a r e n t a l clones showed s i m i l a r o v e r a l l trends. But i n the par e n t a l clones, where up to 8 age l e v e l s were a v a i l a b l e , t a n g e n t i a l and r a d i a l shrinkage increased g r a d u a l l y from age l e v e l 4 t o age l e v e l 8. These r e s u l t s suggest that the amount of l o n g i t u d i n a l shrinkage begins t o s t a b i l i z e around age l e v e l 4, while t a n g e n t i a l and r a d i a l shrinkage and r e l a t i v e density continue t o change beyond age l e v e l 4. 158 2. Is there s i g n i f i c a n t family e f f e c t on these t r a i t s ? H a l f - s i b f a m i l y e f f e c t i s s i g n i f i c a n t f o r l o n g i t u d i n a l shrinkage at age l e v e l 0, f o r r e l a t i v e d e n s i t y at a l l age l e v e l s , f o r t r a c h e i d length at age l e v e l 4 and f o r late-wood g r a i n angle at age l e v e l 3. In r e s t of the cases, h a l f - s i b f a m i l y e f f e c t s are not s i g n i f i c a n t . Based on the population under study, i t can be i n f e r r e d t h a t there i s very l i t t l e f a m i l y e f f e c t on shrinkage, except f o r l o n g i t u d i n a l shrinkage at age l e v e l 0. I n c l u s i o n of these wood q u a l i t y t r a i t s , other than r e l a t i v e d e n s i t y i n a genetic improvement program i s probably unwarranted. However, f o r r e l a t i v e d e n s i t y , there i s considerable f a m i l y v a r i a t i o n and genetic improvement may be worthwhile. 3. What i s the magnitude of the h e r i t a b i l i t i e s of these t r a i t s ? Narrow-sense h e r i t a b i l i t i e s vary f o r t r a i t s at d i f f e r e n t age l e v e l s . Family h e r i t a b i l i t i e s are higher than i n d i v i d u a l h e r i t a b i l i t i e s . Except f o r l o n g i t u d i n a l shrinkage at age l e v e l 0, i n d i v i d u a l and family h e r i t a b i l i t i e s f o r shrinkage were very low. Moderate i n d i v i d u a l and family h e r i t a b i l i t y at a l l age l e v e l s f o r r e l a t i v e d e n s i t y shows genetic c o n t r o l of r e l a t i v e density at a l l age l e v e l s . 159 4. What are the phenotypic and genetic r e l a t i o n s h i p s between shrinkage and other wood t r a i t s ? L o n g i t u d i n a l shrinkage i s p h e n o t y p i c a l l y n e g a t i v e l y c o r r e l a t e d with transverse and r a d i a l shrinkage. The phenotypic c o r r e l a t i o n of l o n g i t u d i n a l with r e l a t i v e d e n s i t y i s p o s i t i v e a t age l e v e l s 0-2 and negative at age l e v e l s 3 and 4. Genetic c o r r e l a t i o n s of l o n g i t u d i n a l shrinkage with transverse and r a d i a l shrinkage are very low except at age l e v e l 0 where there are negative genetic c o r r e l a t i o n s . Transverse and r a d i a l shrinkage are p h e n o t y p i c a l l y p o s i t i v e l y c o r r e l a t e d , genetic c o r r e l a t i o n between these t r a i t s i s n o n s i g n i f i c a n t . The phenotypic c o r r e l a t i o n between transverse shrinkage and r e l a t i v e d e n s i t y i s very low while t h a t between r a d i a l shrinkage and r e l a t i v e d e n s i t y i s moderate. The genetic c o r r e l a t i o n i s a l s o s u b s t a n t i a l between r a d i a l shrinkage and r e l a t i v e d e n sity. This i n d i c a t e s t h a t s e l e c t i o n f o r higher r e l a t i v e d e n s i t y w i l l lead to higher r a d i a l shrinkage. 5. What are the phenotypic and genetic r e l a t i o n s h i p s between wood q u a l i t y t r a i t s and growth characters ? Lon g i t u d i n a l shrinkage i s ph e n o t y p i c a l l y n e g a t i v e l y c o r r e l a t e d with height. This c o r r e l a t i o n was s i g n i f i c a n t at age l e v e l s 0 and 1, while at other age l e v e l s i t was c l o s e to 0. The phenotypic c o r r e l a t i o n between r a d i a l shrinkage and height i s negative, though very low. The phenotypic c o r r e l a t i o n between r a d i a l shrinkage and DBH i s al s o 160 negative. The phenotypic and genetic c o r r e l a t i o n s between height growth and shrinkage and between DBH growth and shrinkage tended to decrease as the age l e v e l increased, i n d i c a t i n g t h a t the growth rate-shrinkage r e l a t i o n s h i p i s p r i m a r i l y a concern i n the j u v e n i l e core only. Negative phenotypic and genetic c o r r e l a t i o n s observed between height growth and r e l a t i v e d e n s i t y a l s o showed a s i m i l a r trend, i n d i c a t i n g t h a t height growth r a t e may not adversely a f f e c t r e l a t i v e density at higher age l e v e l s . In the case of the negative r e l a t i o n observed between DBH growth and r e l a t i v e density, the i n c r e a s i n g phenotypic as w e l l as genetic c o r r e l a t i o n with age l e v e l , i n d i c a t e the p o s s i b i l i t y of decreasing r e l a t i v e d e n s i t y with s e l e c t i o n f o r increased DBH. 6. Based upon the h e r i t a b i l i t i e s and r e l a t i o n s h i p s , what are the options f o r a breeding program ? S e l e c t i o n f o r gain i n l o n g i t u d i n a l shrinkage could lead t o genetic improvement at age l e v e l s 0-1, while there i s minimal advantage f o r s e l e c t i o n a t a l l age l e v e l s f o r transverse shrinkage, and r a d i a l shrinkage. Negative genetic c o r r e l a t i o n between height and l o n g i t u d i n a l shrinkage, and height and r a d i a l shrinkage i n d i c a t e s the p o s s i b i l i t y of reduced l o n g i t u d i n a l shrinkage and r a d i a l shrinkage based on s e l e c t i o n f o r height. However, the negative genetic c o r r e l a t i o n between height and r e l a t i v e density w i l l cause reduction i n r e l a t i v e density. 161 The r e s u l t s of t h i s study support B.C's current t r e e breeding program i n D o u g l a s - f i r t o increase wood production through g e n e t i c improvement i n growth r a t e by showing that s e l e c t i o n f o r r a p i d e a r l y height growth w i l l not r e s u l t i n s u b s t a n t i a l reductions i n s e v e r a l wood q u a l i t y t r a i t s with the exception of r e l a t i v e d e n s i t y . A d d i t i o n a l l y i t shows the prospect of i n d i r e c t l y decreasing l o n g i t u d i n a l and r a d i a l shrinkage a t e a r l y age l e v e l s while s e l e c t i n g f o r f a s t e r growth r a t e . The lack of s u b s t a n t i a l genetic e f f e c t s f o r s e v e r a l t r a i t s demonstrated i n t h i s study, i n d i c a t e s t h a t genetic improvement can progress more r a p i d l y by concentrating on a much smaller number of t r a i t s . 162 LITERATURE CITED Baradat, Ph. 1979. S e l e c t i o n combinee m u l t i c a r a c t e r e chez l e p i n maritime: Divers modeles d'index de s e l e c t i o n u t i l i s e s . 104 e Congres N a t i o n a l des Societes Svantes, Bordeaux, sciences f a s c . I I . pp.299-314. Bastien, J . Ch., B. Roman-Amat ans G. Vonnet 1985. Natural v a r i a b i l i t y of some wood q u a l i t y t r a i t s of c o a s t a l Douglas-f i r i n a French progeny t e s t : Implications on breeding s t r a t e g y . IUFRO S2. 02. 05 - Working Party, Vienna. June, 1985. Becker, W.A 1984. Manual of quantitative genetics. Academic Press, Pullman, Washington, 196p. Bendtsen,B.A. 1978. P r o p e r t i e s of wood from improved and i n t e n s i v e l y managed t r e e s . Forest Products Journal 28(10):61-72. Brown, C L . 1980. Physiology of wood formation i n c o n i f e r s . Wood Science 3(l):8-22. Champion, H.G. 1929. More about s p i r a l g r a i n i n c o n i f e r s . Indian Forester 55(2):57-58. C o c k r e l l , R.A. 1974. A comparison of late-wood p i t s , f i b r i l o r i e n t a t i o n , and shrinkage of normal and compression wood of Giant Sequoia. Wood Science and Technology 8:197-206. Comstock, R.E. and Robinson, H.F. 1952. Estimation of average dominance of genes. In Heterosis. E d i t e d by J.W. Gowen. Iowa State College Press, Ames, Iowa. Corriveau, A., Beaulieu, J . and Daoust, G. 1991. H e r i t a b i l i t y and genetic c o r r e l a t i o n s of wood characters of Upper Ottawa V a l l e y white spruce populations grown i n Quebec. The Forestry Chronicle 67(6):698-705. C o t t e r i l l , P.P and James, J.W. 1984. Number of o f f s p r i n g and p l o t s i z e s f o r progeny t e s t i n g . S i l v a e Genetica 33:203-209. Cown, D.J. 1976. Densitometric studies of the wood of young c o a s t a l D o u g l a s - f i r (Pseudotsuga menziesii (Mirb.) Franco), Ph.D. Thesis, U n i v e r s i t y of B r i t i s h Columbia, 24Ip. Dadswell, H.E. 1958. Wood s t r u c t u r e v a r i a t i o n s occurring during t r e e growth and t h e i r i n f l u e n c e on p r o p e r t i e s . Journal of the I n s t i t u t e of Wood Science 1:11-32. Dadswell, H.E., F i e l d i n g , J.M., N i c h o l l s , J.W.P. and Brown, A.G. 1961. Tree to t r e e v a r i a t i o n and the gross h e r i t a b i l i t y of wood c h a r a c t e r i s t i c s of Pinus radiata. Tappi 44(3):174-179. 163 Dadswell, H.E. and Nicholls,J.W.P. 1959. Assessment of wood q u a l i t y f o r t r e e breeding. CSIRO A u s t r a l i a , D i v i s o n of Forest Products Technology, S c i e n t i f i c Paper. No.4, 16p. D u f f i e l d , J.W. 1964. Tracheid length v a r i a t i o n p a t t e r n s i n D o u g l a s - f i r and s e l e c t i o n of extreme v a r i a n t s . Tappi 47(2):122-124. Einspahr, D.W., van Buijtenen, J.P. and Thode, E.F. 1962. Wood and pulp p r o p e r t i e s determined from s l a s h pine increment core and whole t r e e measurements. S i l v a e Genetica 11:68-77. Erickson, H.D. and Arima, T. 1974. D o u g l a s - f i r wood q u a l i t y s t u d i e s , P a r t I I : E f f e c t of age and stimulated growth on f i b r i l angle and chemical c o n s t i t u e n t s . Wood Science and Technology 8: 255-265. Falconer, D.S. 1989. Introduction to quantitative genetics. Longman S c i e n t i f i c and T e c h n i c a l , England. 438p. Forest Products Lab 1960. Lon g i t u d i n a l shrinkage of wood. Report No. 1093. US Forest Service, F.P.L. Madison . lOp. Gilmore, A.R., Boyce, S.G., and Ryker, R.A. 1966. The r e l a t i o n s h i p of s p e c i f i c g r a v i t y of l o b l o l l y pine t o environmental f a c t o r s i n southern I l l i n o i s . Forest Science 12:399-405. Goggans, J.F. 1964. C o r r e l a t i o n and h e r i t a b i l i t y of c e r t a i n wood p r o p e r t i e s i n l o b l o l l y pine (Pinus taeda L.) . Tappi 47(6):318-322. Gonzalez, J.S. 1989. C i r c u m f e r e n t i a l v a r i a t i o n i n the r e l a t i v e d e n s i t y of lodgepole pine. Canadian Journal of Forest Research 19(2):276-279. Gorman,T.M. 1985. J u v e n i l e wood as cause of seasonal arching i n t r u s s e s . Forest Products Journal 35 (11/12):35-40. H a r r i s , J.M. 1961. A survey of wood p r o p e r t i e s of r a d i a t a pine grown i n the Kaingaroa Forest. Forest Products Report. 76, Forest Research I n s t i t u t e , New Zealand Forest Service, pp.1-16. H a r r i s , J.M. 1989. Spiral grain and wave phenomena in wood formation. Springer-Verlag, B e r l i n , New York, 214p. H a r r i s , J.M. and Meylan, B.A. 1972. The i n f l u e n c e of m i c r o f i b r i l angle on l o n g i t u d i n a l and t a n g e n t i a l shrinkage i n Pinus radiata. Holzforsch 18:146-156. 164 Heaman, J.C. 1967. A review of the p l u s - t r e e s e l e c t i o n program f o r D o u g l a s - f i r i n c o a s t a l B r i t i s h Columbia, B.C. Forest S e r v i c e Research Note 44, 27p. Isebrands, J.G. and Bensend, D.W. 1972. Incidence and s t r u c t u r e of g e l a t i n o u s f i b r e s w i t h i n rapid-growing eastern cotton-wood. Wood and F i b e r 4(2):61-71. Issac, L.A. and Dimock, E.J. 1965. D o u g l a s - f i r . In Silvics of forest trees of United states, U.S. Department of A g r i c u l t u r e Handbook 271, pp. 547-553. Jozsa, L.A., Richards, J . and Johnson, S.G. 1989. R e l a t i v e d e n s i t y . In Second growth D o u g l a s - f i r : I t s management and conversion f o r value. Compiled and e d i t e d by Kellogg, R.M., p 5-22. KarkkSinen, M. and Marcus, M. 1985. Shrinkage p r o p e r t i e s of Norway spruce wood. S i l v a Fennica 19(l):67-72. K e l l e r , R. 1973. C a r a c t e r i s t i q u e s du bois de Pin maritime. V a r i a b i l i t y et transmission h e r e d i t a i r e . Annales des Science F o r e s t i e r e s 30:31-62. Kelsey, K.E. 1963. A c r i t i c a l review of r e l a t i o n s h i p between the shrinkage and s t r u c t u r e of wood. CSIRO Forest Products Technology Paper 28, 33p. K e n d a l l , M.G. and Stuart, A. 1977. The advanced theory of statistics. V o l 1, Hafner P u b l i s h i n g Company, NY. Kennedy, R.W. 1961. V a r i a t i o n and p e r i o d i c i t y of summer wood i n some second-growth D o u g l a s - f i r . Tappi 44:161-165. King, J.N. 1986. S e l e c t i o n of t r a i t s f o r growth, form and wood q u a l i t y i n a population of c o a s t a l D o u g l a s - f i r (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) from B r i t i s h Columbia. Ph. D. t h e s i s , U n i v e r s i t y of A l b e r t a , 174p. King, J.N., Yeh, F . C , Heaman, J.C. 1988. S e l e c t i o n of wood den s i t y and diameter i n c o n t r o l l e d crosses of c o a s t a l D o u g a l s - f i r . S i l v a e Genetica 37(3-4):152-157. K l i n k a , K., Green, R.N., Courtin, P.J. and Nuszdorfer, F.C. 1984. S i t e diagnosis, t r e e species s e l e c t i o n and s l a s h burning g u i d e l i n e s f o r Vancouver Forest Region. Province of B r i t i s h Columbia, M i n i s t r y of Forests and Land Management Report No. 25 18Op. Knigge, W. 1961. Der E i n f l u B verschiedener Wuchsbedingungen auf Eigenschaften und Verwertbarkeit des Nadelholzes. Allgemeine F o r s t - und Jagdzeitung. 132:149-156. 165 Larson, P.R. 1969. Wood formation and concept of wood q u a l i t y . Yale U n i v e r s i t y School of F o r e s t r y B u l l e t t i n 74, 54p. Lassen, L.E. and Okkonen, E.A. 1969. E f f e c t of r a i n f a l l and e l e v a t i o n on s p e c i f i c g r a v i t y of c o a s t a l D o u g l a s - f i r . Wood and F i b e r 1:227-235. Lavton, R.O. 1984. E c o l o g i c a l c o n s t r a i n t s on wood de n s i t y i n a t r o p i c a l montane r a i n f o r e s t . American Journal of Botany 71:261-267. L i n , C Y . 1978. Index s e l e c t i o n f o r genetic improvement of q u a n t i t a t i v e characters. T h e o r e t i c a l and Appl i e d Genetics 52:49-56. Loo-Dinkins, J.A. 1989. F i e l d t e s t design. In Handbook of Forest Quantitative Genetics. Edited by Fi n s , L., Friedman, S. and Br o t s c h o l , J . Loo-Dinkins, J.A. and Gonzalez, J.S. 1991. Genetic c o n t r o l of wood de n s i t y p r o f i l e i n young D o u g l a s - f i r . Canadian Journal of Forest Research 21(6):935-939. Loo, J.A., Tauer, C G . and Mc New, R.W. 1985. Genetic v a r i a t i o n i n the time of t r a n s i t i o n from j u v e n i l e t o mature wood i n l o b l o l l y pine (Pinus taeda). S i l v a e Genetica 34(1):14-19. MacKay, J.F.G. 1989. K i l n d r y i n g lumber. In Second growth Douglas-fir: its management and conversion for value. Compiled and edit e d by R.M.Kellogg, Forintek S p e c i a l P u b l i c a t i o n No. SP-32 pp.39-43. Magnussen, S. and Kei t h , C T . 1991. Genetic improvement of volume and wood p r o p e r t i e s of jack pine: S e l e c t i o n s t r a t e g i e s . F o r e s t r y Chronicle 66(3):281-286. McKimmy, M.D. and Campbell, R.K. 1982. Genetic v a r i a t i o n i n the wood de n s i t y and r i n g width trend i n c o a s t a l Douglas-f i r . S i l v a e Genetica 31(2-3) -.43-50. McKimmy, M.D. and Nicholas, D.D. 1971. Genetic d i f f e r e n c e s i n wood t r a i t s among h a l f - c e n t u r y - o l d f a m i l i e s of Douglas-f i r . Wood and Fi b e r 2:347-355. McKinley, CR., Lowe, W.J. and van Buijtenen, J.P. 1982. Genetic improvement of wood s p e c i f i c g r a v i t y i n l o b l o l l y pine (Pinus taeda L.) and i t s r e l a t i o n to other t r a i t s . In Tappi Research and Development D i v i s i o n Conference, A s h e v i l l e : 153-158. 166 Megraw, R.A. 1985. D o u g l a s - f i r wood p r o p e r t i e s . Proceedings/ D o u g l a s - f i r : Stand management f o r the f u t u r e . 18-20 June, 1985, U n i v e r s i t y of Washinton, S e a t t l e , pp.81-96. Megraw, R.A. and T a l b e r t , C B . (unpublished) . P o t e n t i a l f o r genetic improvement of j u v e n i l e wood q u a l i t y . P r o j e c t #8603035, B i l o g i c a l Sciences, Weyerhaeuser Company, Tacoma, Washington. Mergen, F. and F u r n i v a l , G.M. 1960. Discriminant a n a l y s i s of Pinus thunbergii x Pinus densiflora hybrids. Proceedings of Society of American Foresters meeting 1960: 36-40. Meylan, B.A. 1967. Cause of high l o n g i t u d i n a l shrinkage i n wood. Forests Products Journal 18(4):75-78. Meylan, B.A. 1972. The i n f l u e n c e of m i c r o f i b r i l angle on the l o n g i t u d i n a l shrinkage-moisture content r e l a t i o n s h i p i n Pinus radiata. Wood Science and Technology 6(4):293-301. M i n i s t r y of Forest and Lands, 1991. Report f o r the year 1990-91. B.C. M i n i s t r y of Forests and Lands. Namkoong, G. 1981. .Introduction to quantitative genetics in Forestry. C a s t l e House P u b l i c a t i o n s . Kent. 342p. Namkoong, G. and Roberds, J.H. 1974. Choosing mating designs to e f f i c i e n t l y estimate genetic variance components f o r t r e e s . S i l v a e Genetica 23:43-53. Namkoong, G., Snyder, E.B., and Stonecypher, R.W. 1966. H e r i t a b i l i t y and gain concepts f o r ev a l u a t i n g breeding systems such as see d l i n g seed orchards. S i l v a e Genetica 15:76-84. Namkoong, G., Usanis, R.A., and S i l e n , R.R. 1972. Age-r e l a t e d v a r i a t i o n i n genetic c o n t r o l of height growth i n Do u g l a s - f i r . T h e o r e t i c a l and Applied Genetics 42: 151-159. Nault, J.R. 1989. Lon g i t u d i n a l shrinkage. In Second growth Douglas-fir: its management and conversion for value. Compiled and edit e d by R.M.Kellogg, For i n t e k S p e c i a l P u b l i c a t i o n No. SP-32. pp.39-43. Nepveu, P.G. 1984. Contrdle h e r e d i t a i r e de l a densite et de l a r e t r a c t i b i l i t e du bois de t r o i s especes de Chene (Quercus petraea Quercus robur et Quercus ru b r a ) . S i l v a e Genetica 33(4-5):110-115. Nepveu, P.G. and V e i l i n g , P. 1983. V a r i a b i l i t y genetique i n d i v i d u e l l e de l a q u a l i t e du bois chez Betula pendula Roth. S i l v a e Genetica 32(1-2):37-49. 167 Neter,J., Wasserman, W. and Kunter M.H. 1990. Applied Linear Statistical Models. Irwin Inc. Boston, pp. 491-494. N i c h o l l s , J.W.P. 1986. Within-tree v a r i a t i o n i n wood c h a r a c t e r i s t i c s of Pinus radiata D. Don. A u s t r a l i a n Forest Research 16(4):313-335. N i c h o l l s , J.W.P, Dadswell, H.E. and F i e l d i n g , J.M. 1964. The h e r i t a b i l i t y of wood c h a r a c t e r i s t i c s i n Pinus radiata. S i l v a e Genetica 13:68-71. Noskowiak, A.F. 1963. S p i r a l g r a i n i n t r e e s - A review. Fores t Products Journal 13(7):266-277. Noskowiak, A.F. and Snodgrass, J.D. 1961. E f f e c t of l o c a l i t y of growth on c e r t a i n strength p r o p e r t i e s of D o u g l a s - f i r . F i n a l Report t o Western Pine A s s o c i a t i o n . P r o j e c t RP, 547p. Orr-Ewing, A.L. 1969. The development of a program f o r the genetic improvement of Do u g l a s - f i r i n B r i t i s h Columbia. Fo r e s t r y C h r o n i c l e . 45:395-399. Panshin, A.J. and Zeeuw,C.de. 1980. Textbook of wood technology 4th ed. McGraw-Hill, New York. Robertson, A. 1957. Optimum s i z e i n progeny t e s t i n g and family s e l e c t i o n . Biometrics 13:442-450. Ross, Sheldon 1984. A first course in probability. Macmillan P u b l i s h i n g Co., New York, p 263. SAS I n s t i t u t e , 1987. SAS/STAT Guide f o r personal computers. SAS I n s t i t u t e Inc. Cary, N.C. 1028p. Senft, J.F and Bendsten, B.A. 1984. J u v e n i l e wood: processing and s t r u c t u r a l products co n s i d e r a t i o n s . In: Proceedings of the symposium on U t i l i z a t i o n of changing wood resources, NCSU, Raleigh, 82p. Senft, J.F and Bendsten, B.A. 1985. Measuring m i c r o f i b r i l l a r angles using l i g h t microscopy. Wood and F i b e r Science 17(4):564-567. Seth, M.K., Bala M. and L a i , C. 1987. Intra-increment c i r c u m f e r e n t i a l v a r i a t i o n i n t r a c h e i d length as a b a s i s f o r sampling g e n e t i c a l l y superior trees of deodar. Wood Science and Technology 21(4):293-311. S i l e n , R.R. 1978. Genetics of D o u g l a s - f i r . USDA Forest Service Research Paper WO-35. 34p. Smith, H.F. 1936. A di s c r i m i n a n t f u n c t i o n f o r p l a n t s e l e c t i o n . Annals of Eugenics (London) 7:240-25. 168 Smith, W.J. 1959. Tracheid length and m i c e l l a r angle i n hoop pine - t h e i r v a r i a t i o n , r e l a t i o n s h i p and use as i n d i c a t o r s i n parent t r e e s e l e c t i o n . Queensland Forest S e r v i c e Research Note 8, 61p. Smith, W.J. 1967. The h e r i t a b i l i t y of f i b r e c h a r a c t e r i s t i c s and i t s a p p l i c a t i o n t o wood q u a l i t y improvement i n t r e e s . S i l v a e Genetica 16(2):41-50. Snedecor, G.W. and Cochran, W.G. 1967. Statistical methods. Iowa State U n i v e r s i t y , Ames, Iowa, USA Spurr,S.H. and Hsiung,W.Y. 1954. Growth r a t e and s p e c i f i c g r a v i t y i n c o n i f e r s . Journal of F o r e s t r y 52(3):191-200. S q u i l l a c e , A.E., Echols, R.M., Dorman, K.W. 1962. H e r i t a b i l i t y of s p e c i f i c g r a v i t y and summer-wood percent and r e l a t i o n t o other f a c t o r s i n s l a s h pine. Tappi 45:599-601. S t e e l , R.G.D. and T o r r i e , J.H. 1960. P r i n c i p l e s and procedures i n s t a t i s t i c s . McGraw-Hill Book Company, New York. 481p. Stonecypher, R.W. and Zobel, B.J. 1966. Inheritance of s p e c i f i c g r a v i t y i n 5-year-old seedlings of l o b l o l l y pine. Tappi 49:303-305. USDA 1974. Wood handbook: Wood as an engineering material. A g r i c u l t u r e Handbook No. 72. 408p. van Buijtenen, J.P. 1962. H e r i t a b i l i t y estimates of wood density i n l o b l o l l y pine. Tappi 45:602-605. Vargas-Hernandez, J . and Adams, W.T. 1991. Genetic v a r i a t i o n of wood density components i n young c o a s t a l D o u g l a s - f i r : i m p l i c a t i o n s f o r t r e e breeding. Canadian Journal of Forest Research 21:1801-1807. Vargas-Hernandez, J . and Adams, W.T. 1992. Age-age c o r r e l a t i o n s and e a r l y s e l e c t i o n f o r wood density i n young c o a s t a l D o u g l a s - f i r . Forest Science 38(2):467-478. Voorhies, G. and Groman, W.A. 1982. L o n g i t u d i n a l shrinkage and occurrence of various f i b r i l angles i n j u v e n i l e wood of young-growth ponderosa pine. Forestry Note No. 16, Northern Arizona U n i v e r s i t y , F l a g s t a f f , AZ. 25p. Wahlgren, H.E. 1965. Forest s e r v i c e western woods density survey. Phases II:(increment core processing) and I I I : Estimating t r e e s p e c i f i c g r a v i t y . Symp. density - A key to wood q u a l i t y . Madison WI, 21-35. 169 We 11 wood, R.W. and Smith, J.G. 1962. V a r i a t i o n i n some important q u a l i t i e s of wood from young D o u g l a s - f i r and hemlock t r e e s . Research Paper 50, U n i v e r s i t y of B r i t i s h Columbia, Vancouver, Canada, 15p. Yanchuk, A.D., Dancik, B.P. and Micko,M.M. 1984. V a r i a t i o n and h e r i t a b i l i t y of wood density and f i b r e length of trembling aspen i n A l b e r t a , Canada. S i l v a e Genetica 33(1):11-16. Yanchuk, A.D. and Nicko, M.M. 1990. R a d i a l v a r i a t i o n of wood den s i t y and f i b e r length i n trembling aspen. IAWA B u l l e t t i n 11(2):211-215. Yeh, F. and Heaman, C. 1982. H e r i t a b i l i t i e s and ge n e t i c and phenotypic c o r r e l a t i o n s f o r height and diameter i n c o a s t a l D o u g l a s - f i r . Canadian Journal of Forest Research 12:181-185. Young, S.S.Y. 1961. A f u r t h e r examination of the r e l a t i v e e f f i c i e n c y of three methods of s e l e c t i o n f o r genetic gains under l e s s r e s t r i c t e d c o n d i t i o n s . G e n e t i c a l Research 2:106-121. Zobel, B.J. 1984. The changing q u a l i t y of the world wood supply. Wood Science and Technology 18: 1-17. Zobel, B.J. and K e l l i s o n , R.C. 1972. S h o r t - r o t a t i o n f o r e s t r y i n the Southeast. Tappi 55(8):1205-1208. Zobel, B.J., Stonecypher, R.L., Brown, C. and K e l l i s o n , R.C. 1968. Inheritance of s p i r a l g r a i n i n young l o b l o l l y pine. Forest Science 14:376-379. Zobel, B.J. and van Buitjenen, J.P. 1989. Wood variation, its causes and control. Springer-Verlag, New York, 349p. 170 Appendix 1. H a l f - s i b and f u l l - s i b f a m i l y means f o r l o n g i t u d i n a l shrinkage (%) at d i f f e r e n t age l e v e l s . (Males 1-4; females 1-12; Age l e v e l s 0-4; h a l f - s i b f a m i l y means given i n bold face) Male Age l e v e l 1 2 3 4 0 0.308 0.286 0.346 0.317 1 0.242 0.207 0.220 0.265 2 0.215 0.193 0.177 0.205 3 0.180 0.171 0.157 0.175 4 0.160 0.153 0.140 0.156 0.488 0.521 0.330 0.589 0.445 0.342 0.393 0.283 0.374 0.278 0.257 0.341 0.237 0.219 0.210 0.199 0.289 0.182 0.150 0.158 0.154 0.174 0.155 0.139 0.148 0.277 0.319 0.196 0.332 0.205 0.216 0.232 0.154 0.218 0.250 0.202 0.215 0.163 0.195 0.227 0.170 0.174 0.149 0.180 0.167 0.168 0.171 0.150 0.187 0.164 0.351 0.381 0.428 0.296 0.336 0.251 0.256 0.231 0.271 0.228 0.193 0.204 0.198 0.200 0.161 0.161 0.171 0.191 0.152 0.139 0.149 0.161 0.220 0.122 0.116 0.343 0.354 0.276 0.386 0.327 0.238 0.271 0.206 0.216 0.254 0.194 0.209 0.191 0.171 0.207 0.166 0.160 0.179 0.163 0.167 0.154 0.172 0.143 0.153 0.148 0.251 0.251 0.236 0.210 0.308 0.188 0.210 0.162 0.121 0.258 0.185 0.193 0.192 0.118 0.239 0.175 0.166 0.173 0.130 0.230 0.156 0.154 0.154 0.126 0.181 0.251 0.249 0.278 0.240 0.237 0.225 0.236 0.221 0.201 0.242 0.209 0.208 0.208 0.190 0.229 0.183 0.192 0.185 0.172 0.185 0.173 0.199 0.149 0.179 0.171 Female 1 (Contd.) Appendix 1. contd. Age l e v e l s Males 2 3 Females 0.219 0.161 0.168 0.163 0.146 0.208 0.153 0.163 0.150 0.145 0.212 0.152 0.167 0.145 0.138 0.276 0.168 0.180 0.191 0.142 0.166 0.176 0.160 0.166 0.163 0.299 0.215 0.186 0.157 0.137 0.232 0.165 0.132 0.125 0.132 0.274 0.204 0.170 0.151 0.131 0.378 0.237 0.205 0.165 0.127 0.314 0.266 0.256 0.194 0.158 0.304 0.235 0.186 0.176 0.148 0.229 0.178 0.179 0.161 0.150 0.304 0.207 0.221 0.188 0.164 0.386 0.239 0.173 0.178 0.144 0.307 0.315 0.171 0.178 0.130 10 0.342 0.240 0.211 0.155 0.146 0.273 0.244 0.254 0.158 0.128 0.347 0.214 0.184 0.139 0.130 0.425 0.216 0.178 0.145 0.132 0.323 0.287 0.228 0.178 0.188 11 0.319 0.245 0.196 0.171 0.147 0.302 0.278 0.231 0.182 0.173 0.271 0.239 0.209 0.184 0.154 0.256 0.158 0.144 0.128 0.111 0.446 0.304 0.203 0.191 0.154 12 0.285 0.204 0.165 0.167 0.144 0.211 0.194 0.204 0.201 0.163 0.308 0.209 0.180 0.193 0.165 0.280 0.127 0.116 0.124 0.108 0.357 0.312 0.160 0.147 0.130 172 Appendix 2 . H a l f - s i b and f u l l - s i b f a m i l y means f o r t a n g e n t i a l shrinkage (%) at d i f f e r e n t age l e v e l s (Males 1-4; Females 1-12; Age l e v e l s 0-4; h a l f - s i b f a m i l y means given i n bold face) Male Female 1 Age l e v e l 1 2 3 4 0 4.842 4.896 4.655 4.817 1 5.512 5.407 5.374 4.905 2 7.054 6.616 6.557 6.080 3 7.987 7.763 7.706 7.735 4 8.442 8.064 7.980 8.071 4.573 4.509 5.510 4.105 4.324 5.223 5.409 5.648 5.070 4.749 C.517 6.690 7.035 6.483 5.791 7.381 7.324 7.473 7.214 7.598 7.770 7.717 7.419 7.488 8.415 4.915 4.777 4.999 4.672 5.403 5.351 5.508 5.304 5.541 4.881 C.477 7.234 5.742 6.526 6.004 7.435 7.780 7.283 7.243 7.359 7 . ( 9 3 8.188 7.579 7.273 7.855 4.584 4.402 4.469 4.622 4.873 5.420 5.804 5.975 5.039 4.999 C.936 7.275 7.506 6.540 6.592 7.815 7.764 8.220 7.405 8.188 7.920 7.723 8.618 7.574 8.044 4.419 4.200 4.558 4.452 5.545 5.058 5.093 4.756 5.451 4.715 €.523 6.648 6.212 6.922 6.049 7.320 7.492 7.248 7.352 7.087 7.661 7.756 7.474 7.602 7.817 4.820 4.650 4.697 4.951 4.981 5.045 4.635 5.513 5.317 4.715 5.896 5.758 6.524 6.257 5.047 7.721 7.473 7.887 7.722 7.802 8.513 8.851 8.50.3 8.459 8.256 4.687 4.818 4.514 4.825 4.591 5.022 5.410 4.917 5.191 4.569 C.356 6.565 5.967 6.590 6.302 7.845 7.602 7.572 8.475 7.729 7.928 8.015 7.706 8.022 8.003 (Contd.) Appendix 2. contd. 173 Male Female 4.918 5.463 C.393 7.770 8.285 5.032 5.374 6.510 7.630 8.455 4.966 5.567 6.535 7.792 8.169 4.773 5.528 6.053 7.369 8.187 4.895 5.356 6.502 8.462 8.350 4.995 5.765 7.360 8.481 8.391 5.158 6.278 8.927 9.446 9.132 5.251 5.357 7.181 7.991 7.992 4.977 6.167 6. 698 8.270 8.605 4.483 5.092 6.393 8.128 7.904 4.574 5.214 6.507 8.012 8.185 4.796 5.564 6.838 8.364 8.427 4.527 5.145 6.740 7.941 8.001 4.266 4.992 ,049 694 6, 7. 8.163 4.667 5.126 6.345 8.011 8.131 10 5.187 5.494 6.736 8.415 8.764 5.570 5.864 7.684 9.366 9.836 5.257 5.655 6.552 8.045 8.838 4.965 5.610 6.543 8.550 8.563 4.954 4.848 6.166 7.697 7.778 11 4.920 5.384 6.729 7.984 8.361 5.536 5.991 7.844 8.687 8.431 4.802 5.249 6.839 8.044 8.520 4.647 5.288 6.824 8.001 8.403 4.690 5.007 5.411 7.205 8.077 12 5.174 5.451 6.847 7.781 8.244 5.333 5.326 6.864 7.582 8.453 5.109 5.932 6.775 7.770 8.180 4.938 5.443 7.013 7.923 7.914 5.362 4.987 6.697 7.871 8.398 174 Appendix 3. H a l f - s i b and f u l l - s i b f a m i l y means f o r r a d i a l shrinkage (%) a t d i f f e r e n t age l e v e l s . (Males 1-4; Females 1-12; Age l e v e l s 0-5; H a l f - s i b family means given i n bold face) Male Age l e v e l 1 2 3 4 0 3.204 3.305 3.274 2.984 1 2.934 3.036 2.996 2.736 2 3.569 3.590 3.S04 3.266 3 4.212 4.198 4.155 4.130 4 4.478 4.611 4.437 4.590 Female 1 3.141 3.063 3.643 3.122 2.783 3.075 3.092 3.242 2.930 3.102 3.654 3 .889 3.765 3.597 3.277 4.237 4.193 4.250 4.204 4.327 4.548 4.348 4.731 4.305 4.682 2 3.651 3.673 3.623 3.672 3.616 3.306 3.245 3.358 3.418 3 .175 3.665 3.853 3.625 3.670 3.415 4.319 4.360 4.257 4.054 4.718 4.601 4.196 4.781 4.105 5.222 3 3.512 3.458 3.840 3.757 2.975 3.004 3.087 3.095 3.062 2.725 3.634 3.719 3.823 3.482 3.592 4.355 4.441 4.252 4.231 4.512 4.745 4.479 4.383 4.971 4.981 4 3.233 3.101 3.194 3.735 2.711 3.094 2.913 3.274 3.140 3.116 3.596 3.376 3.664 3.744 3.637 4.156 4.015 4.285 4.227 4.134 4.587 4.203 4.441 4.786 4.905 5 3.118 2.854 4.155 2.670 2.795 2.595 2.181 3.181 2.569 2.448 3.025 2.340 3.647 3.144 2.968 3.676 3.222 4.291 3 .473 3.719 4.182 3.715 4.851 3.552 4.395 6 3.018 3.262 2.882 3.229 2.696 2.545 2.677 2.472 2.623 2.406 3.125 3.264 3.041 3.292 2.901 3.884 3.938 3.853 3.981 3.764 4.310 4.522 4.170 4.262 4.333 (Contd.) Appendix 3. contd. 175 Male 3.097 2.954 3.468 4.180 4.653 2.754 2.701 3.249 4.046 4.562 3.268 3.302 3.567 4.245 4.678 3.224 2.971 3.522 3.883 4.499 3.159 2.805 3.554 4.666 4.840 3.323 3.053 3.889 4.586 4.736 3. 3. 4. 5, 4. I l l 142 552 025 832 3.534 3.037 3.863 4.528 4.701 3.247 3.226 3.543 4.130 4.442 3.443 2.723 3.500 4.684 4.974 3.139 2.706 3.274 3.981 4.390 3.386 2.796 3.388 3.981 4.547 2.951 2.630 3.503 4.165 4.397 3.273 2.829 3 .078 4.035 4.551 2.962 2.585 3.101 3.752 4.008 10 2.802 2.841 3.375 4.271 4.619 3.188 2.935 3.612 4.677 5.302 2.613 2.921 3.525 4.221 4.718 2.918 2.862 3.250 4.200 4.059 2.491 2.646 3.113 3.988 4.268 11 3.022 2.726 3.419 4.131 4.298 3 3 3 4 4 402 149 927 447 146 3.059 2.862 3.476 3.816 4.356 2.511 2.627 3.520 4.752 4.597 3.118 2.268 2.754 3.510 4.065 12 3.148 3.096 3.630 4.283 4.788 2.963 2.991 3.369 4.173 4.713 3.034 3.063 3.642 4.232 5.110 3.328 3.396 3.909 4.632 4.794 3.305 2.880 3.589 4.031 4.451 176 Appendix 4. H a l f - s i b and f u l l - s i b family means f o r r e l a t i v e d e n s i t y a t d i f f e r e n t age l e v e l s (Males 1-4; Females 1-12; Age l e v e l s 0-4; h a l f - s i b family means given i n bold face) Male Female 1 Age l e v e l 1 2 3 4 0 0.398 0.405 0.401 0.386 1 0.381 0.380 0.385 0.369 2 0.361 0.358 0.369 0.356 3 0.374 0.370 0.380 0.365 4 0.392 0.396 0.400 0.393 0.412 0.422 0.421 0.405 0.400 0.390 0.399 0.397 0.386 0.376 0.370 0.383 0.370 0.362 0.361 0.377 0.388 0.383 0.366 0.371 0.403 0.402 0.420 0.377 0.403 0.404 0.416 0.419 0.402 0.376 0.389 0.400 0.395 0.381 0.379 0.369 0.373 0.373 0.363 0.366 0.374 0.376 0.374 0.369 0.379 0.395 0.380 0.403 0.391 0.404 0.403 0.396 0.411 0.408 0.400 0.387 0.380 0.377 0.402 0.382 0.368 0.361 0.367 0.376 0.367 0.379 0.367 0.371 0.391 0.380 0.402 0.376 0.393 0.418 0.414 0.402 0.401 0.419 0.397 0.395 0.389 0.391 0.389 0.390 0.386 0.368 0.363 0.369 0.370 0.372 0.376 0.378 0.384 0.371 0.371 0.403 0.388 0.414 0.407 0.404 0.377 0.373 0.390 0.390 0.357 0.360 0.348 0. 373 0.366 0.351 0.343 0.335 0.343 0.348 0.344 0.350 0.339 0. 353 0.357 0.349 0.369 0.358 0.369 0.374 0.374 0.370 0.365 0.376 0. 377 0.360 0.356 0.350 0.359 0.363 0.352 0.336 0.332 0.340 0.350 0.322 0.349 0.350 0.341 0.359 0.347 0.373 0.372 0. 373 0.371 0.375 Contd. Appendix 4. contd. 177 Male 0.393 0.373 0.356 0.374 0.403 0.383 0.359 0.388 0.355 0.408 0.398 0.380 0.346 0.364 0.392 0.403 0.379 0.379 0.392 0.408 0.388 0.373 0.363 0.388 0.407 0.419 0.392 0.379 0.399 0.408 0.420 0.392 0.379 0.408 0.407 0.419 0.390 0.367 0.388 0.410 0.434 0.402 0.399 0.412 0.418 0.398 0.384 0.369 0.382 0.398 0.389 0.370 0.350 0.364 0.395 0.387 0.379 0.357 0.371 0.392 0. 396 0.372 0.349 0.371 0.405 0.396 0.381 0.358 0.375 0.407 0.377 0.352 0.335 0.341 0.374 10 0.401 0.388 0.375 0.383 0.409 0.401 0.394 0.378 0.392 0.418 0.399 0.384 0.368 0.383 0.410 0.398 0.383 0.382 0.382 0.397 0.404 0.392 0.371 0.374 0.410 11 0.394 0.368 0.355 0.367 0.388 0.396 0.387 0.369 0.378 0.397 0.402 0.369 0.346 0.355 0.380 0.394 0.376 0.357 0.389 0.410 0.384 0.341 0.347 0.347 0.369 12 0.405 0.377 0.359 0.376 0.398 0.392 0.370 0.348 0.375 0.402 0.414 0.378 0.356 0.369 0. 391 0.411 0.397 0.376 0.399 0.410 0.404 0.360 0.353 0.354 0. 384 178 Appendix 5. H a l f - s i b and f u l l - s i b f a m i l y means f o r g r a i n angle (*) at d i f f e r e n t age l e v e l s (Males 1,3; Females 1-4; Age l e v i e s 0-4; h a l f - s i b family means given i n bold face) Male Age l e v e l 1 3 0 0.218 0.016 1 1.080 0.448 2 1.826 0.707 3 2.097 0.698 4 2.532 0.810 Female 1 0.000 0. 000 0.000 0.507 0.667 0.347 0.847 1.229 0.465 0.814 1.295 0.333 1.242 2.014 0.317 2 0.333 0.667 0.000 1.028 1.486 0.563 1.608 2.153 1.056 1.717 2.347 1.077 1.940 2.903 1.202 3 0.032 0. 065 0.000 0.955 1.264 0.646 1.625 2.236 1.014 1.784 2.733 0.993 1.635 2.431 1.094 4 0.096 0.130 0.062 0.569 0.903 0.236 0.993 1.688 0.299 1.199 2.049 0.361 1.505 2.728 0.463 179 Appendix 6. H a l f - s i b and f u l l - s i b f a m i l y means f o r t r a c h e i d length a t di f f e r e n a g e l e v e l s (Males 1,3; Females 1-4; Age l e v e l s 0-4) ( H a l f - s i b family means are shown i n bold face) Male Age l e v e l 1 3 0 1.408 1.386 1 1.934 1.788 2 2.469 2.309 3 2.736 2.636 4 3.015 2.863 Female 1 1.469 1.575 1.364 1.874 2.018 1.729 2.447 2.476 2.418 2.808 2.819 2.798 3.094 3.146 3.042 2 1.509 1.456 1.561 2.011 1.995 2.027 2.456 2.486 2.425 2.785 2.840 2.730 2.960 3.015 2.905 3 1.299 1.330 1.267 1.740 1.893 1.587 2.397 2.509 2.285 2.517 2.656 2.377 2.779 2.869 2.688 4 1.311 1.272 1.350 1.819 1.828 1.810 2.257 2.406 2.108 2.634 2.628 2.639 2.924 3.029 2.819 180 Appendix 7. H a l f - s i b and f u l l - s i b f a m i l y means f o r f i b r i l angle (•) i n early-wood at d i f f e r e n t age l e v e l s (Males 1,3; Females 1-4; Age l e v e l s 0-4; h a l f - s i b f a m i l y means given i n bold face) Male Age l e v e l 1 3 0 27.063 29.800 1 26.225 27.763 2 24.814 27.271 3 23.617 27.333 4 23.220 22.843 Female 1 27.825 28.050 27.600 26.725 25.750 27.700 26.050 24.750 27.350 26.750 24.000 29.500 23.750 23.200 24.300 2 28.250 27.950 28.550 22.775 24.500 21.050 24.100 25.000 28.200 24.300 19.850 28.750 21.367 19.400 22.350 3 32.000 31.750 32.500 31.200 27.750 34.650 27.925 26.050 29.800 24.900 22.800 27.000 24.125 21.750 26.500 4 30.333 28.500 34.000 27.275 26.900 27.650 25.125 23.550 26.700 26.300 27.600 25.000 22.633 30.000 18.950 181 Appendix 8. H a l f - s i b and f u l l - s i b f a m i l y means f o r f i b r i l angle (*) i n late-vood a t d i f f e r e n t age l e v e l s (Males 1,3; Females 1-4; Age l e v e l s 0-4) ( H a l f - s i b family means given i n bold face) Male Age l e v e l 1 3 0 22.950 23.800 1 17.238 20.275 2 15.350 17.8*3 3 13.300 13.513 4 7.764 8.975 Female 1 21.850 21.600 22.100 18.300 18.900 17.700 17.050 18.750 15.350 11.375 12.250 10.500 8.844 9.583 8.400 2 22.400 23.950 20.850 15.325 15.500 15.150 15.900 15.750 16.050 11.425 11.800 11.050 5.575 3.650 7.500 3 25.500 23.400 27.600 22.175 16.000 28.350 17.500 13.800 21.200 17.500 17.100 17.900 11.275 8.550 14.000 4 23.750 22.850 24.650 19.225 18.550 19.900 15.975 13.100 18.850 13.325 12.050 14.600 8.000 10.000 6.000 182 Appendix 9. H a l f - s i b and f u l l - s i b f a m i l y means f o r height ( i n meters) f o r the progeny (Males 1-4; Females 1-12) ( H a l f - s i b f a m i l y means given i n bold face) Male Female 1 2 3 4 12.15 12.75 11.85 13.30 1 11.37 10.02 12.81 10.20 13.72 2 11.96 11.12 13.26 10.63 13.89 3 10.84 10.16 11.73 10.12 12.04 4 11.95 11.52 11.95 11.55 13.21 5 13.36 13 .44 12.96 13.14 13.89 6 12.63 12.36 12.10 12.86 13.20 7 13.03 12.92 12.84 12.66 13.70 8 12.78 13.09 12.96 12.37 12.70 9 13.23 13.92 12.73 12.87 13.34 10 13.40 14.15 13.41 13.07 12.97 11 13.09 13.33 13.07 12.85 13.11 12 13.03 12.67 13.22 12.44 14.04 183 Appendix 10. H a l f - s i b and f u l l - s i b f amily means f o r diameter at breast height ( i n cm) of the progeny (Males 1-4; Females 1-12) ( H a l f - s i b f a m i l y means given i n bold face) Male Female 1 2 3 4 16.12 17.21 16.14 17.60 1 15.88 14.40 18.02 14.32 18.30 2 16.17 15.30 17.46 15.67 16.91 3 15.10 14 .16 16.39 13.80 17.15 4 16.06 15. 07 16.07 15.92 17.74 5 18.07 18.10 17.66 17.90 18.62 6 17.80 17.51 17.23 18.66 17.82 7 17.04 15.75 17.98 16.75 17.67 8 16.17 15.95 16.15 16.27 16.31 9 17.40 17.86 16.59 17.23 17.90 10 16.98 17.66 17.23 16.35 16. 67 11 17.37 16.87 18.18 16.67 17.74 12 17.53 17.54 17.55 16.63 18.67 Appendix 11. Mean l o n g i t u d i n a l shrinkage (%) at d i f f e r e n t age l e v e l s f o r the parental clones Clones 1 2 3 Age 4 l e v e l 5 6 7 8 Mean 28 0. 193 0. 177 0. 176 0. 165 0.155 0. 150 0. 154 0. 154 0.165 49 0. 214 0. 165 0. 160 0. 152 0.156 0. 132 0. 143 0. 166 0. 161 60 0. 173 0. 179 0. 189 0. 194 0.195 0. 230 0. 211 0. 183 0.194 62 0. 131 0. 108 0. 126 0. 176 0.169 0. 178 0. 189 0. 180 0.158 72 0. 245 0. 174 0. 167 0. 167 0.167 0. 164 0. 163 0. 148 0.174 73 0. 397 0. 258 0. 288 0. 269 0.297 0. 231 0. 210 0. 226 0.273 00 Appendix 12. Mean t a n g e n t i a l shrinkage (%) at d i f f e r e n t age l e v e l s i n the parental clones Clones 1 2 3 Age 4 l e v e l 5 6 7 8 Mean 28 5. 006 5. 926 5. 668 5. 224 5.996 6. 885 7. 795 8. 161 6. 333 49 5. 338 6. 015 6. 175 5. 899 6.102 6. 071 6. 683 7. 659 6.243 60 5. 712 6. 110 6. 128 6. 297 5.935 6. 368 6. 779 7. 072 6.300 62 5. 500 5. 897 6. 038 5. 874 6.178 5. 929 6. 753 7. 611 6.230 72 5. 208 5. 342 5. 689 6. 069 6. 279 7. 058 7 . 366 7. 741 6. 321 73 4 . 602 4. 957 5. 052 5. 249 5.489 5. 588 6. 022 6. 254 5.390 Appendix 13. Mean r a d i a l shrinkage (%) at d i f f e r e n t age l e v e l s i n the parental clones Clones Age l e v e l 1 2 3 4 5 6 7 8 Mean 28 3. 162 3 . 352 3.306 2 .834 3 . 428 3.857 4 . 330 4.991 3.648 49 3. 379 3 . 646 3.546 3 .634 3 . 891 3.892 4.400 4.811 3.900 60 3 . 581 3 . 766 3.221 3 .305 3. 357 3.300 3.868 4 . 686 3 . 636 62 3 . 335 3. 047 3 .411 3 . 198 2. 978 3.363 4.110 4.651 3 . 516 72 2. 610 2. 603 2.641 2 .848 3. 063 3.434 3.880 4.195 3.159 73 2. 792 2. 950 3.145 3 .254 3. 497 3.652 3.737 3.415 3.304 CO CTl Appendix 14. Mean r e l a t i v e density at d i f f e r e n t age l e v e l s i n the parental clones Clones 1 2 3 Age 4 l e v e l 5 6 7 8 Mean 28 0. 392 0. 385 0. 383 0. 382 0.400 0. 395 0. 405 0. 416 0.395 49 0. 410 0. 404 0. 398 0. 396 0.405 0. 414 0. 416 0. 419 0.408 60 0. 367 0. 374 0. 378 0. 366 0.355 0. 354 0. 369 0. 388 0. 369 62 0.420 0. 401 0. 418 0. 433 0.419 0. 427 0. 440 0. 455 0.427 72 0. 337 0. 324 0. 313 0. 323 0.333 0. 329 0. 341 0. 346 0.331 73 0.420 0. 394 0. 402 0. 404 0.394 0. 406 0. 395 0. 388 0.401 03 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0106811/manifest

Comment

Related Items