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Chemical and morphological factors of resistance against the twospotted spider mite (Tetranychus urticae… Luczynski, Anna 1988

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CHEMICAL AND MORPHOLOGICAL FACTORS OF RESISTANCE AGAINST THE TWOSPOTTED SPIDER MITE (TETRANYCHUS URTICAE KOCH) IN BEACH STRAWBERRY FRAGARIA CHILOENSIS ( L . ) DUCHESNE by Anna L u c z y n s k i M . S c , A g r i c u l t u r a l U n i v e r s i t y i n L u b l i n A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE i n THE FACULTY OF GRADUATE STUDIES (Department of P l a n t S c i e n c e ) We accep t t h i s t h e s i s as conforming to the r e q u i r e d s tandard THE UNIVERSITY OF BRITISH COLUMBIA A p r i l 1988 © Anna L u c z y n s k i , 1 9 8 8 \ In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written 6 permission. Department of The University of British Columbia Vancouver, Canada DE-6 (2/88) i ABSTRACT H o s t - p l a n t r e s i s t a n c e i s a n i m p o r t a n t c o m p o n e n t o f i n t e g r a t e d p e s t m a n a g e m e n t . H o s t r e s i s t a n c e t o p h y t o p h a g o u s i n s e c t s a n d m i t e s b a s e d o n c h e m i c a l a n d m o r p h o l o g i c a l c h a r a c t e r i s t i c s h a s b e e n i d e n t i f i e d i n v a r i o u s a g r o n o m i c c r o p s . T h e p r e s e n t s t u d y w a s u n d e r t a k e n t o e x a m i n e h o w v a r i a t i o n i n s e l e c t e d m o r p h o l o g i c a l a n d c h e m i c a l c h a r a c t e r i s t i c s o f b e a c h s t r a w b e r r y Fragaria chiloensis ( L . ) D u c h e s n e a f f e c t s p o p u l a t i o n p a r a m e t e r s o f t h e t w o s p o t t e d s p i d e r m i t e Tetranychus urticae K o c h . T h e r e s u l t s f r o m t h i s s t u d y s h o w t h a t c l o n e s o f F. chiloensis a n d t h e c u l t i v a r " T o t e m " v a r y i n s u i t a b i l i t y f o r t h e t w o s p o t t e d s p i d e r m i t e . S e l e c t e d c l o n e s o f F. chiloensis a n d t h e c u l t i v a r " T o t e m " d i f f e r e d a l s o i n t h e f o l l o w i n g f o l i a r c h a r a c t e r i s t i c s : d e n s i t i e s o f g l a n d u l a r a n d n o n g l a n d u l a r t r i c h o m e s a n d c o n c e n t r a t i o n s o f t o t a l a n d c a t e c h o l - b a s e d p h e n o l i c s . I n c o n t r a s t , q u a l i t a t i v e a n a l y s i s o f p h e n o l i c c o m p o u n d s , d e t e r m i n e d v i a H P L C , r e v e a l e d a c l o s e s i m i l a r i t y b e t w e e n F. chiloensis a n d F. x ananassa ( c u l t i v a t e d s t r a w b e r r y ) a n d a m o n g s e l e c t e d c l o n e s o f F. chiloensis. M i t e o v i p o s i t i o n w a s n e g a t i v e l y c o r r e l a t e d w i t h d e n s i t i e s o f g l a n d u l a r a n d n o n g l a n d u l a r t r i c h o m e s a n d c o n c e n t r a t i o n s o f t o t a l f o l i a r p h e n o l i c s . I n s p i t e o f t h e s e s i g n i f i c a n t r e l a t i o n s h i p s , m i t e o v i p o s i t i o n w a s b e s t p r e d i c t e d b y a c o m b i n a t i o n o f i n t e r a c t i n g p l a n t c h a r a c t e r i s t i c s r a t h e r t h a n b y a n y i n d i v i d u a l i i c h a r a c t e r i s t i c . Entrapment by s t i c k y exudates from g l a n d u l a r trichomes appears to e x p l a i n the negative r e l a t i o n s h i p between mite s u r v i v a l and d e n s i t y of g l a n d u l a r trichomes. Spider mite development was n e g a t i v e l y r e l a t e d to c o n c e n t r a t i o n s of f o l i a r p h e n o l i c s ; twospotted s p i d e r mite development i s delayed on leaves with high c o n c e n t r a t i o n s of p h e n o l i c s . The c o r r e l a t i o n between mite development and f o l i a r p h e n o l i c s was g r e a t e r when c a t e c h o l -based p h e n o l i c s were used. TABLE OF CONTENTS ABSTRACT i TABLE OF CONTENTS i i i LIST OF TABLES v i LIST OF FIGURES v i i LIST OF APPENDICES x ACKNOWLEDGMENTS x i 1. INTRODUCTION 1 2. LITERATURE REVIEW 4 2.1 Twospotted Spider Mite and Strawberry 4 2.2 Pl a n t C h a r a c t e r i s t i c s C o n f e r r i n g Arthropod Pest R e s i s t a n c e 8 2.2.1 F o l i a r Pubescence 8 2.2.2 F o l i a r P h e n o l i c s 11 2.3 The E f f e c t of F o l i a r P h e n o l i c s and Pubescence on Arthropod F i t n e s s 20 2.3.1 P h e n o l i c s and Arthropod F i t n e s s 20 2.3.2 F o l i a r Pubescence and Arthropod F i t n e s s 22 2.3.2.1 E f f e c t of Nonglandular Trichomes 22 2.3.2.2 E f f e c t of Glandular Trichomes 24 2.4 Strawberry F o l i a r P h e n o l i c s and Pubescence 25 3. MATERIALS AND METHODS 31 3.1 P l a n t M a t e r i a l 31 3.2 Q u a n t i f i c a t i o n of P h e n o l i c s from Strawberry F o l i a g e 34 3.3 Rearing of Twospotted Spider Mite 35 3.4 Screening Fragaria c h i l o e n s i s f o r Mite 36 Resi stance i v 3.5 I n t e r - a n d - I n t r a C l o n a l V a r i a t i o n i n P h e n o l i c C o n c e n t r a t i o n s 37 3.6 S e p a r a t i o n and Q u a l i t a t i v e A n a l y s i s of S t r a w b e r r y F o l i a r P h e n o l i c s w i t h HPLC 37 3.7 M i t e P o p u l a t i o n Parameters i n R e l a t i o n t o P l a n t Defences 39 3.7.1 M i t e O v i p o s i t i o n and S u r v i v a l 39 3.7.2 E f f e c t of P h e n y l a l a n i n e or Q u i n i c A c i d Treatments on the C o n c e n t r a t i o n of "Totem" Leaf P h e n o l i c s 40 3.7.3 P h e n o l i c C o n c e n t r a t i o n s and M i t e Development 42 3.8 Data A n a l y s e s 44 RESULTS 45 4.1 S c r e e n i n g Fragaria chiloensis f o r M i t e R e s i s t a n c e 45 4.2 I n t e r - a n d - I n t r a C l o n a l V a r i a t i o n i n P h e n o l i c C o n c e n t r a t i o n s 45 4.3 Q u a l i t a t i v e A n a l y s i s of S t r a w b e r r y F o l i a r P h e n o l i c s v i a HPLC 48 4.4 M i t e P o p u l a t i o n Parameters i n R e l a t i o n t o P l a n t Defences 58 4.4.1 M i t e O v i p o s i t i o n 58 4.4.2 M i t e S u r v i v a l 75 4.4.3 E f f e c t of P h e n y l a l a n i n e and Q u i n i c A c i d Treatments on C o n c e n t r a t i o n s of F o l i a r P h e n o l i c s i n "Totem" P l a n t s 87 4.4.4 E f f e c t of P h e n y l a l a n i n e or Q u i n i c A c i d Treatments and M i t e F e e d i n g on C o n c e n t r a t i o n s of F o l i a r P h e n o l i c s 93 4.4.5 The R e l a t i o n s h i p Between M i t e Development and C o n c e n t r a t i o n s of F o l i a r P h e n o l i c s 96 V 5. DISCUSSION 107 5.1 S u i t a b i l i t y of Fragaria c h i l o e n s i s f o r Twospotted Spider Mite O v i p o s i t i o n 107 5.2 I n t e r - a n d - I n t r a s p e c i f i c D i f f e r e n c e s i n Strawberry P h e n o l i c s and Pubescence 108 5.2.1 D i f f e r e n c e s in P h e n o l i c s 108 5.2.2 E f f e c t of Phe n y l a l a n i n e or Q u i n i c a c i d Treatments on C o n c e n t r a t i o n s of F o l i a r P h e n o l i c s 111 5.2.3 D i f f e r e n c e s in Pubescence 113 5.3 Mite P o p u l a t i o n Parameters i n R e l a t i o n to Strawberry P h e n o l i c s and Pubescence 115 5.3.1 O v i p o s i t i o n 115 5.3.2 S u r v i v a l 120 5.3.3 Development 120 5.4 Co n c l u s i o n 121 6. SUMMARY 125 7. LITERATURE CITED 126 8. APPENDICES 146 v i LIST OF TABLES Examples of i n s e c t and mi t e r e s i s t a n c e c o n f e r r e d 12 by g l a n d u l a r pubescence Examples of i n s e c t and mi t e r e s i s t a n c e c o n f e r r e d by 13 n o n g l a n d u l a r pubescence P h e n o l i c compounds i d e n t i f i e d i n s t r a w b e r r y t i s s u e s 27 D i f f e r e n c e s i n m i t e o v i p o s i t i o n among 63 c l o n e s of 47 Fragaria c h i l o e n s i s and "Totem" c u l t i v a r Experiment 1 : D i f f e r e n c e s i n the c o n c e n t r a t i o n 48 (% fwt) of f o l i a r p h e n o l i c s , measured w i t h F o l i n -C i o c a l t e a u and Ammonium-Molybdate D i f f e r e n c e s i n d e n s i t i e s of g l a n d u l a r and 59 n o n g l a n d u l a r t r i c h o m e s and number of t w o s p o t t e d s p i d e r m i t e eggs Experiment 2 : D i f f e r e n c e s i n the c o n c e n t r a t i o n 60 (% fwt) of f o l i a r p h e n o l i c s measured w i t h Ammonium-Molybdate and F o l i n - C i o c a l t e a u D i f f e r e n c e s i n t h e d e n s i t y of g l a n d u l a r t r i c h o m e s 87 (no.\5mm2) a n d mite s u r v i v a l E xperiment 3 : D i f f e r e n c e s i n the c o n c e n t r a t i o n of 88 f o l i a r p h e n o l i c s ( % f w t ) , measured w i t h Ammonium-Molybdate and F o l i n - C i o c a l t e a u r e a g e n t s Experiment 4 : D i f f e r e n c e s i n the c o n c e n t r a t i o n of 94 f o l i a r p h e n o l i c s (% fwt) of "Totem" p l a n t s , measured w i t h F o l i n - C i o c a l t e a u and Ammonium-Molybdate r e a g e n t s . Experiment 5 : D i f f e r e n c e s i n the c o n c e n t r a t i o n of 95 f o l i a r p h e n o l i c s (%fwt) of "Totem" p l a n t s , measured w i t h F o l i n - C i o c a l t e a u and Ammonium-Molybdate v i i L I S T OF FIGURES 1. Three r e p r e s e n t a t i v e s of the most common groups of 16 p h e n o l i c s : s i m p l e p h e n o l i c s r e p r e s e n t e d by b e n z o i c (A) and c i n n a m i c (B) a c i d s and f l a v o n o i d s r e p r e s e n t e d by q u e r c e t i n (C) 2. G l a n d u l a r and n o n g l a n d u l a r t r i c h o m e s from the 29 a b a x i a l l e a f s u r f a c e of Fragaria chiloensis c l o n e 85\D (200 X) 3. The c o l l e c t i o n s i t e s of Fragaria chiloensis, from 33 Vancouver I s l a n d and a l o n g the so u t h w e s t e r n c o a s t of B r i t i s h Columbia 4. Three l o c a t i o n s on the a b a x i a l l e a f s u r f a c e of a 41 l e a f l e t from which d e n s i t i e s of g l a n d u l a r and n o n g l a n d u l a r t r i c h o m e s were d e t e r m i n e d 5. S e p a r a t i o n of compounds from f o l i a r e x t r a c t s 51 of the "Totem" c u l t i v a r , t h a t were p r e v i o u s l y mixed w i t h Dowex 1-X8 a n i o n exchange r e s i n 6. S e p a r a t i o n of p h e n o l i c s from f o l i a r e x t r a c t s 53 of the "Totem" c u l t i v a r , Fragaria chiloensis c l o n e 119/MM and t h e i r b i n a r y m i x t u r e , r e s p e c t i v e l y 7. S e p a r a t i o n of p h e n o l i c s from f o l i a r e x t r a c t s of the 55 "Totem" c u l t i v a r , Fragaria chiloensis c l o n e 20/PP and t h e i r b i n a r y m i x t u r e , r e s p e c t i v e l y 8. S e p a r a t i o n of p h e n o l i c s from f o l i a r e x t r a c t s of the 57 "Totem" c u l t i v a r , Fragaria chiloensis c l o n e 52/E and t h e i r b i n a r y m i x t u r e , r e s p e c t i v e l y 9. The r e l a t i o n s h i p between s p i d e r m i t e o v i p o s i t i o n 62 and the d e n s i t y of g l a n d u l a r t r i c h o m e s 10. The r e l a t i o n s h i p between s p i d e r mite o v i p o s i t i o n 65 and the d e n s i t y of n o n g l a n d u l a r t r i c h o m e s 11. The a c c u m u l a t i o n of g l a n d u l a r t r i c h o m e exudates 67 on the a d u l t female m i t e t a r s i . A - g e n e r a l view (X 150), B - the t a r s i c o a t e d w i t h a d h e s i v e exudates (X 1000) 12. The a b a x i a l f o l i a r s u r f a c e of Fragaria chiloensis 68 c l o n e 85/D (A,a) and 72/J (B,b) a t 200 and 500 X m a g n i f i c a t i o n v i i i 13. The r e l a t i o n s h i p between s p i d e r m i t e o v i p o s i t i o n 72 and the c o n c e n t r a t i o n of t o t a l p h e n o l i c s a s s a y e d w i t h F o l i n - C i o c a l t e a u reagent 14. The r e l a t i o n s h i p between s p i d e r m i t e o v i p o s i t i o n 74 and the c o n c e n t r a t i o n of t o t a l p h e n o l i c s a s s a y e d w i t h Ammonium-Molybdate reagent 15. Observed m i t e o v i p o s i t i o n p l o t t e d v s . p r e d i c t e d 77 o v i p o s i t i o n . The r e g r e s s i o n l i n e s y m b o l i z e s the p e r f e c t f i t . 16. The r e l a t i o n s h i p between m i t e o v i p o s i t i o n and 79 c o n c e n t r a t i o n s of c a t e c h o l - b a s e d p h e n o l i c s (X3 2) a t f i v e c o n s t a n t l e v e l s of the i n t e r a c t i o n g l a n d u l a r (x-|) x n o n g l a n d u l a r t r i c h o m e s ( X 2 ) (c = b i X ^ o ) : - 0.033, -0.169, - 0.648, - 1.152, - 1.980 17. The r e l a t i o n s h i p between m i t e o v i p o s i t i o n and 81 the d e n s i t y of g l a n d u l a r t r i c h o m e s ( x ^ a t f i v e c o n s t a n t l e v e l s of the i n t e r a c t i o n c o n c e n t r a t i o n of c a t e c h o l - b a s e d p h e n o l i c s (X3) x d e n s i t y of n o n g l a n d u l a r t r i c h o m e s ( x 2 ) ( c = b 1 x 3 X 2 ) : _ 0.006, --0.004, - 0.005, - 0.007, - 0.009. The square term of the c o n c e n t r a t i o n of c a t e c h o l - b a s e d p h e n o l i c s ( x j ) i s kept c o n s t a n t a t each i n t e r a c t i o n l e v e l . 18. The r e l a t i o n s h i p between m i t e o v i p o s i t i o n and 83 d e n s i t y of n o n g l a n d u l a r t r i c h o m e s ( x 2 ) a t f i v e c o n s t a n t l e v e l s of the i n t e r a c t i o n c o n c e n t r a t i o n of c a t e c h o l - b a s e d p h e n o l i c s (X3) x d e n s i t y of g l a n d u l a r t r i c h o m e s (x-|) (c = b i X 3 X 1 ) : - 0.005, -0.011, - 0.015, - 0.021, - 0.030. The square term of the c o n c e n t r a t i o n of c a t e c h o l - b a s e d p h e n o l i c s ( X 3 2 ) i s kept c o n s t a n t a t each i n t e r a c t i o n l e v e l . 19. The r e l a t i o n s h i p between s p i d e r m i t e s u r v i v a l 85 and the d e n s i t y of g l a n d u l a r t r i c h o m e s 20. Time c o u r s e of p h e n o l i c c o n c e n t r a t i o n s (measured 90 w i t h the Ammonium-Molybdate) among t h r e e d i s t i n c t l e a f ages: young expanding (Age 1 ) , young f u l l y expanded (Age 2) and o l d (Age 3) 21. Time c o u r s e of p h e n o l i c c o n c e n t r a t i o n s (measured 92 w i t h the F o l i n - C i o c a l t e a u ) among t h r e e d i s t i n c t l e a f ages: young expanding (Age 1 ) , young f u l l y expanded (Age 2) and o l d (Age 3) i x 22. The r e l a t i o n s h i p between male m i t e development 98 s t a g e s ( ¥ 1 , 2 , 3 ) and the c o n c e n t r a t i o n of c a t e c h o l - based p h e n o l i c s : 0 p r o t o n y p h , 1 deutonymph and 2 a d u l t s t a g e . The p o i n t s (o) r e p r e s e n t f r e q u e n c i e s , and the c u r v e s r e p r e s e n t the p r o b a b i l i t y d i s t r i b u t i o n f o r each d e v e l o p m e n t a l stage 23. The r e l a t i o n s h i p between male m i t e development 100 s t a g e s ( Y ^ , ? ^ ) and the c o n c e n t r a t i o n of t o t a l p h e n o l i c s : 0 p r o t o n y p h , 1 deutonymph and 2 a d u l t s t a g e . The p o i n t s (o) r e p r e s e n t f r e q u e n c i e s , and the c u r v e s r e p r e s e n t the p r o b a b i l i t y d i s t r i b u t i o n f o r each d e v e l o p m e n t a l s t a g e 24. The r e l a t i o n s h i p between male m i t e development 103 s t a g e s ( ¥ 1 , 2 , 3 ) and the c o n c e n t r a t i o n of c a t e c h o l -based p h e n o l i c s i n the r e p e a t e d experiment : 0 p r o t o n y p h , 1 deutonymph and 2 d u l t s t a g e . The p o i n t s (o) r e p r e s e n t f r e q u e n c i e s , and the c u r v e s r e p r e s e n t the p r o b a b i l i t y d i s t r i b u t i o n f o r each d e v e l o p m e n t a l stage 25. The r e l a t i o n s h i p between male m i t e development 105 s t a g e s ( ¥ 1 , 2 , 3 ) and the c o n c e n t r a t i o n of t o t a l p h e n o l i c s i n the r e p e a t e d e x p e r i m e n t : 0 p r o t o n y p h , 1 deutonymph and 2 a d u l t s t a g e . The p o i n t s (o) r e p r e s e n t f r e q u e n c i e s , and the c u r v e s r e p r e s e n t the p r o b a b i l i t y d i s t r i b u t i o n f o r each d e v e l o p m e n t a l stage X LIST OF APPENDICES 4.1 Means and s t a n d a r d e r r o r s (+SE) o f m i t e o v i p o s i t i o n 146 ( e g g s \ 7 2 h r ) f o r b l o c k s a n d c l o n e s 5.1 Means and s t a n d a r d e r r o r s (+SE) o f c o n c e n t r a t i o n s 147 o f c a t e c h o l - b a s e d p h e n o l i c s f o r 16 c l o n e s o f F. c h i l o e n s i s a n d t h r e e l e a f age c a t e g o r i e s 5.2 Means and s t a n d a r d e r r o r s (+SE) o f c o n c e n t r a t i o n s 148 o f t o t a l p h e n o l i c s f o r 16 c l o n e s o f F. c h i l o e n s i s and t h r e e l e a f c a t e g o r i e s 4.4.1 R e t e n t i o n t i m e s a n d peak a r e a s o f "Totem", 149 F. c h i l o e n s i s c l o n e 119 a n d t h e i r b i n a r y m i x t u r e 4.4.2 R e t e n t i o n t i m e s a n d peak a r e a s o f "Totem", 150 F. c h i l o e n s i s c l o n e 20 a n d t h e i r b i n a r y m i x t u r e 4.4.3 R e t e n t i o n t i m e s a n d peak a r e a s o f "Totem" 151 F. c h i l o e n s i s c l o n e 52 a n d t h e i r b i n a r y m i x t u r e 9.1 Means and s t a n d a r d e r r o r s (+SE) o f c o n c e n t r a t i o n s 152 o f c a t e c h o l - b a s e d p h e n o l i c s f o r t r e a t m e n t s , s a m p l i n g d a y s a n d l e a f age c a t e g o r i e s 9.2 Means a n d s t a n d a r d e r r o r s (+SE) o f c o n c e n t r a t i o n s 152 o f t o t a l p h e n o l i c s f o r t r e a t m e n t s , s a m p l i n g d a y s and l e a f age c a t e g o r i e s x i ACKNOWLEDGEMENTS I wish to extend s i n c e r e thanks to Dr. Murray B. Isman fo r h i s guidance and c o n t i n u a l support throughout t h i s p r o j e c t . I a l s o wish to thank s i n c e r e l y Dr. Dave A. Raworth for t r a i n i n g and advice throughout the l a s t four years and fo r p r o v i d i n g access to the greenhouse f a c i l i t i e s of A g r i c u l t u r e Canada Research S t a t i o n i n Vancouver. G r a t e f u l acknowledgment i s a l s o extended t o Dr. M. Shaw fo r h i s guidance and to Dr. V.C. Runeckles who was a l s o on my t h e s i s committee. I wish to thank Dr, G.W. Eaton f o r h i s continuous advice i n the d e s i g n i n g experiments. I a l s o wish to thank Cho-kai Chan ( A g r i c u l t u r e Canada Research S t a t i o n ) who d i d the SEM photographic work. F i n a l l y , I wish to acknowledge and thank my husband K r i s f o r h i s support and encouragement over the l a s t f i v e y e a r s . 1 1 . I N T R O D U C T I O N I t has long been recognized that phytophagous i n s e c t s can be h i g h l y s e l e c t i v e with r e s p e c t to t h e i r host p l a n t s and that host p l a n t s can d i f f e r i n s u i t a b i l i t y f o r i n s e c t growth. Both i n s e c t s e l e c t i v i t y and p l a n t s u i t a b i l i t y can change d u r i n g e i t h e r i n d i v i d u a l ' s l i f e time, and each stage may i n f l u e n c e the dynamics and complexity of the i n s e c t -h o s t - p l a n t r e l a t i o n s h i p s (Rausher, 1983). The r e f o r e the study of these r e l a t i o n s h i p s are o f t e n approached from e i t h e r of two d i r e c t i o n s ; that of the i n s e c t i n f l u e n c i n g f i t n e s s of the host p l a n t or that of the p l a n t a f f e c t i n g the behaviour or f i t n e s s . o f the i n s e c t . While both approaches are e q u a l l y v a l i d , a g r i c u l t u r a l entomologists and p l a n t breeders favor the l a t t e r approach because t h e i r o b j e c t i v e s are to o p t i m i z e growth and development of the p l a n t at the expense of the i n s e c t (Jenkins, 1980). P l a n t s have evolved numerous p h y s i c a l , chemical and e c o l o g i c a l t a c t i c s f o r defence a g a i n s t i n s e c t h e r b i v o r y . These d e f e n s i v e s t r a t e g i e s range from d i s r u p t i o n of i n s e c t behavior and growth to the compensation f o r damaged caused by i n s e c t f e e d i n g ( N o r r i s and Kogan, 1980). Both m o r p h o l o g i c a l and chemical c h a r a c t e r i s t i c s of p l a n t f o l i a g e are known to a f f e c t i n s e c t behaviour and growth. The p o t e n t i a l of p l a n t morphological c h a r a c t e r i s t i c s i n r e s i s t a n c e a g a i n s t i n s e c t s has long been recognized and 2 r e s i s t a n c e based on p l a n t m o r p h o l o g i c a l t r a i t s has long been u t i l i z e d as a componenet of pest management (Gregory, 1986 b). Advances i n the chemical a n a l y s i s of p l a n t a l l e l o c h e m i c s have added new p e r s p e c t i v e s to s t u d i e s of the r e l a t i o n s h i p s between i n s e c t s and t h e i r h o s t s . I t i s c u r r e n t l y accepted that c h e m i c a l l y - b a s e d r e s i s t a n c e i s the most e f f e c t i v e defense s t r a t e g y a g a i n s t h e r b i v o r e s i n a v a r i e t y of p l a n t genera ( B e l l , 1984). However, the impact of v a r i a t i o n i n p l a n t chemical c h a r a c t e r i s t i c s on i n s e c t f i t n e s s has not been e x t e n s i v e l y s t u d i e d . The twospotted s p i d e r mite Telranychus urticae Koch i s a major pest of c u l t i v a t e d strawberry Fragaria x ananassa Duchesne. Feeding of the twospotted s p i d e r mite occurs p r i m a r i l y on the a b a x i a l l e a f s u r f a c e and a f f e c t s the rate of l e a f t r a n s p i r a t i o n and pho t o s y n t h e s i s (Sances et al . , 1979 a,b). I n t e n s i t y and d u r a t i o n of mite f e e d i n g are n e g a t i v e l y c o r r e l a t e d with strawberry y i e l d (Sances et al., 1981 ) . Development of r e s i s t a n c e to many p e s t i c i d e s makes chemical c o n t r o l of the twospotted s p i d e r mite p a r t i c u l a r l y d i f f i c u l t . T h e r e f o r e , the establishment of i n t e g r a t e d pest management i s e s s e n t i a l to the c o n t r o l of t h i s p e s t . S e v e r a l attempts have been made i n the past to assess strawberry c u l t i v a r s and s p e c i e s f o r r e s i s t a n c e a g a i n s t the twospotted s p i d e r mite. In s p i t e of d i f f e r e n c e s i n mite r e s i s t a n c e among strawberry c u l t i v a r s the hig h e s t l e v e l s of r e s i s t a n c e have been found in s e l e c t e d clones of beach 3 strawberry Fragaria c h i l o e n s i s (L.) Duchesne (Shanks and B a r r i t t , 1975 and 1984). To date no attempts have been made to r e l a t e the v a r i a t i o n i n morphological and chemical c h a r a c t e r i s t i c s of the f o l i a g e of F. c h i l o e n s i s to twospotted s p i d e r mite r e s i s t a n c e , i n s p i t e of the f a c t that some asp e c t s of mite behaviour and performance are thought to have host chemical and m o r p h o l o g i c a l c o r r e l a t e s . The present study was undertaken to examine how v a r i a t i o n i n s e l e c t e d m o rphological and chemical c h a r a c t e r i s t i c s of beach strawberry Fragaria c h i l o e n s i s a f f e c t s p o p u l a t i o n parameters of the twospotted s p i d e r mite T e t r a n y c h u s u r t i c a e . R e l a t i o n s h i p s between i n d i v i d u a l or combined p l a n t c h a r a c t e r i s t i c s and s e l e c t e d mite p o p u l a t i o n parameters are examined and p o t e n t i a l use of p l a n t c h a r a c t e r i s t i c s as i n d i c e s i n s e l e c t i o n f o r twospotted s p i d e r mite r e s i s t a n c e i s d i s c u s s e d . 4 2. LITERATURE REVIEW 2 . 1 The Twospot ted S p i d e r M i t e and S t rawber ry Amongst s e v e r a l economically important arthropod pests found on strawberry, the twospotted s p i d e r mite Tetranychus urticae i s perhaps of g r e a t e s t concern to North America growers. The twospotted s p i d e r mite i s a polyphagous s p e c i e s with an extremely broad host range. I t overwinters as a d i a p a u s i n g a d u l t female and begins reproducing as temperatures i n c r e a s e i n the s p r i n g . The developmental time and f e c u n d i t y of the mite i s s e n s i t i v e to a v a r i e t y of i n t r i n s i c and e x t r i n s i c f a c t o r s ( L a ing, 1969; Wrensch, 1985). Under f a v o r a b l e c o n d i t i o n s , a female s p i d e r mite produces 30-150 eggs in her l i f e span, which r e q u i r e about two weeks to develop to the a d u l t stage ( Van de V r i e et al ., 1972). The high f e c u n d i t y and short developmental time e x p l a i n why under optimal c o n d i t i o n s a twospotted s p i d e r mite p o p u l a t i o n can explode to damaging l e v e l s i n a r e l a t i v e l y short time. The twospotted s p i d e r mite feeds by p i e r c i n g and sucking c e l l c o n tents p r i m a r i l y on the a b a x i a l l e a f s u r f a c e . As a r e s u l t of mite f e e d i n g the spongy mesophyll and lower p a l i s a d e mesophyll l a y e r s are damaged and t h e i r c h l o r o p h y l l content i s reduced (Sances et al., 1979 a ) . . Even a t low i n f e s t a t i o n l e v e l s (2.5 mites/cm 2/day) p h o t o s y n t h e t i c r a t e and t r a n s p i r a t i o n of the host are reduced (Sances et 5 al.,1979 b ) . Changes i n l e a f c h e m i s t r y and a r e d u c t i o n i n s t r a w b e r r y y i e l d were r e p o r t e d as a consequence of m i t e f e e d i n g . Sances et a-/., (1981) r e p o r t e d t h a t s t r a w b e r r y y i e l d was n e g a t i v e l y c o r r e l a t e d w i t h m i t e d e n s i t i e s and d u r a t i o n of f e e d i n g . K i e l k i e w i c z (1981) and Inoue et al., (1985) found i n c r e a s e d l e v e l s of p h e n o l i c compounds and i n c r e a s e d a c t i v i t y of p h e n y l a l a n i n e ammonia l y a s e (PAL) i n l e a v e s i n f e s t e d w i t h the t w o s p o t t e d s p i d e r m i t e . C h emical c o n t r o l of the t w o s p o t t e d s p i d e r m i t e appears t o be more p r o b l e m a t i c than t h a t of a p h i d s . These problems i n c l u d e development of r e s i s t a n c e t o many a c a r i c i d e s , d e s t r u c t i o n of n a t u r a l enemies, as w e l l as i n c r e a s e i n the s e v e r i t y of m i t e i n f e s t a t i o n s d u r i n g f r u i t i n g , which l i m i t s the use of more p e r s i s t e n t a c a r i c i d e s ( S c h a e f e r s , 1983; Maas, 1984). Because of i n c r e a s i n g r e s i s t a n c e t o a number of p e s t i c i d e s , new a c a r i c i d a l c h e m i c a l s such as c h i n o m e t h i o n a t ( M o r e s t a n ) , c y h e x a t i n ( P l i c t r a n ) and p r o p a r g i t e (Omite) have been i n t r o d u c e d f o r the c o n t r o l of the t w o s p o t t e d s p i d e r m i t e on s t r a w b e r r i e s (Poe, 1973). The l a t t e r two have been r e g i s t e r e d and used w i d e l y i n Canada s i n c e 1971, but P l i c t r a n seems t o be the most e f f e c t i v e a c a r i c i d e and i s l e a s t d i s r u p t i v e t o p r e d a t o r y m i t e s . R e c e n t l y , however, P l i c t r a n has been withdrawn from the market as i t appears t o be t e r a t o g e n i c t o l a b o r a t o r y a n i m a l s (Anonymous, 1987). The w i t h d r a w a l of t h i s most e f f e c t i v e a c a r i c i d e has l e f t s t r a w b e r r y growers i n the p r e c a r i o u s s i t u a t i o n of b e i n g l e f t w i t h m i t e - s u s c e p t i b l e v a r i e t i e s 6 w h i l e the c u r r e n t c o n t r o l methods a r e not e n t i r e l y e f f e c t i v e and new c h e m i c a l s are u n a v a i l a b l e a t p r e s e n t . Such a s i t u a t i o n p o i n t s out the need t o e s t a b l i s h an i n t e g r a t e d p e s t management program f o r t w o s p o t t e d s p i d e r m i t e on s t r a w b e r r y , t o l e s s e n growers' dependency on c h e m i c a l c o n t r o l . In C a l i f o r n i a , where the t w o s p o t t e d s p i d e r m i t e on s t r a w b e r r y i s a key economic problem, c o n t r o l t h r e s h o l d s of 2 t o 5 m i t e s per l e a f l e t i n s p r i n g and 5 to 10 m i t e s per l e a f l e t i n summer are used (Mass, 1985). In B r i t i s h Columbia a d e n s i t y of 5 m i t e s / l e a f l e t two weeks b e f o r e h a r v e s t c o n s t i t u t e s the economic t h r e s h o l d (Raworth, 1986). The o b s e r v a t i o n of the economic t h r e s h o l d can r e s u l t i n r e d u c t i o n s of both y i e l d l o s s e s and c o s t s of c h e m i c a l c o n t r o l . B i o l o g i c a l c o n t r o l of the t w o s p o t t e d s p i d e r m i t e i s b e i n g e x t e n s i v e l y i n v e s t i g a t e d i n C a l i f o r n i a and B r i t i s h C o l umbia. S e v e r a l p r e d a t o r y a r t h r o p o d s have been a s s e s s e d f o r c o n t r o l of s p i d e r m i t e p o p u l a t i o n s , i n c l u d i n g two s p e c i e s of t h r i p s , f o u r s p e c i e s of p h y t o s e i d m i t e s , l a c e -wings and s y r p h i d s ( S c h a e f e r s , 1983). F u t u r e a p p l i c a t i o n of b i o l o g i c a l c o n t r o l on a commercial p r o d u c t i o n s c a l e appears t o be a p r o m i s i n g a s p e c t of i n t e g r a t e d pest management. S e v e r a l a t t e m p t s have been made t o e v a l u a t e s t r a w b e r r y c u l t i v a r s f o r r e s i s t a n c e t o the t w o s p o t t e d s p i d e r m i t e . Shanks and B a r r i t t (1975, 1980), B a r r i t t and Shanks (1981), and K i s h a b a et al .,(1972) r e p o r t e d c o n s i d e r a b l e v a r i a t i o n i n 7 r e l a t i v e r e s i s t a n c e among s t r a w b e r r y c u l t i v a r s and advanced s e l e c t i o n s . However the h i g h e s t l e v e l s of r e s i s t a n c e t o s p i d e r m i t e s have been found i n s e l e c t e d c l o n e s of the w i l d s p e c i e s F. chiloensis (Shanks and B a r r i t t , 1975 and 1984). The beach s t r a w b e r r y F. chiloensis, grows a l o n g the P a c i f i c c o a s t of N o r t h America from A l a s k a t o C a l i f o r n i a , i n C h i l e , and i n H a w a i i . I t o c c u p i e s t h r e e major h a b i t a t t y p e s : sandy dunes, headland s c r u b , and woodland-meadows (Darrow, 1966). The o c t o p l o i d s p e c i e s F. chiloensis and F. virginiana Duchesne a r e the p a r e n t s of the h y b r i d s p e c i e s Fragaria x ananassa Duchesne, t o which most of the c u l t i v a t e d s t r a w b e r r i e s b e l o n g . Except f o r the f r u i t s i z e , much of the q u a l i t y of to d a y s ' s t r a w b e r r y has been d e r i v e d from F. virginiana (Darrow, 1966). R e c e n t l y , the i n t e r e s t of p l a n t b r e e d e r s has f o c u s e d on F. chiloensis because c l o n e s of t h i s s p e c i e s a r e g e n e t i c a l l y d i v e r s e and thus p o t e n t i a l l y u s e f u l s o u r c e s of r e s i s t a n c e t o many s t r a w b e r r y d i s e a s e s and p e s t s ( B r i n g h u r s t et al ., 1977). S e l e c t e d c l o n e s of F. chiloensis were found t o be r e s i s t a n t t o Phyt opht hor a, Verticilium, Botrytis and many o t h e r s t r a w b e r r y pathogens ( B r i n g h u r s t et al., 1977; Hancock and B r i n g h u r s t , 1979; Anonymous, 1982). Other c l o n e s of t h i s s p e c i e s e x h i b i t a h i g h degree of r e s i s t a n c e t o the s t r a w b e r r y a p h i d s Chaetosiphon fragaefolii and C. thomasi, and s t r a w b e r r y w e e v i l s Otiorhynchus sulcatus and O. ovatus (Shanks and B a r r i t t , 1974; Crock et al.,1982; Shanks et a/., 1984; Shanks and Doss, 1986). However, the s e a r c h f o r 8 s p i c i e r m i t e - r e s i s t a n t g e r m p l a s m h a s r e c e i v e d more a t t e n t i o n t h a n f o r t h a t o f any o t h e r s t r a w b e r r y p e s t . I n a d d i t i o n , s e v e r a l a t t e m p t s h a v e been made t o d e t e r m i n e t h e h e r i t a b i l i t y o f m i t e r e s i s t a n c e among s t r a w b e r r y c u l t i v a r s a n d a d v a n c e d s e l e c t i o n s . R e s u l t s t o d a t e i n d i c a t e t h a t m i t e r e s i s t a n c e i s m o d e r a t e l y t o h i g h l y h e r i t a b l e a n d t h a t a d d i t i v e g e n e t i c f a c t o r s p l a y a m a j o r r o l e i n t h e i n h e r i t a n c e o f t h i s t r a i t ( S h a n k s a n d B a r r i t t , 1975 and 1980; B a r r i t t a n d S h a n k s , 1981; C h a p l i n et al., 1 9 7 0 ) . D e s p i t e t h e f a c t t h a t s t r a w b e r r y i n t e r - a n d - i n t r a -s p e c i f i c d i f f e r e n c e s i n m i t e r e s i s t a n c e a r e w e l l d o c u m e n t e d and h e r i t a b i l i t y o f t h i s t r a i t h a s been p a r t i a l l y d e t e r m i n e d , v e r y few a t t e m p t s h a v e been made t o i n v e s t i g a t e s p e c i f i c m e c h a n i s m s a c c o u n t i n g f o r m i t e r e s i s t a n c e . F o r e x a m p l e , K i s h a b a et al ., (1972) i m p l i c a t e d s t r a w b e r r y p u b e s c e n c e a s a p o s s i b l e f a c t o r i n m i t e r e s i s t a n c e . D a b r o w s k i a n d R o d r i g u e z (1972) f o u n d t h a t f o l i a r p h e n o l i c s f r o m c u l t i v a t e d s t r a w b e r r i e s a d v e r s e l y a f f e c t e d m i t e b e h a v i o r a n d p h y s i o l o g y when a d d e d t o an a r t i f i c i a l d i e t . A number o f e s s e n t i a l o i l s f r o m s t r a w b e r r y f o l i a g e were a l s o r e p o r t e d t o r e p e l T. urticae ( D a b r o w s k i a n d R o d r i g u e z 1 9 7 1 ) . 2.2 P l a n t C h a r a c t e r i s t i c s C o n f e r r i n g Arthropod Pest R e s i s t a n c e 2.2.1 F o l i a r Pubescence 9 Numerous s t u d i e s have f o c u s e d on i n t e r - a n d - i n t r a -s p e c i f i c d i f f e r e n c e s i n a r t h r o p o d p e s t r e s i s t a n c e . Most of the p l a n t r e s i s t a n t p r o p e r t i e s , as a s s e s s e d by n o n p r e f e r e n c e or a n t i b i o s i s ( P a i n t e r , 1951), appear t o be r e l a t e d t o p l a n t m o r p h o l o g i c a l or c h e m i c a l c h a r a c t e r i s t i c s . P l a n t s d i s p l a y an a r r a y of m o r p h o l o g i c a l and c h e m i c a l d e f e n s i v e a d a p t a t i o n s a g a i n s t i n s e c t s and m i t e s , which t o a l a r g e e x t e n t d etermine p l a n t a c c e p t a b i l i t y or s u i t a b i l i t y (Beck and Schoonhoven, 1980). F o l i a r m o r p h o l o g i c a l d e f e n s e s i n c l u d e pubescence, s u r f a c e waxes, s i l i c a t i o n and s c l e r o t i z a t i o n of the l e a f t i s s u e . These d e f e n c e s can i n t e r f e r e p h y s i c a l l y w i t h i n s e c t and m i t e f e e d i n g , movement, mating and o v i p o s i t i o n ( N o r r i s and Kogan, 1980; Beck and Schoonhoven, 1980). F o l i a r pubescence i s the most f r e q u e n t l y s t u d i e d m o r p h o l o g i c a l t r a i t a s s o c i a t e d w i t h a r t h r o p o d r e s i s t a n c e , because i t p r o v i d e s a d e f e n s i v e b a r r i e r a g a i n s t many s p e c i e s of phytophagous i n s e c t s and m i t e s (Webster, 1975). Trichomes are e p i d e r m a l appendages of d i v e r s e form and s t r u c t u r e . They a r e g e n e r a l l y c l a s s i f i e d as n o n g l a n d u l a r or g l a n d u l a r based on whether or not they f u n c t i o n as s e c r e t o r y s t r u c t u r e s (Esau, 1965; P e t t e r s o n and Varmeer, 1984). Trichomes are u n i v e r s a l l y d i s t r i b u t e d i n h i g h e r p l a n t s and have been u s e f u l f o r p h y l o g e n e t i c and taxonomic p u r p o s e s . Trichomes commonly v a r y i n m o r p h o l o g i c a l form or d e n s i t y w i t h i n and between t a x a . These d i f f e r e n c e s have a g e n e t i c b a s i s and s t r o n g g e o g r a p h i c a l c o r r e l a t i o n s ( L e v i n 1973; Mehlenbaher et al ., 1983, 1984). The i n h e r i t a n c e of 10 the m o r p h o l o g i c a l t y p e s and d e n s i t i e s of t r i c h o m e s have been e x t e n s i v e l y s t u d i e d i n the genera Lycopersicon and Sol anum. Trichomes t y p e s and d e n s i t y are h e r i t a b l e (Mehlenbacher et al.,1983,1894; C a r t e r and Snyder, 1986; T i n g e y et a l . , 1982; G e n t i l e et al .,1969). G l a n d u l a r and n o n g l a n d u l a r pubescence tends t o i n c r e a s e s w i t h a l t i t u d e , and a r i d i t y . The c o r r e l a t i o n between a r i d i t y and n o n g l a n d u l a r pubescence appears t o be r e l a t e d t o p l a n t water economy ( E h l e r i n g e r , 1984). The g l a n d u l a r t r i c h o m e s , however, have l i t t l e e f f e c t on b i o p h y s i c a l p r o p e r t i e s of the l e a f s u r f a c e , t h e r e f o r e i t i s u n l i k e l y t h a t a r i d i t y e x e r t s s e l e c t i o n p r e s s u r e on g l a n d u l a r t r i c h o m e s ( L e v i n 1973). I n i t i a t i o n of t r i c h o m e p r o d u c t i o n has a g e n e t i c b a s i s but i t can be m o d i f i e d by the environment (Johnson 1975). Trichome i n i t i a t i o n can p e r s i s t t hroughout ontogeny of p l a n t organ as i n Cannabis sativa (Mahlberg et al ., 1984), or i t may o c c u r once a t the b e g i n n i n g of the p l a n t organ ontogeny. G l a n d u l a r t r i c h o m e s can e i t h e r p e r s i s t t h r o u g h the l i f e of the organ or they may became ephemeral ( d e v o i d e d of p r o t o p l a s t and r e t a i n e d i n the d r y s t a t e ) (Esau, 1965; C u t t e r 1976). In some c a s e s , g l a n d u l a r t r i c h o m e s may l a c k the a b i l i t y t o produce exudates (Rasmy, 1985; C r a i g et a l . , 1986) . In a d d i t i o n t o the p r e v e n t i o n of water l o s s and the d e p o s i t i o n of s e c r e t o r y compounds, t r i c h o m e s a r e i m p l i c a t e d i n d efence a g a i n s t a v a r i e t y of h e r b i v o r e s ( L e v i n , 1973). Both g l a n d u l a r and n o n g l a n d u l a r t r i c h o m e s were r e p o r t e d t o 11 be f a c t o r s of i n s e c t r e s i s t a n c e i n a v a r i e t y of p l a n t s p e c i e s (Table 1). The r o l e of g l a n d u l a r trichomes of c e r t a i n Solarium and Lycoper si con s p e c i e s i n r e s i s t a n c e a g a i n s t arthropod pests has r e c e n t l y became an area of c o n s i d e r a b l e r e s e a r c h . In the major crops a l f a l f a , potato and tomato, g l a n d u l a r pubescence i s being i n v e s t i g a t e d f o r i t s a p p l i c a b i l i t y i n host r e s i s t a n c e . Nonglandular trichomes have been a l s o a s s o c i a t e d with r e s i s t a n c e to i n s e c t s i n s e v e r a l major crops (Table 2 ) . In c o t t o n , wheat and soybeans u t i l i z a t i o n of host r e s i s t a n c e i s an important t a c t i c i n arthropod pest management. 2 .2 .2 F o l i a r P h e n o l i c s For many p l a n t s p e c i e s c h e m i c a l l y - b a s e d r e s i s t a n c e appears to be the major component of the p l a n t ' s t o t a l defense a g a i n s t h e r b i v o r e s ( N o r r i s and Kogan, 1980). Higher p l a n t s produce an array of " a l l e l o c h e m i c s " , n o n - n u t r i t i v e chemicals which a f f e c t the behavior and ph y s i o l o g y of other s p e c i e s (Whittaker, 1970). They i n c l u d e a l k a l o i d s , cyanogenic g l y c o s i d e s , t o x i c l i p i d s , g l u c o s i n o l a t e s , s t e r o i d s , p h e n o l i c s , and other compounds ( S c r i b e r , 1984; Beck and Schoonhoven, 1980; Swain, 1977; Rhodes,1979). Ph e n o l i c compounds are thought to be one of the more important groups of p l a n t chemical defenses ( N o r r i s and Kogan, 1980; Jones, 1983). 12 Table 1. Examples of i n s e c t and mite r e s i s t a n c e c o n f e r r e d by g l a n d u l a r pubescence. Host s p e c i e s Pest References Solarium spp. Potato leafhopper n Green Peach Aphid » S e v e r a l S. ber t haul t i i Potato B e e t l e Solanum spp. Potato F l e a b e e t l e S. neocardenasi iGreen Peach Aphid S.pannellii Potato Aphid S. pol yadeni um ?• Lycopersi con spp. Potato Aphid " W h i t e f l y »i Tobacco F l e a b e e t l e « Twospotted Spider H Mite L. hi r sut um n L. esculent um Fruitworm L.hirsutum f. glab. n L.esculentum W h i t e f l y Medicago spp. A l f a l f a Weevil Nicotiana spp. Twospotted Spider Pelargonium spp. Mite Tingey and Gibson (1978) Tingey and Laubengayer (1981) ; Tingey et al., (1982) , Tingey and Sinden (1982), Dimock and Tingey (1987), Gibson (1978), Lapointe and Tingey (1986) G e n t i l e and Stoner (1968a) Gibson (1974) and (1971) G e n t i l e and Stoner(1968a) G e n t i l e el al.,(1968c) G e n t i l e and Stoner (1968c) Stoner et al.,(1968), Aina et al., (1972), Snyder and C a r t e r (1984) G e n t i l e et at ., (1969) Duffey and Isman (1 981 ) Dimock and Kennedy (1983) Kisha (1981) Johnson et al., (1980) Pa t t e r s o n et al ., (1974) Gerhold el al.,(1984) 13 T e b l e 2. Examples of i n s e c t and m i t e r e s i s t a n c e c o n f e r r e d by n o n g l a n d u l a r pubescence. Host s p e c i e s P e s t R e f e r e n c e s Fragaria chiloensis B l a c k V i n e W e e v i l Shanks and Doss (1986) Humulus lupulus Twospotted S p i d e r P e t e r s and B e r r y ( l 9 8 0 ) M i t e Gossypium spp. H e l i o t h i s spp. L u k e f a h r et al .,(1971) Soybean v a r i e t i e s >< H i l l h o u s e and P i t r e (1976) Triticum v a r i e t i e s C e r e a l Leaf B e e t l e Hoxie et al ., (1975) Tl I t G a l l u n et al., (1966) Soybean v a r i e t i e s P o t a t o Leafhopper Broersma el al.,(1972) 14 The t e r m " p h e n o l i c compounds" e m b r a c e s a w i d e r a n g e o f p l a n t s u b s t a n c e s w h i c h p o s s e s s i n common an a r o m a t i c r i n g w i t h a t l e a s t one h y d r o x y l s u b s t i t u e n t (Thomson, 1 9 6 4 ) , o r d e r i v a t i v e s t h e r e o f . P h e n o l i c s a r e w i d e l y d i s t r i b u t e d t h r o u g h o u t t h e p l a n t k i n g d o m a nd t h o u s a n d s o f s t r u c t u r e s o f n a t u r a l l y o c c u r r i n g p h e n o l i c compounds a r e known. A l l a r i s e f r o m a common b i o s y n t h e t i c i n t e r m e d i a t e , p h e n y l a l a n i n e , o r i t s c l o s e p r e c u r s o r s h i k i m i c a c i d . The most common g r o u p s o f p h e n o l i c s i n c l u d e t h e s i m p l e p h e n o l i c a c i d s , f l a v o n o i d s a n d t a n n i n s ( F i g . 1) ( S w a i n , 1979; R i b e r e a u - G a y o n , 1 9 7 2 ) . V a r i a t i o n i n p l a n t p h e n o l i c s , a s w e l l a s t h a t f o r t h e m a j o r i t y o f a l l e l o c h e m i c s , a p p e a r s t o have a g e n e t i c b a s i s (Chew a nd Rodman, 1979; K r i s c h i k a n d Denno, 1 9 8 3 ) . However a v a r i e t y o f b i o t i c a n d a b i o t i c f a c t o r s c a n e x t e n s i v e l y m o d i f y t h e i r p a t t e r n . C o n s i d e r a b l e d i f f e r e n c e s i n p l a n t p h e n o l i c s may r e s u l t f r o m h e r b i v o r e p r e s s u r e , n u t r i e n t a v a i l a b i l i t y , l i g h t q u a l i t y a n d s e a s o n a l c h a n g e s ( d e l M o r e l , 1972; M o l e et al., 1988; Woodhead 1981; K r i s c h i k a n d Denno 1 9 8 3 ) . P l a n t i n d i v i d u a l s , p o p u l a t i o n s a n d s p e c i e s d i f f e r commonly i n q u a l i t y o r q u a n t i t y o f p h e n o l i c compounds ( C r e a s y , 1964; Woodhead, 1981; L e v y a n d F u j i i , 1 9 7 8 ) . P h e n o l i c s , l i k e many a l l e l o c h e m i c s , h a v e a d i v e r s e b i o c h e m i c a l b a c k g r o u n d . T h i s i s p r o b a b l y why one e x p e c t s g r e a t v a r i a t i o n i n h e r i t a b i l i t y o f t h e s e compounds (McKey, 1979; Chew Rodman, 1 9 7 9 ) . 15 F i g . 1 T h r e e r e p r e s e n t a t i v e s o f t h e m o s t c o m m o n g r o u p s o f p h e n o l i c s : s i m p l e p h e n o l i c s r e p r e s e n t e d b y b e n z o i c ( A ) a n d c i n n a m i c ( B ) a c i d s a n d f l a v o n o i d s r e p r e s e n t e d b y q u e r c e t i n ( C ) . 16 COOH Benzoic a c i d CH=CHCOOH Cinnamic a c i d Quercetin 17 S e v e r a l a u t h o r s have r e p o r t e d the e x i s t e n c e of heterogenous d i s t r i b u t u i o n of a l l e l o c h e m i c s ( i n c l u d i n g p h e n o l i c s ) w i t h i n a p l a n t (McKey, 1979; Roupp and Denno, 1983; M c C l u r e , 1983). T h i s heterogeneous d i s t r i b u t i o n p r o b a b l y r e s u l t s from d i f f e r e n t r a t e s of s y n t h e s i s , d e g r a d a t i o n or t r a n s l o c a t i o n among p l a n t t i s s u e of v a r i o u s ages or m o r p h o l o g i c a l t y p e s (McKey, 1979). In g e n e r a l , c o n c e n t r a t i o n s of p h e n o l i c a c i d s and f l a v o n o i d s t e n d t o be h i g h e r i n young l e a v e s than i n mature ones (Larson and B e r r y , 1984; C o l e y , 1983; K r i s c h i k and Denno 1983), w h i l e the r e v e r s e p a t t e r n seems t o be t r u e f o r t a n n i n s (Lane and S c h u s t e r , 1981; Rhoades, 1979). P h e n o l i c compounds r a r e l y occur i n a f r e e s t a t e i n l i v i n g p l a n t t i s s u e , presumably because of t h e i r t o x i c i t y ( H arborne, 1979). A l t h o u g h the m o d e - o f - a c t i o n of p h e n o l i c s i s not f u l l y u n d e r s t o o d , e v i d e n c e from in v i t r o s t u d i e s s u g g e s t s t h a t the most common p o l y p h e n o l s b i n d non-s p e c i f i c a l l y w i t h p r o t e i n s , c o n s e q u e n t l y d e c r e a s i n g d i e t a r y p r o t e i n a v a i l a b i l i t y or i n h i b i t i n g enzyme a c t i v i t y (van Sumere, 1975). Hydrogen bonding p l a y s an i m p o r t a n t r o l e i n the a s s o c i a t i o n of p h e n o l i c s w i t h p r o t e i n s . However, o t h e r r a p i d l y formed and more s t a b l e bonds a l s o o c c u r . For example, c h l o r o g e n i c a c i d , c a f f e i c a c i d and o t h e r r e l a t e d o r t h o - d i h y d r o x y p h e n o l s ( c a t e c h o l - b a s e d p h e n o l i c s ) o x i d i z e r e a d i l y t o o r t h o - q u i n o n e s i n the p r e s e n c e of oxygen. The o r t h o - q u i n o n e s are h i g h l y r e a c t i v e and have a p a r t i c u l a r l y h i g h a f f i n i t y f o r l y s i n e , w i t h which they r e a c t f u r t h e r t o 18 form c o v a l e n t bonds ( P i e r p o i n t , 1969; P i e r p o i n t et al ., 1977; H u r r e l et al., 1982). One consequence of such b i n d i n g i s r e s t r i c t e d d i e t a r y a v a i l a b i l i t y of l y s i n e ( D a v i e s et al., 1978), which d e c r e a s e s the n u t r i t i o n a l v a l u e of p l a n t m a t e r i a l t o many h e r b i v o r o u s organisms. P h e n o l i c compounds a r e i m p l i c a t e d i n r e s i s t a n c e a g a i n s t a r t h r o p o d p e s t s i n a v a r i e t y of h o r t i c u l t u r a l and a g r i c u l t u r a l c r o p s . For example, r e s i s t a n c e i n c o t t o n s t r a i n s a g a i n s t Heliothis s p e c i e s i s r e p o r t e d t o be p o s i t i v e l y c o r r e l a t e d w i t h the c o n c e n t r a t i o n s of the t e r p e n o i d p h e n o l i c g o s s y p o l ( L u k e f a h r and H o u g h t a i 1 i n g , 1969). The c o n c e n t r a t i o n of t h i s p h e n o l i c i n r e s i s t a n t p l a n t s i s r e p o r t e d t o be a p p r o x i m a t e l y t w i c e t h a t of s u s c e p t i b l e p l a n t s (Seaman et a/., 1977). R e s i s t a n c e of young sorghum p l a n t s t o a t t a c k by Locust a migratoria and o t h e r a c r i d i d s i s p a r t l y r e l a t e d t o the l e v e l of p h e n o l i c a c i d s i n the p l a n t t i s s u e (Woodhead and Bernays, 1978). C o n s i d e r a b l e v a r i a t i o n i n l e v e l s of thes e p h e n o l i c s a r e r e p o r t e d among Sorghum c u l t i v a r s (Woodhead, 1981). R e s i s t a n c e i n l e t t u c e t o the l e t t u c e r o o t a p h i d i s p o s i t i v e l y c o r r e l a t e d w i t h c o n c e n t r a t i o n s of i s o c h l o r o g e n i c a c i d i n the r o o t t i s s u e ( C o l e , 1984). T h i s t r e n d i s r e v e r s e d i n c a r r o t w i t h c o n c e n t r a t i o n s of c h l o r o g e n i c a c i d i n c a r r o t r o o t s b e i n g p o s i t i v e l y c o r r e l a t e d w i t h c a r r o t f l y l a r v a l damage ( C o l e , 1985 and 1987). I n s e c t r e s i s t a n c e i n tomato p l a n t s i s p a r t l y a t t r i b u t e d t o the presence of p h e n o l i c compounds. P h e n o l i c s from 19 tomato g l a n d u l a r trichomes are r e p o r t e d to s i g n i f i c a n t l y reduce growth of Heliothis zea l a r v a e (Duffey and Isman, 1981). However, the c o n c e n t r a t i o n of f o l i a r c a t e c h o l s from tomato does not appear to be c o r r e l a t e d with growth of t h i s i n s e c t (Isman and Duffey, 1982 a ) , d e s p i t e the f a c t that c o n c e n t r a t i o n s of p h e n o l i c s i n the f o l i a g e were comparable to those causing s i g n i f i c a n t r e d u c t i o n i n l a r v a l growth when the same compounds were i n c o r p o r a t e d i n t o a r t i f i c i a l d i e t (Isman and Duffey, 1982 b ) . Resistance i n maize, Zea mays to H. zea i s a s s o c i a t e d with the c o n c e n t r a t i o n of the t o x i c f l a v o n o i d maysin. A r e s i s t a n t v a r i e t y had a s i x f o l d higher c o n c e n t r a t i o n of t h i s f l a v o n o i d than a s u s c e p t i b l e one ( E l l i g e r et al., 1979; Waiss et al., 1979). In b a r l e y , r e s i s t a n c e to the greenbug, Schizaphis graminum i s a s s o c i a t e d with the presence and c o n c e n t r a t i o n of p h e n o l i c compounds bearing ortho-dihydroxy s u b s t i t u t i o n (Todd et al., 1979). The l i t e r a t u r e reviewed c l e a r l y i n d i c a t e s that p h e n o l i c compounds are a s s o c i a t e d with r e s i s t a n c e to i n s e c t s i n s e v e r a l major cr o p s . In b a r l e y , sorghum, c o t t o n , l e t t u c e and tomato the u t i l i z a t i o n of host r e s i s t a n c e c o u l d be an important t a c t i c i n arthropod pest management. 20 2.3 E f f e c t s of F o l i a r P h e n o l i c s and Pubescence on A r t h r o p o d F i t n e s s 2 .3 .1 P h e n o l i c s and A r t h r o p o d F i t n e s s The exact mode-of-action of p h e n o l i c s i n arthropods i s s t i l l unknown, but p h e n o l i c s e l i c i t a wide range of b e h a v i o r a l and p h y s i o l o g i c a l responses i n i n s e c t s and mites. The outcome of s p e c i f i c p h e n o l i c - a r t h r o p o d i n t e r a c t i o n s depends on s e v e r a l f a c t o r s . These i n c l u d e the a r t h r o p o d s p e c i e s and developmental stage as w e l l as the c l a s s or s p e c i f i c s t r u c t u r a l p r o p e r t i e s of the p h e n o l i c s . The e f f e c t s of t a nnins on i n s e c t s are w e l l documented and have been e x t e n s i v e l y reviewed by Bernays (1981). I t was o r i g i n a l l y proposed t h a t tannins act p r i m a r i l y by i n h i b i t i n g d i g e s t i v e processes in the arthropod's gut (Swain, 1977), or by reducing the a v a i l a b i l i t y of d i e t a r y p r o t e i n (Feeny, 1976). The measurable response of i n s e c t s reared on t a n n i n e n r i c h e d d i e t s i s u s u a l l y apparent as growth i n h i b i t i o n (Bernays, 1981), but more d e t a i l examination i n d i c a t e s that reduced consaumption most o f f t e n accounts f o r the i n h i b i t i o n of growth. In some cases, i n s e c t performance i s not a f f e c t e d even though l a r g e q u a n t i t i e s of tannins where i n c o r p o r a t e d i n t o the d i e t (Bernays, 1978; Bernays et al., 1980). T h i s and other o b s e r v a t i o n s l e d Bernays (1981) to hypothesize that tannins act p r i m a r i l y as feeding d e t e r r e n t s . F l a v o n o i d s have r e c e i v e d c o n s i d e r a b l e a t t e n t i o n as f e e d i n g d e t e r r e n t s a g a i n s t a wide v a r i e t y of i n s e c t s ( N o r r i s 21 and Kogan, 1980; Dreyer and Jo n e s , 1981; Dreyer et al., 1981), but they a re a l s o known t o e l i c i t o t h e r b e h a v i o r a l and p h y s i o l o g i c a l r esponses when added t o a r t i f i c i a l d i e t s . These i n c l u d e f e e d i n g s t i m u l a t i o n (Matsuda, 1978), growth i n h i b i t i o n (Isman and D u f f e y , 1982 b; E l l i g e r et al., 1979; Shaver and L u k e f a h r , 1969) and growth enhancment (McFarlane and D i s t l e r , 1982). The e f f e c t s of f l a v o n o i d s appear t o depend more on the s p e c i e s of i n s e c t t e s t e d than on the s p e c i f i c f l a v o n o i d . For example, m o r i n , d - c a t e c h i n , q u e r c e t i n and o t h e r f l a v o n o i d s were r e p o r t e d t o d e t e r or i n h i b i t i n s e c t s of one s p e c i e s but t o a t t r a c t or s t i m u l a t e o t h e r s p e c i e s ( N o r r i s and Kogan, 1980). Q u e r c e t i n and the p h e n y l p r o p e n o i d m y r i s t i c i n have been r e p o r t e d t o a c t as s y n e r g i s t s and i n c r e a s e t o x i c i t y of c a r b a r y l ( s y n t h e t i c i n s e c t i c i d e ) or s i n i g r i n , a c o - o c c u r r i n g c o n s t i t u e n t of many c r u c i f e r c r o p s , t o Heliothis zea (Berenbaum and N e a l , 1987 c i t e d i n N e a l and Berenbaum, i n p r e s s ) . Many of the b i o l o g i c a l a c t i v i t i e s e l i c i t e d by f l a v o n o i d s a r e a l s o e l i c i t e d by s i m p l e b e n z o i c and c i n n a m i c a c i d s . S e v e r a l of the s e compounds were found t o be a c t i v e a g a i n s t i n s e c t s and o t h e r a r t h r o p o d s when i n c o r p o r a t e d i n t o a r t i f i c i a l d i e t s . Responses i n c l u d e d improvement of growth (Bernays and Woodhead, 1982 a,b; K a t o , 1978) and i n h i b i t i o n of growth, f e e d i n g and r e p r o d u c t i o n (Isman and D u f f e y , 1982 a; V a l i e l a et at., 1979; Todd et al., 1979). S i m p l e p h e n o l s , p h e n o l i c a c i d s , and some f l a v o n o i d s a r e a l s o known to be p o t e n t a n t i m i c r o b i a l agents (Harborne, 1979) and thus 22 may i n t e r f e r e with the endosymbiotic m i c r o f l o r a i n the i n s e c t gut (McFarlane and D i s t l e r , 1982). The twospotted s p i d e r mite i s a l s o known to be a f f e c t e d by p h e n o l i c compounds, when the l a t t e r are i n c o r p o r a t e d i n t o a d i e t or ingested from p l a n t t i s s u e s . Dabrowski and Rodriguez (1972) s t u d i e d the e f f e c t of i n c o r p o r a t i o n of 14 p h e n o l i c compounds i n t o s p i d e r mite a r t i f i c i a l d i e t . The p h e n o l i c s c o n s i s t e d of benzoic and cinnamic a c i d d e r i v a t i v e s i n c l u d i n g f l a v o n o i d s , a l l of which were p r e v i o u s l y r e p o r t e d to be present i n strawberry l e a f t i s s u e . T h e i r r e s u l t s showed that p r a c t i c a l l y a l l of the p h e n o l i c s a f f e c t e d mite behavior or p h y s i o l o g y through decreased f e e d i n g , r e p e l l e n c y or t o x i c i t y . Lane and Schuster (1981) have shown that the suppression of mite p o p u l a t i o n s i n p r i m i t i v e c o t t o n races was c o r r e l a t e d to high c o n c e n t r a t i o n s of condensed tannins from the l e a f t i s s u e . Larson and Berry (1984) have r e p o r t e d that p h e n o l i c s from peppermint f o l i a g e a f f e c t mite behavior, o v i p o s i t i o n and developmental time. 2 .3 .2 F o l i a r Pubescence and Arthropods F i t n e s s 2 . 3 . 2 . 1 E f f e c t s of Nonglandular Trichomes Nonglandular trichomes can exert d i r e c t mechanical e f f e c t s on arthropods but they may a l s o a f f e c t arthropods i n d i r e c t l y by a l t e r i n g the m i c r o c l i m a t e on a l e a f s u r f a c e (Willmer 1986). The r e l a t i o n s h i p between an arthropod and nonglandular trichomes depends on many c h a r a c t e r i s t i c s of the trichomes. They i n c l u d e o r i e n t a t i o n , l e n g t h , shape and 23 d e n s i t y . The arthropod c h a r a c t e r i s t i c s such as body s i z e , mode of locomotion, f e e d i n g type and o t h e r s , a l s o appear to be important i n determining the outcome of these r e l a t i o n s h i p s ( N o r r i s and Kogan, 1980). Small arthropods with p i e r c i n g - s u c k i n g mouth p a r t s may be prevented from u t i l i z i n g a p l a n t by long and dense pubescence (Quiros et al., 1977), whereas small mandibulate i n s e c t s may feed l e s s when simple trichomes became p a r t of t h e i r d i e t (Shanks et al ., 1984; Doss et al ., 1987). M o r p h o l o g i c a l c h a r a c t e r i s t i c s of the p l a n t s u r f a c e are f r e q u e n t l y of paramount importance i n determining the a c c e p t a b i l i t y of the p l a n t f o r o v i p o s i t i o n by an a r t h r o p o d . Lukefahr et al., (1971) and Greene and Thurston (1971) r e p o r t e d that Heliothis virescens moths showed o v i p o s i t i o n a l p r e f e r e n c e f o r Nicotiana s p e c i e s with a pubescent s u r f a c e and nonpreference to glabrous s t r a i n s of Gossypium s p e c i e s . The d e n s i t y of f o l i a r trichomes has been found to a f f e c t m o b i l i t y of numerous small arthropod pests (Webster 1975), whereas the o r i e n t a t i o n or l e n g t h of trichomes are more important to others (Broersma et al., 1972, Hoxie et al.,1975). D e n s i t i e s of nonglandular trichomes do not g e n e r a l l y a f f e c t small arthropods such as phytophagous mites. For example, densely pubescent wheat supported the g r e a t e s t p o p u l a t i o n s of the wheat c u r l mite Eriophyes tulipe (Harvey and M a r t i n , 1980), while v a r i a t i o n i n f o l i a r pubescence of apple t r e e s had no a f f e c t on p o p u l a t i o n s of Panonychus ulmi 24 (Goonewardene et al . ,1980 and 1982; P i a v a and J a n i c , 1980). O c c a s i o n a l l y , however, d e n s i t y of s i m p l e h a i r s may i n t e r f e r e w i t h m i t e performance ( P e t t e r s and B e r r y , 1980). 2.3.2.2 E f f e c t s of Gl a n d u l a r Trichomes P l a n t s a l s o r e l y on g l a n d u l a r t r i c h o m e s t o i m m o b i l i z e , r e p e l or p o i s o n s m a l l phytophagous i n s e c t s and m i t e s ( S t i p a n o v i c , 1983). In a v a r i e t y of p l a n t s p e c i e s , r e s i s t a n c e t o i n s e c t s and m i t e s has been a s s o c i a t e d w i t h impeded movement and entrapment by a d h e s i v e exudates of g l a n d u l a r t r i c h o m e s . T h i s mechanism was found t o be a s i g n i f i c a n t f a c t o r of r e s i s t a n c e i n Lycopersi con s p e c i e s a g a i n s t a broad complex of p e s t s p e c i e s i n c l u d i n g w h i t e f l i e s ( G e n t i l e et al., 1969; K i s h a , 1981), p o t a t o a p h i d s ( G e n t i l e and S t o n e r , 1968 a ) , and f l e a b e e t l e s ( G e n t i l e and S t o n e r , 1968 b ) . A s i m i l a r mechanism ac c o u n t e d f o r the p a r t i a l r e s i s t a n c e i n Solanum s p e c i e s a g a i n s t p o t a t o l e a f h o p p e r s (Tingey and G i b s o n , 1978), f l e a b e e t l e s ( G i b s o n , 1978), and green peach a p h i d s ( L a p o i n t e and Ti n g e y , 1984 and 1986). In a d d i t i o n t o i m m o b i l i z a t i o n , exudates of g l a n d u l a r t r i c h o m e s may c o n t a i n c h e m i c a l s which a r e b i o l o g i c a l l y a c t i v e a g a i n s t i n s e c t s p e s t s . A r e d u c t i o n i n growth of H. zea l a r v a e , f o r example, was a t t r i b u t e d t o p h e n o l i c compounds i n tomato g l a n d u l a r t r i c h o m e s ( D u f f e y and Isman, 1981). F o l i a g e of the w i l d tomato Lycopersicon hirsutum f. glabratum c o n t a i n s h i g h e r c o n c e n t r a t i o n s of 2 - t r i d e c a n o n e than c u l t i v a t e d L. hirsutum. T h i s c h e m i c a l i s a p o t e n t 25 t o x i n t o Manduca sexta, H. zea and Aphis gossypii ( W i l l i a m s et al., 1980; Dimock and Kennedy, 1983). The c h e m i s t r y of g l a n d u l a r t r i c h o m e exudates and t h e i r r o l e i n defense a g a i n s t i n s e c t s has been e x t e n s i v e l y r e v i e w e d by K e l s e y et al., (1984), S t i p a n o v i c (1983), D u f f e y (1986) and Gregory (1986 a ) . Much of the e v i d e n c e f o r the r o l e of g l a n d u l a r t r i c h o m e s i n p l a n t d e f e n c e s a r o s e from s t u d i e s of the t e t r a n y c h i d m i t e s T. urticae and T. ci nnabari nus. G l a n d u l a r t r i c h o m e s a r e i m p l i c a t e d i n mite r e s i s t a n c e i n s e v e r a l p l a n t s p e c i e s i n c l u d i n g Pelargonium x hortorum ( G e r h o l d et al., 1983; C r a i g et al ., 1986), Nicotiana s p e c i e s ( P a t t e r s o n et al., 1974), Lycoprsicon s p e c i e s (Rasmy, 1985) and Sol anum s p e c i e s ( G e n t i l e et al., 1969). Mechanisms of g l a n d u l a r t r i c h o m e - b a s e d r e s i s t a n c e i n c l u d e entrapment and i m m o b i l i z a t i o n by s t i c k y exudates ( G e n t i l e et al., 1969; S t o n e r et al ., 1968), t o x i c i t y of g l a n d u l a r e x u dates ( A i n a et al ., 1972; G e r h o l d et al . ,1983, C r a i g et al.,1986), as w e l l as the combined e f f e c t of both f a c t o r s (Rasmy, 1985; P a t t e r s o n et al., 1975; Snyder and C a r t e r 1984). 2.3 Strawberry F o l i a r P h e n o l i c s and Pubescence In the p a s t , s e v e r a l a t t e m p t s have been made t o det e r m i n e the i n t e r - a n d - i n t r a s p e c i f i c v a r i a t i o n i n q u a l i t y of s t r a w b e r r y p h e n o l i c s and d e n s i t y of f o l i a r pubescence. The q u a l i t a t i v e a n a l y s i s of s t r a w b e r r y p h e n o l i c s was performed w i t h the use of paper and gas chromatography. The 26 examined t i s s u e c o n s i s t e d of r o o t s , leaves and f r u i t s and were e x t r a c t e d from s e v e r a l c u l t i v a r s of F.x ananassa, F. vesca ( L ) . c u l t i v a r " A l p i n e " or c u l t i v a t e d F. chiloensis. The r e s u l t s i n d i c a t e that strawberry t i s s u e s c o n t a i n a d i v e r s e assortment of meth a n o l - e x t r a c t a b l e p h e n o l i c s , with the most common being benzoic and cinnamic a c i d s . F l a v o n o i d s , i n c l u d i n g anthocyanins and tannins are a l s o present (Table 3). Nemec (1973) r e p o r t e d that p h e n o l i c s i n strawberry r o o t s c o n s i s t mostly of f l a v o n o i d s and t a n n i n s . A number of other s t u d i e s have r e p o r t e d that e x t r a c t s of strawberry l e a v e s and f r u i t s c o n t a i n mostly f l a v o n o i d s i n c l u d i n g anthocyanins, and benzoic and cinnamic a c i d s (Williams and Wender, 1952; Ryan, 1971; Stohr and Herrmann, 1975; Creasy 1964; Bate-Smith, 1958). The e x i s t e n c e of i n t e r - a n d - i n t r a s p e c i f i c d i f f e r e n c e s i n both q u a l i t y and q u a n t i t y of strawberry p h e n o l i c s have been r e p o r t e d (Nemec, 1973 and 1976; Creasy, 1964). Strawberry p l a n t s possess two types of trichomes on the a b a x i a l l e a f s u r f a c e ( F i g . 2); nonglandular and g l a n d u l a r trichomes. Although the presence and v a r i a t i o n i n d e n s i t i e s of nonglandular trichomes have r e c e i v e d c o n s i d e r a b l e a t t e n t i o n (Hancock, 1977; Hancock and B r i n g h u r s t , 1979; Doss et al . , 1987), there i s no c u r r e n t i n f o r m a t i o n on v a r i a t i o n i n d e n s i t i e s of gl a n d u l a r trichomes. F. chiloensis i s c h a r a c t e r i z e d as having dense pubescence. S i g n i f i c a n t i n t e r - a n d - i n t r a - p o p u l a t i o n v a r i a t i o n i n trichome d e n s i t i e s 27 Table 3. P h e n o l i c compounds i d e n t i f i e d i n strawberry t i s s u e s . Compound(s) References A . B. Leaf e l l a g i c , c a f f e i c and p-coumaric a c i d quercet in,kaempferol c y a n i d i n Bate-Smith (1961) d - c a t e c h i n c h l o r o g e n i c a c i d b i f l a v a n g a l l i c , g e n t i s i c , Bate-Smith (1961), Creasy et a l . , (1964), W i l l i a m s and Wender (1952) Creasy et a l . , (1964) Nemec (1973) c i t e Durbin et a l . , (1960) Creasy and Swain (1965). Dabrowski and Rodriguez (1972) c i t e f e r u l i c and v a n i l l i c a c i d Runkowa et a l . , (1968) p-hydroxyphenylacetic a c i d Bate-Smith (1961) Roots kaempferol, q u e r c e t i n Nemec (1973) c y a n i d i n l e u c o c y a n i d i n , b i f l a v a n , d - c a t e c h i n and g a l l i c a c i d e l l a g i c a c i d , g a l l o y l e s t e r and u n i d e n t y f i e d h y d r o l y s a b l e t a n n i n s c h l o r o g e n i c a c i d 28 Table 1. Continued s c o p o l e t i n a r b u t i n d e r i v a t i v e C. F r u i t s ( +)-catechin Stohr and Herrmann (1975) ( - ) - e p i c a t e c h i n ( + ) - g a l l o c a t e c h i n p-coumaric, c a f f e i c and f e r u l i c a c i d 4-hydroxybenzoic, p - c a t e c h u i c , v a n i l l i c , s a l i c y l i c , g e n t i s i c and g a l l i c a c i d kaempferol and q u e r c e t i n Ryan (1971) F i g . 2 G l a n d u l a r and n o n g l a n d u l a r t r i c h o m e s f r o m t h e a b a x i a l l e a l s u r f a c e o f Fragaria chi I oensis c l o n e 85\D (200 X ) . 30 has been r e p o r t e d t o occur i n t h i s s p e c i e s (Hancock, 1977; Hancock and B r i n g h u r s t , 1979). The n o n g l a n d u l a r t r i c h o m e s have been r e p o r t e d t o be r e l a t e d t o r e s i s t a n c e a g a i n s t a d u l t b l a c k v i n e w e e v i l s (Doss et al., 1987). P o s s i b l e v a r i a t i o n i n q u a l i t y and q u a n t i t y of p h e n o l i c compounds i n F. chiloensis f o l i a g e and the e x i s t e n c e of v a r i a t i o n i n d e n s i t i e s of t r i c h o m e s p r o v i d e s i n t e r e s t i n g avenues f o r s t u d y i n g s t r a w b e r r y r e s i s t a n c e t o s p i d e r m i t e s . These a s p e c t s a r e p a r t i c u l a r l y i n t e r e s t i n g i n t h a t each f a c t o r has p r e v i o u s l y been a s s o c i a t e d w i t h m i t e r e s i s t a n c e i n o t h e r c r o p p l a n t s . The immediate o b j e c t i v e s of the p r e s e n t study were: 1. i n v e s t i g a t e d i f f e r e n c e s i n s u i t a b i l i t y f o r m i t e o v i p o s i t i o n among 63 c l o n e s of F. chiloensis and cv. "Totem" 2. examine d i f f e r e n c e s i n d e n s i t i e s of both t y p e s of t r i c h o m e s and d i f f e r e n c e s i n q u a l i t y and q u a n t i t y of f o l i a r p h e n o l i c s among c l o n e s of F. chiloensis and c v . "Totem" 3. t o a s s e s s the e f f e c t of v a r i a t i o n i n f o l i a r p h e n o l i c s and d e n s i t i e s of each type of t r i c h o m e s on o v i p o s i t i o n , s u r v i v a l and l a r v a l development of the t w o s p o t t e d s p i d e r m i t e . 31 3. MATERIAL AND METHODS 3.1 P l a n t M a t e r i a l The p l a n t m a t e r i a l used i n t h i s study c o n s i s t e d of two strawberry s p e c i e s , Fragaria x ananassa Duchesne and Fragaria chiloensis (L.) Duchesne. F. x ananassa was repre s e n t e d by the m i t e - s u s c e p t i b l e c u l t i v a r "Totem". F. chiloensis was represented by 63 g e n e t i c a l l y d i f f e r e n t c l o n e s , each c o l l e c t e d from a d i f f e r e n t (minimum 10 m apar t ) c o l l e c t i o n s i t e on Vancouver I s l a n d and along the southwestern coast of B r i t i s h Columbia ( F i g . 3 ) . Strawberry p l a n t s were propagated e i t h e r by d i v i s i o n of branch crowns or by r o o t i n g the s t o l o n s . They were p l a n t e d i n 12 cm pots c o n t a i n i n g a mixture of s o i l , p e r l i t e and peat (5:1:1), and grown i n the greenhouse at A g r i c u l t u r e Canada, Vancouver B.C., under i n s e c t - f r e e c o n d i t i o n s . The o c c a s i o n a l appearance of the twospotted s p i d e r mite (Tetranychus urticae Koch) on the p l a n t s was c o n t r o l l e d by fumigation with methylbromide. Every three weeks the p l a n t s were f e r t i l i z e d with NPK (20:20:20). Powdery mildew, Sphaerotheca macularis ( W a l l r . ex Fr.) J a c z . f . sp. fragariae, was c o n t r o l l e d by d u s t i n g the p l a n t s with s u l f u r . For a l l experiments, the p l a n t s were maintained i n a walk-in growth chamber at 21° +1° C, 65% RH and a 16:8 LD photo p e r i o d . 32 F i g . 3 The c o l l e c t i o n s i t e s of Fragaria chiloensis, from Vancouver I s l a n d and a long the southwestern c o a s t of B r i t i s h C o l u m b i a . 33 34 3.2 Q u a n t i f i c a t i o n of P h e n o l i c s from Strawberry F o l i a g e P h e n o l i c c o n t e n t of s t r a w b e r r y f o l i a g e was d e t e r m i n e d c o l o r i m e t r i c a l l y i n f i v e s e p a r a t e e x p e r i m e n t s performed d u r i n g September 1985, June and J u l y 1986, and J a n u a r y and March 1987. In two e x p e r i m e n t s l e a f t i s s u e used f o r the c o l o r i m e t r i c e s t i m a t i o n of p h e n o l i c s was t a k e n from l e a v e s r e p r e s e n t i n g t h r e e d i s t i n c t age c l a s s e s : young ex p a n d i n g , young f u l l y expanded and o l d l e a v e s . In the r e m a i n i n g e x p e r i m e n t s o n l y e x t r a c t s from young f u l l y expanded l e a f l e t s were a n a l y z e d . From each l e a f l e t two d i s k s were punched out w i t h a c o r k b o r e r (3 mm d i a ) and the p h e n o l i c s were e x t r a c t e d s e p a r a t e l y from each d i s k u s i n g 2.5 ml of 25% aqueous MeOH. The samples were brought t o a b o i l , then the t e m p e r a t u r e was reduced and kept a t 60^ C o v e r n i g h t . The e x t r a c t s were brought back t o the i n i t i a l volume, then 0.5 ml and 1.0 ml a l i q u o t s were taken and assayed c o l o r i m e t r i c a l l y f o r t o t a l p h e n o l i c s and f o r c a t e c h o l - b a s e d p h e n o l i c s r e s p e c t i v e l y . F o l i n - C i o c a l t e a u reagent was used to e s t i m a t e t o t a l f o l i a r p h e n o l i c s ( S i n g l e t o n and R o s s i , 1965). Ammonium molybdate reagent was used f o r the e s t i m a t i o n of c a t e c h o l - based p h e n o l i c s (Pesez and B a r t o s , 1974). The l a t t e r method g i v e s a v i s i b l e c o l o r o n l y i n the p r e s e n c e of two a d j a c e n t p h e n o l i c h y d r o x y l groups ( o r t h o -d i h y d r o x y s u b s t i t u t i o n ) , and does not r e a c t w i t h p h e n o l i c s b e a r i n g o t h e r s u b s t i t u t i o n p a t t e r n s . E s t i m a t i o n s of p h e n o l i c c o n t e n t were based on a s t a n d a r d c u r v e f o r c h l o r o g e n i c a c i d . C o n c e n t r a t i o n s of p h e n o l i c compounds are 35 expressed as the percentage of the f r e s h weight (%fwt) of l e a f t i s s u e . 3.3 R e a r i n g of Twospotted S p i d e r M i t e s O v i p o s i t i o n and developmental r a t e i n the twospotted s p i d e r mite Tetranychus urticae i s s e n s i t i v e to a v a r i e t y of i n t r i n s i c and e x t r i n s i c c o n d i t i o n s . The e x t r i n s i c f a c t o r s i n c l u d e temperature, humidity, photoperiod and v a r i o u s f e a t u r e s of the host p l a n t . Among i n t r i n s i c f a c t o r s are the mite's genome and l e v e l of i n b r e e d i n g , colony d e n s i t y , age of the female and i t s ' f e r t i l i z a t i o n s t a t u s as w e l l as v a r i o u s a s p e c t s of mite behavior (Van de V r i e et al ., 1972; Crooker, 1985). To study s p i d e r mite responses to one of the e x t r i n s i c f a c t o r s alone, r e q u i r e s that the remaining f a c t o r s be kept as constant as p o s s i b l e . T h e r e f o r e the mites used i n the assessment of o v i p o s i t i o n a l performance among strawberry clones were reared i n an environmental chamber at 20° +2° C, approximately 65% RH, and a 16:8 LD photoperiod. For each experiment a new colony of mites was e s t a b l i s h e d . Detached l e a f l e t s of a s i n g l e F. chiloensis clone were used to rear the mites. To a v o i d p o s s i b l e p r e f e rence f o r t h i s c l o n e , r e s u l t i n g from the r e a r i n g regime, i t was not i n c l u d e d as a t e s t clone i n the experiments. A mature l e a f l e t from t h i s c l o n e was p o s i t i o n e d with the a b a x i a l s u r f a c e uppermost on a water s a t u r a t e d c o t t o n pad con t a i n e d i n a 15 cm p e t r i d i s h . Adult female mites were t r a n s f e r r e d to the l e a f l e t s and allowed to o v i p o s i t f o r a p e r i o d of 48 hours. Subsequent development of these eggs r e s u l t e d i n a cohort of evenly-aged mites. Three day-old (+1 day) females were used f o r the o v i p o s i t i o n experiments. Mites f o r the developmental r a t e experiments were reared i n the same way except that the parent females were unmated, so t h e i r progeny were a l l h a p l o i d males. Neonate l a r v a e were used i n the development experiments. 3.4 Screening Fragaria chiloensis For Mite R e s i s t a n c e . The o v i p o s i t i o n a l performance of T. urticae was chosen as the c r i t e r i o n to screen the c o l l e c t i o n of F. chiloensis f o r mite r e s i s t a n c e . The 63 c l o n e s of F. chiloensis and the "Totem" c u l t i v a r were arranged i n three blocks i n a randomized complete block d e s i g n . Blocks were maintained i n the greenhouse dur i n g establishment of the p l a n t s and i n the growth chamber d u r i n g the execution of the experiments. One three day-old female mite was t r a n s f e r r e d to the lower s u r f a c e of a young f u l l y expanded l e a f l e t on each p l a n t . A f t e r 72 hours, the female was removed and her eggs were counted. Mite movement on a l e a f l e t was r e s t r i c t e d by a t t a c h i n g a 2.3 cm diameter c l i p - o n cage. Based on the r e s u l t s of t h i s experiment, nineteen clones of F. chiloensis were chosen from the o r i g i n a l c o l l e c t i o n to represent a spectrum of mite r e s i s t a n c e w i t h i n F. chiloensis f o r the f o l l o w i n g experiments. 37 3.5 I n t e r - a n d I n t r a - c l o n a l V a r i a t i o n i n P h e n o l i c C o n c e n t r a t i o n s An experiment was d e s i g n e d t o a s s e s s d i f f e r e n c e s i n the c o n c e n t r a t i o n s of the p h e n o l i c compounds among and w i t h i n 15 c l o n e s of F. chiloensis and c v . "Totem". Four c l o n e s of F. chiloensis were e x c l u d e d from the experiment as they had v i s i b l e symptoms of powdery mildew. The experiment was r e p l i c a t e d t h r e e t i m e s i n a c o m p l e t e l y random d e s i g n . Leaf t i s s u e from t h r e e d i s t i n c t age c l a s s e s and t h r e e subsamples w i t h i n each age c l a s s was a n a l y z e d f o r c o n c e n t r a t i o n s of t o t a l p h e n o l i c s and c a t e c h o l - b a s e d p h e n o l i c s u s i n g the c o l o r i m e t r i c methods d e s c r i b e d i n s e c t i o n 3.2. 3.6 S e p a r a t i o n and Q u a l i t a t i v e A n a l y s i s of S t r a w b e r r y F o l i a r P h e n o l i c s w i t h HPLC Three c l o n e s of F. chiloensis ( c l o n e 20\PP, 119\MM and 52\E) and c v . "Totem" were chosen f o r a n a l y s i s v i a h i g h performance l i q u i d chromatography (HPLC). The chosen c l o n e s r e p r e s e n t e d s u s c e p t i b l e , m o d e r a t e l y r e s i s t a n t and r e s i s t a n t c l o n e s , r e s p e c t i v e l y (Sec. 3.4). For each c l o n e , 200mg of f r e s h t i s s u e from young f u l l y expanded l e a v e s c o l l e c t e d from s e v e r a l p l a n t s , was e x t r a c t e d i n 2.5ml of 25% MeOH. The samples were brought t o a b o i l then the temp e r a t u r e was reduced and kept a t 60^C o v e r n i g h t . The e x t r a c t s were brought back t o the i n i t i a l volume of 2.5ml and then c e n t r i f u g e d a t 2000 rpm (15000 g) f o r 15 minutes t o remove the s o l i d s . P a r t of the e x t r a c t from c v . "Totem" was mixed 38 w i t h 10% (w/v) Dowex 1-X8 a n i o n exchange r e s i n , which i s known t o complex r e a d i l y w i t h p h e n o l i c compounds (Lam and Shaw, 1970). The s u s p e n s i o n was shaken twenty m i n u t e s , c e n t r i f u g e d a t 2000 rpm f o r 15 minutes and f i l t e r e d u s i n g a 0.45 um m i l i p o r e f i l t e r . Twenty u l of each e x t r a c t were used f o r HPLC a n a l y s i s . The HPLC system c o n s i s t e d of a Waters 840 l i q u i d chromatograph equipped w i t h a model M490 programmable m u l t i w a v e l e n g t h UV d e t e c t o r and a Rheodyne 7125 i n j e c t o r . Data i n t e g r a t i o n was performed on a D i g i t a l PDP-11 computer u s i n g the Waters " E x p e r t " chromatography program. The f o l i a r e x t r a c t s were r e s o l v e d on a 3.9mm x 15cm column of NOVAPACK C18 ( r e v e r s e d phase w i t h a p a r t i c l e s i z e of 4 m i c r o n s ) , u s i n g a g r a d i e n t s o l v e n t system of methanol and 2% aqueous a c e t i c a c i d . UV absorbance was m o n i t o r e d a t 254 nm. The s o l v e n t program c o n s i s t e d of a l i n e a r g r a d i e n t of 0-6% methanol i n 12 minutes f o l l o w e d by a convex n o n l i n e a r g r a d i e n t of 6-70% methanol f o r an a d d i t i o n a l 80 m i n u t e s . The f l o w r a t e was 0.4 ml/min. The e x t r a c t s were chromatographed i n d i v i d u a l l y and co-chromatographed as a 1:1 m i x t u r e of e x t r a c t s from the "Totem" c u l t i v a r and one of the t h r e e F. chiloensis c l o n e s . T h i s method a l l o w e d d e t e c t i o n of q u a l i t a t i v e d i f f e r e n c e s between the two s p e c i e s . R e s u l t s of the p h e n o l i c a n a l y s e s a r e t h e r e f o r e p r e s e n t e d i n t h r e e s e t s of chromatographs, each s e t c o n t a i n i n g chromatographs f o r cv. "Totem", one of the F. chiloensis c l o n e s , and t h e i r b i n a r y m i x t u r e , 39 r e s p e c t i v e l y . P - h y d r o x y b e n z o i c a c i d , ( + ) - c a t e c h i n , c h l o r o g e n i c a c i d , and r u t i n were co-chromatographed as s t a n d a r d s . 3.7 M i t e P o p u l a t i o n Parameters i n R e l a t i o n t o P l a n t Defences 3.7 .1 M i t e O v i p o s i t i o n and S u r v i v a l The f o l l o w i n g experiment was d e s i g n e d t o more c l o s e l y examine s p i d e r m i t e o v i p o s i t i o n a l performance and t o a s s e s s m i t e s u r v i v a l among 19 c l o n e s of F. chiloensis and c v . "Totem", s e l e c t e d i n the p r e v i o u s s e c t i o n ( 3 . 4 ) . These p l a n t s were t e s t e d i n a randomized complete b l o c k d e s i g n which was r e p l i c a t e d t e n t i m e s . B l o c k s were m a i n t a i n e d i n the greenhouse d u r i n g p r o p a g a t i o n and the growth chamber d u r i n g the e x p e r i m e n t . Two young but f u l l y expanded l e a f l e t s were chosen from each p l a n t ; one f o r the assessment of m i t e o v i p o s i t i o n , the o t h e r f o r the assessment of m i t e s u r v i v a l . O v i p o s i t i o n was d e t e r m i n e d as d e s c r i b e d i n s e c t i o n 3.4. S u r v i v a l was a s s e s s e d by t r a n s f e r r i n g one t o t h r e e , d a y - o l d female m i t e s t o the lower s u r f a c e of young f u l l y expanded l e a f l e t s . M i t e movement was r e s t r i c t e d by a t t a c h i n g a c l i p cage t o the l e a f l e t . A f t e r 48 hours the females and a l l but ten eggs were removed from each l e a f l e t . Ten days l a t e r the number of m i t e s found dead and t r a p p e d t o the s u r f a c e of the l e a f l e t s were counted. S u r v i v a l was e x p r e s s e d as the d i f f e r e n c e between the i n i t i a l number of eggs and f i n a l number of dead, t r a p p e d m i t e s . 40 The d e n s i t i e s of g l a n d u l a r and nonglandular trichomes and the c o n c e n t r a t i o n s of p h e n o l i c compounds were determined as f a c t o r s of p l a n t r e s i s t a n c e . Measurements of these c h a r a c t e r i s t i c s were always taken from the area under the c l i p cage. The d e n s i t i e s of trichomes were determined c o n s i s t e n t l y from the same three l o c a t i o n s on the a b a x i a l l e a f s u r f a c e : c l o s e to the midvein, c l o s e to the edge of the l e a f l e t , and between v e i n s i n the middle of the l e a f l e t ( F i g . 4). The d e n s i t i e s r e p o r t e d represent the mean of these three measurements. Trichome counts were made using a b i n o c u l a r microscope at 100 X m a g n i f i c a t i o n . Scanning e l e c t r o n microscopy (SEM) was used to examine the accumulation of g l a n d u l a r trichome exudates on mite t a r s i . The same technique was a l s o used to study the s t r u c t u r a l d i f f e r e n c e s i n g l a n d u l a r trichomes between F. chiloensis c l o n e s 85\D and 72\J. C o n c e n t r a t i o n s of f o l i a r p h e n o l i c s were a s s e s s e d by punching out l e a f d i s k s from the d e s i g n a t e d l e a f area and a n a l y z i n g the d i s k e x t r a c t s with the F o l i n -C i o c a l t e a u and Ammonium-Molybdate methods. Only the d e n s i t y of g l a n d u l a r trichomes was determined from the l e a f l e t s used to a ssess mite s u r v i v a l . 3.7.2 E f f e c t of P h e n y l a l a n i n e or Q u i n i c A c i d Treatment on C o n c e n t r a t i o n s of "Totem" Leaf P h e n o l i c s Accumulation of phenylpropanoids i n higher p l a n t s i s known to be c o n t r o l l e d at the l e v e l of s u b s t r a t e ( p h e n y l a l a n i n e ) supply (Margna, 1977). Therefore exogenous .4 Three l o c a t i o n s on the a b a x i a l s u r f a c e of a l e a f l e t from which d e n s i t i e s of g l a n d u l a r and nonglandular trichomes were determined. 42 supp ly of p h e n y l a l a n i n e or o ther s u b s t r a t e p r e c u r s o r s , u s u a l l y s t i m u l a t e s a c c u m u l a t i o n of p h e n y l p r o p a n o i d s i n a v a r i e t y of p l a n t s p e c i e s (Towers, 1964; Margna, 1977). To i n v e s t i g a t e the e f f e c t s of such t rea tments on s t r a w b e r r y , p l a n t s of the "Totem" c u l t i v a r were t r e a t e d w i th aqueous s o l u t i o n s of p h e n y l a l a n i n e or q u i n i c a c i d . S i x t r e a t m e n t s , aqueous s o l u t i o n of p h e n y l a l a n i n e ( 5 x 1 M and 10~ 2 M) , q u i n i c a c i d ( 5 X 1 0 ~ 3 M, 2 X 1 0 ~ 2 M and 10~ 2 M) and d i s t i l l e d water as the c o n t r o l were a p p l i e d in a c o m p l e t e l y randomized d e s i g n r e p l i c a t e d four t i m e s . Four subsamples of the l e a f t i s s u e from each of t h r e e age c a t e g o r i e s , young not expanded, young f u l l y expanded and o l d l e a v e s were c o l l e c t e d at f i r s t , t h i r d ' a n d f i f t h day a f t e r i n i t i a l a p p l i c a t i o n of the s o l u t i o n s . P h e n o l i c c o n c e n t r a t i o n s were determined u s i n g the c o l o r i m e t i c method d e s c r i b e d in s e c t i o n 3 . 2 . Po tass ium c a r b o n a t e was used to a d j u s t the pH of s o l u t i o n s to 5 . 5 . Treatments were a p p l i e d to the s t rawber ry r o o t s f o r f i v e c o n s e c u t i v e days (12 hours per d a y ) , u s i n g the double p o t s method d e s c r i b e d by C a r r a s c o et a l . , (1978) . 3 . 7 . 3 P h e n o l i c C o n c e n t r a t i o n s and M i t e Development The f o l l o w i n g exper iment was d e s i g n e d to examine the r e l a t i o n s h i p between c o n c e n t r a t i o n s of f o l i a r p h e n o l i c s the development of the twospot ted s p i d e r m i t e . In a d d i t i o n , the e f f e c t s of p h e n y l a l a n i n e or q u i n i c a c i d t rea tments and s p i d e r mite f e e d i n g on c o n c e n t r a t i o n s of f o l i a r p h e n o l i c s were examined. 43 A one-way f a c t o r i a l experiment was conducted i n January 1986. Two mite i n f e s t a t i o n l e v e l s (1 neonate male m i t e / l e a f l e t and 0 m i t e s / l e a f l e t ) were combined with three q u a l i t a t i v e treatments: aqueous s o l u t i o n of p h e n y l a l a n i n e (10~ 2 M), q u i n i c a c i d (2x10~ 2 M) and d i s t i l l e d water as the c o n t r o l . Treatments and l e v e l s were arranged i n a randomized complete block design with s i x r e p l i c a t i o n s i n each of three b l o c k s . Neonate male l a r v a e were t r a n s f e r r e d to l e a f l e t s and c l i p cages were atta c h e d to each l e a f l e t to r e s t r i c t mite movement. E s t i m a t i o n of p h e n o l i c c o n c e n t r a t i o n s was performed on three sampling days (4,7 and 12 days a f t e r a p p l i c a t i o n of t r e a t m e n t s ) , each time e x c i s i n g one l e a f l e t from the chosen l e a f . The a p p l i c a t i o n of treatments was as d e s c r i b e d i n s e c t i o n 3.7.2. Numbers and developmental stages of the male mites which fed on the l e a f l e t s f o r e i g h t days were recorded. The c o l o r i m e t r i c data were analyzed by ANOVA to examine the e f f e c t s of v a r i o u s treatments on the c o n c e n t r a t i o n of f o l i a r p h e n o l i c s . To determine the r e l a t i o n s h i p between the l a t t e r and mite developmental stages, data were analyzed by l o g i s t i c r e g r e s s i o n (SAS, P r o c e d u r e : L o g i t ) . The experiment was repeated u s i n g the same methods and treatments. However, p l a n t s without mites were not i n c l u d e d in the d e s i g n . 44 3.8 Data A n a l y s e s U n i v a r i a t e a n a l y s i s of v a r i a n c e (ANOVA) was a p p l i e d t o the d a t a t o d e t e c t b o t h d i f f e r e n c e s i n s e l e c t e d p l a n t c h a r a c t e r i s t i c s among s t r a w b e r r y c l o n e s and d i f f e r e n c e s i n examined m i t e r e s p o n s e s . R e g r e s s i o n a n a l y s e s were used t o d e f i n e r e l a t i o n s h i p s between s p e c i f i c p l a n t c h a r a c t e r i s t i c s and t w o s p o t t e d s p i d e r m i t e r e s p o n s e s . When n e c e s s a r y , d a t a t r a n s f o r m a t i o n s were performed t o a s s u r e random d i s t r i b u t i o n of r e s i d u a l s . The l o g i s t i c model ( C h a t t e r j e e and P r i c e , 1977) was used t o a n a l y z e c a t e g o r i c a l d a t a , u s i n g the s t a t i s t i c a l a n a l y s i s system (SAS P r o c e d u r e : L o g i t ) . The d a t a were t r a n s f o r m e d f o r a n a l y s i s u s i n g the L o g i t t r a n s f o r m a t i o n (1) and then t r a n s f o r m e d back t o the o r i g i n a l s c a l e f o r p r e s e n t a t i o n of the r e s u l t s . Parameters f o r the l o g i s t i c models were d e f i n e d u s i n g the p r i n c i p l e of maximum-l i k e l i h o o d . Y N= Ln (Y / 1 - Y) ( 1 ) Where Y' i s the p r o b a b i l i t y of r e a c h i n g one of t h r e e d e v e l o p m e n t a l s t a g e s (Y) f o r the l a r v a e r e a r e d on a l e a f l e t w i t h a known c o n c e n t r a t i o n of p h e n o l i c s . 45 4. RESULTS 4.1 S c r e e n i n g Fragaria chiloensis f o r Mite R e s i s t a n c e The number of eggs d e p o s i t e d by female s p i d e r m i t e s w i t h i n 72 hours ranged from 2.6 t o 29.3 and was s i g n i f i c a n t l y d i f f e r e n t (P<0.01) between s t r a w b e r r y c l o n e s (Table 4, Appendix 4.1). There were a l s o s i g n i f i c a n t d i f f e r e n c e s (P< 0.05) i n m i t e o v i p o s i t i o n due t o b l o c k e f f e c t s . The r e s u l t s suggest t h a t m i t e o v i p o s i t i o n a l performance i s s t r o n g l y i n f l u e n c e d by g e n e t i c a l l y d i f f e r e n t s t r a w b e r r y c l o n e s and t o a l e s s e r degree by the growth regime of a p a r t i c u l a r c l o n e . 4.2 Inter-and I n t r a - c l o n a l V a r i a t i o n i n P h e n o l i c C o n c e n t r a t i o n s Amongst 15 c l o n e s of F. chiloensis and the "Totem" c u l t i v a r , the mean c o n c e n t r a t i o n of t o t a l p h e n o l i c s ranged from 1.3% t o 2.8% f r e s h w e i g h t . For the same p l a n t m a t e r i a l mean c o n c e n t r a t i o n of c a t e c h o l based p h e n o l i c s ranged from 0.6% t o 1.3% f r e s h w e i g h t . C o n c e n t r a t i o n s of f o l i a r p h e n o l i c s , measured w i t h e i t h e r r e a g e n t , d i f f e r e d s i g n i f i c a n t l y (P< 0.01) among c l o n e s of F. chiloensis and the "Totem" c u l t i v a r but were not s t a t i s t i c a l l y d i f f e r e n t (P> 0.05) f o r p l a n t s w i t h i n a c l o n e ( T a b l e 5; Appendices 5.1, 5.2). P h e n o l i c c o n c e n t r a t i o n s d i f f e r e d s i g n i f i c a n t l y (P< 0.001) among young exp a n d i n g , young f u l l y expanded, and o l d l e a v e s . The young 46 Table 4. D i f f e r e n c e s i n m i t e o v i p o s i t i o n among 63 c l o n e s of F r a g a r i a c h i l o e n s i s and the "Totem" c u l t i v a r . Source of v a r i a t i o n DF MS F v a l u e B l o c k 2 108.07 3.90 * Clone 63 88.39 3.19 *** E r r o r 126 27.65 s i g n i f i c a n t a t 5%, 1% and 0.01%, r e s p e c t i v e l y . 47 T a b l e 5. Experiment 1: D i f f e r e n c e s i n the c o n c e n t r a t i o n (% fwt) of f o l i a r p h e n o l i c s , measured with F o l i n -C i o c a l t e a u and Ammonium-Molybdate reagents. Source Method of p h e n o l i c s ' assay of Ammon i um-Mo1y bda t e F o l i n - C i o c a l t e a u v a r i a t i o n DF MS E r r o r F value MS E r r o r F value Clone (C) 1 5 0. 85 P/C 2.8 ** 4 .44 P/C 2 .8 ** P l a n t ( P ) / C l o n e 32 0. 29 A*P/C 1 .5 NS 1 .55 A* P/C 1 .2 NS Age (A) 2 2. 70 A* P/C 13. g *** 17 .76 A*P/C 1 3 .9 *** Age*Clone 30 0. 40 A*P/C 2.0 ** 1 .62 A*P/C 1 .2 NS Age*P/Clone 64 0. 19 E r r o r 5.6 * * * 1 .27 E r r o r 1 1 . 1 *** E r r o r 288 0. 03 — 0 . 1 1 -- • *,**,***,NS S i g n i f i c a n t at 5%, 1%, 0.1% and not s i g n i f i c a n t , r e s p e c t i v e l y . 48 expanding l e a v e s always had h i g h e r mean c o n c e n t r a t i o n s of p h e n o l i c s than e i t h e r of the two r e m a i n i n g l e a f ages: 2.59% compared t o 1.92% and 2.06% f r e s h weight f o r F o l i n -C i o c a l t e a u reagent and 1.28% compared t o 1.01% and 1.09% f r e s h weight f o r Ammonium Molybdate r e a g e n t . The Age*Clone i n t e r a c t i o n was s i g n i f i c a n t (P< 0.01) o n l y f o r the c a t e c h o l -based p h e n o l i c s . The A g e * P l a n t / C l o n e i n t e r a c t i o n , however, was s i g n i f i c a n t (P< 0.001) when measured w i t h e i t h e r of the r e a g e n t s . R e s u l t s from t h i s e xperiment suggest the e x i s t e n c e of c l e a r d i f f e r e n c e s i n the c o n c e n t r a t i o n of f o l i a r p h e n o l i c s among g e n e t i c a l l y d i f f e r e n t c l o n e s and w i t h i n p l a n t s among d i f f e r e n t l e a f ages.. 4.3 Q u a l i t a t i v e A n a l y s i s of S t r a w b e r r y F o l i a r P h e n o l i c s v i a HPLC The v a s t m a j o r i t y of compounds s e p a r a t e d v i a HPLC were removed from the e x t r a c t of the "Totem" c u l t i v a r , when the e x t r a c t was mixed w i t h Dowex 1-X8 a n i o n exchange r e s i n ( F i g . 5 ) . T h i s r e s u l t a l o n g w i t h the method of e x t r a c t i o n and UV a b s o r p t i o n c h a r a c t e r i s t i c s , s t r o n g l y s u g g e s t s t h a t the U V - v i s i b l e components of the "Totem" e x t r a c t b e l o n g t o the c l a s s of p h e n o l i c compounds. The s e p a r a t i o n of t h e s e compounds v i a HPLC r e v e a l e d the presence of over t h i r t y p eaks, which appear on the chromatographs i n o r d e r of d e c r e a s i n g p o l a r i t y ( F i g s . 6, 7 and 8 ) . Q u a l i t a t i v e 49 comparisons i n d i c a t e a c l o s e resemblance between the two s t r a w b e r r y s p e c i e s , F.x ananassa ("Totem") and F. chiloensis ( c l o n e 20\PP, 52\E and 119\MM) and among c l o n e s of F. chiloensis. However, q u a l i t a t i v e and q u a n t i t a t i v e d i f f e r e n c e s between the s e s p e c i e s o c c u r . For example, comparison of the c h r o m a t o g r a p h i c s e p a r a t i o n of b i n a r y m i x t u r e s of p l a n t e x t r a c t s w i t h t h e i r component, pure e x t r a c t s r e v e a l e d the presence of a unique peak f o r the "Totem" c u l t i v a r a t 37.03 min and the presence of a unique peak f o r F. chiloensis a t a p p r o x i m a t e l y 38.5 min. F u r t h e r m o r e , comparison of the p r o f i l e s of p h e n o l i c compounds between the s e two s p e c i e s i n d i c a t e t h a t some peaks c o n t r i b u t e more towards t o t a l p h e n o l i c c o n c e n t r a t i o n i n one s p e c i e s than i n the o t h e r . For example, the unknown peak a t 40.98 min i n F. chiloensis c o n t r i b u t e s more towards the t o t a l c o n c e n t r a t i o n than the same peak (40.96 min) i n F. x ananassa. From about f o r t y UV a b s o r b i n g peaks p r e s e n t i n each chromatograph, f o u r were t e n t a t i v e l y i d e n t i f i e d as p - h y d r o x y b e n z o n i c a c i d , ( + ) - c a t e c h i n , c h l o r o g e n i c a c i d , and r u t i n as they co-chromatographed w i t h pure s t a n d a r d s of t h e s e p h e n o l i c compounds. The r e t e n t i o n times and peak a r e a s f o r each s e t of chromatographs are p r e s e n t e d i n Appendices 4.3.1, 4.3.2 and 4.3.3. 50 F i g . 5 S e p a r a t i o n of compounds from f o l i a r e x t r a c t s of the "Totem" c u l t i v a r , t h a t were p r e v i o u s l y mixed w i t h Dowex 1-X8 a n i o n exchange r e s i n . 51 732.600 -1.50O 10 15 £0 Minutes Peak Name Ret t ime A r e a Heiqht T v p e RF Unknown peak 1 .36 133350 10463 BB 0 . 0G00e+00 Unknown peak 3.12 53213 5704 0 . 0 000e+00 Unknown peak 3.43 703284 42125 VB 0 . 0000e+00 Unknown peak 23.73 216354 13226 BB 0 .0 000e+00 Unknown peak 25.22 132326 12751 BB 0 .0000e+00 •Unknown peak 23 .36 3362783 73204 BB 0 . 0000e+00 52 F i g . 6 S e p a r a t i o n of p h e n o l i c s from f o l i a r e x t r a c t s of the "Totem" c u l t i v a r , F r a g a r i a c h i l o e n s i s c l o n e 119\MM and t h e i r b i n a r y m i x t u r e , r e s p e c t i v e l y . Z*S5.000 1245. OOq -5.000 F.i inanissa 'Tatet' - 4 - [LA i i 1 ~r 5 10 15 2 T 1 1 25 30 35 40 45 50 54 F i g . 7 S e p a r a t i o n of p h e n o l i c s from f o l i a r e x t r a c t s of the "Totem" c u l t i v a r , Fragaria chiloensis c l o n e 20\PP and t h e i r b i n a r y m i x t u r e , r e s p e c t i v e l y . 1495.0'X-I F.i m i n i s Si 'Totei' Binutfs F i g . 8 S e p a r a t i o n of p h e n o l i c s from f o l i a r e x t r a c t s of the "Totem" c u l t i v a r , Fragaria chiloensis c l o n e 52\E and t h e i r b i n a r y m i x t u r e , r e s p e c t i v e l y . 2495.000 ~1 F.i i n i n i s s i 'Tate*' 2435.000 ~] • F.chiloensis Clone 52 Ninutes 58 4.4 Mite P o p u l a t i o n Parameters in R e l a t i o n to P l a n t Defences 4.4.1 Mite O v i p o s i t i o n A n a l y s i s of v a r i a n c e r e v e a l e d s i g n i f i c a n t d i f f e r e n c e s (P< 0.001) i n the d e n s i t i e s of both g l a n d u l a r and n o n g l a n d u l a r t r i c h o m e s among s t r a w b e r r y c l o n e s (Table 6 ) . B l o c k s were a l s o s i g n i f i c a n t l y d i f f e r e n t (P< 0.001). The r e s u l t s i n d i c a t e t h a t s t r a w b e r r y pubescence i s a h i g h l y v a r i a b l e p l a n t c h a r a c t e r i s t i c and t h a t the d i f f e r e n c e s r e s u l t from both g e n e t i c f a c t o r s and growth c o n d i t i o n s . The number of eggs o v i p o s i t e d by female s p i d e r m i t e s was s i g n i f i c a n t l y i n f l u e n c e d by s t r a w b e r r y c l o n e (P< 0.001) and b l o c k i n g (P> 0.01). T h i s r e s u l t was c o n s i s t e n t w i t h t h a t from the i n i t i a l s c r e e n i n g experiment ( S e c . 4 . 1 ) . In both e x p e r i m e n t s , m i t e o v i p o s i t i o n a l performance was a f f e c t e d by s t r a w b e r r y c l o n e and t o the l e s s e r degree by the growth c o n d i t i o n of t h e s e p l a n t s . C o n c e n t r a t i o n s of t o t a l and c a t e c h o l - b a s e d p h e n o l i c s v a r i e d s i g n i f i c a n t l y (P<0.01) among s t r a w b e r r y c l o n e s (Table 7 ) . There were a l s o s i g n i f i c a n t d i f f e r e n c e s (P< 0.01) i n p h e n o l i c c o n c e n t r a t i o n s r e s u l t i n g from b l o c k e f f e c t s . R e s u l t s from t h i s experiment are i n a c c o r d w i t h the p r e v i o u s f i n d i n g s (Sec. 4.2) and i n d i c a t e t h a t c l e a r d i f f e r e n c e s do e x i s t among s t r a w b e r r y c l o n e s , and among p l a n t s e x p e r i e n c i n g d i f f e r e n t growth c o n d i t i o n s . Simple l i n e a r r e g r e s s i o n r e v e a l e d a s i g n i f i c a n t (P<0.01), n e g a t i v e r e l a t i o n s h i p between m i t e o v i p o s i t i o n and t h e d e n s i t y of g l a n d u l a r t r i c h o m e s ( F i g . 9 ) . M i t e T a b l e 6. D i f f e r e n c e s i n d e n s i t i e s of g l a n d u l a r and n o n g l a n d u l a r t r i c h o m e s and number of t w o s p o t t e d s p i d e r m i t e eggs. Source of D e n s i t y (no./5mm^) of Trichomes Number of v a r i a t i o n N o n g l a n d u l a r G l a n d u l a r Eggs/72 hours DF MS F v a l u e MS F v a l u e MS F v a l u e B l o c k 9 1436.5 4.1 *** 4864.5 3.9 *** 93.6 2.6 ** Clone 19 3601.0 10.4 *** 43386.0 34.8 *** 408.6 11.3 *** E r r o r 171 343.4 ~ 1245.8 — 35.9 -- . **^*** s i g n i f i c a n t a t 1% and 0.1% l e v e l , r e s p e c t i v e l y . T a b l e 7. Experiment 2 : D i f f e r e n c e s i n the c o n c e n t r a t i o n (% fwt) of the f o l i a r p h e n o l i c s measured w i t h Ammonium-Molybdate and F o l i n - C i o c a l t e a u r e a g e n t s . Source Method of p h e n o l i c s ' assay of F o l i n - C i o c a l . Amm. Molybdate v a r i a t i o n DF MS F v a l u e MS F v a l u e . B l o c k 9 1.52 3.90 ** 0.76 12.84 *** Clone 19 1.50 3.85 ** 0.17 2.96 ** E r r o r 171 0.39 — 0.05 ~ **,*** S i g n i f i c a n t a t 1% and 0.1% l e v e l , r e s p e c t i v e l y . 61 F i g . 9 The r e l a t i o n s h i p between s p i d e r m i t e o v i p o s i t i o n and the d e n s i t y of g l a n d u l a r t r i c h o m e s . 62 63 o v i p o s i t i o n was a l s o n e g a t i v e l y c o r r e l a t e d (P<0.5) w i t h the d e n s i t y of n o n g l a n d u l a r t r i c h o m e s ( F i g . 10). The e f f e c t of g l a n d u l a r t r i c h o m e s on m i t e o v i p o s i t i o n appears t o be of a m e c h a n i c a l n a t u r e . The g l a n d u l a r t r i c h o m e s exude a s t i c k y m a t e r i a l which c o l l e c t s on m i t e s t o form an a d h e s i v e c o a t i n g around the t a r s i ( F i g s . 11 a , b ) , which h i n d e r s m i t e movement. R e d u c t i o n i n m i t e o v i p o s i t i o n may r e s u l t from s t r e s s a s s o c i a t e d w i t h encumbered movement and s t r u g g l i n g . However, the e f f e c t of s t i c k y exudates appears t o be p r o p o r t i o n a l t o the amount of exudates accumulated around the t a r s i . Only e x c e s s i v e a c c u m u l a t i o n of a d h e s i v e exudate can r e s u l t i n entrapment t o the l e a f s u r f a c e and the death of the m i t e . In s p i t e of the e x i s t a n c e of a h i g h l y s i g n i f i c a n t r e l a t i o n s h i p between m i t e o v i p o s i t i o n and d e n s i t y of g l a n d u l a r t r i c h o m e s , o n l y 32% of the v a r i a t i o n i n mite o v i p o s i t i o n i s e x p l a i n e d by the r e g r e s s i o n model. To i n v e s t i g a t e t h i s phenomenon i n more d e t a i l I photographed the f o l i a r s u r f a c e of c l o n e 85/D and 12/3. Both c l o n e s had a p p r o x i m a t e l y the same mean d e n s i t y of g l a n d u l a r t r i c h o m e s (145.9 and 151.6 per 5mm2) but the o v i p o s i t i o n a l response of female m i t e s t o these c l o n e s was s u b s t a n t i a l l y d i f f e r e n t ; 2.6 eggs compared t o 17.9 eggs, r e s p e c t i v e l y ( F i g . 12 a , b ) . F i g u r e 12 a and b show the l e a f s u r f a c e of t h e s e s t r a w b e r r y c l o n e s a t m a g n i f i c a t i o n s of 200 X and 500 X. There appear t o be no s u b s t a n t i a l d i f f e r e n c e s e i t h e r i n the shape or i n the d e n s i t y of t r i c h o m e s , s u g g e s t i n g t h a t o t h e r f a c t o r s i n f l u e n c e d m ite o v i p o s i t i o n . 64 F i g . 1 0 The r e l a t i o n s h i p between s p i d e r mite o v i p o s i t i o n and the d e n s i t y of n o n g l a n d u l a r t r i c h o m e s . 65 66 F i g . 1 1 The a c c u m u l a t i o n of g l a n d u l a r t r i c h o m e exudates on the a d u l t female m i t e t a r s i . A - g e n e r a l view (X 150), B - the t a r s u s c o a t e d w i t h a d h e s i v e exudate (X 1000). Fig. 1 2 The a b a x i a l f o l i a r s u r f a c e of F r a g a r i a c h i l o e n s i s c l o n e 85/D (A,a) and 72/J (B,b) a t 500 and 200 X magni f i c a t i o n . 69 70 A s i g n i f i c a n t (P<0.05), n e g a t i v e r e l a t i o n s h i p was d e t e c t e d between s p i d e r m i t e o v i p o s i t i o n and the c o n c e n t r a t i o n of t o t a l p h e n o l i c s , based on F o l i n - C i o c a l t e a u reagent ( F i g . 13). The r e l a t i o n s h i p between m i t e o v i p o s i t i o n and the c o n c e n t r a t i o n of c a t e c h o l - b a s e d p h e n o l i c s ( F i g . 14) was a l s o n e g a t i v e , but 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 (P>0.05). A l t h o u g h most of the p l a n t c h a r a c t e r i s t i c s examined were s i g n i f i c a n t l y c o r r e l a t e d w i t h m i t e o v i p o s i t i o n , none of them a l o n e i s s t r o n g l y i m p l i c a t e d i n r e s i s t a n c e t o the t w o s p o t t e d s p i d e r m i t e . O v i p o s i t i o n a l performance i s u s u a l l y a f f e c t e d by numerous c h a r a c t e r i s t i c s of a h o s t -p l a n t . A n a l y z i n g the r e l a t i o n s h i p s between m i t e o v i p o s i t i o n and each p l a n t c h a r a c t e r i s t i c a l o n e does not e x p l a i n the c o m p l e x i t y of these r e l a t i o n s h i p s . T h e r e f o r e , m u l t i p l e r e g r e s s i o n w i t h f o r w a r d s s e l e c t i o n , was used t o d e v e l o p the b e s t model f o r the p r e d i c t i o n of s p i d e r mite o v i p o s i t i o n . The v a r i a b l e s which were e n t e r e d i n t o the e q u a t i o n c o n s i s t e d of the d e n s i t i e s of both t y p e s of t r i c h o m e s , the c o n c e n t r a t i o n s of p h e n o l i c s measured w i t h each r e a g e n t , the s q u ares of each term and the i n t e r a c t i o n s terms. The f o l l o w i n g model was d e r i v e d : Y = bg + b-| x l X 2 x 3 + b 2 x 3 2 where b 0 = 6.31, b 1 = - 0.000072 and b 2 = - 1.06; the f i r s t term i n the e q u a t i o n r e p r e s e n t s the i n t e r a c t i o n between the d e n s i t i e s of g l a n d u l a r ( x ^ and n o n g l a n d u l a r ( x 2 ) t r i c h o m e s and the c o n c e n t r a t i o n of c a t e c h o l - b a s e d 71 F i g . 1 3 The r e l a t i o n s h i p between s p i d e r mite o v i p o s i t i o n and the c o n c e n t r a t i o n of t o t a l p h e n o l i c s a s s a y e d w i t h F o l i n - C i o c a l t e a u r e a g e n t . 73 F i g . 1 4 The r e l a t i o n s h i p between s p i d e r m i t e o v i p o s i t i o n and the c o n c e n t r a t i o n of c a t e c h o l - b a s e d p h e n o l i c s assayed w i t h Ammonium Molybdate r e a g e n t . 74 75 p h e n o l i c s ( x 3 ) ; the second term i n the e q u a t i o n i s t h e square term of the c o n c e n t r a t i o n of c a t e c h o l - b a s e d p h e n o l i c s and s u g g e s t s a c u r v a t u r e i n the r e l a t i o n s h i p . The model p r o v i d e s good f i t ( F i g . 15), i s s i g n i f i c a n t (P< 0.001) and e x p l a i n s 55% of the v a r i a t i o n i n s p i d e r mite o v i p o s i t i o n . T h i s r e s u l t i m p l i e s t h a t mite o v i p o s i t i o n i s be s t d e s c r i b e d by a c o m b i n a t i o n of i n t e r a c t i n g p l a n t c h a r a c t e r i s t i c s r a t h e r than by a s i n g l e c h a r a c t e r i s t i c . F i g u r e s 16, 17 and 18 i l l u s t r a t e how the r e g r e s s i o n model changes, when two i n t e r a c t i n g v a r i a b l e s a r e kept c o n s t a n t a t f i v e d i f f e r e n t l e v e l s (c) w h i l e the t h i r d v a r i a b l e changes. 4.4.2 M i t e S u r v i v a l M i t e s u r v i v a l d i f f e r e d s i g n i f i c a n t l y (P< 0.001) among 19 c l o n e s of F. chiloensis and cv. "Totem" (Table 8 ) . B l o c k e f f e c t s had no s i g n i f i c a n t i n f l u e n c e (P> 0.05) on m i t e s u r v i v a l . The d e n s i t y of g l a n d u l a r t r i c h o m e s v a r i e d s i g n i f i c a n t l y (P< 0.001) among s t r a w b e r r y c l o n e s and among b l o c k s . T h i s r e s u l t i s i n a c c o r d w i t h t h a t p r e s e n t e d i n s e c t i o n 4.4.1. There was a s i g n i f i c a n t n e g a t i v e r e l a t i o n s h i p between the d e n s i t y of g l a n d u l a r t r i c h o m e s and mit e s u r v i v a l ( F i g . 19). P h y s i c a l entrapment of m i t e s by a d h e s i v e exudates from g l a n d u l a r t r i c h o m e s appears t o account f o r the r e d u c t i o n i n mite s u r v i v a l . The v a s t m a j o r i t y of m i t e s found dead ( t r a p p e d t o the l e a f s u r f a c e ) belonged t o the l a r v a l s t a g e , i n d i c a t i n g t h a t t h i s d e v e l o p m e n t a l s t a g e i s the most v u l n e r a b l e t o i m m o b i l i z a t i o n by a d h e s i v e exudates or t o the s t r e s s a s s o c i a t e d w i t h i t . 76 F i g . 1 5 Observed mite o v i p o s i t i o n p l o t t e d a g a i n s t p r e d i c t e d o v i p o s i t i o n . The r e g r e s s i o n l i n e s y m b o l i z e s the p e r f e c t f i t . Predic ted F i g . 1 6 The r e l a t i o n s h i p between m i t e o v i p o s i t i o n and c o n c e n t r a t i o n s of c a t e c h o l - b a s e d p h e n o l i c s ( x 3 ) a t f i v e c o n s t a n t l e v e l s of the i n t e r a c t i o n g l a n d u l a r (x-,) x n o n g l a n d u l a r ( x 2 ) t r i c h o m e s (c = b 1 x 1 x 2 ) . _. Symbol c = b 1 x 1 2 £ £ - 0.033 X X ~ 0.169 0 g - 0.648 13 -0 - 1 . 1 52 £ £ - 1.980 OVIPOSITION (eggs/72 hr sqrt-trans) 80 Fig.17 The r e l a t i o n s h i p between m i t e o v i p o s i t i o n and the d e n s i t y of g l a n d u l a r t r i c h o m e s (x-j) a t f i v e c o n s t a n t l e v e l s of the i n t e r a c t i o n c o n c e n t r a t i o n of c a t e c h o l -based p h e n o l i c s ( x 3 ) x d e n s i t y of n o n g l a n d u l a r t r i c h o m e s ( x 2 ) (c = b 1 x 2 x 3 ) . The square term of the c o n c e n t r a t i o n of c a t e c h o l - b a s e d p h e n o l i c s ( x 3 2 ) i s kept c o n s t a n t a t each i n t e r a c t i o n l e v e l . Symbol c = b 1 x 2 x 3 x 3— 4 . 4 - 0.006 1.21 X X ~ 0.004 1 .44 Q Q - 0.005 1 .69 g - 0.007 1 .96 g g - 0.009 2.25 81 5 - i Density of g landular t r i chomes (no . / 5mm 2 ) 8 2 Fig.18 The r e l a t i o n s h i p between m i t e o v i p o s i t i o n and d e n s i t y of n o n g l a n d u l a r t r i c h o m e s ( x 2 ) a t f i v e c o n s t a n t l e v e l s of the i n t e r a c t i o n c o n c e n t r a t i o n of c a t e c h o l -based p h e n o l i c s ( x 3 ) x d e n s i t y of g l a n d u l a r t r i c h o m e s ( x ^ (c = b 1 x 1 x 3 ) . The square term of the c o n c e n t r a t i o n of c a t e c h o l - b a s e d p h e n o l i c s ( x 3 2 ) i s kept c o n s t a n t a t each i n t e r a c t i o n l e v e l . Symbol c = b^ x ^  x 3 x 3 — & & - 0 . 0 0 5 1.21 - 0 . 0 1 1 1 . 4 4 g JJJ - 0 . 0 1 5 1 . 6 9 g g - 0 . 0 2 1 1 . 9 6 £ - 0 . 0 3 0 2 . 2 5 83 n i i r 1 1 — 1 r -10 20 30 40 50 60 70 80 Densi ty of nonglandular tr ichomes(no./5mrr?) 84 F i g . 1 9 The r e l a t i o n s h i p between s p i d e r m i t e s u r v i v a l and the d e n s i t y of g l a n d u l a r t r i c h o m e s . 85 0.4-1 1 1 , 1 1 1 50 100 150 200 250 300 Densi ty of glandular t r i chomes (no /5mm 2 ) 86 Tab l e 8. D i f f e r e n c e s i n the d e n s i t y of g l a n d u l a r t r i c h o m e s (no.\5mm2) and mi t e s u r v i v a l . Source D e n s i t y (no.\5mm/) of M i t e of G l a n d u l a r Trichomes S u r v i v a l v a r i a t i o n DF MS F v a l u e MS F v a l u e . B l o c k 9 3490.30 3.92 *** 1.14 0.90 NS Clone 19 38740.00 43.58 *** 31.00 24.67 *** E r r o r 171 888.79 — 1.25 ***, NS S i g n i f i c a n t a t 0.01% and not s i g n i f i c a n t , r e s p e c t i v e l y . 87 4 . 4 . 3 E f f e c t of P h e n y l a l a n i n e and Q u i n i c A c i d Treatments on C o n c e n t r a t i o n s of F o l i a r P h e n o l i c s i n "Totem" P l a n t s P h e n o l i c c o n c e n t r a t i o n s d i f f e r e d s i g n i f i c a n t l y (P> 0.001) between l e a f ages and between s a m p l i n g days; (P> 0.001) f o r t o t a l and (P> 0.05) f o r c a t e c h o l - b a s e d p h e n o l i c s (Table 9; Appendices 9.1, 9.2). But t h e r e was a l a c k of correspondence between the r e s u l t s o b t a i n e d w i t h the Ammonium Molybdate and F o l i n - C i o c a l t e a u methods, w i t h r e s p e c t t o d i f f e r e n c e s i n p h e n o l i c c o n c e n t r a t i o n s r e s u l t i n g from t r e a t m e n t e f f e c t s . The r e s u l t s i n d i c a t e t h a t c o n c e n t r a t i o n s of f o l i a r p h e n o l i c s a r e a h i g h l y v a r i a b l e p l a n t c h a r a c t e r i s t i c . C o n s i d e r a b l e v a r i a t i o n i n p h e n o l i c c o n c e n t r a t i o n s i s apparent from the g r a p h i c a l p r e s e n t a t i o n of the r e s u l t s ( F i g s . 20, 2 1 ) . In s p i t e of t h i s v a r i a b i l i t y , c o n c e n t r a t i o n s of p h e n o l i c s d i d show some c o n s i s t e n c y i n the d i s t r i b u t i o n p a t t e r n over t i m e . I r r e s p e c t i v e of the t r e a t m e n t and the method of p h e n o l i c a s s a y , t h e r e was a t r e n d f o r p h e n o l i c s t o d e c l i n e s l i g h t l y i n young expanding and f u l l y expanded l e a v e s . T h i s d e c l i n e i n the p h e n o l i c c o n c e n t r a t i o n s i s c o n t r a r y t o the e x p e c t e d r e s u l t s and s u g g e s t s t h a t the d i f f e r e n c e s i n p h e n o l i c c o n c e n t r a t i o n s p r o b a b l y r e s u l t e d from the i n t e r a c t i o n between a c c l i m a t i o n t o the low l i g h t i n t e n s i t y i n the growth chamber and the t r e a t m e n t e f f e c t s . T h e r e f o r e no c o n c l u s i o n as t o the e f f e c t s of the t r e a t m e n t s can be drawn from t h i s e x p e r i m e n t . 88 Ta b l e 9. Experiment 3 : D i f f e r e n c e s i n the c o n c e n t r a t i o n of f o l i a r p h e n o l i c s (% f w t ) , measured w i t h Ammonium-Molybdate and F o l i n - C i o c a l t e a u r e a g e n t s . Source Method of p h e n o l i c assay of Ammon i um-Molybda t e F o l i n - C i o c a l t e a u v a r i a t i o n DF MS ERROR F v a l u e MS ERROR F v a l u e Treatment (T) 5 0. 74 P/T*D 1 .9 NS 15.10 P/T*D 7 .5 *** Days (D) 2 2. 62 P/T*D 6 .7 *** 10.53 P/T*D 5 .2 * T * D 10 0. 57 P/T*D 1 .4 NS 9.03 P/T*D 4 .4 *** P l a n t ( P ) / T * D 36 0. 38 A*P/T*D 2 . 1 *** 2.01 A*P/T*D 1 . 1 NS Age (A) 2 7. 36 A*P/T*D 40 .2 *** 36.35 A*P/T*D 19 .7 *** A * T 1 0 0. 63 A*P/T*D 3 .4 *** 5.53 A*P/T*D 3 .0 * A * D 4 0. 69 A*P/T*D 3 .7 *** 2.56 A*P/T*D 1 .3 NS A *T * D 20 0. 35 A*P/T*D 1 .9 * 4.06 A*P/T*D 2 .2 ** A * P/T* D 72 0. 18 4 . 1 *** 1 .83 4 .0 *** E r r o r 438 0. 04 0.45 --* f** f*** f N S S i g n i f i c a n t a t 1%, 5%, 0.1% l e v e l and not s i g n i f i c a n t , r e s p e c t i v e l y . 89 F i g . 2 0 Time c o u r s e of p h e n o l i c c o n c e n t r a t i o n s (measured w i t h the Ammonium-Molybdate) among t h r e e d i s t i n c t l e a f ages: young expanding (Age 1 ) , young f u l l y expanded (Age 2) and o l d (Age 3 ) . Symbol Treatment  g a P h e n y l a l a n i n e (5 x 1 0 - ^ M) % . ^ P h e n y l a l a n i n e (10 2 M) g gj Q u i n i c a c i d (5 x 1 0 - 2 M) * ^ Q u i n i c a c i d (2 x 1 0 - 2 M) g. g Q u i n i c a c i d ( 1 0 - 2 M) A A C o n t r o l Cone, of catechol-based phenolics (%fwt) O 91 F i g . 2 1 Time c o u r s e of p h e n o l i c c o n c e n t r a t i o n s (measured w i t h F o l i n - C i o c a l t e a u r e a g e n t ) among t h r e e d i s t i n c t l e a f ages: young ex p a n d i n g , young f u l l y expanded and o l d . Symbol Treatment . S B P h e n y l a l a n i n e (5 x 1 0 - ^ M) * x P h e n y l a l a n i n e ( 1 0 ~ 2 M) |g |g Q u i n i c a c i d (5 x 1 0 ~ 2 M) * ^ Q u i n i c a c i d (2 x 1 0 " 2 M) g g Q u i n i c a c i d ( 1 0 ~ 2 M) A: A C o n t r o l H o u r s 93 4 . 4 . 4 The E f f e c t of P h e n y l a l a n i n e or Q u i n i c A c i d Treatment and M i t e F e e d i n g on C o n c e n t r a t i o n s of F o l i a r P h e n o l i c s C o n c e n t r a t i o n s of f o l i a r p h e n o l i c s , a s s a y e d w i t h e i t h e r of the two r e a g e n t s , d i d not d i f f e r s i g n i f i c a n t l y as a r e s u l t of t r e a t m e n t a p p l i c a t i o n s or b l o c k e f f e c t s ( T able 10). However, independent comparison between t r e a t m e n t s , r e v e a l e d the presence of s i g n i f i c a n t d i f f e r e n c e s (P< 0.05) i n c o n c e n t r a t i o n s of t o t a l p h e n o l i c s between p l a n t s t r e a t e d w i t h p h e n y l a l a n i n e and q u i n i c a c i d s o l u t i o n s . The c o n c e n t r a t i o n s of l e a f l e t p h e n o l i c s were not s i g n i f i c a n t l y i n f l u e n c e d (P> 0.05) by f e e d i n g of a s i n g l e s p i d e r m i t e . Only c o n c e n t r a t i o n s of t o t a l p h e n o l i c s (based on F o l i n -C i o c a l t e a u r e a g e n t ) v a r i e d s i g n i f i c a n t l y (P< 0.05) between sampling days. The M i t e * T r e a t m e n t w i t h i n Block*Days i n t e r a c t i o n was s i g n i f i c a n t when measured w i t h e i t h e r of the r e a g e n t s . The r e m a i n i n g i n t e r a c t i o n s were not s i g n i f i c a n t . Because the l a t t e r r e s u l t s were e q u i v o c a l w i t h r e s p e c t t o the e f f e c t s of t r e a t m e n t s , the experiment was r e p e a t e d . I t d i d not i n c l u d e , however, the m i t e f e e d i n g f a c t o r i n the e x p e r i m e n t a l d e s i g n as m i t e f e e d i n g d i d not a f f e c t p h e n o l i c l e v e l s ( T a b l e 10). The r e s u l t s ( T a b l e 11) were s i m i l a r t o those p r e s e n t e d i n T a b l e 10 and showed t h a t c o n c e n t r a t i o n s of f o l i a r p h e n o l i c s d i d not d i f f e r s i g n i f i c a n t l y (P> 0.05) as a r e s u l t of tre a t m e n t a p p l i c a t i o n s . S i g n i f i c a n t b l o c k e f f e c t s were d e t e c t e d , (P< 0.05), but o n l y when the Ammonium-Molybdate reagent was used. 94 T a b l e 10. Experiment 4 : D i f f e r e n c e s i n the c o n c e n t r a t i o n of f o l i a r p h e n o l i c s (% fwt) of "Totem" p l a n t s , measured w i t h F o l i n - C i o c a l t e a u and Ammonium-Molybdate r e a g e n t s . Source of Method of p h e n o l i c s assay F o l i n - C i o c a l t e a u Ammonium-v a r i a t i o n DF MS ERROR F v a l u e MS ERROR F v a l u e B l o c k (B) 2 0 .05 ERROR1 0 .25 NS 0.09 ERROR1 1 . 21 NS M i t e (M) 1 0 .26 B * M 0 .94 NS 0.03 B * M 0. 39 NS B * M 2 0 .27 ERROR1 1 .23 NS 0.09 ERROR1 1 . 25 NS Treatment (T)2 1 .12 B * T 5 .80 NS 0.11 B * T 1 . 34 NS PQ/C 1 0. 67 3. 50 NS 0.08 1 .05 NS P/Q 1 1 . 56 8. 10 * 0.13 1 .64 NS B * T 4 0 .19 ERROR1 0 .85 NS 0.08 ERROR 1 1 . 10 NS M * T 2 0 .03 B*M*T 0 . 1 5 NS 0.02 B*M*T 0. 32 NS B * M * T 4 0 .22 ERROR1 0 .99 NS 0.06 ERROR1 0. 82 NS E r r o r 1 90 0 .22 4 .52 ** 0.07 3. 62 ** Days (D) 2 1 .68 MT/B*D 5 .33 * 0.12 MT/B*D 1 . 18 NS D * M 2 0 .00 MT/B*D 0 .00 NS 0.05 MT/B*D 0. 49 NS D * T 4 0 .23 MT/B*D 0 .73 NS 0.13 MT/B*D 1 . 23 NS D*M*T 4 0 .10 MT/B*D 0 .32 NS 0.06 MT/B*D 0. 57 NS MT/B*D 24 0 .31 6. 29 ** 0.10 5. 07 ** E r r o r 2 180 0 .05 -- 0.02 • *, **, NS S i g n i f i c a n t a t 5% and 1% l e v e l , not s i g n i f i c a n t . P, Q, C P h e n y l a l a n i n e ( 1 0 ~ 2 M), q u i n i c a c i d ( 2 X 1 0 ~ 2 M) and c o n t r o l , r e s p e c t i v e l y . 95 Ta b l e 11. Experiment 5 : D i f f e r e n c e s i n the c o n c e n t r a t i o n of f o l i a r p h e n o l i c s (% f w t ) , measured w i t h F o l i n -C i o c a l t e a u and Ammonium-Molybdate reagent Source of Method of p h e n o l i c s assay F o l i n - C i o c a l t e a u Ammonium-M( v a r i a t i o n DF MS ERROR F v a l u e MS ERROR F v a l u e B l o c k (B) 2 0. 24 E r r o r 10.86 NS 0. 1 4 E r r o r 13.69 * Treatment(T) 2 0. 45 B * T 3.18 NS 0. 06 B * T 4.13 NS PQ/C 1 0. 65 4.53 NS 0. 94 6.20 NS P/Q 1 0. 26 1.82 NS 0. 31 2.04 NS B * T 4 0. 14 E r r o r 1 0.50 NS 0. 01 E r r o r 1 0.38 NS E r r o r 1 45 0. 28 4.32 ** 0. 03 2.01 ** Day (D) 2 0. 71 B*T*D 11.50 ** 0. 38 B*T*D 6.96 ** B * D 4 0. 12 B*T*D 2.04 NS 0. 03 B*T*D 1.33 NS T * D 4 0. 05 B*T*D 0.91 NS 0. 00 B*T*D 0.13 NS B*T*D 8 0. 06 E r r o r 2 1 .00 NS 0. 02 E r r o r 2 1.00 NS E r r o r 2 90 0. 06 0. 01 • *,**,*** NS S i g n i f i c a n t a t 5%, 1%, 0.01% and not s i g n i f i c a n t . P, Q, C P h e n y l a l a n i n e ( 1 0 ~ 2 M), q u i n i c a c i d ( 2 x l 0 ~ 2 M) and c o n t r o l , r e s p e c t i v e l y . 96 U n l i k e the p r e v i o u s experiment p h e n o l i c c o n c e n t r a t i o n s v a r i e d s i g n i f i c a n t l y (P< 0.001) between samp l i n g days r e g a r d l e s s of t h e reagent used. None of the i n t e r a c t i o n terms was s i g n i f i c a n t . The combined r e s u l t s from both ANOVA's suggest t h a t the e x t e r n a l a p p l i c a t i o n of p h e n y l a l a n i n e and q u i n i c a c i d d i d not a f f e c t the c o n c e n t r a t i o n of p h e n o l i c s e x t r a c t e d by the method d e s c r i b e d i n s e c t i o n 3.2. The c o n c e n t r a t i o n s of p h e n o l i c s v a r i e d , however, w i t h the s a m p l i n g d a t e . T h i s o b s e r v a t i o n i s i n a c c o r d w i t h t h a t p r e s e n t e d i n s e c t i o n 4.4.3, and i n d i c a t e t h a t c o n c e n t r a t i o n s of f o l i a r p h e n o l i c s a r e h i g h l y v a r i a b l e . 4.4.5 The R e l a t i o n s h i p Between M i t e Development and C o n c e n t r a t i o n s of F o l i a r P h e n o l i c s A l o g i s t i c model was a p p l i e d t o d e f i n e the r e l a t i o n s h i p between the d e v e l o p m e n t a l s t a g e a t t a i n e d by a m i t e i n a d e f i n e d p e r i o d of time and the c o n c e n t r a t i o n of f o l i a r p h e n o l i c s , a s s a y e d w i t h each r e a g e n t . The r e l a t i o n s h i p s d e s c r i b e d by the l o g i s t i c model were s i g n i f i c a n t (P< 0.001) and had r 2 = 0.68, when p h e n o l i c c o n c e n t r a t i o n s were based on the Ammonium-Molybdate r e a g e n t , and r ^ = 0.38, when they were based on the F o l m - C i o c a l t e a u r e agent ( F i g s . 22, 2 3 ) . A f t e r e i g h t days of f e e d i n g on s t r a w b e r r y l e a v e s w i t h mean c o n c e n t r a t i o n s of c a t e c h o l - b a s e d p h e n o l i c s r a n g i n g from a p p r o x i m a t e l y 0.6 t o 0.8% f r e s h w e i g h t , the p r o b a b i l i t y of a s p i d e r m i t e d e v e l o p i n g from the l a r v a t o the a d u l t s t a g e was almost 1.0. As c o n c e n t r a t i o n s 97 F i g . 22 The r e l a t i o n s h i p between male m i t e d e v e l o p m e n t a l s t a g e s (YQ, Y 1 , Y 2 ) and the c o n c e n t r a t i o n of c a t e c h o l -based p h e n o l i c s ; 0 protonymph, 1 deutonymph and 2 a d u l t s t a g e . The p o i n t s (o) r e p r e s e n t f r e q u e n c i e s , and the c u r v e s r e p r e s e n t the p r o b a b i l i t y d i s t r i b u t i o n f o r each d e v e l o p m e n t a l s t a g e . _. Symbol P r o b a b i l i t y d i s t r i b u t i o n . . P(Y=0) . P(Y=1) DEVELOPMENTAL STAGES PROBABILITY 99 F i g . 23 The r e l a t i o n s h i p between male mite d e v e l o p m e n t a l s t a g e s ( Y Q ,Y f 1,Y 2) and the c o n c e n t r a t i o n of t o t a l p h e n o l i c s : 0 protonymph, 1 deutonymph and 2 a d u l t s t a g e . The p o i n t s (o) r e p r e s e n t f r e q u e n c i e s , and the c u r v e s r e p r e s e n t the p r o b a b i l i t y d i s t r i b u t i o n f o r each d e v e l o p m e n t a l s t a g e . Symbol P r o b a b i l i t y d i s t r i b u t i o n . . p(y=o) . . P(Y=1) . . P(Y=2) DEVELOPMENTAL STAGES PROBABILITY 101 of c a t e c h o l - b a s e d p h e n o l i c s i n c r e a s e d , the p r o b a b i l i t y of m i t e s r e a c h i n g the a d u l t stage w i t h i n e i g h t days d e c l i n e d and the p r o b a b i l i t y of f i n d i n g deutonymphs or protonymphs i n c r e a s e d . The same t r e n d f o r male mite development was obs e r v e d when the c o n c e n t r a t i o n s of p h e n o l i c s were based on F o l i n - C i o c a l t e a u reagent or when t h e experiment was r e p e a t e d ( F i g s . 24, 2 5 ) . In the l a t t e r c a s e , the r e l a t i o n s h i p s between m i t e development and f o l i a r p h e n o l i c s were a l s o h i g h l y s i g n i f i c a n t (P< 0.001) and had r 2 = 0.41, when p h e n o l i c s were assayed w i t h Ammonium-Molybdate, and r 2 =0.36 when they were assayed w i t h F o l i n - C i o c a l t e a u r e a g e n t . In both e x p e r i m e n t s the c o r r e l a t i o n between mite development and p h e n o l i c c o n c e n t r a t i o n s was g r e a t e r when Ammonium-Molybdate was used. The r e s u l t s from both e x p e r i m e n t s imply t h a t m i t e s f e e d i n g on l e a v e s w i t h h i g h c o n c e n t r a t i o n s of p h e n o l i c compounds would p r o b a b l y e x p e r i e n c e a d e l a y i n t h e i r development. 102 F i g . 24 The r e l a t i o n s h i p between male m i t e d e v e l o p m e n t a l s t a g e s ( Y Q , Y 1 , Y 2 ) and the c o n c e n t r a t i o n of c a t e c h o l -based p h e n o l i c s i n the r e p e a t e d e x p e r i m e n t : 0 protonymph, 1 deutonymph and 2 a d u l t s t a g e . The p o i n t s (o) r e p r e s e n t f r e q u e n c i e s , and the c u r v e s r e p r e s e n t the p r o b a b i l i t y d i s t r i b u t i o n f o r each d e v e l o p m e n t a l s t a g e . _. Symbol P r o b a b i l i t y d i s t r i b u t i o n . . P(Y=0) P(Y=1) . . P(Y=2) 104 F i g . 25 The r e l a t i o n s h i p between male m i t e d e v e l o p m e n t a l s t a g e s (YQ,Y 1,Y2) and the c o n c e n t r a t i o n of t o t a l p h e n o l i c s i n the r e p e a t e d e x p e r i m e n t : 0 protonymph, 1 deutonymph and 2 a d u l t s t a g e . The p o i n t s (o) r e p r e s e n t f r e q u e n c i e s , and the c u r v e s r e p r e s e n t the p r o b a b i l i t y d i s t r i b u t i o n f o r each d e v e l o p m e n t a l s t a g e . _. Symbol P r o b a b i l i t y d i s t r i b u t i o n . . P(Y=0) . ^ P(Y=1) . . P(Y=2) ,105 1 06 5.DISCUSSION 5.1 S u i t a b i l i t y of F. chiloensis f o r Twospotted S p i d e r M i t e O v i p o s i t i o n S e v e r a l a u t h o r s have r e p o r t e d i n t e r - and i n t r a - s p e c i f i c d i f f e r e n c e s i n host s u i t a b i l i t y f o r growth, r e p r o d u c t i o n and development of i n s e c t s and m i t e s . I t was t h e r e f o r e , not s u r p r i s i n g t o f i n d s i g n i f i c a n t d i f f e r e n c e s i n s u i t a b i l i t y of c l o n e s of F. chiloensis and cv. "Totem" f o r T. urticae o v i p o s i t i o n . D i f f e r e n c e s i n h o s t - p l a n t s u i t a b i l i t y f o r tw o s p o t t e d s p i d e r m i t e s have been r e p o r t e d from numerous p l a n t genera. P a t t e r s o n e t a l . (1974) f o r example, examined 54 Nicotiana s p e c i e s and 17 c u l t i v a r s w i t h r e s p e c t t o s u i t a b i l i t y f o r mi t e s u r v i v a l , growth and o v i p o s i t i o n . A l l measurements of mite performance were s t r o n g l y a f f e c t e d by to b a c c o c l o n e s . S c h u s t e r et al. (1972 a and 1972 b) r e p o r t e d s i g n i f i c a n t d i f f e r e n c e s i n s u i t a b i l i t y of p r i m i t i v e r a c e s and c u l t i v a r s of Gossypium s p e c i e s , f o r m i t e o v i p o s i t i o n and l o n g e v i t y . S i m i l a r r e s u l t s have been o b t a i n e d by Rasmy (1985) and A i n a et al.,(1972), who s t u d i e d d i f f e r e n c e s i n s u i t a b i l i t y among Lycoper s i con s p e c i e s and Sol anum s p e c i e s f o r s p i d e r mite o v i p o s i t i o n and development. S u i t a b i l i t y of PeI argoni um f o r mi t e o v i p o s i t i o n and l o n g e v i t y v a r i e d s i g n i f i c a n t l y among s p e c i e s and v a r i e t i e s ( S n e t s i n g e r e t a l . , 1966). F u r t h e r m o r e , s u i t a b i l i t y of tomato f o r T. urticae o v i p o s i t i o n v a r i e d s i g n i f i c a n t l y among 54 v a r i e t i e s t e s t e d ( S t o n e r and S t r i n g f e l l o w 1967). D i f f e r e n c e s i n host s u i t a b i l i t y were a l s o r e p o r t e d f o r a v a r i e t y of i n s e c t s . Moran (1981) s t u d i e d i n t e r - a n d -i n t r a s p e c i f i c d i f f e r e n c e s i n s u i t a b i l i t y of Solidago s p e c i e s as h o s t p l a n t s f o r the a p h i d Uroleucon caligatum. A l l measurements of a p h i d performance were s t r o n g l y a f f e c t e d by g e n e t i c a l l y d i v e r s e p l a n t c l o n e s . C l o n a l d i f f e r e n c e s i n F. chiloensis a r e a l s o r e p o r t e d f o r the o v i p o s i t i o n of the b l a c k v i n e w e e v i l Otiorhynchus sulcatus (Shanks and Doss, 1986). The r e s u l t s o b t a i n e d i n the p r e s e n t study a r e i n a c c o r d w i t h t h o s e p r e s e n t e d by o t h e r s and s t r o n g l y suggest the e x i s t e n c e of a g e n e t i c component which d e t e r m i n e s the s u i t a b i l i t y of the h o s t - p l a n t f o r i n s e c t and m i t e growth, development and r e p r o d u c t i o n . In a d d i t i o n t o the g e n e t i c component, e n v i r o n m e n t a l c o n d i t i o n s can a f f e c t the s u i t a b i l i t y of the h o s t - p l a n t f o r the t w o s p o t t e d s p i d e r m i t e . Changes i n the p l a n t p h y s i o l o g y due t o weather and s o i l c o n d i t i o n s and a p p l i c a t i o n s of p e s t i c i d e s may a l t e r p l a n t s u i t a b i l i t y t o m i t e s ( H u f f a k e r et al . , 1969). S o i l and f o l i a r n i t r o g e n have been a l s o r e p o r t e d t o a f f e c t s u i t a b i l i t y of the h o s t - p l a n t f o r the t w o s p o t t e d s p i d e r m i t e (Dabrowski and B i e l a k , 1978; Rod r i g u e z et al.,1970). 108 5.2 I n t e r - a n d - I n t r a s p e c i f i c D i f f e r e n c e s in S t rawber ry P h e n o l i c s and Pubescence 5 .2 .1 D i f f e r e n c e s in P h e n o l i c s As noted e a r l i e r i n t h i s t h e s i s , p h e n o l i c compounds commonly v a r y i n q u a l i t y among p l a n t s p e c i e s , among p o p u l a t i o n s of one s p e c i e s and among l e a v e s of v a r i o u s ages on i n d i v i d u a l p l a n t s . The da t a from the q u a n t i t a t i v e a n a l y s i s of f o l i a r p h e n o l i c s show s i g n i f i c a n t d i f f e r e n c e s i n t o t a l and c a t e c h o l - b a s e d p h e n o l i c s among examined c l o n e s of F. chiloensis and c v . "Totem" ( T a b l e s 2 and 4 ) . S i m i l a r l y , q u a n t i t a t i v e d i f f e r e n c e s have been r e p o r t e d between F. vesca v a r i e t y " A l p i n a " and F. x ananassa c v . "Lassen" ( C r e a s y , 1964). C o n c e n t r a t i o n s of t o t a l p h e n o l i c s a l s o v a r y among Sorghum c u l t i v a r s (Woodhead, 1981). F u r t h e r m o r e , s i g n i f i c a n t d i f f e r e n c e s i n c o n c e n t r a t i o n s of t a n n i n s were r e p o r t e d among c o t t o n c u l t i v a r s and p r i m i t i v e r a c e s (Lane and S c h u s t e r , 1981). The r e s u l t s from my study a l s o i n d i c a t e s i g n i f i c a n t d i f f e r e n c e s i n t o t a l and c a t e c h o l - b a s e d p h e n o l i c s among s t r a w b e r r y l e a v e s of d i f f e r e n t age c l a s s e s (Table 2 ) . C o n c e n t r a t i o n s of p h e n o l i c s appear t o be h i g h e r i n young l e a v e s than i n mature ones. A s i m i l a r p a t t e r n of t o t a l p h e n o l i c d i s t r i b u t i o n was a l s o r e p o r t e d by C o l e y (1983), who examined d i f f e r e n c e s w i t h i n p l a n t s i n t o t a l p h e n o l i c c o n c e n t r a t i o n s i n 46 s p e c i e s of t r e e s i n a l o w l a n d t r o p i c a l r a i n f o r e s t . In 85% of s p e c i e s examined young l e a v e s had h i g h e r c o n c e n t r a t i o n s of t o t a l p h e n o l i c s than mature ones. 109 L a r s o n and B e r r y (1984) have r e p o r t e d s i g n i f i c a n t l y h i g h e r c o n c e n t r a t i o n s of t o t a l p h e n o l i c s i n young l e a v e s of peppermint p l a n t s . Numerous examples of a l l e l o c h e m i c a l v a r i a t i o n w i t h i n a p l a n t have been p r e s e n t e d by Whitham (1983) and K r i s c h i k and Denno (1983). F u r t h e r m o r e , a g r a d i e n t of p h e n o l i c c o n c e n t r a t i o n s was r e p o r t e d w i t h i n a s i n g l e l e a f of a n a r r o w l e a f cottonwood. Zucker (1981) s t u d i e d the r o l e of t o t a l p h e n o l i c s i n host s e l e c t i o n by the g a l l i n g a p h i d Pemphi gus betae and found a w i t h i n - l e a f g r a d i e n t of c o n c e n t r a t i o n s which i n c r e a s e d a c r o p e t a l l y . The e v i d e n c e o b t a i n e d i n the p r e s e n t study s u g g e s t s t h a t d i f f e r e n c e s i n c o n c e n t r a t i o n s of t o t a l and c a t e c h o l -based p h e n o l i c s do oc c u r among s t r a w b e r r y c l o n e s . In a d d i t i o n t h e r e i s a c o n s i d e r a b l e g r a d i e n t of p h e n o l i c c o n c e n t r a t i o n s w i t h i n a p l a n t among l e a v e s of d i f f e r e n t ages. I t would be i n t e r e s t i n g t o a s s e s s whether d i f f e r e n c e s i n p h e n o l i c c o n c e n t r a t i o n s would be s u s t a i n e d i n f i e l d c o n d i t i o n s and whether they would p e r s i s t t h rough the growing season. D i f f e r e n c e s i n c o n c e n t r a t i o n s of p h e n o l i c s among s t r a w b e r r y c l o n e s p r e s e n t a p o t e n t i a l b a s i s of r e s i s t a n c e a g a i n s t the t w o s p o t t e d s p i d e r m i t e . Can the i n t r a - p l a n t v a r i a t i o n i n c o n c e n t r a t i o n s of p h e n o l i c s a l s o be a p o t e n t i a l t o o l i n s t r a w b e r r y d e f e n s e a g a i n s t the t w o s p o t t e d s p i d e r mite ? Whitham (1980; 1983) s t u d i e d the impact of i n t r a -p l a n t v a r i a t i o n on r e s i s t a n c e i n n a r r o w l e a f cottonwood a g a i n s t g a l l a p h i d s . He c o n c l u d e d t h a t the v a r i a t i o n w i t h i n a s i n g l e p l a n t may a c t t o s t a b i l i z e the p e s t p o p u l a t i o n p r i m a r i l y t h r o u g h the d i f f e r e n t i a t i o n of s u i t a b i l i t y of the h o s t - p l a n t f o r i n s e c t growth and p r e v e n t i o n of a d a p t a t i o n t o r e s i s t a n c e f a c t o r s . Whitham (1983) s u g g e s t s t h a t , i n t r a -p l a n t v a r i a t i o n may c o n s t i t u t e a l o n g term defence s t r a t e g y a g a i n s t r a p i d l y e v o l v i n g p e s t s . In a d d i t i o n t o the q u a n t i t a t i v e d i f f e r e n c e s , p l a n t p h e n o l i c s commonly v a r y q u a l i t a t i v e l y among and w i t h i n s p e c i e s . Levy and F u j i i (1978) showed i n t r a p o p u l a t i o n q u a l i t a t i v e d i f f e r e n c e s i n f l a v o n o i d s of Phlox Carolina. Creasy {et al., 1964) found c o n s i d e r a b l e d i f f e r e n c e s i n f o l i a r p h e n o l i c s between two s t r a w b e r r y s p e c i e s : F. v e s c a c v . " A l p i n e " and F. x ananassa c v . " L a r s e n " . In c o n t r a s t , d a t a from the p r e s e n t study show a c l o s e s i m i l a r i t y i n the q u a l i t y of p h e n o l i c s between s e l e c t e d c l o n e s of F. c h i l o e n s i s and F. x ananassa cv. "Totem". The d i s c r e p a n c y between my f i n d i n g s and those of Creasy c o u l d be due t o the p h y l o g e n e s i s of F. x ananassa and F. chi I oensis. The F. c h i l o e n s i s i s one of two o c t o p l o i d p a r e n t s of the h y b r i d s p e c i e s F. x ananassa and, hence s i m i l a r i t y between F.chiloensis and F.x ananassa. The F. vesca, a d i p l o i d , i s p h y l o g e n e t i c a l l y d i s t i n c t from F. x ananassa ( S c o t t 1951). In s p i t e of t h e s i m i l a r i t y between p h e n o l i c p r o f i l e s , F. c h i l o e n s i s and F. x ananassa can be d i s t i n g u i s h e d on the b a s i s of d i f f e r e n c e s i n p r o p o r t i o n s of c e r t a i n compounds or the presence or absence of compounds unique t o each s p e c i e s . 111 S i m i l a r d i f f e r e n c e s i n p r o p o r t i o n s of p h e n o l i c compounds or t h e i r p resence or absence have been r e p o r t e d t o e x i s t among s t r a w b e r r y c u l t i v a r s (Nemec, 1973 and 1976). A c l o s e resemblance i n p h e n o l i c p r o f i l e s between c v . "Totem" and the s e l e c t e d c l o n e s of F. chiloensis j u s t i f y the use of e i t h e r s p e c i e s f o r examining the e f f e c t of p h e n o l i c c o n c e n t r a t i o n s on the f i t n e s s of the t w o s p o t t e d s p i d e r m i t e . 5.2.2 E f f e c t of P h e n y l a l a n i n e or Q u i n i c A c i d Treatment on C o n c e n t r a t i o n s of F o l i a r P h e n o l i c s The s y n t h e s i s of p h e n o l i c g l y c o s i d e s or e s t e r s i n some p l a n t s p e c i e s can be r e a d i l y enhanced in vivo by a d m i n i s t e r i n g d i l u t e s o l u t i o n s of a p h e n o l i c or i t s p r e c u r s o r p h e n y l a l a n i n e t o l i v i n g p l a n t s or p l a n t t i s s u e s . Numerous examples of the a p p l i c a t i o n of t h i s method f o r a l t e r i n g the p h e n o l i c c o m p o s i t i o n of l i v i n g p l a n t s have been r e p o r t e d by Towers (1964). Creasy (1968 and 1971) r e p o r t e d s i g n i f i c a n t i n c r e a s e s i n a c c u m u l a t i o n of c i n n a m i c a c i d s as the r e s u l t of p h e n y l a l a n i n e a p p l i c a t i o n t o s t r a w b e r r y l e a f d i s k s . In the p r e s e n t s t u d y , however, the a p p l i c a t i o n of p h e n y l a l a n i n e or q u i n i c a c i d d e c r e a s e d p h e n o l i c c o n c e n t r a t i o n s i n one case ( S e c t i o n 4.4.3; F i g s . 20 and 21) and d i d not a f f e c t the a c c u m u l a t i o n of p h e n o l i c s i n the l e a f t i s s u e i n two o t h e r e x p e r i m e n t s ( S e c t i o n 4.4.4 T a b l e 10 and 11). The de c r e a s e i n p h e n o l i c c o n c e n t r a t i o n s was c o n t r a r y t o e x p e c t e d r e s u l t s and p r o b a b l y r e s u l t e d from p l a n t a c c l i m a t i o n t o the lower l i g h t i n t e n s i t y of the growth chamber used. Low l i g h t i n t e n s i t y has been r e p o r t e d t o d e c r e a s e the s y n t h e s i s of p h e n o l i c s i n a v a r i e t y of p l a n t genera (Woodhead, 1981; Mole et al., 1988). The l a c k of s i g n i f i c a n t t r e a t m e n t e f f e c t s on c o n c e n t r a t i o n s of f o l i a r p h e n o l i c s i s c o n t r a r y t o r e s u l t s p r e s e n t e d by Creasy (1968, 1971). The d i s c r e p a n c y between my r e s u l t s and those of Creasy can be e x p l a i n e d i n p a r t by the d i f f e r e n t r o u t e s of a d m i n i s t r a t i o n of t r e a t m e n t s . C r easy both a p p l i e d and measured the e f f e c t of p h e n y l a l a n i n e i n l e a f d i s k s whereas i n my experiment p h e n y l a l a n i n e or q u i n i c a c i d were a p p l i e d t o p l a n t r o o t s , but t h e i r e f f e c t s were measured i n the f o l i a g e . E l - B a s y o u n i et al .,(1964) t r e a t e d s h o o t s and r o o t s of wheat s e e d l i n g s w i t h r a d i o -l a b e l e d p h e n y l a l a n i n e or carbon d i o x i d e and d e t e c t e d the p r e s e n c e of the r a d i o - l a b e l e d compounds i n s h o o t s . C a r r a s c o et al . , (1978), s t u d i e d the e f f e c t of p h e n y l a l a n i n e and q u i n i c a c i d a p p l i c a t i o n t o r o o t s of p l a n t s , and r e p o r t e d a s i g n i f i c a n t i n c r e a s e i n c o n c e n t r a t i o n s of p h e n o l i c s i n both tomato r o o t s and s h o o t s . A l t e r n a t i v e l y , i t i s p o s s i b l e t h a t the p h e n y l a l a n i n e or q u i n i c a c i d t r e a t m e n t s a f f e c t e d the c o n c e n t r a t i o n of f o l i a r p h e n o l i c s i n s t r a w b e r r y , but o n l y those p h e n o l i c s which were not e x t r a c t a b l e by the method d e s c r i b e d i n s e c t i o n 3.2. A d m i n i s t r a t i o n of p h e n y l a l a n i n e t o the p l a n t t i s s u e was r e p o r t e d t o more r e a d i l y i n c r e a s e the s y n t h e s i s of c i n n a m i c a c i d s bound t o i n s o l u b l e r e s i d u e s than i n t o e t h a n o l s o l u b l e d e r i v a t i v e s ( E l - B a s y o u n i et al . , 1964). 1 13 P l a n t t i s s u e s a t t a c k e d by pathogens or a r t h r o p o d p e s t s f r e q u e n t l y show an i n c r e a s e i n c o n c e n t r a t i o n s of p h e n o l i c compounds. K i e l k i e w i c z and van de V r i e (1982), and Inoue et al., (1984) r e p o r t e d an i n c r e a s e i n c o n c e n t r a t i o n s of s t r a w b e r r y f o l i a r p h e n o l i c s and an i n c r e a s e i n the a c t i v i t y of p h e n y l a l a n i n e ammonia l y a s e (PAL) as a r e s u l t of s p i d e r m i t e f e e d i n g . In the p r e s e n t s t u d y , however, t h e c o n c e n t r a t i o n s of f o l i a r p h e n o l i c s were not a f f e c t e d by f e e d i n g of s i n g l e s p i d e r m i t e s . 5.2.3 D i f f e r e n c e s i n Pubescence D e n s i t i e s of t r i c h o m e s commonly v a r y among and w i t h i n s p e c i e s . The genus Fragaria p r o v i d e s an i n t e r e s t i n g example t o s t u d y t h e s e d i f f e r e n c e s . Hancock (1977) s t u d i e d i n t e r -a n d - i n t r a s p e c i f i c d i f f e r e n c e s i n the d e n s i t i e s of n o n g l a n d u l a r t r i c h o m e s of Fragaria s p e c i e s c o l l e c t e d from Washington, Oregon and C a l i f o r n i a . R e s u l t s from t h i s e x t e n s i v e s t u d y show s i g n i f i c a n t d i f f e r e n c e s i n t r i c h o m e d e n s i t i e s between F. virginiana, F. vesca and F'. chi I oensi s , t h e l a t t e r s p e c i e s b e i n g the most pubescent. F u r t h e r m o r e , h i g h l y s i g n i f i c a n t i n t e r - a n d - i n t r a - p o p u l a t i o n d i f f e r e n c e s i n d e n s i t i e s of n o n g l a n d u l a r t r i c h o m e s were r e p o r t e d t o e x i s t i n F. chiloensis. The r e s u l t s of my study s u p p o r t Hancock's f i n d i n g s (1977), and i n d i c a t e t h a t c l o n a l d i f f e r e n c e s i n d e n s i t i e s of n o n g l a n d u l a r t r i c h o m e s a r e a common f e a t u r e of t h i s s p e c i e s . However, the magnitude of d e n s i t i e s r e p o r t e d by each study appear t o d i f f e r c o n s i d e r a b l y . I n Hancock's c o l l e c t i o n t he grand mean of n o n g l a n d u l a r t r i c h o m e d e n s i t i e s was l63.3/5mm 2 and ranged from 70-300, w h i l e the grand mean from the c o l l e c t i o n used i n the p r e s e n t study was 55.13/5mm2 and ranged from 30-90. T h i s f i n d i n g s u g g ests t h a t F. chiloensis n a t i v e t o B.C. i s m o d e r a t e l y pubescent as compared t o those from Washington, Oregon or C a l i f o r n i a , and t h a t a source of more pubescent c l o n e s c o u l d be found, i f t h i s t r a i t i s of v a l u e . The r e s u l t s from t h i s work a l s o i n d i c a t e h i g h 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 d e n s i t i e s of g l a n d u l a r t r i c h o m e s among c l o n e s of F. chiloensis and c v . "Totem". A l t h o u g h t h e r e i s no p u b l i s h e d e v i d e n c e t o date t o su p p o r t t h i s r e s u l t i n genus Fragaria, i n t e r - and i n t r a - s p e c i f i c d i f f e r e n c e s i n g l a n d u l a r t r i c h o m e d e n s i t i e s appear t o be a common f e a t u r e i n a v a r i e t y of o t h e r p l a n t genera. In a d d i t i o n t o c l o n a l d i f f e r e n c e s , d e n s i t i e s of both t y p e s of t r i c h o m e v a r y commonly w i t h i n a p l a n t , among l e a v e s of v a r i o u s degrees of e x p a n s i o n , and among mature l e a v e s of v a r i o u s s i z e s . A d e c r e a s e i n d e n s i t y of t r i c h o m e s w i t h l e a f e x p a n s i o n has been r e p o r t e d by Snyder and C a r t e r (1986) and Tinge y et al ., (1982). A s i m i l a r phenomenon appears t o e x p l a i n d i f f e r e n c e s i n both t y p e s of t r i c h o m e s between expanding and f u l l y expanded s t r a w b e r r y l e a v e s . In a d d i t i o n , t r i c h o m e d e n s i t y i n s t r a w b e r r y appears t o be n e g a t i v e l y r e l a t e d t o the s i z e of the l e a f l e t . L e a f l e t s i z e i s d e t e r m i n e d to the l a r g e e x t e n t by the number of c e l l s (Arney, 1954) and t h e r e f o r e v a r i a t i o n i n l e a f l e t s i z e w i l l 115 p r o b a b l y a f f e c t t he d e n s i t y of t r i c h o m e s per a r e a . V a r i a t i o n i n l e a f e x p a n s i o n and s i z e can p a r t l y e x p l a i n s i g n i f i c a n t d i f f e r e n c e s i n both t r i c h o m e d e n s i t i e s r e s u l t i n g from b l o c k e f f e c t s . 5.3 M i t e P o p u l a t i o n Parameters in R e l a t i o n to S t rawber ry P h e n o l i c s and Pubescence 5 .3 .1 O v i p o s i t i o n G l a n d u l a r t r i c h o m e s have been a s s o c i a t e d w i t h m i t e and s m a l l i n s e c t r e s i s t a n c e i n numerous p l a n t g e n e r a . My study s u p p o r t s t h i s phenomenon and shows s i g n i f i c a n t n e g a t i v e r e l a t i o n s h i p s between d e n s i t i e s of s t r a w b e r r y g l a n d u l a r t r i c h o m e s and mi t e o v i p o s i t i o n . R e d u c t i o n i n m i t e o v i p o s i t i o n appears t o be p a r t l y a s s o c i a t e d w i t h a c c u m u l a t i o n of g l a n d u l a r exudates on mi t e t a r s i ( S e c t i o n 4.4.1; F i g . 1 1 ) and a s s o c i a t e d w i t h s t r e s s , encumbered movement or entrapment. A s i m i l a r mechanism a c c o u n t e d f o r r e d u c t i o n i n mite o v i p o s i t i o n i n a v a r i e t y of o t h e r p l a n t s p e c i e s . In Lycopersi con and Sol anum s p e c i e s r e d u c t i o n i n o v i p o s i t i o n of t w o s p o t t e d s p i d e r m i t e and carmine s p i d e r m i t e was p r i m a r i l y a s s o c i a t e d w i t h i m m o b i l i z a t i o n by g l a n d u l a r t r i c h o m e s ( S t o n e r et a l . , 1968; G e n t i l e et a l . , 1969). In Lycopersi con, Solanum and Geranium s p e c i e s o v i p o s i t i o n of the t w o s p o t t e d s p i d e r mite was s i g n i f i c a n t l y reduced by s t i c k y exudates from g l a n d u l a r t r i c h o m e s (Rasmy, 1985; C a r t e r and Snyder, 1986; Snyder and C a r t e r , 1984; C r a i g e t a l . , 1986). However, i n none of thes e t e s t e d 1 16 s p e c i e s were g l a n d u l a r t r i c h o m e s the s o l e b a s i s of r e s i s t a n c e a g a i n s t m i t e s . The p r e s e n t work s u p p o r t s t h e s e f i n d i n g s and i n d i c a t e s t h a t o t h e r f a c t o r s a l s o i n f l u e n c e m ite o v i p o s i t i o n . More r e s e a r c h i s r e q u i r e d t o e s t a b l i s h whether or not g l a n d u l a r t r i c h o m e s of Fragaria chiloensis d i f f e r among c l o n e s i n t h e i r p e r s i s t e n c e , c h e m i c a l n a t u r e or a b i l i t y t o produce e x u d a t e s , as each of the s e p r o p e r t i e s may i n f l u e n c e the r e l a t i o n s h i p between t w o s p o t t e d s p i d e r m i t e o v i p o s i t i o n and the d e n s i t y of g l a n d u l a r t r i c h o m e s . M i t e o v i p o s i t i o n was a l s o s i g n i f i c a n t l y a f f e c t e d by the d e n s i t y of n o n g l a n d u l a r t r i c h o m e s ( S e c t i o n 4.4.1 F i g . 10). There i s an apparent c o n t r a d i c t i o n between r e s u l t s o b t a i n e d i n the p r e s e n t study and those r e p o r t e d by o t h e r s , w i t h r e s p e c t t o m i t e performance and n o n g l a n d u l a r pubescence. P e t e r s and B e r r y (1980) f o r example, r e p o r t e d a s i g n i f i c a n t , p o s i t i v e r e l a t i o n s h i p between t w o s p o t t e d s p i d e r m i t e o v i p o s i t i o n and the d e n s i t i e s of n o n g l a n d u l a r t r i c h o m e s i n hop c u l t i v a r s . S i m i l a r l y , p o s i t i v e r e l a t i o n s h i p s were shown to e x i s t between wheat pubescence and the abundance of the wheat c u r l m i t e (Harvey and M a r t i n 1980). Goonewardene et al.,(1980 and 1982) and P i v a and J a n i k (1980) have r e p o r t e d t h a t t h e r e i s no r e l a t i o n s h i p between a p p l e l e a f pubescence and abundance of the European r e d m i t e . F i n a l l y , K i s h a b a et al . , (1972) suggest t h a t a heavy n o n g l a n d u l a r pubescence i n s t r a w b e r r y i s p o s i t i v e l y r e l a t e d t o m i t e s u s c e p t i b i l i t y . However, the l a s t a u t h o r s ' s u g g e s t i o n s were based on the o b s e r v a t i o n of a s i n g l e c l o n e of F. chiloensis and t h e r e f o r e do not p r o v i d e a s t r o n g argument. The l a c k of correspondence between d a t a p r e s e n t e d i n t h i s s tudy and those j u s t c i t e d can be e x p l a i n e d i n p a r t by the d i f f e r e n c e s i n the magnitude of n o n g l a n d u l a r t r i c h o m e d e n s i t i e s or l e n g t h of t r i c h o m e s among examined s p e c i e s . For example, d e n s i t i e s of s t r a w b e r r y t r i c h o m e s appear t o be s e v e r a l o r d e r s of magnitude h i g h e r than those of hop and a p p l e . Wheat t r i c h o m e s a r e s u b s t a n t i a l l y s h o r t e r . S e v e r a l f a c t o r s may e x p l a i n the o b s e r v e d r e l a t i o n s h i p . N o n g l a n d u l a r pubescence may a f f e c t m i t e o v i p o s i t i o n by h i n d e r i n g m i t e movement or r e d u c i n g the a v a i l a b i l i t y of o v i p o s i t i o n s i t e s . N o n g l a n d u l a r t r i c h o m e s may a f f e c t m i t e o v i p o s i t i o n i n d i r e c t l y by a l t e r i n g the m i c r o c l i m a t e of the l e a f s u r f a c e . As reviewed e a r l y i n t h i s t h e s i s ( S e c t i o n 2.3.1) p h e n o l i c compounds in pi ant a and i n a r t i f i c i a l d i e t s a r e i m p l i c a t e d i n the r e d u c t i o n of f i t n e s s i n a v a r i e t y of i n s e c t s and m i t e s . R e s u l t s from the p r e s e n t study support t h i s view and show t h a t o v i p o s i t i o n of the t w o s p o t t e d s p i d e r m i t e i s n e g a t i v e l y c o r r e l a t e d w i t h c o n c e n t r a t i o n s of t o t a l p h e n o l i c s . However, the r e l a t i o n s h i p between c a t e c h o l - b a s e d p h e n o l i c s and m i t e o v i p o s i 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 (P> 0.05). In s p i t e of t h i s , the r e s u l t s from t h i s work support f i n d i n g s of L a r s o n and B e r r y (1984), who r e p o r t e d a s i g n i f i c a n t n e g a t i v e c o r r e l a t i o n between m i t e o v i p o s i t i o n and c o n c e n t r a t i o n s of t o t a l p h e n o l i c s from 118 peppermint f o l i a g e . A s i m i l a r , n e g a t i v e r e l a t i o n s h i p between o v i p o s i t i o n of P. ulmi and c o n c e n t r a t i o n s of c h l o r o g e n i c a c i d i n a p p l e f o l i a g e was shown by Dabrowski and B i e l a k (1978). The d a t a from the p r e s e n t study do not p r o v i d e e v i d e n c e t o suggest whether a d e c r e a s e i n the o v i p o s i t i o n a l performance of s p i d e r m i t e s was due t o reduced f e e d i n g or t o an a d v e r s e e f f e c t of f o o d q u a l i t y on m i t e p h y s i o l o g y . The p h e n o l i c compounds commonly p r e s e n t i n s t r a w b e r r y f o l i a g e were r e p o r t e d t o be r e p e l l e n t and t o x i c when i n c o r p o r a t e d i n t o t w o s p o t t e d s p i d e r m i t e a r t i f i c i a l d i e t (Dabrowski and R o d r i q u e z 1972). I t i s t h e r e f o r e p o s s i b l e t h a t b o t h mechanisms c o u l d account f o r reduced o v i p o s i t i o n . In s p i t e o f . a s i g n i f i c a n t n e g a t i v e c o r r e l a t i o n between t o t a l p h e n o l i c c o n c e n t r a t i o n s and m i t e o v i p o s i t i o n , the c o n c e n t r a t i o n of f o l i a r p h e n o l i c s a l o n e a r e not s t r o n g l y i m p l i c a t e d i n s t r a w b e r r y r e s i s t a n c e t o t w o s p o t t e d s p i d e r m i t e . More e v i d e n c e i s a c c u m u l a t i n g t o show t h a t r a r e l y , i f e v e r , i s one f a c t o r r e s p o n s i b l e f o r h o s t - p l a n t r e s i s t a n c e a g a i n s t a r t h r o p o d p e s t s . U s u a l l y s e v e r a l f a c t o r s a r e i n v o l v e d and i n t e r a c t i n h o s t - p l a n t r e s i s t a n c e . Many c l e a r examples of i n t e r a c t i n g r e s i s t a n c e f a c t o r s o r i g i n a t e d from work on t r i c h o m e s and t h e i r r o l e i n d efence a g a i n s t a r t h r o p o d s . The mechanisms by which f o l i a r t r i c h o m e s a f f e c t p e s t s may be based on the i n t e r a c t i o n s between m o r p h o l o g i c a l t y p e s of g l a n d u l a r t r i c h o m e s or i n t e r a c t i o n s between t h e i r c h e m i c a l and p h y s i c a l p r o p e r t i e s . T ingey and Laubengayer 119 (1981) f o r example, showed t h a t the m o r p h o l o g i c a l t y p e s of p o t a t o g l a n d u l a r t r i c h o m e s i n t e r a c t e d t o produce g r e a t e r l e v e l s of p e s t r e s i s t a n c e than e i t h e r type a l o n e . Two m o r p h o l o g i c a l t y p e s of t r i c h o m e s i n Solanum berthaultii c o n t r i b u t e d t o r e s i s t a n c e a g a i n s t the green peach a p h i d Myzus persicae by complex i n t e r a c t i o n s of m o r p h o l o g i c a l and c h e m i c a l f a c t o r s (Mehlenbacher et al ., 1983, 1984). More e v i d e n c e f o r the r o l e of m u l t i p l e f a c t o r s i n p l a n t r e s i s t a n c e has a r i s e n from s t u d i e s of t r i c h o m e s i n r e l a t i o n t o o t h e r l e a f c h a r a c t e r i s t i c s . C a r t e r and Snyder (1986) and Snyder and C a r t e r (1984) r e p o r t e d t h a t m i t e o v i p o s i t i o n was a f f e c t e d by m u l t i p l e f a c t o r s of tomato f o l i a g e i n c l u d i n g d e n s i t y of type VI g l a n d u l a r t r i c h o m e s , c o n t e n t of t r i c h o m e s t i p s , l e a f e x p a n s i o n and typ e s of l e a f l e t s u r f a c e . The p r e s e n t s t u d y p r o v i d e s an a d d i t i o n a l p i e c e of e v i d e n c e t o support the t h e o r y of m u l t i p l e - f a c t o r s as d e t e r m i n a n t s of h o s t - p l a n t r e s i s t a n c e . D e n s i t i e s of g l a n d u l a r and n o n g l a n d u l a r t r i c h o m e s and c o n c e n t r a t i o n s of c a t e c h o l - b a s e d p h e n o l i c s a r e s i g n i f i c a n t l y r e l a t e d t o s t r a w b e r r y r e s i s t a n c e a g a i n s t T. urticae ( a s s e s s e d by o v i p o s i t i o n a l performance) by complex c u r v a l i n e a r i n t e r a c t i o n s ( S e c t i o n 4.4.1; F i g s . 16,17,18). 120 5 . 3 . 2 S u r v i v a l S e v e r a l a u t h o r s r e p o r t e d t h a t g l a n d u l a r t r i c h o m e s e n t r a p or i m m o b i l i z e s m a l l i n s e c t s and m i t e s w i t h s t i c k y e xudates and hence reduce t h e i r s u r v i v a l . T h i s mechanism ac c o u n t e d f o r reduced s u r v i v a l of T. urticae i n Lycopersicon s p e c i e s , and was a s s o c i a t e d w i t h the d e n s i t y of type IV t r i c h o m e s ( C a r t e r and Snyder 1986; Snyder and C a r t e r 1984). The d e c r e a s e i n s u r v i v a l of the a p h i d s Myzus persicae and Macrosiphum euphorbiae i s a l s o r e l a t e d t o entrapment and i m m o b i l i z a t i o n by exudates of g l a n d u l a r t r i c h o m e s of Sol anum s p e c i e s (Gibson 1971; Tingey and Laubengayer, 1981; T i n g e y et al ., 1982; Tingey and Sinden 1982). A s i m i l a r mechanism appears t o e x p l a i n the r e d u c t i o n i n s u r v i v a l of the t w o s p o t t e d s p i d e r m i t e on s t r a w b e r r y f o l i a g e ( T a b l e 8; F i g . 19). Not a l l d e v e l o p m e n t a l s t a g e s of the mite were e q u a l l y a f f e c t e d by exu d a t e s . The v a s t m a j o r i t y of m i t e s t r a p p e d t o the l e a f s u r f a c e were of the l a r v a l s t a g e , s u g g e s t i n g t h a t e i t h e r the l a r v a l s t age i s p a r t i c u l a r l y v u l n e r a b l e t o entrapment or t h a t o t h e r s t a g e s can escape t h i s mechanism t h r o u g h f o r example, shedding o l d , t r a p p e d e x o s k e l e t o n s . I t i s a l s o p o s s i b l e t h a t the reduced s u r v i v a l of T. urticae i s r e l a t e d t o the c h e m i c a l p r o p e r t i e s of g l a n d u l a r e x u d a t e s . E v i d e n c e f o r reduced s u r v i v a l r e s u l t i n g from c h e m i c a l p r o p e r t i e s of exudates i s p r e s e n t e d by G e r h o l d (1984), Rasmy (1985), A i n a et al . , ( 1972) and Dimock and Kennedy (1983). 121 5.3.3 Development As n o t e d e a r l i e r i n t h i s t h e s i s , p h e n o l i c compounds i s o l a t e d from p l a n t s i n h i b i t i n s e c t and m ite growth or development i n l a b o r a t o r y b i o a s s a y s . However, e v i d e n c e f o r the e f f i c a c y of p h e n o l i c s in pi ant a i s l i m i t e d . There a r e o n l y a few documented c a s e s wherein the c o n c e n t r a t i o n s of p h e n o l i c s in pi ant a a r e r e l a t e d t o i n s e c t or m i t e development and even th e s e are c o n t r a d i c t o r y . Isman and D u f f e y (1982 a) s t u d i e d the e f f e c t of p h e n o l i c c o n t e n t of tomato l e a v e s on growth of H. zea l a r v a e and found no c o r r e l a t i o n between l a r v a l growth and p h e n o l i c c o n c e n t r a t i o n s . In c o n t r a s t , L a r s o n and B e r r y (1984) r e p o r t e d s i g n i f i c a n t l y l o n g e r d e v e l o p m e n t a l t i m e s of the t w o s p o t t e d s p i d e r m ite on peppermint l e a v e s w i t h h i g h c o n c e n t r a t i o n s of t o t a l p h e n o l i c s . The r e s u l t s from the c u r r e n t work s u p p o r t the f i n d i n g s of L a r s o n and B e r r y and i n d i c a t e t h a t d e v e l o p m e n t a l t i m e s i n c r e a s e w i t h c o n c e n t r a t i o n s of f o l i a r p h e n o l i c s . R e l a t i o n s h i p s between development of t w o s p o t t e d s p i d e r m i t e and f o l i a r c o n c e n t r a t i o n s of p h e n o l i c s were b e t t e r d e s c r i b e d when p h e n o l i c c o n c e n t r a t i o n s were e x p r e s s e d as c a t e c h o l - b a s e d p h e n o l i c s . 5.4 C o n c l u s i o n s Host r e s i s t a n c e i s an i m p o r t a n t component of i n t e g r a t e d p e s t management. The i d e n t i f i c a t i o n of r e s i s t a n t genotypes 122 and p l a n t c h e m i c a l or m o r p h o l o g i c a l c h a r a c t e r i s t i c s r e l a t e d t o m i t e r e s i s t a n c e i s the f i r s t s t e p i n a l o n g p r o c e s s toward b r e e d i n g m i t e - r e s i s t a n t s t r a w b e r r i e s . T h i s study p r e s e n t s a comprehensive approach i n both the s e a r c h f o r d i f f e r e n c e s i n mite r e s i s t a n c e among c l o n e s of Fragaria chiloensis, and i n the assessment of r e l a t i o n s h i p s between p o p u l a t i o n parameters of the t w o s p o t t e d s p i d e r m i t e and c h e m i c a l and m o r p h o l o g i c a l c h a r a c t e r i s t i c s of s t r a w b e r r y f o l i a g e . The r e s u l t s from t h i s s t u d y i n d i c a t e t h a t c l o n e s of F.chiloensis d i f f e r s i g n i f i c a n t l y i n s u i t a b i l i t y f o r mi t e o v i p o s i t i o n . The r e s u l t s i n d i c a t e f u r t h e r t h a t c o n c e n t r a t i o n s of f o l i a r p h e n o l i c s and d e n s i t i e s of t r i c h o m e s a r e n e g a t i v e l y c o r r e l a t e d w i t h t h r e e m i t e p o p u l a t i o n p a r a m e t e r s : o v i p o s i t i o n , s u r v i v a l and development. The l a t t e r t h r e e a r e the major parameters d e t e r m i n i n g the i n t r i n s i c r a t e of i n c r e a s e of p o p u l a t i o n ( B i r c h 1948). I t seems, t h e r e f o r e , r e a s o n a b l e t o expect t h a t the major impact of s e l e c t i o n f o r t e s t e d c h e m i c a l and m o r p o l o g i c a l c h a r a c t e r i s t i c s of s t r a w b e r r y c o u l d r e s u l t i n a dec r e a s e i n the i n t r i n s i c r a t e of s p i d e r m ite p o p u l a t i o n i n c r e a s e . The r a t e of p o p u l a t i o n i n c r e a s e i s a f f e c t e d t o a much g r e a t e r e x t e n t by the r a t e of development than by r a t e s of o v i p o s i t i o n or s u r v i v a l (Lewontin 1965). T h e r e f o r e a f i n a l c o n c l u s i o n from t h i s work i s t h a t c o n c e n t r a t i o n s of f o l i a r p h e n o l i c s , i n p a r t i c u l a r l y c a t e c h o l - b a s e d p h e n o l i c s , are the most p r o m i s i n g p u t a t i v e r e s i s t a n c e f a c t o r s amongst 123 t h o s e examined, because they a r e s t r o n g l y i m p l i c a t e d i n the d e l a y of m i t e development. S e l e c t i o n of m i t e r e s i s t a n c e can be g r e a t l y improved by d e t e r m i n i n g the degree of r e s i s t a n c e a s s o c i a t e d w i t h each p l a n t c h a r a c t e r i s t i c and then i n c o r p o r a t i n g t h i s i n f o r m a t i o n i n t o s e l e c t i o n i n d i c e s . The use of t r i c h o m e d e n s i t y as the s e l e c t i o n index i n the s c r e e n i n g f o r m i t e r e s i s t a n c e appears f e a s i b l e . However, p r e d i c t i o n of m i t e performance based on t h i s c h a r a c t e r i s t i c would have t o be a d j u s t e d f o r the degree of l e a f e x p a n s i o n and l e a f s i z e . More r e s e a r c h i s needed t o deter m i n e the e x t e n t t o which environment a f f e c t s d e n s i t i e s of g l a n d u l a r and n o n g l a n d u l a r t r i c h o m e s i n F. chiloensis. In c o n t r a s t , the use of p h e n o l i c c o n c e n t r a t i o n s as the s e l e c t i o n cue appears t o be of l i m i t e d v a l u e . As emphasized i n t he L i t e r a t u r e Review, p h e n o l i c compounds a r e r e a d i l y a f f e c t e d by a v a r i e t y of b i o t i c and a b i o t i c f a c t o r s , t h e r e f o r e p r e d i c t i o n s of m i t e performance based on t h i s t r a i t may be prone t o p r o d u c i n g ambiguous r e s u l t s . I t needs t o be proven whether or not the e n v i r o n m e n t a l p l a s t i c i t y of p h e n o l i c compounds c o u l d be of v a l u e i n b r e e d i n g f o r i n s e c t and m i t e r e s i s t a n c e . The a b i l i t y of p l a n t s t o r a p i d l y respond t o b i o t i c f a c t o r s has found r e c e n t a p p l i c a t i o n i n the concept of induced p l a n t d e f e n c e s (Rhoades 1983). The a p p l i c a b i l i t y of t h i s d e f e n s i v e s t r a t e g y i s a s u b j e c t of i n t e n s e c u r r e n t r e s e a r c h . Three phenomena determine whether p l a n t c h a r a c t e r i s t i c s i d e n t i f i e d i n t h i s s tudy c o u l d be u s e f u l t r a i t s i n b r e e d i n g f o r m i t e r e s i s t a n c e i n s t r a w b e r r y : the e x t e n t t o which the environment a f f e c t s the e x p r e s s i o n of these t r a i t s , h e r i t a b i l i t y of t h e s e t r a i t s , and c o r r e l a t i o n s w i t h o t h e r c h a r a c t e r i s t i c s . These t h r e e phenomena i n d i c a t e some d i r e c t i o n s f o r f u r t h e r r e s e a r c h on t w o s p o t t e d s p i d e r m i t e r e s i s t a n c e i n s t r a w b e r r y . 125 6. SUMMARY 1. M i t e o v i p o s i t i o n d i f f e r e d s i g n i f i c a n t l y among 63 c l o n e s of F. chiloensis and c v . "Totem". 2. C o n c e n t r a t i o n s of f o l i a r t o t a l and c a t e c h o l - b a s e d p h e n o l i c s v a r y s i g n i f i c a n t l y among c l o n e s of F. chiloensis and c v . "Totem", and w i t h i n a s i n g l e c l o n e among l e a v e s of d i f f e r e n t age c a t e g o r i e s . 3. Q u a l i t a t i v e a n a l y s i s of p h e n o l i c compounds, d e t e r m i n e d v i a HPLC, r e v e a l e d a c l o s e s i m i l a r i t y between F. chiloensis and F. x ananassa and among s e l e c t e d c l o n e s of F. chi I oens i s . 4. M i t e o v i p o s i t i o n was n e g a t i v e l y c o r r e l a t e d w i t h d e n s i t i e s of g l a n d u l a r and n o n g l a n d u l a r t r i c h o m e s and c o n c e n t r a t i o n s of f o l i a r p h e n o l i c s . However, m i t e o v i p o s i t i o n was be s t p r e d i c t e d by a c o m b i n a t i o n of i n t e r a c t i n g p l a n t c h a r a c t e r i s t i c s r a t h e r than by any i n d i v i d u a l c h a r a c t e r i s t i c . 5. Entrapment by s t i c k y exudates from g l a n d u l a r t r i c h o m e s appears t o e x p l a i n the n e g a t i v e r e l a t i o n s h i p between mi t e s u r v i v a l and d e n s i t y of g l a n d u l a r t r i c h o m e s . 6. C o n c e n t r a t i o n s of f o l i a r p h e n o l i c s of "Totem" p l a n t s were not a f f e c t e d by the a p p l i c a t i o n of aqueous s o l u t i o n s of p h e n y l a l a n i n e or q u i n i c a c i d . 7. M i t e development was n e g a t i v e l y c o r r e l a t e d w i t h c o n c e n t r a t i o n s of f o l i a r p h e n o l i c s ; mite development appears t o be d e l a y e d on l e a v e s w i t h h i g h c o n c e n t r a t i o n s of p h e n o l i c s . 8. C o n c e n t r a t i o n s of c a t e c h o l - b a s e d p h e n o l i c s were more s t r o n g l y c o r r e l a t e d w i t h both m i t e o v i p o s i t i o n and development. 126 7. LITERATURE CITED A i n a , O.J., J.G. R o d r i g u e z and D.E. K n a v e l . 1972. C h a r a c t e r i s i n g r e s i s t a n c e t o Tetranychus urticae i n tomato. J . Econ. Entomol.65:641-643. Anonymous. 1982. S t r a w b e r r y g e n e t i c r e s o u r c e s : An assessment and p l a n f o r C a l i f o r n i a . N a t i o n a l C o u n c i l on Gene Res o u r c e s , B e r k e l e y , C a l i f o r n i a , pp. 252. Anonymous. 1987. P r e s s r e l e a s e from A g r i c u l t u r e Canada. R. P a r i s i e n . j Ottawa, O n t a r i o . Arney, S.E. 1954. S t u d i e s of growth and development i n the genus Fragaria. I I I . The growth of l e a v e s and s h o o t s . Ann. Bot. 18: 349-365. B a r r i t t , B.H., C.H. Shanks, J r . 1981. Pa r e n t s e l e c t i o n i n b r e e d i n g s t r a w b e r r i e s r e s i s t a n t t o t w o s p o t t e d s p i d e r m i t e s . H o r t s c i e n c e 16: 323-324. B a t e - S m i t h , E.C. 1961. Chromatography and taxonomy i n the Rosaceae, w i t h s p e c i a l r e f e r e n c e t o Pot ent i 11 a and Prunus. J . L i n n . Soc. Bot. 58: 39-54. Beck, S.D. and L.M. Schoonhoven. 1980. I n s e c t b e h a v i o r and p l a n t r e s i s t a n c e . I_n: F.G. Maxwell and P.R. J e n n i n g s ( E d s . ) . B r e e d i n g P l a n t s R e s i s t a n t t o I n s e c t s . J . W i l e y & Sons, I n c . pp. 116-133. Berenbaum, M.R. and J . J . N e a l . 1987. I n t e r a c t i o n s among a l l e l o c h e m i c a l s and i n s e c t s . R e s i s t a n c e i n c r o p p l a n t s . I_n: A l e l l o c h e m i c a l s : R o l e i n A g r i c u l t u r e and F o r e s t r y . G.R. W a l l e r ( E d . ) . ACS Symposium S e r i e s 330. pp. 416-430. Bern a y s , E.A. 1978. T a n n i n s : an a l t e r n a t i v e v i e w p o i n t . Entomol. Exp. A p p l . 24^: 44-53. B e r n a y s , E.A., D.. Chamb e r l i a n and P. McCarthy. 1980. The d i f f e r e n t i a l e f f e c t s of i n g e s t e d t a n n i c a c i d on d i f f e r e n t s p e c i e s of A c r i d o i d a e . Entomol. Exp. A p p l . 28: 158-166. 127 Bernays, E.A. 1981. P l a n t t a n n i n s and i n s e c t h e r b i v o r e s : An a p p r a i s a l . E c o l . Entomol. 6: 353-360. Bernays, E.A. and S. Woodhead. 1982. I n c o r p o r a t i o n of d i e t a r y p h e n o l s i n t o the c u t i c l e i n the t r e e l o c u s t Anacridium me I ano r hodo n . J . I n s e c t . P h y s i o l . 28: 60 1 -604. Bernays, E.A. and S. Woodhead. 1982. P l a n t p h e n o l s u t i l i z e d as n u t r i e n t s by a phytophagous i n s e c t . S c i e n c e 216: 201-202. B i r c h , L.C. 1948. The i n t r i n s i c r a t e of n a t u r a l i n c r e a s e of an i n s e c t p o p u l a t i o n . J . Anim a l E c o l . JT7: 15-26. B r i n g h u r s t , R.S., J.F. Hancock and V. Vot h . 1977. The beach s t r a w b e r r y , an impo r t a n t n a t u r a l r e s o u r c e . C a l i f . A g r i c . 3J_: 10. Broersma, D.B., R.L. B e r n a r d and W.H. Luckmann. 1972. Some e f f e c t s of soybean pubescence on p o p u l a t i o n of the p o t a t o l e a f h o p p e r . J . Econ. Entomol. 65: 78-82. C a r r a s c o , A. A.M. Boudet and G. M a r i g o . 1978. Enhanced r e s i s t a n c e of tomato p l a n t s t o Fusarium by c o n t r o l l e d s t i m u l a t i o n of t h e i r n a t u r a l p h e n o l i c p r o d u c t i o n . P h y s i o l o g i c a l P l a n t P a t h o l o g y j_2: 225-232. C a r t e r , C D . and J.C. Snyder. 1986. M i t e r esponses and tr i c h o m e c h a r a c t e r s i n a f u l l - s i b F 2 f a m i l y of Lycoper si con esculentum x L. hirsutum. J . Amer. Soc. H o r t . S c i . 111: 130-133. C h a p l i n , C.E., L.P. S t o l t z and J.G. R o d r i g u e z . 1970. Br e e d i n g b e h a v i o r of m i t e - r e s i s t a n t s t r a w b e r r i e s . J . Amer. Soc. H o r t . S c i . 95: 330-333. C h a t t e r j e e , S. and B. P r i c e . 1977. R e g r e s s i o n A n a l y s i s by Example. John W i l e y & Sons, New York U n i v e r s i t y , pp. 117-119. 128 Chew, F.S. and J.E. Rodman. 1979. P l a n t r e s o u r c e s f o r c h e m i c a l d e f e n s e . In: G.A. R o s e n t h a l and D.H. Janzen ( E d s . ) . H e r b i v o r e s : T h e i r I n t e r a c t i o n w i t h Secondary P l a n t M e t a b o l i t e s . Academic P r e s s , New York. pp. 271-307. C o l e , R.A. 1985. R e l a t i o n s h i p between the c o n c e n t r a t i o n of c h l o r o g e n i c a c i d i n c a r r o t r o o t s and the i n c i d e n c e of c a r r o t f l y l a r v a l damage. Ann. A p p l . B i o l . 106: 211-217. C o l e , R.A. 1984. P h e n o l i c a c i d s a s s o c i a t e d w i t h the r e s i s t a n c e of l e t t u c e c u l t i v a r s t o the l e t t u c e r o o t a p h i d . Ann. A p p l . B i o l . 105: 129-145. C o l e , R.A., K. P h e l p s P.R. E l l i s and J.A. Hardman. 1987. The e f f e c t s of time of sowing and h a r v e s t on c a r r o t b i o c h e m i s t r y and the r e s i s t a n c e of c a r r o t s t o c a r r o t f l y . Ann. A p p l . B i o l . JMJ): 135-143. C o l e y , P.D. 1983. H e r b i v o r y and d e f e n s i v e c h a r a c t e r i s t i c s of t r e e s p e c i e s i n a l o w l a n d t r o p i c a l f o r e s t . E c o l o g i c a l Monographs. 53: 209-233. C r a i g , R., R.O. Mumma, D.L. G e r h o l d , B.L. Winner and R. S n e t s i n g e r . 1986. G e n e t i c c o n t r o l of a b i o c h e m i c a l mechanism f o r m i t e r e s i s t a n c e i n geraniums. In: J.B. Harborne ( E d . ) . N a t u r a l R e s i s t a n c e of P l a n t s t o P e s t s . R o l e of A l l e l o c h e m i c a l s . , ASC Symposium. Ser.296, American Chemical Soc. Washington, D.C. pp. 169-176. C r e a s y , L.L. 1971. R o l e of p h e n y l a l a n i n e i n the b i o s y n t h e s i s of f l a v o n o i d s and c i n n a m i c a c i d s i n s t r a w b e r r y l e a f d i s k s . P h y t o c h e m i s t r y . J_0: 2705-2711. C r e a s y , L.L., E.C. Maxie and V.L. S i n g l e t o n . 1964. C h a r a c t e r i z a t i o n of f l a v o n o i d s i n Fragaria. Am. Soc. H o r t . S c i . 85: 325-331. C r e a s y , L.L. 1968. The i n c r e a s e i n p h e n y l a l a n i n e ammonia-l y a s e a c t i v i t y i n s t r a w b e r r y l e a f d i s k s and i t s c o r r e l a t i o n w i t h f l a v o n o i d s y n t h e s i s . P h y t o c h e m i s t r y 7: 441-446. Crock, J.E., C.H. Shanks, J r . and B.H. B a r r i t t . 1982. R e s i s t a n c e i n Fragaria chiloensis and F. x ananassa t o the a p h i d s Chaetosiphon fragaefoli and C. thomasi. H o r t s c i e n c e 17: 959-960. C r o o k e r , A. 1985. Embryonic and j u v e n i l e development. I n : W. H e l l e and M.W. S a b e l i s ( E d s . ) . S p i d e r M i t e s , T h e i r B i l o g y , N a t u r a l Enemies and C o n t r o l . E l s e v i e r S c i . P u b l . Comp. I n c . , Amsterdam, N e t h e r l a n d s , pp 149-160. C u t t e r , E.G. 1971. P l a n t Anatomy: Experiment and I n t e r p r e t a t i o n . Edward A r n o l d , London, pp. 118-196. D a b r o w s k i , Z.T. and J.G. R o d r i g u e z . 1971. S t u d i e s on r e s i s t a n c e of s t r a w b e r r i e s t o m i t e s . 3. P r e f e r e n c e and no n p r e f e r e n c e responses of Tetranychus urticae and T. turkestani t o e s s e n t i a l o l i s of f o l i a g e . J . Econ. Entomol. 64: 387-390. Da b r o w s k i , Z.T. and J.G.Rodriguez. 1972. G u s t a t o r y r e s p o n s e s of Tetranychus urticae Koch t o p h e n o l i c compounds of s t r a w b e r r y f o l i a g e . Zesz. Prob. P o s t . Nauk R o l . 129: 69-78. Da b r o w s k i , Z.T. and B. B i e l a k . 1978. E f f e c t of some p l a n t c h e m i c a l compounds on the b e h a v i o r and r e p r o d u c t i o n of s p i d e r m i t e s (Acarina: Tetranychi dae). Entomol. Exp. A p p l . 24: 117-126. Darrow, G.M. 1966. The S t r a w b e r r y . H o l t , R i n e h a r t and Wins t o n , New York. 447 pp. D a v i e s , M.C., V.K. Newby and R.L.M. Synge. 1978. Bound q u i n i c a c i d as a measure of c o u p l i n g of l e a f and su n f l o w e r seed p r o t e i n w i t h c h l o r o g e n i c a c i d congeners: Loss of a v a i l a b i l i t y of l y s i n e . J . S c i . Fd. A g r i c . 29: 33-41. Dimock, M.G. and G.G. Kennedy. 1983. The r o l e of g l a n d u l a r t r i c h o m e s i n the r e s i s t a n c e of Lycoper s i con hirsutum F. glabratum t o Heliothis zea. Entomol. Exp. A p p l . 33: 263-268. 130 Dimock, M.G., W.M. Tingey and G.G Kennedy. 1986. Solanum neocardenasii : A new sour c e of p o t a t o r e s i s t a n c e t o the C o l o r a d o p o t a t o b e e t l e {Coleoptera: Chrysomel idae). J . Econ. Entomol. 79: 1269-1275. Dimock, M.B. and W.M. T i n g e y . 1987. M e c h a n i c a l i n t e r a c t i o n between l a r v a e of the C o l o r a d o p o t a t o b e e t l e and g l a n d u l a r t r i c h o m e s of Sol anum b e r t h a u l t i i Hawkes. Am. P o t a t o J . 64: 507-516. Doss, R.P., C. H. Shanks, J r . , J.D. Chamberlain and J.K.L. G a r t h . 1987. Role of l e a f h a i r s i n r e s i s t a n c e of a c l o n e of beach s t r a w b e r r y , Fragaria c h i l o e n s i s , t o f e e d i n g by a d u l t v i n e w e e v i l , Otiorhynchus sulcatus (Coleoptera: Cur ul i oni dae) . E n v i r o n . Entomol. 1 6 : 764-768. D r e y e r , D.L. and K.C. Jones. 1981. Fe e d i n g d e t e r r e n c y of f l a v o n o i d s and r e l a t e d p h e n o l i c s towards Schizaphis graminum and Myzus persicae: A p h i d f e e d i n g d e t e r r e n t s i n wheat. P h y t o c h e m i s t r y 20: 2489-2493. D r e y e r , D.L., J.C. Reese and K.C. Jones. 1981. Ap h i d f e e d i n g d e t e r r e n t s i n sorghum. J . Chem. E c o l o g y 7: 273-283. D u f f e y , S.S. and M.B. Isman. 1981. I n h i b i t i o n of i n s e c t l a r v a l growth by p h e n o l i c s i n g l a n d u l a r t r i c h o m e s of tomato l e a v e s . E x p e r i e n t i a 3_7: 574-576. D u f f e y , S.S. 1986. P l a n t g l a n d u l a r t r i c h o m e s : T h e i r p a r t i a l r o l e i n defense a g a i n s t i n s e c t s . I_n: B. J u n i p e r and S i r R. Southwood ( E d s . ) . I n s e c t s and the P l a n t S u r f a c e . Edward A r n o l d , London, pp 150-172. E h l e r i n g e r , J . 1984. Ec o l o g y and e c o p h y s i o l o g y of l e a f pubescence i n N o r t h American d e s e r t p l a n t s . I_n: E. R o d r i g u e z , P.L. Healey and J . Mehta ( E d s . ) . B i o l o g y and C h e m i s t r y of P l a n t T r i chomes. Plenum P r e s s New York. pp. 113-133. E l - B a s y o u n i , S.Z., A.C. N e i s h and G.H.N. Towers. 1964. The p h e n o l i c a c i d s i n wheat - I I I . I n s o l u b l e d e r i v a t i v e s of p h e n o l i c c i n n a m i c a c i d s as n a t u r a l i n t e r m e d i a t e s i n l i g n i n b i o s y n t h e s i s . Phytochem. 3: 627-639. 131 E l l i g e r , C.A., B.G. Chan, A.C. Wa i s s , R.E. L u n d i n and W.F. Haddon. 1979. C - G l y c o s y l f l a v o n e s from Zea mays t h a t i n h i b i t i n s e c t development. Phytochem. V9: 293-297. Esau, K. 1965. P l a n t Anatomy. W i l e y , New York. pp. 167-171 and 309-311. Feeny, P. 1976. P l a n t apparency and c h e m i c a l d e f e n s e . Recent Adv. Phytochem. j_0: 1-40. G a l l u n , R.L., R. Ruppel and E.H. E v e r s o n . 1966. R e s i s t a n c e of s m a l l g r a i n s t o the c e r e a l l e a f b e e t l e . J . Econ. Entomol. 59: 827-829. G e n t i l e , A.G. and A.K. S t o n e r . 1968a. R e s i s t a n c e i n Lycoper si con and sol anum s p e c i e s t o the p o t a t o a p h i d . J . Econ. Entomol. 61: 1152-1154. G e n t i l e , A.G. and A.K. S t o n e r . 1968b. R e s i s t a n c e i n Lycopersi con spp. t o the t o b a c c o f l e a b e e t l e . J . Econ. Entomol. 61: 1347-1349. G e n t i l e , A.G., R.E. Webb and A.K. S t o n e r . 1968. R e s i s t a n c e i n Lycopersi con and Sol anum t o greenhouse w h i t e f l i e s . J . Econ. Entomol. 61: 1355-1357. G e r h o l d , D.L., R. C r a i g and R.O. Mumma. 1983. A n a l y s i s of tr i c h o m e exudate from m i t e - r e s i s t a n t geraniums. J . Chem. E c o l o g y U): 713-722. G i b s o n , R.W. 1971. G l a n d u l a r h a i r s p r o v i d i n g r e s i s t a n c e t o a p h i d i n c e r t a i n w i l d p o t a t o s p e c i e s . Ann. A p p l . B i o l . 68: 113-119. G i b s o n , R.W. 1978. R e s i s t a n c e i n g l a n d u l a r - h a i r e d w i l d p o t a t o e s t o f l e a b e e t l e s . Am. P o t a t o J . 55: 595-599. Goonewardene, H.F., W.K. Kowolek, D.F. Dayton and R.H. Havden. 1980. P r e f e r e n c e of the European r e d m i t e f o r s t r a i n s of " d e l i c i o u s " a p p l e w i t h d i f f e r e n c e s i n l e a f pubescence. J . Econ. Entomol. 73_: 101-103. 132 Goonewardene, H.F., W.F. Kowolek and D.F. Dayton. 1982. Comparison of s u s c e p t i b i l i t y t o European r e d mi t e (Acari: Tehanychi dae) of t h r e e groups of r e l a t e d a p p l e c r o s s e s w i t h and w i t h o u t scab r e s i s t a n c e . E n v i r o n . Entomol. 11: 724-726. Greene, G.L. and R. T h u r s t o n . 1971. O v i p o s i t i o n p r e f e r e n c e of Heliothis virescens f o r Nicotiana s p e c i e s . J . Econ. Entomol. 64: 641-643. Gr e g o r y , P. W.M. Ti n g e y , D.A. Ave and P.Y. B o u t h y e t t e . 1986 a. P o t a t o g l a n d u l a r t r i c h o m e s : A p h y s i o c h e m i c a l d e f e nse mechanism a g a i n s t i n s e c t s . I_n: M.B. Green and P.A. Hedin (Eds.) N a t u r a l R e s i s t a n c e of P l a n t s t o P e s t s . R o l e of A l l e l o c h e m i c a l s , ACS Symposium. Ser 296, American Chemical Soc. Washington, D.C. pp. 160-167. G r e g o r y , P., D.A. Ave, P.Y. B o u t h y e t t e and W.M. Ti n g e y . 1986 b. I n s e c t d e f e n s i v e c h e m i s t r y of p o t a t o g l a n d u l a r t r i c h o m e s . I_n: B. J u n i p e r and S i r R. Southwood ( E d s . ) . I n s e c t s and the P l a n t S u r f a c e . Edward A r n o l d , London, pp 173-184. Hancock, J.F . , J r . 1977. E c o g e n e t i c s of C a l i f o r n i a s p e c i e s of Fragaria; h a b i t a t s , morphology, enzymes and p h y s i o l o g i c a l t o l e r a n c e of o c t o p l o i d F. chiloensis and F. virginiana, and F. vesca. PhD, U n i v e r s i t y of C a l i f o r n i a , D a v i s . Hancock, J.F . , J r . and R.S. B r i n g h u r s t . 1979. E c o l o g i c a l d i f f e r e n t i a t i o n i n p e r e n n i a l o c t o p l o i d s p e c i e s of Fragaria. Ann. J . Bot. 6_6: 367-375. Harborne, J.B. 1979. V a r i a t i o n i n and f n c t i o n a l s i g n i f i c a n c e of p h e n o l i c s i n p l a n t s . I_n: T.Swain, J.B. Harborne and C.F. Van Sumere ( E d s . ) . B i c h e m i s t r y of P l a n t P h e n o l i c s . Plenum P r e s s , pp. 457-475. Harvey, T.L. and T.J. M a r t i n . 1980. E f f e c t s of wheat pubescence on i n f e s t a t i o n of wheat c u r l m i t e and i n c i d e n c e of wheat s t r e a k mosaic. J . Econ. Entomol. 73: 225-227. 133 Herrmann, K. 1976. F l a v o n o l s and f l a v o n e s i n f o o d p l a n t s : A r e v i e w . J . Food T e c h n o l . 11: 433-448. H o x i e , R.P., S.G. W e l l s o and J.A. Webster. 1975. C e r e a l l e a f b e e t l e response t o wheat t r i c h o m e l e n g t h and d e n s i t y . E n v i r o n . Entomol. 4: 365-370. H u f f a k e r , K.B., M. van de V r i e and J.A. McMurry. 1969. The e c o l o g y of t e t r a n y c h i d m i t e s and t h e i r n a t u r a l enemies. Ann. Rev. Entomol. 14: 125-174. H u r r e l , R.F., P.A. F i n o t and J.L. Cuq. 1982. P r o t e i n p o l y p h e n o l r e a c t i o n s . 1. N u t r i t i o n a l and m e t a b o l i c consequence of the r e a c t i o n between o x i d i z e d c a f f e i c a c i d and the l y s i n e r e s i d u e s of c a s e i n . Br. J . N u t r . 47: 191-211. Inoue, M. S. S e z a k i , T. S o r i n and T. S u g i u r a . 1985. Change of p h e n y l a l a n i n e ammonia-lyase i n s t r a w b e r r y l e a v e s i n f e s t e d w i t h the t w o s p o t t e d s p i d e r m i t e , Tetranychus urticae Koch. (Acarina: Tetranychi dae). A p p l . E n t . Z o o l . 20: 348-349. Isman, M.B. and D u f f e y , S.S. 1982a. T o x i c i t y of tomato p h e n o l i c compounds t o the f r u i t w o r m , Heliothis zea. Entomol. Exp. A p p l . 3J_: 370-376. Isman, M.B. and S.S. D u f f e y . 1982b. P h e n o l i c compounds i n the f o l i a g e of commercial tomato c u l t i v a r s as growth i n h i b i t o r s t o the f r u i t w o r m , Heliothis zea. J . Amer. Soc. H o r t i c . S c i . 107: 167-170. J e n k i n s , J.N. 1980. The use of p l a n t and i n s e c t models. I n : F.G. Maxwell and P.R. J e n n i n g s ( E d s . ) . B r e e d i n g P l a n t R e s i s t a n t t o I n s e c t s . J . W i l e y and Sons I n c . , New York. pp. 215-223. Jo n e s , C.G. 1983. P h y t o c h e m i c a l v a r i a t i o n , c o l o n i z a t i o n , and i n s e c t communities; The case of Braken Fern (Pteridium aqui I i num) . I_n : R.F. Denno and M.S. McClure ( E d s . ) . V a r i a b l e P l a n t s and H e r b i v o r e s i n N a t u r a l and Managed Systems, pp. 513-549. Johnson, H.B. 1975. P l a n t pubescence: An e c o l o g i c a l p e r s p e c t i v e . Bot. Review. 4J_: 223-258. 134 K a t o , M. 1978. P h enols as i n d i s p e n s i b l e components of the s y n t h e t i c d i e t of the s i l k w o r m Bombyx mori . Entomol. Exp. A p p l . 24: 285-290. K e l s e y , R.G., G.W. Reynolds and E. R o d r i g u e z . B i o l o g i c a l l y a c t i v e c o n s t i t u e n t s i n p l a n t s g l a n d u l a r t r i c h o m e s . 1984. I_n: E. R o d r i g u e z , P.L. Healey and J . Metha ( E d s . ) . B i o l o g y and C h e m i s t r y of P l a n t Trichomes. Plenum P r e s s , New York. Pp. 187-241. K i e l k i e w i c z , M. and Van de V r i e . 1982. H i s t o l o g i c a l s t u d i e s on s t r a w b e r r y l e a v e s damaged by the t w o s p o t t e d s p i d e r m i t e (Tetranychus urticae): Some a s p e c t s of p l a n t s e l f d e f e n c e . In.: J.H. V i s s e r and A.K. Minks ( E d s . ) . P r o c e e d i n g s of the 5 t h I n t e r n a t i o n a l Symposium on I n s e c t - P l a n t R e l a t i o n s h i p . C e n t r . Agr. P u b l . D o c , Wageningen. pp. 389-391. K i s h a , J.S.A. 1981. O b s e r v a t i o n s on the t r a p p i n g of the w h i t e f l y Bemisia t abaci by g l a n d u l a r h a i r s on tomato l e a v e s . Ann. A p p l . B i o l . £7:123-127. K i s h a b a , A.N. V.Voth, A.F. Howland, R.S. B r i n g h u r s t and H.H. Toba. 1972. Twospotted s p i d e r m i t e r e s i s t a n c e i n C a l i f o r n i a n s t r a w b e r r i e s . J . Econ. Entomol. 6_6: 117-119. K l o c k e , J.A. and B.G. Chan. 1982. E f f e c t s of c o t t o n condensed t a n n i n of f e e d i n g and d i g e s t i o n i n the c o t t o n p e s t Heliothis zea. J . I n s e c t P h y s i o l . 28:911-915. K r i s c h i k , V.A. and R.F. Denno. 1983. I n d i v i d u a l , p o p u l a t i o n and g e o g r a p h i c p a t t e r n s i n p l a n t d e f e n s e . I n : R.F. Denno and M.S. McClure ( E d s . ) . V a r i a b l e P l a n t s and H e r b i v o r e s i n N a t u r a l and Managed Systems. Academic P r e s s . pp. 463-512. L a i n g , J.E. 1969. L i f e h i s t o r y and l i f e t a b l e of Tetranycluis urticae Koch. A c a r o l o g i a 3_2: 42-57. Lam, T.H. and M. Shaw. 1970. Removal of p h e n o l i c s from p l a n t e x t r a c t s by g r i n d i n g w i t h a n i o n exchange r e s i n . B i o c h . Biophy. Res. Comm. 3_9: 965-968. 135 Lane, H.C. and S c h u s t e r , M.F. 1981. Condensed t a n n i n s of c o t t o n l e a v e s . P h y t o c h e m i s t r y 20: 425-427. L a p o i n t e , S.L., W.M. T i n g e y . 1984. Fee d i n g response of green peach a p h i d (Homopt er a: Aphi di dae) t o p o t a t o g l a n d u l a r t r i c h o m e s . J . Econ. Entomol. 77: 386-389. L a p o i n t e , S.L. and W.M. Ti n g e y . 1986. G l a n d u l a r t r i c h o m e s of Solarium neocar denasi i c o n f e r r e s i s t a n c e t o green peach a p h i d (Homoptera: Aphi di dae) J . Econ. Entomol. 79: 1265-1268. L a r s o n , K.C. and R.E. B e r r y . 1984. I n f l u e n c e of peppermint p h e n o l i c s and monoterpenes on t w o s p o t t e d s p i d e r m i t e (Acari: Tetranychi dae). E n v i r o n . Entomol. V3: 282-285. L e v i n , D. 1973. The r o l e of t r i c h o m e s i n p l a n t d e f e n s e . Q u a r t . Rev. B i o l . 48: 3-15. Levy, M. and K. F u j i i . 1978. Geographic v a r i a t i o n of f l a v o n o i d s i n Phlox Carolina. Biochem. S y s t . E c o l . 6: 117-125. L e w o n t i n , M. 1965. S e l e c t i o n f o r c o l o n i z i n g a b i l i t y . I n : H.G. Baker and G.L. S t e b b i n s ( E d s . ) . The G e n e t i c s of C o l o n i z i n g S p e c i e s . Academic P r e s s , New York. Pp. 77-94. L u k e f a h r , M.J. and J.E. H o u g h t a i l i n g . 1969. R e s i s t a n c e of c o t t o n s t r a i n s w i t h h i g h g o s s y p o l c o n t e n t t o Heliothis spp. J . Econ. Entomol. 6J_: 588-591. L u k e f a h r , M.J., J.E. H o u g h t a l i n g and H.M. Graham. 1971. S u p p r e s s i o n of Heliothis p o p u l a t i o n w i t h g l a b r o u s c o t t o n s t r a i n s . J . Econ. Entomol. 64: 486-488. Maas, J . L . ( E d . ) . 1984. Compendium of s t r a w b e r r y d i s e a s e s . Amer. P h y t o p a t h . Soc. pp. 23-24. 136 M a h l b e r g , P.G., C.T. Hammond, J.C. Turner and J.K. H e m p h i l l . 1984. S t r u c t u r e , development and c o m p o s i t i o n of g l a n d u l a r t r i c h o m e s of Cannabis sativa L. I_n: E. R o d r i g u e z , P.L. Healey and J . Mehta ( E d s . ) . B i o l o g y and C h e m i s t r y of P l a n t Trichomes. Plenum P r e s s , New York. pp. 23-51. Margna, U. 1977. C o n t r o l a t the l e v e l of s u b s t r a t e s u p p l y - An a l t e r n a t i v e i n r e g u l a t i o n of p h e n y l p r o p a n o i d a c c u m u l a t i o n i n p l a n t c e l l s . Phytochem. J_6: 419-426. Matsuda, K. 1978. Fe e d i n g s t i m u l a t i o n of f l a v o n o i d s f o r v a r i o u s l e a f b e e t l e s (Coleopt era: Chrysomel i dae). A p p l . Entomol. Z o o l . J_3: 228-230. M c C l u r e , M.S. 1983. C o m p e t i t i o n between h e r b i v o r e s and i n c r e a s e d r e s o u r c e h e t e r o g e n i t y . I_n: R.F. Denno and M.S. McClure ( E d s . ) . V a r i a b l e P l a n t s and H e r b i v o r e s i n N a t u r a l and Managed Systems. Academic P r e s s , New Yo r k , pp. 125-150. M c F a r l a n e , J.E. and M.H.W. D i s t l e r . 1982. The e f f e c t of r u t i n on growth, f e c u n d i t y and food u t i l i z a t i o n i n Acheta domesticus ( L . ) . J . I n s e c t P h y s i o l . 2J3: 85-88. McKey, D. 1979. The d i s t r i b u t i o n of secondary compounds w i t h i n p l a n t s . I_n: G.A. R o s e n t h a l and D.H. Janzen ( E d s . ) . H e r b i v o r e s : T h e i r I n t e r a c t i o n w i t h Secondary P l a n t M e t a b o l i t e s . Academic P r e s s , New York. pp. 56-133. Mehlenbacher, S.A., R.L. P l a i s t e d and W.M. T i n g e y . 1983. I n h e r i t a n c e of g l a n d u l a r t r i c h o m e s i n c r o s s e s w i t h Sol anum berthaultii. Am. P o t a t o J . 60: 699-708. Mehlenbacher, S.A., R.L. P l a i s t e d and W.M. T i n g e y . 1984. H e r i t a b i l i t y of t r i c h o m e d e n s i t y and d r o p l e t s i z e i n i n t e r s p e c i f i c p o t a t o h y b r i d s and r e l a t i o n s h i p t o a p h i d r e s i s t a n c e . Crop. S c i . 224: 320-322. Mole, S., J.A.M. Ross and P.G. Waterman. 1988. L i g h t -i n d u c e d v a r i a t i o n i n p h e n o l i c l e v e l s i n f o l i a g e of r a i n - f o r e s t p l a n t s . J . Chem. E c o l . J_4: 1-22. 1 3 7 d e l M o r a l , R. 1 9 7 2 . On the v a r i a b i l i t y of c h l o r o g e n i c a c i d c o n c e n t r a t i o n . O e c o l o g i a 9: 2 8 9 - 3 0 0 . Moran, N. 1 9 8 1 . I n t r a s p e c i f i c v a r i a b i l i t y i n h e r b i v o r e performance and h o s t q u a l i t y : A f i e l d s t u d y of Uroleucon caligatum (Homopt er a: Aphi di dae) and i t s Soli dago h o s t s (Asteraceae). E c o l . Entomol. 6: 301 -3 0 6 . Nemec, S. 1 9 7 3 . P h e n o l i c s i n the s t r a w b e r r y r o o t . Ann. Bot. (London). 3 7 : 9 3 5 - 9 4 1 . Nemec, S. 1 9 7 6 . Response of t h r e e r o o t r o t f u n g i t o s t r a w b e r r y p h e n o l i c s and the r e l a t i o n of p h e n o l i c s t o d i s e a s e r e s i s t a n c e . M y c o p a t h o l o g i a J59: 3 7 - 4 0 . N o r r i s , D.M. and M. Kogan. 1 9 8 0 . B i o c h e m i c a l and m o r p h o l o g i c a l bases of r e s i s t a n c e . I_n: F.G. Maxwell and P.R. J e n n i n g s . B r e e d i n g P l a n t s R e s i s t a n t t o I n s e c t s . J . W i l e y & Sons I n c . , New York. pp. 2 4 - 6 0 . P a i n t e r , R.H. 1 9 5 1 . I n s e c t R e s i s t a n c e i n Crop P l a n t s . M a c M i l l a n Co., New York, pp 5 2 0 . P a i v a , M. and J . J a n i c k . 1 9 8 0 . R e l a t i o n s h i p between l e a f pubescence and r e s i s t a n c e t o European r e d m i t e i n a p p l e . H o r t s c i e n c e J_5: 5 1 1 - 5 1 2 . P a t t e r s o n , C.G., R. T h u r s t o n and J.G. R o d r i g u e z . 1 9 7 4 . Twospotted s p i d e r m i t e r e s i s t a n c e i n Nicotiana s p e c i e s . J . Econ. Entomol. 6 7 : 3 4 1 - 3 4 4 . P a t t e r s o n , C.G., D.E. K n a v e l , T.R. Kemp and J.G. R o d r i g u e z . 1 9 7 5 . Chemical b a s i s f o r r e s i s t a n c e t o Tetranychus urticae (Koch.) i n tomatoes. E n v i r o n . Entomol. 4: 6 7 0 - 6 7 4 . Pesez, M. and J . B a r t o s . 1 9 7 4 . C o l o r i m e t r i c and F l o u r i m e t r i c a n a l y s i s of o r g a n i c compounds and drugs . M. Dekker, I n c . , New York, pp 2 4 3 . 138 P e t e r s , K.M. and R.E. B e r r y . 1980. E f f e c t of hop l e a f morphology on t w o s p o t t e d s p i d e r m i t e . J . Econ. Entomol. 73: 235-238. P e t e r s o n , R.L. and J . Vermeer. 1984. H i s t o c h e m i s t r y of t r i c h o m e s . I_n: E. R o d r i g u e z , P.L. Healey and J . Mehta ( E d s . ) . B i o l o g y and C h e m i s t r y of P l a n t Trichomes. Plenum P r e s s , New York. pp. 71-95. P i e r p o i n t , W.S. 1969. O-Quinones formed i n p l a n t e x t r a c t s . T h e i r r e a c t i o n s w i t h amino a c i d s and p e p t i d e s . Biochem. J . 112: 609-616. P i e r p o i n t , W.S., R.J. I r e l a n d and J.M. C a r p e n t e r . 1977. M o d i f i c a t i o n of p r o t e i n s d u r i n g the o x i d a t i o n of l e a f p h e n o l s : R e a c t i o n of p o t a t o v i r u s X w i t h C h l o r o g e n o q u i n o n e . P h y t o c h e m i s t r y j_6: 29-34. Poe, S.L. 1973. S u p p r e s s i o n w i t h a c a r i c i d e s of t w o s p o t t e d s p i d e r m i t e p o p u l a t i o n s on F l o r i d a s t r a w b e r r i e s . J . Econ. Entomol. 66: 490-495. Q u i r o s , C.F., M.A. S t e v e n s , C M . R i c k and M.L. Kok-Yokomi. 1977. R e s i s t a n c e i n tomato t o the p i n k form of the p o t a t o a p h i d Macrosiphum euphorbiae (Thomas): The r o l e of anatomy, e p i d e r m a l h a i r s and f o l i a g e c o m p o s i t i o n . J . Amer. Soc. H o r t . S c i . 102: 166-171. Rasmy, A.H. 1985. The b i o l o g y of the t w o s p o t t e d s p i d e r m i t e Tetranychus urticae as a f f e c t e d by r e s i s t a n t Sol anaceous p l a n t s . A g r i c . Ecosystems E n v i r o n . 13: 325-328. Raupp, M.J. and R.F. Denno. 1983. Leaf age as a p r e d i c t o r of h e r b i v o r e d i s t r i b u t i o n and abundance. I_n: R.F. Denno and M.S. McClure ( E d s . ) . V a r i a b l e P l a n t s and H e r b i v o r e s i n N a t u r a l and Managed Systems. Academic P r e s s , New York. pp. 91-125. Rausher, M.D. 1983. E c o l o g y of h o s t s e l e c t i o n b e h a v i o r i n phytophagous i n s e c t s . I_n: R.F. Denno and M.S. McClure ( E d s . ) . V a r i a b l e P l a n t s and H e r b i v o r e s i n N a t u r a l and Managed Systems. Academic P r e s s , New York. pp. 223-250. 139 Raworth, D.A. 1986. An economic t h r e s h o l d f u n c t i o n f o r the t w o s p o t t e d s p i d e r m i t e , Tetranychus urticae (Acari: Tetranychi dae), on s t r a w b e r r i e s . Can. Ent. 118: 9-16. Reese, J.C., B.G. Chan and A.C. Waiss, J r . 1982. E f f e c t of c o t t o n condensed t a n n i n , maysin ( c o r n ) and p i n i t o l (soybeans) on Heliothis zea growth and development. J . Chem. E c o l . 8: 1429-1436. Ribereau-Gayon, P. 1972. P l a n t p h e n o l i c s . 0. Boyd E d i n b o u r g h . pp 254. Rhoades, D.F. 1979. E v o l u t i o n of p l a n t c h e m i c a l d e f ense a g a i n s t h e r b i v o r e s . I_n: G.A. R o s e n t h a l and D.H. Janzen ( E d s . ) . H e r b i v o r e s : T h e i r I n t e r a c t i o n w i t h Secondary P l a n t M e t a b o l i t e s . Academic P r e s s , New York, pp. 3-48. Rhoades, D.F. 1983. H e r b i v o r e p o p u l a t i o n dynamics and p l a n t c h e m i s t r y . I_n: R.F. Denno and M.S. McClure ( E d s . ) . V a r i a b l e P l a n t s and H e r b i v o r e s i n N a t u r a l and Managed systems. Academic P r e s s , New York. pp. 155-220. R o d r i g u e z , J.G., C.E. C h a p l i n , L.P. S t o l t z , A.M. Lasheen. 1970. S t u d i e s on r e s i s t a n c e of s t r a w b e r i e s t o m i t e s . I . E f f e c t s of p l a n t n i t r o g e n . J . Econ. Entomol. 63: 1855-1858. Ryan, J . J . 1971. F l a v o n o i d g l y c o s i d e s of the c u l t i v a t e d s t r a w b e r r y . J . Food S c i . 36: 867-870. Sances, F.V., J.A. Wyman and J.P. T i n g . 1979a. M o r p h o l o g i c a l responses of s t r a w b e r r y l e a v e s t o i n f e s t a t i o n of t w o s p o t t e d s p i d e r m i t e . J . Econ. Entomol. 72: 710-713. Sances, F.V., J.A. Wyman and J.P. T i n g . 1979b. P h y s i o l o g i c a l responses t o s p i d e r mite i n f e s t a t i o n on s t r a w b e r r i e s . E n v i r o n . Entomol. 8: 711-714. Sances, F.V., J.A. Wyman, J.P. T i n g , R.A. VanSteennyk and E.R. Oatman. 1981. S p i d e r m i t e i n t e r a c t i o n w i t h p h o t o s y n t h e s i s , t r a n s p i r a t i o n and p r o d u c t i v i t y of s t r a w b e r r y . E n v i r o n . Entomol. j_0: 442-448. S c h a e f e r s , G.A. 1983. Pes t management system f o r s t r a w b e r r y i n s e c t s . I_n: D. P i m e n t a l ( E d . ) . Handbook of P e s t Management i n A g r i c u l t u r e V o l . 3. CRC P r e s s , Boca Raton, F l . pp. 377-393. S c h u s t e r , M.F., F.G. Maxwell and J.N. J e n k i n s . 1972. A n t i b i o s i s t o t w o s p o t t e d s p i d e r m i t e i n u p l a n d and American pima c o t t o n . J . Econ. Entomol. 6_5: 1110-1111. S c h u s t e r , M.F., F.G. Maxwell and J.N. J e n k i n s . 1972. R e s i s t a n c e t o the t w o s p o t t e d s p i d e r m i t e i n c e r t a i n Gossipium hirsutum r a c e s . Gossipium s p e c i e s and g l a n d e d - g l a n d l e s s c o u n t e r p a r t c o t t o n s . J . Econ. Entomol. 65: 1108-1110. S c o t t , D. 1951. C y t o l o g i c a l s t u d i e s on p o l y p o i d s d e r i v e d from t e t r a p l o i d Fragaria vesca and c u l t i v a t e d s t r a w b e r r i e s . G e n e t i c s 36: 311-324. S c r i b e r , J.M. 1984. H o s t - p l a n t s u i t a b i l i t y . I n : W.J. B e l l and R.T. Carde ( E d s . ) . Chemical E c o l o g y of I n s e c t s . Chapman and H a l l L t d . pp. 160-202. Seaman, F.M., M.J. L u k e f a h r and T.J. Marby. 1977. The c h e m i c a l b a s i s of the n a t u r a l r e s i s t a n c e of Gossypi urn hirsutum L. t o H e l i o t h i s z e a . P r o c . B e l t w i d e C o t t o n P r o d . Res. Conf.: 102-103. S e r v i c e , P. 1984. The d i s t r i b u t i o n of a p h i d s i n response t o v a r i a t i o n among i n d i v i d u a l h o s t p l a n t s : Uroleucon rudmeckiae (Homopt e r a: Aphi di dae) and Rudbecki a laciniata (Asteraceae). E c o l . Entomol. 9: 321-328. Shanks, C.H., J r . and B.H. B a r r i t t . 1974. Fragaria chiloensis c l o n e s r e s i s t a n t t o the st r a w b e r y a p h i d . H o r t s c i e n c e 9: 202-203. Shanks, C.H., J r . and B.H. B a r r i t t . 1975. R e s i s t a n c e of s t r a w b e r r i e s t o the t w o s p o t t e d s p i d e r m i t e . J . Econ. Entomol. 68: 7-10. 141 Shanks, C.H., J r . and B.H. B a r r i t t . 1980. Twospotted s p i d e r m i t e r e s i s t a n c e of Washington s t r a w b e r r i e s . J . Econ. Entomol. 73: 419-423. Shanks, H.C. and B.H. B a r r i t t . 1984. R e s i s t a n c e of Fragaria chiloensis clones to the twospotted spider mite. Hort science 15: 640-641. Shanks, H.C, D.L. Chase and J.D. C h a m b e r l a i n . 1984. R e s i s t a n c e of c l o n e s of w i l d s t r a w b e r r y , F r a g a r i a c h i l o e n s i s , t o a d u l t O t i o r h y n c h u s s u l c a t u s and 0. ouatus ( C o l e o p t e r a : C u r c u l i o n i d a e ) . E n v i r o n . Entomol. 13: 1042-1045. Shanks, C H . and R.P. Doss. 1986. B l a c k v i n e w e e v i l (Coleoptera: Curculionidae) f e e d i n g and o v i p o s i t i o n on l e a v e s of w e e v i l - r e s i s t a n t and s u s c e p t i b l e s t r a w b e r r y c l o n e s p r e s e n t e d i n v a r i o u s q u a n t i t i e s . E n v i r o n . Entomol. 5: 1074-1077. Shaver, T.N. and M.J. L u k e f a h r . 1969. E f f e c t of f l a v o n o i d pigments and g o s s y p o l on growth and development of the bollworm, tobacco budworm and p i n k bollworm. J . Econ. Entomol. 62: 643-645. S i n g e l t o n , V.L. and J.A. R o s s i J r . 1965. C o l o r i m e t r y of t o t a l p h e n o l i c s w i t h p h o s p h o - m o l y b d i c - p h o s p h o t u n g i s t i c a c i d r e a g e n t s . Amer. J . E n o l . V i t i c . j_6: 1 44-1 58. S n e t s i n g e r , R., C P . B a l d e r s t o n e and R. C r a i g . 1966. R e s i s t a n c e t o the t w o s p o t t e d s p i d e r m i t e i n Pelargonium. J . Econ. Entomol. 5_9: 76-78. Snyder, J.C. and C D . C a r t e r . 1984. Leaf t r i c h o m e s and r e s i s t a n c e of Lycopersi con hirsutom and L. esculentum t o s p i d e r m i t e s . J . Amer. Soc. H o r t . S c i . 109: 837-843. S t o h r , H. and K. Herrmann. 1975. D i e P h e n o l i s h e n I n h a l t s s t o f f e des Obst e s . Z. Lebenssm. U n t e r s . F o r c h . ( G e r ) . 159: 341-348. 142 S t i p a n o v i c , R.D. 1983. F u n c t i o n and c h e m i s t r y of p l a n t t r i c h o m e s and g l a n d s i n i n s e c t r e s i s t a n c e . I_n: P.A. Hedin ( E d . ) . P l a n t R e s i s t a n c e t o I n s e c t s . ACS Symposium S e r i e s 208. pp. 70-100. S t o n e r , A.K. and T. S t r i n g f e l l o w . 1967. R e s i s t a n c e of tomato v a r i e t i e s t o s p i d e r m i t e . P r o c . Amer. Soc. H o r t . S c i . 90: 324-329. S t o n e r , A.K., J.A. Frank and A.G. G e n t i l e . 1968. The r e l a t i o n s h i p of g l a n d u l a r h a i r s on tomatoes t o s p i d e r m i t e r e s i s t a n c e . P r o c . Amer. Soc. H o r t . S c i e n c e . 93: 532-539. Swain, T. and J.L. G o l d s t e i n . 1964. The q u a n t i t a t i v e a n a l y s i s of p h e n o l i c compounds. I_n: J.D. Pridham ( E d . ) . Methods i n P o l y p h e n o l s C h e m i s t r y . Pergamon P r e s s , O x f o r d , E n g l a n d . pp. 131-146. Swain, T. 1977. Secondary compounds as p r o t e c t i v e a g e n t s . Ann. Rev. P l a n t P h y s i o l . 28: 479-501. Swain, T. 1979. Tannins and l i g n a n s . I_n: H e r b i v o r e s . T h e i r I n t r e r a c t i o n W i t h Secondary P l a n t M e t a b o l i t e s . G.A. R o s e n t h a l and D.H. Janzen ( E d s . ) , Academic P r e s s , London, pp. 657-682. Thomson, R.H. 1964. S t r u c t u r e and r e a c t i v i t y of p h e n o l i c compounds. I_n: J.B. Harborne ( E d . ) . B i o c h e m i s t r y of P h e n o l i c Compounds. Academic P r e s s , New York. pp. 1-33. T i n g e y , W.M. and R.W. G i b s o n . 1978. Fee d i n g and m o b i l i t y of the p o t a t o l e a f h o p p e r i m p a i r e d by g l a n d u l a r t r i c h o m e s of Solatium berthaultii and Solarium pol yadeni um. J . Econ. Entomol. 7J_: 856-858. T i n g e y , W.M. and J.E. Laubengayer. 1981. Defense a g a i n s t the green peach a p h i d and p o t a t o l e a f h o p p e r by g l a n d u l a r t r i c h o m e s of Sol anum bertheultii. J . Econ. Entomol. 74: 721-725. 143 T i n g e y , W.M., R.L. P l a i s t e d , J.E. Laubengayer and S.A. Mehlenbacher. 1982. Green peach a p h i d r e s i s t a n c e by g l a n d u l a r t r i c h o m e s i n Solanum tuberosum x S. berthaultii h y b r i d s . Am. P o t a t o J . 59: 241-251. T i n g e y , W.M. and S.L. S i n d e n . 1982. G l a n d u l a r pubescence, g l y c o a l k a l o i d c o m p o s i t i o n , and r e s i s t a n c e t o the green peach a p h i d , p o t a t o l e a f h o p p e r , and p o t a t o f l e a b e e t l e i n Sol anum berthaultii. Am. P o t a t o J . 59: 95-106. Todd, G.W., A. Getahun and D.C. C r e s s . 1971. R e s i s t a n c e i n b a r l e y t o the greenbug Schizaphis grami num. 1. T o x i c i t y of p h e n o l i c and f l a o n o i d compounds and r e l a t e d s u b s t a n c e s . Ann. Entomol. Soc. Amer. 61: 718-722. Towers, G.H.N. 1964. M e t a b o l i s m of p h e n o l i c s i n h i g h e r p l a n t s and m i c r o - o r g a n i s m s . Ijn: J.B. Harborne ( E d . ) . B i o c h e m i s t r y of P h e n o l i c Compounds. Academic P r e s s , New York. pp. 249-295. V a l i e l a , J . , L. Koumjian and T. Swain. 1979. Cinnamic a c i d i n h i b i t i o n of d e t r i t u s f e e d i n g . Nature (London). 280: 55-57. Van de V r i e , M., J.A. McMurtry and C.G. H u f f a k e r . 1972. Ec o l o g y of t e t r a n y c h i d m i t e s and t h e i r n a t u r a l enemies: A r e v i e w . I I I . B i o l o g y , e c o l o g y and pes t s t a t u s and h o s t - p l a n t r e l a t i o n of t e t r a n y c h i d s . H i l g a r d i a 41: 343-432. Van Sumere, C.F., J.A.A. Dedonder, H. de Po o t e r and J . Pe. 1975. P l a n t p r o t e i n s and p h e n o l i c s . I n : J.B. Harborne and C.F. van Sumere ( E d s . ) . The C h e m i s t r y and B i o c h e m i s t r y of P l a n t P r o t e i n s . Academic P r e s s , New York. Pp. 211-256. Waiss, A . C . J r . , B.G. Chan, C.A. E l l i g e r , B.R. Wiseman, W.W M c M i l l a n , N.W. Widstrom, M.S. Zuber and A . J . K e a s t e r . 1979. M a y s i n , a f l a v o n e g l y c o s i d e from c o r n s i l k s w i t h a n t i b i o t i c a c t i v i t y toward c o r n earworm. J . Econ. Entomol. 72: 256-258. Webster, J.A. 1975. A s s o c i a t i o n of p l a n t h a i r s and i n s e c t r e s i s t a n c e . M i s c e l l a n e o u s P u b l i c a t i o n No. 1297. Agr. Res. S e r v i c e , U.S. Dept. of A g r i c . 1 44 Whitham, T.G. 1980. The t h e o r y of h a b i t a t s e l e c t i o n : Examined and extended u s i n g Pemphi gus a p h i d s . Amer. Nat. 115: 449-466. Whitham, T.G. 1983. Host m a n i p u l a t i o n of p a r a s i t e s : W i t h i n - p l a n t v a r i a t i o n as a defense a g a i n s t r a p i d l y e v o l v i n g p e s t s . I_n: R.F. Denno and M.S. McClure ( E d s . ) . V a r i a b l e P l a n t s and H e r b i v o r e s i n N a t u r a l and Managed Systems. Academic P r e s s , New York. pp. 15-42. W h i t t a k e r , R.H. 1970. The b i o c h e m i c a l e c o l o g y of h i g h e r p l a n t s . I_n: Sondheimer and Simeone ( E d s . ) . C h e m i c a l E c o l o g y . Academic P r e s s , I n c . , New York. pp. 43-70. W i l l i a m s , B.L. and S.H. Wender. 1952. The i s o l a t i o n and i d e n t i f i c a t i o n of kampf e r o l and q u e r c e t i n from s t r a w b e r r i e s {Fragaria chiloensis). J . Am. Chem. Soc. 74: 5919-5920. W i l l i a m s , W.G., G.G. Kennedy, R.T. Yamamoto, J.D. Thacker and J . Bordner. .1980. 2-Tridecanone: A n a t u r a l l y o c c u r i n g i n s e c t i c i d e from the w i l d tomato Lycopersi con hirsutum f. glabrat um. S c i e n c e 207: 888-889. W i l l m e r , P. 1986. M i c r o c l i m a t i c e f f e c t s on i n s e c t s a t the p l a n t s u r f a c e . In: B. J u n i p e r and S i r R. Southwood ( E d s . ) . I n s e c t s and the P l a n t S u r f a c e . Edward A r n o l d , London. pp. 65-81. Woodhead, S. 1981. E n v i r o n m e n t a l and b i o t i c f a c t o r s a f f e c t i n g the p h e n o l i c c o n t e n t of d i f f r e n t c u l t i v a r s of Sorghum bicol or. J . Chem. E c o l . 7: 1035-1047. Woodhead, S. and E.A. Bernays. 1978. The c h e m i c a l b a s i s of r e s i s t a n c e of Sorghum bicolor t o a t t a c k by Locust a migratoria. Entomol. Exp. A p p l . TA: 123-144. Wrensch, D.L. 1985. R e p r o d u c t i v e p arameters. I_n: W. H e l l e and M.W. S a b e l i s ( E d s . ) . S p i d e r M i t e s , T h e i r B i o l o g y , N a t u r a l Enemies and C o n t r o l . E l s e v i e r S c i e n c e Pub., The N e t h e r l a n d s . A: 165-170. 145 Zucker, W.V. 1982. How a p h i d s choose l e a v e s : The r o l e of p h e n o l i c s i n ho s t s e l e c t i o n by a g a l l i n g a p h i d . E c o l o g y 63: 972-981. 146 8. APPENDICES Appendix 4.1 Means and s t a n d a r d e r r o r s (+SE) of mi t e o v i p o s i t i o n (eggs\72 h r ) f o r b l o c k s and c l o n e s . B l o c k 14.52,( + 6.62); 16.59,(+ 6.54 ) ; 16.91 (+7.54) Clone 0-10 16/J , 2.66, (+1.15); 62/D, 4.33, (+4.16); 52/E ,3.33, (+3.21); 85/D, 2.66, (+2.08); 118/K,9.66, (+2.51); 25/G, 6.00,(+7.81); 497c, 7.00, (+5.56); 105/J, 5.33, (+2.08); 10-20 111/J, 14.67, (+4.72); 19/J, 15.00,(+6.24); 112/Z, 13.67, (+4.16); 40/B, 13.67,(+9.07); 50/C, 11.00, (+4.00); 74/E, 10.33,(+0.57); 108/J, 13.67,(+6.11); 100/C,15.00, (+7.00); 71/E, 15.00,(+1.00); 122/V, 13.67, (+10.697; 78/E, 12.33, (+2.51); 81/G, 12.67, (+9.71); 44/P, 15.00, (+2.64); 18/J, 13.00, (+2.64); 103/B, 14.64, T+3.05); 120 / Q Q , 14.00, (+7.55); 76/G, 11 .67,(+8.73); 73/G, 13.33, (+2.51); 21/D, 17.67, (+3.21); 45/E, 19.00, (+6.24); 34/E, 19.00, (+3.60); 55/E, 18.00,(+7.00); 119/MM, 15.67, (+4.16); 107/K, 16.00,(+7.817; 58/A, 18.00, (+2.00); 106/T, 17.00, (+5.00); 110/F, 16.33, (+2.08); 88/B, 18.33, (+6.80); 137G, 17.67,(+3.05); 86/F, 18.00,(+2.00); 121/KK, 17.00,(+5.007; 66/D, 20.00, (+9.53); 56/E, 20.00, (+3.46); 79/C, 18.00, (+1.00); 109/L,17.67,(+3.05); 697J, 20.00,(+10.82); 547MM, 17.67,(+6.50), SOOK/1,18.33, ( + 3 . 0 5 ) ; 92/D, 19.67, (+7.37); 26/B, 16.67,(+6.02); 51/B, 18.33, (+3.21); 28/E, 17.00, (+5.56); 20-30 83/A, 21.00,(+4.53); PP/20, 21.00,(+4.00); 60/F, 22.00, ( + 5.007; 53/A, 22 . 67,(+ 4. 1 6 ) ; 8/B, 21.33, (+5.78); 29/A, 22.33,(+ 1.52); 114/T, 21 . 00,(+6 . 2 4 ) ; 20/G, 21.33, (+10.07); 87/D, 22.33,(+2.51 ); 7 2 / J , 20.33,(+4.61); 75/D, 23.00,(+4.35); TOTEM, 20.33, (+1.55); 104/E, 22.00,(+2.647; 46/D, 29.33,(+7.63). * C l o n e s shown i n b o l d f a c e were chosen t o r e p r e s e n t F. chiloensis i n f o l l o w i n g e x p e r i m e n t s . 147 Appendix 5.1 Means and s t a n d a r d e r r o r s (+SE) of c o n c e n t r a t i o n s of c a t e c h o l - b a s e d p h e n o l i c s f o r 16 c l o n e s of F. c h i l o e n s i s and t h r e e l e a f age c a t e g o r i e s . C l o n e 49\C, 1.250, (+0.366); 34\E, 1.233, (+0.277); 20\PP, 1 . 1 3 8 , (+0 . 2 7 2 T ; 52\E, 1.204, (+0 . 5 2 0 7 ; 28\E, 1.195, ( + 0 . 3 2 0 ) ; 62\D, 1 . 3 5 8 , ( + 0 . 3 1 0 ) , 85\D, 1.121, (+0.323); 7 2 \ J , 1 . 0 7 8 , ( + 0 . 2 8 7 ) ; 25\G, 1 . 2 9 5 , (+0.446); "TOTEM", 1 . 1 4 8 , (+0.336); 16\J, 1.188, ( + 0 . 2 9 5 ) ; 119\MM, 1 . 0 7 5 , ( + 0 . 3 2 5 ) ; 1 0 5 \ J , 1 . 2 6 7 , (+0.466); 46\D, 0 . 6 3 7 , (+0.223); 112\Z, 0 . 8 6 3 , ( + 0 . 2 7 0 ) ; 104\T, 1 . 0 8 2 , T+0.338); Age (Age 1 ) , 1 . 2 8 1 , ( + 0 . 3 4 9 ) ; (Age 2 ) , 1 . 0 1 3 , ( + 0 . 3 5 1 ) , (Age 3 ) , 1 . 0 9 8 , ( + 0 . 3 8 9 ) . Appendix 5.2 Means and s t a n d a r d e r r o r s (+SE) of c o n c e n t r a t i o n s of t o t a l p h e n o l i c s f o r 16 c l o n e s of F. chiloensis and t h r e e l e a f age c a t e g o r i e s . C l o n e 49\D, 2.824, (+0.951); 34\E, 2.221, (+0.712); 20\PP, 2.063, (+0.7747; 52\E, 2.079, (+0.8347; 28\E, 2.323, (+0.925); 62\D, 2.427, (+0.671); 85\D, 2.347, (+0.875); 7 2 \ J , 1.798, (+0.535); 25\G, 2.419, (+1.104); "TOTEM", 2.684, (+0.651); 16\J, 2.274, (+0.642); 119\MM. 2.260, (+0.558); 105\J, 2.554, (+0.869); 49\D, 1.401, (+0.470); 112\Z, 1.341, (+0.581); 104\T, 2.094, T+0.860); Age (Age 1 ) , 2.591, (+0.856); (Age 2 ) , 1.923, (+0.792); (Age 3 ) , 2.068, (+0.769). 149 Appendix 4.4.1 R e t e n t i o n times and peak a r e a s of e x t r a c t s of "Totem", F. chiloensis c l o n e 119 and t h e i r b i n a r y m i x t u r e . TOTEM (1) CLONE 119 (2) M i x t u r e 1 and 2 Peak name Ret.t i m e Area R e t . t i m e Area R e t . t i m e Area Unknown peak 1 3. 38 6887066 3 .35 11511165 3. 46 11611341 Unknown peak 2 4. 24 7723313 4 .26 13269202 4. 33 7567683 Unknown peak 3 4. 35 7983380 4. 45 8008520 Unknown peak 4 4. 77 25515601 4 .69 19462031 4. 88 22718597 Unknown peak 5 7. 00 806388 7. 03 629161 Unknown peak 6 8. 18 5170248 7 .89 5200354 8. 1 4 5170219 Unknown peak 7 1 1 .74 5936643 1 1 .32 10157348 12 .09 7928313 Unknown peak 8 18 .39 5577647 1 7 .72 7780779 19 .91 6468247 Unknown peak 9 20 .73 3713403 20 .37 6680648 21 .36 4436843 Unknown peak 10 21 . 1 4 9032428 20 .82 3647645 21 .76 7674528 Unknown peak 1 1 21 .52 1552861 Unknown peak 12 21 .24 2445442 Unknown peak 1 3 21 .96 1728042 21 .60 2232592 22 .38 1457042 pHydroxybenzoic 22 .26 1868366 21 .98 4374165 22 .96 3964086 Unknown peak 1 4 22 .33 2474222 Unknown peak 1 5 22 .63 2244211 Unknown peak 1 6 22 .78 8079934 23 .32 3028740 Unknown peak 17 23 .00 5065254 23 .59 2351318 Unknown peak 18 23 .90 5809202 24 .23 2245291 Unknown peak 19 24 .19 8061142 24 .54 4143442 (+) C a t e c h i n 24 .66 3368601 24 .25 6142223 24 .98 4352082 Unknown peak 20 25 .31 7731190 25 .02 9288561 25 .61 8259241 Unknown peak 21 25 .52 7372550 25 .27 12719113 25 .75 10241265 Unknown peak 22 26 . 1 6 3302040 25 .85 4912797 26 .40 3622540 Unknown peak 23 26 .42 2650359 C h l o r o g e n i c a i . 27 .06 6740146 26 .77 10068199 27 .31 8832391 Unknown peak 24 27 .63 372421 1 27 .92 2045502 Unknown peak 25 28 .2114434964 28 .09 23405372 28 .59 16885118 Unknown peak 26 29 .07 1282187 28 .67 3253016 29 .25 2925790 Unknown peak 27 29 .47 4405800 29 .30 14503653 29 .86 8058871 Unknown peak 28 30 .2229118304 30 .08 59956706 30 .54 47059019 Unknown peak 29 31 .21 1765734 31 .01 2538243 31 .52 2506282 Unknown peak 30 31 .91 6671955 31 .76 1 4114153 32 . 1 9 9119466 Unknown peak 31 32 .44 9629404 32 .36 18885212 32 .68 15149871 Unknown peak 32 34 .71 1356308 34 .55 1803788 34 .90 1592290 Unknown peak 33 35 .33 1477218 35 .04 4210212 35 .50 2827496 Unknown peak 34 37 .03 7835695 37 .16 3889057 Unknown peak 35 38 .21 1432745 Unknown peak 36 40 .90 9836635 40 .22 22190821 40 .66 15619403 R u t i n 41 .96 3965574 41 .53 8698681 41 .99 5852097 Unknown peak 37 43 .422 ! 1608419 42 .89 31804026 43 .42 26773085 150 Appendix 4.4.2 R e t e n t i o n times and peak area s of e x t r a c t s of "Totem", F.chiloensis c l o n e 20 and t h e i r b i n a r y m i x t u r e . TOTEM (1) CLONE 20 (3) M i x t u r e 1 and 3 Peak name Ret. time Area R e t . t i m e Area R e t . t i m e Area Unknown peak 1 3 .38 6887066 3. 36 11019416 3. 50 11176956 Unknown peak 2 4 .24 7723313 4. 27 7815718 4. 39 7982520 Unknown peak 3 4 .35 7983380 4. 39 8129085 4. 53 9603944 Unknown peak 4 4 .77 25515601 4. 83 23295148 4. 98 ; 23866291 Unknown peak 5 7 .00 806388 7. 21 554727 Unknown peak 6 8 .18 5170248 8. 33 5635979 8. 44 5486503 Unknown peak 7 1 1 .74 5936643 1 1 . 98 6573452 12. 61 4983186 Unknown peak 8 12. 95 3682142 Unknown peak 9 17. 29 2365265 Unknown peak 10 18 .39 5577647 18. 64 4858224 19 .32 4489101 Unknown peak 1 1 20 .73 3713403 20. 83 7933068 21 .07 4952117 Unknown peak 12 21 . 1 4 9032428 21 . 23 6460993 21 .47 9699694 Unknown peak 13 21 .52 1552861 21 . 55 2025327 22 . 12 1898084 Unknown peak 14 21 .96 1728042 22. 02 2501854 pHydroxybenzoic 22 .26 1868366 22. 36 5298080 22 .51 3379818 Unknown peak 15 22 .63 2244211 22. 72 2725305 22 .71 2433546 Unknown peak 16 23 .00 5065254 23. 1 0 9599129 23 .09 7364178 Unknown peak 17 24 . 1 9 8061142 24. 03 4538866 24 .01 3383949 ( + ) C a t e c h i n 24 .66 3368601 24. 33 2342504 24 .27 4051101 Unknown peak 18 24 .74 7802440 24. 73 5598623 Unknown peak 19 25 .31 7731190 25. 40 17777846 25 .3817282647 Unknown peak 20 25 .52 7372550 Unknown peak 21 26 .16 3302040 26. 26 3020022 26 . 1 6 2949531 Unknown peak 22 26 .75 2570042 C h l o r o g e n i c a i . 27 .06 6740146 27. 18 5962942 27 .04 7138859 Unknown peak 23 27 .63 3724211 27 .66 1883521 Unknown peak 24 28 .21 1 4434964 28. 43 21093334 28 . 1717616795 Unknown peak 25 29 .07 1282187 29. 04 2175086 29 .03 1824408 Unknown peak 26 29 .47 4405800 29. 77 5918824 29 .46 4775397 Unknown peak 27 30 .2229118304 30. 63 20300563 30 . 1924230936 Unknown peak 28 31 .21 1765734 31 . 63 2799131 31 .18 1941102 Unknown peak 29 31 .91 6671955 32. 37 12701584 31 .96 8485228 Unknown peak 30 32 .44 9629404 32. 84 11205360 32 .49 9838545 Unknown peak 31 34 .71 1356308 35. 05 2724286 34 .91 1918342 Unknown peak 32 35 .33 1477218 35. 76 3285441 35 .37 2449540 Unknown peak 33 37 .03 7835695 36 .96 4272076 Unknown peak 34 39. 00 1572762 Unknown peak 35 40 .90 9836635 40. 98 20715207 40 .3616116052 R u t i n 41 .96 3965574 42. 45 5617558 41 .62 5222510 Unknown peak 36 43. 30 7426026 Unknown peak 37 43 .42 21608419 43. 91 28615278 43 .0731093415 151 Appendix 4.4.3 R e t e n t i o n t i m e s and peak a r e a s of e x t r a c t s of "Totem", F. chiloensis c l o n e 52 and t h e i r b i n a r y m i x t u r e . "Totem"(1) CLONE 52 (4) M i x t u r e 1 and 4 Peak Name R e t . t i m e Area R e t . t i m e Area R e t . t i m e Area Unknown peak 1 3. 38 6887066 3. 32 14353075 3. 48 12337563 Unknown peak 2 4. 24 7723313 4. 22 14565303 4. 34 17022032 Unknown peak 3 4. 35 7983380 Unknown peak 4 4. 77 5515601 4. 50 23303727 4. 80 26409910 Unknown peak 5 7. 00 806388 6. 90 893402 Unknown peak 6 8. 18 5170248 7 .46 5996769 7. 95 6275321 Unknown peak 7 1 1 . 74 5936643 10 .92 12570901 1 1 . 81 8401922 Unknown peak 8 18. 39 5577647 1 7 .66 10069871 20. 24 7899356 Unknown peak 9 20. 73 3713403 20 .44 10076357 21 . 55 6106217 Unknown peak 10 21 . 14 9032428 20 .91 4256454 21 .94 8160656 Unknown peak 1 1 21 .36 3198053 Unknown peak 1 2 21 . 52 1552861 Unknown peak 13 21 . 96 1728042 21 .77 2785401 22 .04 1428934 pHydroxybenzoic 22. 26 1868366 22 . 1 4 4416001 23 .01 4417559 Unknown peak 1 4 22. 63 2244211 22 .53 3499577 Unknown peak 1 5 23. 00 5065254 22 .94 7348107 23 .35 4284672 Unknown peak 1 6 23 .28 2054719 Unknown peak 1 7 23 .54 1997752 Unknown peak 18 24. 19 8061142 23 .71 2183584 Unknown peak 19 24 . 1 1 7896495 24 .26 2647136 () C a t e c h i n 24. 66 3368601 24 .47 7528709 24 .98 3520734 Unknown peak 20 25. 31 7731190 25 .25 13219748 Unknown peak 21 25. 52 7372550 25 .51 17294370 25 .36 19462800 Unknown peak 22 26. 1 6 3302040 26 . 1 1 7678003 26 .28 2907453 C h l o r o g e n i c a t . 27. 06 6740146 26 .69 3542177 27 .17 6386067 Unknown peak 23 27. 63 3724211 27 .011 4926011 27 .81 3498201 Unknown peak 24 28. 21 1 4434964 28 .28 35052374 28 .47 16591917 Unknown peak 25 29. 07 1282187 28 .73 3779190 Unknown peak 26 29. 47 4405800 29 .40 19090006 29 .71 6954168 Unknown peak 27 30. 2229118304 30 . 1 4 99054854 30 .44 54155866 Unknown peak 28 31 . 21 1765734 31 . 1 1 3626643 31 .45 1295156 Unknown peak 29 31 . 91 6671955 31 .81 19966167 32 .17 10324506 Unknown peak 30 32. 44 9629404 32 .38 28783864 32 .62 18348664 Unknown peak 31 34. 71 1356308 34 .69 2593922 35 .04 2120400 Unknown peak 32 35. 33 1477218 35 .23 4338992 35 .57 3009430 Unknown peak 33 37. 03 7835695 37 .22 3972971 Unknown peak 34 38 .44 1385424 38 .64 719669 Unknown peak 35 40. 90 9836635 40 .333 4949993 40 .60 22804030 Rut i n 41 . 96 3965574 41 .681 2597415 41 .90 7760750 Unknown peak 36 43. 4221608419 43 .073 5466955 43 .31 28188288 Appendix 9.1 Means and s t a n d a r d e r r o r s (+SE) of c o n c e n t r a t i o n s of c a t e c h o l - b a s e d p h e n o l i c s f o r t r e a t m e n t s , s a m p l i n g days and l e a f age c a t e g o r i e s . Treatments 0.898, (+0.336); 1.065, (+0.430); 0.900, (+0.446); 1.079, (+0.388); 0.911,(+0.276); 1.052,(+0.344) ; Day 1.110, (+0.426); 0.969, (+0.348); 0.892, (+0.331); Age 0.811, (+0.308); 1.181, (+0.413); 0.980 (+0.319); Appendix 9.2 Means and s t a n d a r d e r r o r s of c o n c e t r a t i o n s of t o t a l p h e n o l i c s f o r t r e a t m e n t s , s a m p l i n g days and l e a f age c a t e g o r i e s . Treatment 1.938, (+1.143); 1.956, (+1.099); 1.795, (+0.928); 1.908, (+1.246); 2.204, (+0.741); 2.816, (+1.261); day 2.319, (+1.240); 2.112, (+1.109); 1.878, (+1.002): Age 1.645, (+1.038); 2.438, (+1.039); 2.228, (+1.126); 

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