UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Association of economic characters in rhizoma alfalfa Eek, Catherine J. 1943-12-31

You don't seem to have a PDF reader installed, try download the pdf

Item Metadata

Download

Media
UBC_1943_A4 E3 A7.pdf [ 7.1MB ]
Metadata
JSON: 1.0105658.json
JSON-LD: 1.0105658+ld.json
RDF/XML (Pretty): 1.0105658.xml
RDF/JSON: 1.0105658+rdf.json
Turtle: 1.0105658+rdf-turtle.txt
N-Triples: 1.0105658+rdf-ntriples.txt
Original Record: 1.0105658 +original-record.json
Full Text
1.0105658.txt
Citation
1.0105658.ris

Full Text

ASSOCIATION of ECONOMIC. CHARACTERS 33T RHIZOMA ALFALFA A Thesis Submitted i n P a r t i a l F u l f i l m e n t of the Requirements f o r the Degree of Master of Science i n A g r i c u l t u r e i n the Department of Agronomy* by Catherine J . Eek The U n i v e r s i t y of B r i t i s h Columbia A p r i l 1943 ACKNOWLEDGMENT Gra t e f u l acknowledgment I f here made to Dr. V. G. Brink5 Dr. G. G. Moe, and Dr. A. H. Hutchinson, under whose guidance t h i s paper was w r i t t e n * TABLE OF CONTENTS Page INTRODUCTION 1 REVIEW OF LITERATURE 6 MATERIALS AND METHODS 10 ASSOCIATION OF SEED 'YIELD JnD OTHER CHARACTERS 12 1» A s s o c i a t i o n of Pod Shape and Number of Seeds 12 Per P6d • " 12 13 14 (a) S e l f p o l l i n a t e d a l f a l f a (b) Open p o l l i n a t e d a l f a l f a •  (g,)* _ Seed set i n grams 2. A s s o c i a t i o n of Flower Abundance and Number of Seeds 16 3. Seed S e t t i n g Compared i n Racemes Which Have Been S e l f e d and Open P o l l i n a t e d - 17 4. A s s o c i a t i o n of Flower Color and Seed Y i e l d 20 5. Comparison of Seed Y i e l d f o r Two Successive Years 22 6» D i s t r i b u t i o n of Seed Y i e l d Classes 22 7. Comparison of Seed Y i e l d , P l a n t Heights and 24 Plant Weights i n F i and F 2. 8. Comparison of Seed Y i e l d ' i n Fj_ plants & F 2 Progeny 25 ASSOCIATION OF FACTORS NOT INVOLVING SEED YIELD 27 1. Comparison of Height and.Weight Between F^ & F 2 27 ,2. A s s o c i a t i o n of Y i e l d and Height 29 3. A s s o c i a t i o n of Leaf Spotting Incidence and the Percentage of Ovules Developing on the Racemes. 30 4. A s s o c i a t i o n of Leaf Spotting and Leaf Color 31 5. A s s o c i a t i o n of Leaf Spotting and Flower Abundance 32 6. A s s o c i a t i o n of Stem Thickness and Plant Height 32 7. A s s o c i a t i o n of Height and Spread 33 Page 8 A s s o c i a t i o n of Flower Abundance and Raceme Supportin Ovules 35 9 As s o c i a t i o n of Foliage Colour and Flower Abundance 36 10 A s s o c i a t i o n of Flower Abundance andFlower F a l l 37 FLOWER COLOR INHERITANCE 38 DISCUSSION 41 CONCLUSIONS 43 SUMMARY • " 45 1 ASSOCIATION' CO? ECONOMIC CHARACTERS IN RHIZOMA ALFALFA •' > ;, A l f a l f a j to-days i s one of the world's leading forage crops, I n the regions favoring i t s grovvth, a,nd these are now many,, no crop.used f o r fodder surpasses i t i n general u t i l i t y and y i e l d . For thousands of years a l f a l f a was h i g h l y regarded i n south-western A s i a , i n which area i t was endemic, as forage sine qua hon. Slowly, s e l e c t e d . s t r a i n s made t h e i r way_into the a g r i  c u l t u r a l regions of North A f r i c a , , and southern Europe u n t i l "by the end of the' 19th century a l l of tempera-te -~; E u r a s i a knew i t as a valuahle a d d i t i o n to the forage resources. The value of the crop •was recognized "by the ea r l y white s e t t l e r s i n the Y/estern .hemisphere and, undoubtedly i n many separate occasions the plant was introduced to the new a g r i c u l t u r a l area. However, p r i o r to 1900 i t i s doubtful i f the t o t a l acreage i n "both western continents, exceeded 3 m i l l i o n "acres. Since^that':, date a t r u l y phenomenal expansion i n acreage has taken place e s p e c i a l l y i n the United States, the Argentine, Uraguay, Paraguay, Mexico and i n A u s t r a l i a , In the U.S.A. alone present crop acreage must ..now exceed 20 m i l l i o n acres. . . • C.anada has not "been excluded i n the "march" of a l f a l f a over the glohe. With the development of winter hardy s t r a i n s f o r cooler and more humid areas a l f a l f a acreage spread i n Canada. Ontario, B r i t i s h Columbia and the p r a i r i e provinces now maintain a combined crop area of ij? m i l l i o n acres. In B r i t i s h 'Columbia/ a l f a l f a has become the standard hay and pasture crop i n the c a t t l e ranching and i r r i g a t e d d i s t r i c t s . A l f a l f a , u n l i k e many other forage crops which posses, a few commendable c h a r a c t e r i s t i c s , has to i t s c r e d i t many desir a b l e agronomic features. I t i s t h i s combination or blending of so many desir a b l e agronomic features which account f o r I t s popularity.. A l f a l f a i s a legume and as such i s a.well known source of p l a n t p r o t e i n and a-'highly regarded s o i l enricher. Few crops produce p r o t e i n so e f f i c i e n t l y } from three tons of . a l f a l f a hay (an average crop) 625 pounds of digestable p r o t e i n are obtained' A comparable crop of timothy (1.5 Tons) produces by compai-ison only 90 pounds of digestable p r o t e i n ; a crop of clover . (3 Tkns) , 40Q pounds and a barley crop (50 B u s h e l s ) 5 200 pounds. In common w i t h most legumes, . a l f a l f a w i t h associated FJraobia, f i x e s appreciable q u a n t i t i e s of atmospheric nitrogen and as such plays an important p a r t i n main t a i n i n g the s o i l n itrogen balance on the farm. The significa,nce of t h i s at the present time i s w e l l por- . trayed by Wilson i n a recent p u b l i c a t i o n . . . . A l f a l f a has a f u r t h e r marked advantage as a forage crop i n that i t i s a perennial and agressive. Once .•established a stand competes e f f e c t i v e l y w i t h weeds and i n most l o c a l i t i e s w i l l maintain i t s e l f w i t h l i t t l e or no care f o r at l e a s t 6 - 7 years. Then again the deep ro o t i n g h a b i t of many s t r a i n s of lucerne has established the crop as a drought t o l e r a n t species. As such i t i s . w e l l known i n the subhumid and a r i d regions of t h i s continent. Recent s e l e c t i o n s of winter hardy s t r a i n s have f u r t h e r advanced i t s reputation as a crop f o r cold dry climates of the north and f a r south. Although the .desirable agronomic features of a l f a l f a f a r outweigh . the undesirable, the crop ..has. c e r t a i n l i m i t a t i o n s which cause the p l a n t breeder concern. For one things the 'plant, as we know i t i n commerce Is a n o t o r i o u s l y poor seed s e t t e r . Seed* as a consequence i s h i g h p r i c e d . In recent years:, too, a t t e n t i o n has been drawn to the increasing.importance of :crown i n j u r y i n standard s t r a i n s and the f a i l u r e of i n j u r e d plants to overcome attacks from i n s e r t s and fungus pests. Then, again coincident, w i t h the expansion of a l f a l f a , acreage i n the world, has come a growing r e a l i z a t i o n of the handicaps i n producti©£l r e s u l t i n g from such diseases as w i l t , l e a f s p o t and v i r u s . The a t t e n t i o n of_the p l a n t breeders,then has been . a t t r a c t e d by the r e c o g n i t i o n of these imperfections and already many programs f o r a l f a l f a Improvement have been undertaken. One of the e a r l i e s t consibus attempts at a l f a l f a • improvement-' through "breeding and s e l e c t i o n has much of i t s ' h i s t o r y l a i d at the U n i v e r s i t y of B r i t i s h Columbia from 1918 onwards. The early objects"of the program was to produce through i n t e r s p e c i f i c h y b r i d i z a t i o n a s t r a i n of a l f a l f a w i t h a crown and root system s u i t a b l e f o r subhumid conditions when a r e l a t i v e l y h i g h water table p r e v a i l e d over much of 'the year. The e a r l y work.on t h i s p r o j e c t has been adequately reviewed by Hoe (23) and only, a, b r i e f reference w i l l be .made'' to i t . With the growing importance of a l f a l f a i n the a g r i c u l t u r a l economy and a 'deeper: r e a l i z a t i o n of i t s problems., i t i s i n conformity that the a l f a l f a improvement programme should change, should broaden i n I t s scope and purpose.'. F i e l d records, some complete, some incomplete,, are a v a i l a b l e i n the programme f o r some twenty years of i t s - h i s t o r y . Therefore i t seemed appropriate at t h i s time to survey these records i n the l i g h t of present knowledge. In a d d i t i o n some records -taken by the author on the l o c a l m a t e r i a l i n the summer of 1941-42 and 1942-43 were studied. P r i n c i p a l l y the report i s a study of- the a s s o c i a t i o n of economic characters i n the a l f a l f a grown at the U n i v e r s i t y of B r i t i s h Columbia. Charactei-s vvere chosen such as seed weight, seed number, pla n t height and the l i k e and t h e i r a s s o c i a t i o n w i t h general c h a r a c t e r i s t i c s such as seed s e t t i n g , p l a n t y i e l d and crown c h a r a c t e r i s t i e s s c r u t i n i z e d . For plant breeding i s not the simple s e l e c t i o n of d e s i r a b l e c h a r a c t e r i s t i c s and the mere i n c o r p o r a t i o n of these i n a s i n g l e desirable s t r a i n . I t i s a study i n i n t e r a c t i o n and li n k a g e , complex to a high degree? the combination of features of merit must i n t i m a t e l y be represented i n many s t r a i n s and not i n one aiohe and the procedure used i n accomplishing t h i s are at once both an a r t and a science. How successful t h i s study i n a s s o c i a t i o n has been, w i l l be f o r the reader to decide; d i f f i c u l t i e s such as incomplete records, poor seed s e t t i n g and the l i k e , hare upset the study from time to time. I t i s hoped however that something has been added to our knowledge of the behaviour of economic characters i n the i n t e r s p e c i f i c h y b r i d a l f a l f a such as that at the U n i v e r s i t y of B r i t i s h Columbia. REVIEW OE LITERATURE At present .the most important problem as f a r as a l f a l f a i s concerned i s the improvement of i t s seed set 7. A large amount of work on t h i s problem has de a l t w i t h the e f f e c t of t r i p p i n g on seed set. Tripping can be brought about by weather, Insects or a r t i f i c i a l means. O f a l l there i n s e c t s studies Megachile species have been found the most s a t i s f a c t o r y . Lejeune and Olson (19) found that honeybees brought about very l i t t l e t r i p p i n g . Hay (13) found that the l a c k of s u i t a b l e i n s e c t s and •unfavourable weather conditions f o r t r i p p i n g contributed to the low seed y i e l d . Clark and Eryer ( 7 ) , Carlson ("6). and Bouthworth (5) conclude that t r i p p i n g increases seed y i e l d . K i r k (17) has developed a s e l f t r i p p i n g (autogamous) a l f a l f a which gives promise of overcoming t h i s d i f f i c u l t y . Various studies have been done on h y b r i d i z a t i o n s as a means to in c r e a s i n g seed y i e l d . Dwyer selected high y i e l d i n g s t r a i n s by inbreeding, then crossed them to regain v i g o r . Englebert (10) found that the seed y i e l d of any s i n g l e hybrid v a r i e d w i t h the environmental conditions. A number of papers have been w r i t t e n on the development of an inbred strain-which w i l l give &, good seed y i e l d K i r k (16) found that.seed y i e l d was•inherited to a c e r t a i n degree. Tysdai and Clark (29), Bolton and Eryer (2) and Southworth (25) found that the general seed y i e l d went down on inbreeding but a few high y i e l d i n g p l a n t s segregated which "bred true f o r t h i s q u a l i t y . S e l f s t e r i l i t y i n a l f a l f a has given r i s e to many studies. B r i n k and Cooper (3) found that there were fewer f e r t i l e ovules i n s e l f e d m a t e r i a l and that the lower ovules were r a r e l y f e r t i l e . Bolton and Fryer (2) working on p o l l e n s t e r i l i t y d ivided i t i n t o two classes: (a) c l e a r empty grains,- (b) normal appearing which d i d not germinate. Brink and Cooper (3)- found a f a i l u r e of f e r t i l i z a t i o n even a f t e r t r i p p i n g . P o l l e n tubes.'were produced and i n some cases f e r t i l e ovules starte d to develop but f a i l e d to mature. The embryos of low seed y i e l d e r s developed more slowly and there was .a'-large percentage of.abor^fesMU ovules. Brink and Cooper (3)' found that f e r t i l i z a t i o n was prevented due to abnormal p o s i t i o n a l r e l a t i o n s h i p between anthers and' stigma. The part of•enviromental e f f e c t must not be overlooked i n relation-; to seed set. Bolton and Fryer (2) found that . s o i l moisture and the .stage.of the seasonal development contributed a great deal to seed set. They found that the normal appearing p o l l e n , mentioned above, would germinate under favorable c l i m a t i c conditions. Preeman (11) cautions that h e r e d i t a r y f a c t o r s can only show up to advantage- i n a s u i t a b l e environment. .-Tysdal and Clark (7) emphasize the e f f e c t of temperature and l i g h t on seed production. • Southworth (25) stresses the e f f e c t of moisture, he con cludes that there should be s u f f i c i e n t moisture to f i l l the seed a f t e r i t has set but i n the e a r l y stages of 8 development abundant moisture w i l l stimulate the develop ment of leaves and height at the expense of seed; set. Englebert (10) substantiates Southworth's work $ fi n d i n g , that seed set was better i n years when there was a l i m i t e d r a i n f a l l i n J u l y and poor when there was excessive r a i n f a l l f o r t h i s month. H y b r i d i z a t i o n has been used as another method o f improving a l f a l f a . Among the c h a r a c t e r i s t i c s which have been given s p e c i a l emphasis are disease r e s i s t a n c e , root types, winter h a r d i n e s s s e e d y i e l d and weight of p l a n t s . The cytology of these hybrids has .yielded a great deal •of information of i n t e r e s t g e n e t i c a l l y . The cross i n a l l cases was only successful i f H. f a l a c a t a was used as the p i s t i l l a t e parent. I)wyer (9) found that a cross between M. s a t i v a and M. Lupulina gave a poor forage y i e l d . Southworth (23) i n t r y i n g to develop a s e l f t r i p p i n g v a r i e t y used Iffi. l u p i l i n a , as the p i s t i l l a t e parent because of i t s s e l f g r i p p i n g c h a r a c t e r i s t i c s . The F l and E2 gave a great v a r i e t y of types but a very poor seed y i e l d . I n the E3 a few good _seed producing pl a n t s appear,. A few, s e l f t r i p p i n g v a r i e t i e s appeared i n the E4 but were not s e l f f e r t i l e . I t was not u n t i l the 3?6 that one s e l f t r i p p i n g ^ s e l f f e r t i l e p l a n t appeared. The flower color i n these i n t e r s p e c i f i c cross has provoked considerable i n t e r e s t . ' The Iff., f a l a c a t a i s pure breeding yellow and the M. s a t i v a blue. - The E l and , succeeding generations give a wide v a r i e t y of color from white to yellow and deep purples. Burton (5) found that flower color had no p o s i t i v e c o r r e l a t i o n s with any of a number of other c h a r a c t e r i s t i c s . Hay (13) found that color had no e f f e c t on seed set, while Moe(23) on the other hand suggested that white flowered plants v/ere poor seed y i e l d e r s . Lepper and Odland (20) conclude that flower color i n a l f a l f a was due to three f a c t o r s . •'During the many breeding experiments i n v o l v i n g a l f a l f a , a number of abnormal t i e s have come to l i g h t . Lepper and Odland (19) mention a c r i n k l y . l e a f mutation. Stewart (24) mentions a p e c u l i a r v e g i t a t i v e p r o l i f e r a t i o n , which replaces the a l f a l f a flowers. MeVicar (22) found white seeds were due to a homozygous recessive f a c t o r as a r e s u l t of the absence of a f a c t o r f o r yellow. Black seed required at l e a s t three f a c t o r p a i r s and arose o r i g i n a l l y as a s i n g l e gene mutation. This only very s u p e r f i c i a l l y touches on a few of the l i n e s of i n v e s t i g a t i o n being c a r r i e d on w i t h a l f a l f a . Winter hardiness and disease r e s i s t a n c e are problems which are r e c e i v i n g a great deal.; of a t t e n t i o n i n other parts of the continent. In t h i s vast improvement Work w i t h a l f a l f a many in t e r e s t i n g ' f a c t s are being brought to l i g h t which are c o n t r i b u t i n g g r e a t l y to the improvement -of. a l f a l f a , and p l a n t improvement work i n general. 10 MATERIALS AED METHODS. The materials used i n these studies were the h i g h l y heterozygous population which r e s u l t e d from s i x hybrids of a cross M. f a l a c a t a ( $ ) X M. s a t i v a ( <jp ) . D e t a i l s of the h y b r i d i z a t i o n and subsequent treatment of the progeny are given by Moe (23). "A few of the more important features of t h i s plant m a t e r i a l might be b r i e f l y emphasized. I t should be noted that t h e ' p i s t i l l a t e parent-.in the cross was u s u a l l y the low growing yellow flowered ffi. f a l a c a t a Yar. Don. and that the p o l l e n parent was a t a l l purple flowered v a r i e t y of Grimm one of the Ontario "Variegated type. Seed obtained from the hybrids was grown out and s i x t a l l growing hybrids' were d i f f e r e n t i a t e d from the low growing hybrids. , The hybrids proved to be considerably f e r t i l e and produced some seed i n good seed years both from s e l f e d and open p o l l i n a t e d racemes. . The flower color of the hybrids was variegated but showed a preponderance of yellow pigment. The hybrids were s e l f e d and the seed thus produced was subjected to progeny -row t e s t s . The seed was then taken from these, selected p l a n t s -and- i t s e l f set out i n progeny rows. At t h i s time l i t t l e or no attempt was made to c o n t r o l p o l l i n a t i o n but there was no opportunity f o r admixture of p o l l e n from other s t r a i n s or v a r i e t i e s . The progeny from the F2 and subsequent generations 11 showed an enormous degree of segregation. Many of the selected p l a n t s showed a great v a r i a t i o n as to type of growth, vigor and degree of s t e r i l i t y . ; . Careful s e l e c t i o n of i n d i v i d u a l plant progeny was c a r r i e d on f o r f i v e generations "but at the end of that time there was s t i l l a high degree of segregation; I.e. no s t a b i l i t y of type had, as yet "been established. From the F2 arid succeeding generations the pppulations Yirere the subject of a mass s e l e c t i o n program. In' t h i s work emphasis was placed, on seeking a higher y i e l d i n g a l f a l f a with,the spread c h a r a c t e r i s t i c s of the M. f a l a c a t a parent and the q u a l i t y c h a r a c t e r i s t i c s of the M. s a t i v a . Records were taken by the Department of Agronony on many morpholigical c h a r a c t e r i s t i c s of both the hybrids arid p l a n t s of. subsequent generations. From these records • data on spread, height, seed y i e l d , pod shape and flower color were used. During the summer of 1941 plan t s were selected at f - random from the f i f t h generation m a t e r i a l and Roger's a l f a l f a . ' From there p l a n t s data on pod slaape, number of seeds per pod, seed set, f o l i a g e c o l o r , flower c o l o r , flower f a l l , stem thickness, plant height and degree of l e a f s p o t t i n g , were taken. The f o l l o w i n g s t a t i s t i c a l a n a l y s i s was used as the best method of organizing and i n t e r p r e t i n g t h i s data. EXPERIMENTAL WORK I As s o c i a t i o n of Pod Shape and Number of Seeds Per Pod, (a) S e l f p o l l i n a t e d a l f a l f a It,was thought there might be some a s s o c i a t i o n between the seed y e i l d and the s i z e of the pod, i . e . the number of tw i s t s i n i t . Cooper and Brink (3) have found that s t r a i n s which produce a large number of seeds continue to do so and s t r a i n s g i v i n g a small amount of seed tend to continue t h i s low seed y e i l d i n future generations. Bo^toE* and Fryer (2) are of the opinion that the number of seeds per pod i s a better index of inherent f e r t i l i t y than the percentage of flowers which give r i s e to f u l l y developed pods* They also s t a t e t h a t seed s e t i s due to genetic f a c t o r s and the number of seeds per pod i s a good i n d i c a t i o n of t h i s inherent capacity, A good seed s e t t i n g s t r a i n w i l l tend to continue t h i s abundant seed s e t t i n g cap a c i t y , even of s e l f i n g . Table I gives the d i s t r i b u t i o n of the number oj seeds per pod against the number of t w i s t s per pod. The number dh brackets i n each case i s the expected number the number above the the a c t u a l number, The number of t w i s t s per pod were d i v i d e d i n t o three catagories curved ( s e m i - c i r c l e ) , one c i r c l e , and more than one c i r c l e . The number of seeds per pod were also d i v i d e d i n t o three ca t e g o r i e s , 2, 4, and 6 seeds per pod; M a t e r i a l used f o r t h i s study was data taken by the author from Rogers (24) a l f a l f a . The t o t a l number of samples taken here i s fifty-nine<> A la r g e r number might y e i l d somewhat d i f f e r e n t r e s u l t s . The c h i square f o r 4 degrees of freedom at the 1% l e v e l i s only;13.28| the c h i square f o r expectation i s 28.10. In dependence i s therefore u n l i k e l y and a strong a s s o c i a t i o n of h i g h l y - c u r l e d seeds and a large number of seeds per pod i s l i k e l y . Table I 1- 1. a 2 i 6 T o t a l lvL • - 16 (9.4) 7 (9.1) i- 0 . i (3.5) 1 t 23 b 8 (9.4) 14 (9.1) 1 (3.5) 1 1 23 c 0 (5.3) •''/ 5 / (5.8) 8 (2.9) : 13 To t a l ; 24 •: 26 9 / . 59 a — curved b — one c i r c l e c — more than one c i r c l e . •, (b) Open p o l l i n a t e d This study i s the same as the previous one i n a l l respects except t h a t the m a t e r i a l was open p o l l i n a t e d instead of s e l f e d . Table 2"gives the d i s t r i b u t i o n of the seeds and the shape of•the pods. The' categories are the same as Table 1. Table 2 2 4 . e Total a 9 (2*5) 2 (4.3) 0 (2.5) 11 b 3 (2.6) 16 (7.5) 0 (7.1) ! 19 c 0 (5.3) 3 (7.1) 20 (8.6) T o t a l 12 21 20 • 53 The c h i square f o r 4 degrees of freedom at the 1% l e v e l of s i g n i f i c e n c e i s 13.28 which shows an a s s o c i a t i o n between the the number of seeds per pods and the number of t w i s t s per pod. K i r k (17) found that the seed y i e l d upon open p o l l i n a t i o n was greater than upon s e l f i n g but high y e i l d i n g s t r a i n s tended to remain good seed producers whether open or s e l f e d . As i n the previous case the number of samples are s m a l l , making these r e s u l t s f a r from conclusive,, (c) Seed set i n grams Larger number were a v a i l a b l e f o r t h i s study. There were 26 progeny rows (open p o l l i n a t e d ) from a l l of the hybrids (1928), g i v i n g a t o t a l of 770 p l a n t s . Table 3 gives the d i s t r i b u t i o n of seed y i e l d i n grams com pared w i t h the shape of the pod. The categories have been en larged i n both cases. Table 3 15 Table 3 Seed -weight i n ' grams Ho.of t w i s t s 0-2 1 2-4 |4-6' 6-8 i i 18-10 10-12 total 12 (7.7) 1 (.4) 1 13 144' ! ,110.3) '< - „ / 22 (25.9) 8 (4.4) 4 (9.8) 1 (6.4) 2 (6.2) 4 "T (12;. " . • 190 199,8) 52 (47.1) 25 (24.8) 18 (17.9) 14 (11.?:) 13' (11.3) 24 . (23.1) 336 1-|~2 98 116.5) 30 (27.5) 17 :(14.5) 14 (10.4) 10 (6.8) 8 (6.6) 19 : (13,5) 196 14 23.7) 4 (5.1) 7 (2.9) 5 (2.1) -'"1. '- (1,4) ; 3 (1.1) 6 (2.7) 40 T o t a l 458 1 108 57 41 27 26 53 770 The number of t w i s t s bears no s t a t i s t i c a l r e l a t i o n to the weight of seed set per p l a n t . This however does not imply that there i s no c o r r e l a t i o n between the number of t w i s t s per pod and the number or weight of seed set per pod. In t a b l e 4 the categories have been reduced to 3 f o r y i e l d and 3 f o r number of t w i s t s per pod. 16 Table 4 1 1 1 JTo. of t w i s t s Amount of Seed Set (Grams) Total 8 1 | . 0 - 1 l , • 0 .- 4 4 -8 • 8 - 14 178 (145.5) 12 (25.2) 8 (27.25) 198 1 1 - 2 1 370 (391) 74 (67.7) 88 (73.23) 532 1 2 - 3 18 (29.4) 12 (5.09) 10 (5.5) 40 T o t a l 566 98 106 770 The c h i square f o r 4 degrees: of freedom at the 1% l e v e l of p r o b a b i l i t y is' 13 0 28. One might conclude that there i s a s i g n i f i c a n t a s s o c i a t i o n between low y i e l d of seed and the s m a l l amount of t w i s t i n g i n the pod. In t h i s connection Brink and Cooper (3) found that the lower ovules i n the c a r p e l d i d not develop into mature seeds due to (a) f a i l u r e o f . f e r t i l i z a t i o n (b) ovule abortion or (c) i n f e r t i l i t y of the ovule. 2. A s s o c i a t i o n of Flower Abundance and Number of Seeds The F^ plants d i f f e r e d g r e a t l y i n the number of flowers produced. A c h i square was run on t h i s c h a r a c t e r i s t i c to see i f i t had any bearing on the seed y i e l d . The flower abundance was put i n 3 categories, poor, f a i r and good. The i n d i v i d a u l seeds produced were counted and d i v i d e d i n t o 3 categories 0 - 3 0 , 30 - 60, 60 and more. Table 5 gives the d i s t r i b u t i o n . 17 Table 5 Flower Abundance Number of Seeds 0 - 3 0 30 -SO "1 : j- 60 + Total Poor 10 (7.9) 1 • 1. s ; (4.8) 1 (3.2) 16 F a i r i 14 . (13.3) ! 11 (8.2) 2 (5.4) 27 Good 10 (12.8) •(7.9) 11 C5*5) | 26 . - T o t a l 34 21 14, 69 The c h i square at the 5% l e v e l of p r o b a b i l i t y and 4 degrees of freedom i s 9.49. An a s s o c i a t i o n i s i n d i c a t e d , however, data are too few to place much confidence i n these r e s u l t s . A d d i t i o n a l work using l a r g e r numbers might y i e l d d i f f e r e n t r e s u l t s . Bolton and Fryer (2) are 6f the opinion that flower abundance i s no i n d i c a t i o n of seed y i e l d . And Cooper and Brink (3) found that t r i p p i n g increases the number of flowers forming seed. 3. Seed S e t t i n g (expressed as seeds per pod per plant) Com pared i n Racemes Which Have Been S e l f e d and Open P o l l i n a t e d . Rogers (24) a l f a l f a was used f o r t h i s c o r r e l a t i o n . Plants were s e l e c t e d on the basis of flower colour. S i x colour des ignations were given, white, paJLe y e l l o w 9 y e l l o w , variegated 18 purple yellow, dark purple, pale purple. Open p o l l i n a t e d racemes were tagged, while s e l f p o l l i n a t e d ones were r o l l e d i n the f i n g e r s and tagged. Table 6 gives the seed y i e l d per raceme i n number of seeds. There too few seeds to weigh. Table 6 Seed S e t t i n g (expressed as seeds per pod per plan t ) Compared .in-Racemes'-Which Have Been S e l f e d and Open P o l l i n a t e d . PLANT No. Seeds per Raceme (average) No • S e l f e d Open (x) (y) . 1 1 6 2 15 4 1 2 2 3 16 3 5 3 2. • 4 17 4 1 4 3 3 18 3 1 5 4 '• 4 ; 19 2 2 6 i • q 4 20 2 2 7 2 2 21 5 5 8 4 3 " .* 22. : '5 3 9 6 •" • 8 23 7 3 10 4 2 24 9 • 2 - 11 3 3 25 7 .• 12 ; 4' A 3 26 6 ® 13 4 3 27 3 1 14 i 6 j 28 6 , 3 19 29 " . 4 4 43 2 4 30 4 ' 4 44 6 6 31 4 4 45 2 2 4 2 46 5 2 33 6 V 2 47 4 4 34 5 5 48 1 2 35 6 2 \'-: 49 4 36 2 '."2; • 50 4 ' 3 37 : 4 :. 4 : 51 6 5 38 5 6 52 '4 2 39 3 2 53 2 2 40 4 3 54 6 3 41 6 2 55 5 4 42 •5. — 1 > One may s a f e l y conclude t h a t the open p o l l i n a t e d racemes set more seed per pod than d i d the s e l f p o l l i n a t e d racemes. The d i f f e r e n c e , however, i s not" large and would i n d i c a t e that the degree of s e l f s t e r i l i t y In the F5 plants used i s not high. S e l f i n c o m p a t a b i l i t y f a c t o r s e t c e t e r a might be set f o r t h and the influence of tagging andjJaandiiHg might have been d e l e t e r i o u s . AhnormaX p o l l e n Is - as abundant i n the open as i n the . s e l f ed.plant m a t e r i a l . -It 'could not therefore be a reason f o r the lower y i e l d i n the f i r s t case. However, plants which tend to set seed abundantly In the open p o l l i n a t e d m a t e r i a l tand to set seed w e l l i n the s e l f e d . 20 The a s s o c i a t i o n i s not strong b i o l o g i c a l l y although s t a t i s t i c a l l y i t i s h i g h l y s i g n i f i c a n t . I t would seem there~ fore that there i s some evidence to support the i n d i c a t i o n s of s e l f i n c o m p a t a b i l i t y f a c t o r s . Kirk. (17) on comparing s e l f and open p o l l i n a t e d m a t e r i a l found a general decrease i n y i e l d - w i t h s e l f i n g , however, a fewe s t r a i n s segregated which gave c o n s i s t e n t l y good y i e l d . Tysdal and Clark (28) and Cla r k and Fryer (7) substantiates K i r k ' s work. 4. A s s o c i a t i o n of Flower Color and Seed Y i e l d M a t e r i a l s used here were the 1928 records of the F 4 progeny. There were a great many flower c o l o r types e x h i b i t e d i n the f i e l d and i t was thought t h a t the seed y i e l d might be associated with f l o w e r ^ c o l o r . Although there were about 15 d i f f e r e n t c o l o r designations they were e i t h e r predominantly purple or yellow. The flower c o l o r was therefore d i v i d e d into 4 classes on the b a s i s , purple, variegated purple, yellow, and variegated yellow. The seed y i e l d was taken i n grams per plan t and d i v i d e d into 4 categories as shown i n Table 7' Table 7 - F ' . t'Seed s Flower- Color Purple. Var.. Purple Yellow Var. Yellow T o t a l Y i e l d i n grams per plan t 0-1 1-6 6-10 10 - 15 23 •8 29 61 1 29 69 15 12 25 T o t a l 38 52 76 170 21 Many r a t i o s weretried to determine the genetics of flower color inheritance hut none f i t t e d . No doubt these could be. worked out w i t h c o n t r o l l e d p o l l i n a t i o n . Two f a c t o r s (a) f a i l u r e of c o n t r o l l e d p o l l i n a t i o n ( s e l f i n g ) and (b) the prob a b i l i t y of complex p o l y p l o i d r a t i o s complicated t h i n g s . Lepper and Odland (20) set f o r t h a 3 f a c t o r basis for flower c o l o r inheritance i n a l f a l f a . , They only took t h e i r work to the F p, but had they c a r r i e d t h e i r i n v e s t i g a t i o n s on to the Fg they might have found flower color inheritance more complex, i . e . p o l y p l o i d y was involved* In connection w i t h flower c o l o r an& seed y i e l d , Moe (23) found t h a t white flowered plants tended to give a low seed y i e l d while Hay (14) e?n the other hand, found no a s s o c i a t i o n between flower c o l o r and seed y i e l d . Table 8 gives the d i s t r i b u t i o n of seed y i e l d ( i n grams) and flower color using more c o l o r designations than Table 7. Table 8 Seed y i e l d (Grams per p l a n t ) Flower Color ; o - i 1-6 6-10 10- T o t a l Blue 7 12 5 2 ' 26 Purple 13 15 4 6 38 Variagated 51 59 11 20 141 Green 7 9 • 7 " :; :. 7 30 Yellow 2 2 4 White: . ; 1 1 1 T o t a l 80 98 21 35 240 22 In both Tables 7 and 8 no a s s o c i a t i o n was found between seed y i e l d and flower c o l o r . In the above studies formation of classes f o r flower color w>as d i f f i c u l t due to various f i e l d workers idea of c o l o r . The flowers tended to change co l o r during the blooming period which made an accurate color des i g n a t i o n d i f f i c u l t . In t h i s connection i t was noted that the darker colors - blues and purples tended to predominate,Whether t h i s i s due to dominance or a greater gene frequency i s un known* 5, Comparison of Seed Y i e l d f o r Two Successive Years, A comparison of the seed y i e l d of the progeny of the hybrids f o r two d i f f e r e n t years was made. The mean y i e l d f o r the f i r s t year was 1,52 grams and f o r the second ,60 grams. This lower seed y i e l d i s probably due to environmental causes and bears out the work of Hay (14), Bolton & Fryer (2) Freeman (11), Southw#t*F^23) arid Englebert (10) In both years though, good seed y i e l d e r s tend to y i e l d seed w e l l and poor seed y i e l d e r s to give poor seed y i e l d s . This consistancy of seed y i e l d suggests the operation of her e d i t y f a c t o r s , 6, D i s t r i b u t i o n of Seed Y i e l d Classes. The accompanying graph shows the d i s t r i b u t i o n of plants as to seed y i e l d . Plants 38 36 34 \ O CO 01 ~3 CD F-1 <D O O O €> O r d i n a r i l y i t would be expected to f i n d the seed y i e l d f a l l i n g i n a normal d i s t r i b u t i o n curve. This d i s t r i b u t i o n i s h i g h l y skewed, there are d i s t i n c t l y more high y i e l d i n g plants than expected i n a normal d i s t r i b u t i o n . This would seem to i n d i c a t e the operation of h e r e d i t a r y f a c t o r s . 24 7 Comparison of Seed Y i e l d , Plant Heights and Plant Weights i n F]_ and F- ' The materials used f o r t h i s . s t u d y were the o r i g i n a l 7 hybrids and t h e i r F^ and S*2 progeny. The seed y i e l d and plant weight were ..taken i n grams . and the height i n inches. Table 9 gives the seed y i e l d , plant weight, and plant height f o r the,7•hybrids f-also the average seed y i e l d , plant weight and p l a n t height f o r the Fg progeny of the hybrids. Table .9 Designation of Plants Seed Y i e l d (g) Plant Wt. 'Plant (") Ht. • Hybrid -7 • V7.0 172 28 " -56 • .1.4. : 148 24 » -68 0.9 r 123 20 " -71 ; ;0-,3 : ; > 136 23 »' -156 2.4 100 24 " -190 3.5 263 30 F 2 of H-7 1.5 (ave. )tj 92.4(Ave] ••25.4 (ave.) 11 " H-56 1,6 •»»•"/.; 57 © 2 ti 20,3 ii'.. i it ti H _ 6 8 0.8 » L'~ 55,7 it 19.7 it " " H-71 0.4 " •: 24,-9 It • 13,5 \\ 0.8 " -.3 32.7 H ' 14,8 II " "H-190 ••.••,1.7.,; 48.9 11 14.9 H . 1 Kirk- (17) found a reduction of v a r i a b i l i t y i n the F 2 w i t h s e l f i n g . The above f i g u r e s would i n d i c a t e h y b r i d v i g o r . Comparisons of previous tables on seed y i e l d s i n d i c a t e that the seed y i e l d and pl a n t v i g o r are c o r r e l a t e d , I.e. the same f a c t o r s which are responsible f o r low seed y i e l d are i n a l l p r o b a b i l i t y responsible f o r a lessening of v i g o r . From Table 9 can be seen the s t r i k i n g reduction i n height and weight o.f the Fg over the F i but a few plants i n the F gave an increased y i e l d over the F-,, Ct. Throughout there seems to be a small c o r r e l a t i o n i n y i e l d of the Ft and the y i e l d of t h e i r progeny. This may be a s i g - n i f i c a t n observation i n terms of t h e i r chromosome number. 8. Comparison of. Seed Y i e l d i n F. Plants and F2 Progeny (Open p o l l i n a t e d prevaling) The Fj_ here used were the or i g i n a l J T hybrids. T;<. The weight i n each case was taken i n grams. The seed y i e l d of the progeny i s l i s t e d i n 2 columns, the average seed y i e l d and the maximum seed y i e l d . Table 10 gives these seed y i e l d s . . • Table 10 ' "1 Hybrid No. • Hybrid Seed Y i e l d (grams) Progeny Sample Average gms.. per p l a n t Seed Y i e l d Maximum- gms • per p l a n t . # 7 * 7.0 1.5 ,4.7 ; 56 1.4 1 , . • . 1.6 11.5 68 0.9 0.8 6.0 71 0.3 0.4 6.2 , 168 j 2.4 0.8 4,0 • 190 3.5 1.7' ; 7.0 Average 2.56 0.9 6.6 26 The progeny on the average tended to repeat the seed y i e l d i n g a b i l i t i e s of the p a r e n t a l hybrids. -The maximum seed y i e l d e d by any one i n d i v i d u a l i n progeny bears l i t t l e r e l a t i o n s h i p to the c o n s t i t u t i o n of i t s hybrid. The data were too few f o r I f x y but the j f x y — ^".45 which was s i g n i f i c a n t f o r columns a and b. ASSOCIATION' OF FACTORS NOT INVOLVING SEED YIELD. 1. Comparison of Height and Weight Between F ^ and Fg. • Materials used f o r t h i s study were the weights and heights of the hybrids and the average heights and weights of random samplings of t h e i r progeny. Both K i r k ( 1 7 ) , Stewart ( 2 6 ) , Tysdal & Clark ( 2 8 ) and Southworth ( 2 5 ) found a reduction of v a r i a b i l i t y on succeeding generations. Table 1 2 gives the d i s t r i b u t i o n of height and weight f o r the F-^  and Fg« The lower number f o r the Fg would point to the action of h y b r i d v i g o r . The F]_ c e r t a i n l y gives high f i g u r e s than the parent M. f a l a c a t a p l a n t which i s low gown and low y i e l d i n g . Table 1 2 i n d i c a t e s that the v i g o r of the plants decreases on s e l f i n g , which i s shown by the s t r i k i n g decrease i n height and weight of the F over the Fq_. 28 Table 12A ; Wt. Comparisons j 1 Hybrid number 4 . 5 r !Wt. of hybrid, [ i n grams) f i P l a n t s F. Av, Wt. of progeny (samples i n grams) Fg -- - Maximum Wt. f o r progeny j sample I F f 2 172 ! . 92..4. 208 56 148 ' . -57.2 j 167 ; 68 123 55 » 7 j 9 1 1 71 136 24.9 41 100 - ; ; 32.7 1 • 76 190 263 48.9 1 79. Average 157 52 © 1 j 120.3 . .,' L _ _ _|: J Table 12B Ht. Comp ar i s ons . Hybrid number Ht. of h y b r i d ^in inches) .Plants Av. Ht. f o r ! , tprogeny sample, ( i n i n c h e s ) ! Maximum Ht J f o r progenj- sample ( i n : inches) 28 25 «> 4. .. i 32 ' 56. '' j 24 20.3 ' 29 " 68 . 20 19.7 27 • 23.: 13.5 . 156 24 14.8 2.L- 1 190 ! 30 1 14,9 22 Average 24.8 j i s . i 25.1 29 2. Y i e l d and Pleight A great amount of data was a v a i l a b l e f o r t h i s c o r r e l a t i o n . The m a t e r i a l used was the f o u r t h generation plants from the o r i g i n a l 7 hybrids. Plants were s e l e c t e d at random from t h i s large group and c o r r e l a t i o n s run on them. Unfortunately there was only a v a i l a b l e the data f o r 1928 making impossible to make a year to study. The r e s u l t s are g i v e n i n Table I Table I C o r r e l a t i o n No. of Plants F i e l d C o r r e l a t i o n Numbers Designation C o e f f i c i e n t s The c o r r e l a t i o n s are a l l p o s i t i v e and range from -/- 0.35 to -f- 0.88. By f a r the l a r g e r number have a high c o r r e l a t i o n which would seem to i n d i c a t e that there i s 3. high c o r r e l a t i o n between height of p l a n t and y i e l d of p l a n t . The same r e s u l t s were obtained by Hacbarth and Ufer (29), Burton (5) and K i r k (17). This c o r r e l a t i o n , however, i s not absolute as seen i n the 30 two values which give -h 0,35 and -f- 0.45, 3» A s s o c i a t i o n Leaf Spotting Incidence and % Ovules Developing on Racemes* Leaf s p o t t i n g i s very prevalent and i s due to a disease ffeeudopeziea medicaginis. I t was thought that there might be an impairment of p h y s i o l o g i c a l a c t i v i t y due to l e a f s p o t t i n g . I f there i s any i t does not manifest i t s e l f i n the number of ovules developing on the racemes. Table 2 shows the l e a f s p o t t i n g incidence p l o t t e d against the % ovule development. Table 2 Leaf Spot •'•Incidence 0 -50% 50% -80% 80% - 100% % • 1 • 3 (4.2) ' '21V' - (19.6) 11 (11.2) 35 2 6 (4.8) 21 (22.4). 13 (12.8) 40 Dotal 9 .,. 42 24 '"75 ' '. Mo, 1 denotes high incidence and 2. low. The top v a l u e . i s the a c t u a l number while the lower i s the t h e o r e t i c a l . The c h i square f o r 2 degrees of freedom at the 5% l e v e l of s i g n i f icanc e i s 5.99 9 wMehh Indicates that there i s no a s s o c i a t i o n between the degree of l e a f spot present and the number of ovules developing. 31 4» A s s o c i a t i o n of Leaf Spotting and Leaf Color. L i t t l e i s mentioned i n the l i t e r a t u r e regarding the e f f e c t that l e a f spot may have on a l f a l f a . Present i n d i c a t i o n s are that i t i s i n c r e a s i n g . Table 3 gives the d i s t r i b u t i o n f o r the incidence of l e a f spot and l e a f c o l o r . Table 3 • Leaf .Spot Incidence 5 1 • 1 . 2 Foliage Color Dark 23 (24.1) 26 (15.4) 49 L i g h t 15 (13.8) 13 (14.1) 28 - 38 / 39 77 m Leaf Spotting? 1 high incidence 2 med» .& low incidence The m a t e r i a l s used here were 77 plants s e l e c t e d at random f r o m t h e F^ progeny. The c h i square f o r 1 degree of freedom at the 5% l e v e l of p r o b a b i l i t y was 3.84 . This i n d i c a t e s there i s no s p e c i a l s i g  n i f i c a n c e between f o l i a g e c o l o r and the amount of l e a f s p o t t i n g . It should be noted i n t h i s connection that a boron d e f i c i e n c y w i l l a f t e n give a p a l e r l e a f . However, i n t h i s ease the d i f f e r e n t colors of leaves could hardly be a t t r i b u t e d to n u t r i t i o n a l f a c t o r s . 32 5, As s o c i a t i o n l e a f spot and Flower Abundance. Instead of a f f e c t i n g the seed y i e l d d i r e c t l y the l e a f spot might have reduced the number of flowers,thereby decreasing the seed y i e l d . -A comparison of flower abundance and l e a f s p o t t i n g i s given i n Table 4. Random s e l e c t i o n s from the F^ progeny were used f o r these s t u d i e s . Table 4 Poor F a i r Good 1 13 (918) 13 (14.3) 13 (13.8) 38 2 7 (10.1) 16 (14.7) 16 (14.2) 39 T o t a l 20 29 28 77 The l e a f spot incidence was d i v i d e d i n t o 2 categories Xdenoting high degree of l e a f s p o t t i n g and 2 low. The flower abundance was d i v i d e d i n t o 3 c l a s s e s , poor, f a i r , and good. The c h i square at 2 degrees of freedom at the 5% of prob a b i l i t y was 5.99, which would i n d i c a t e t h a t l e a f s p o t t i n g has not s e r i o u s l y influenced the number of fl o w e r s . The number^ of samples used was s m a l l and a d i f f e r e n t a s s o c i a t i o n might be obtained using l a r g e r numbers. 33 6. A s s o c i a t i o n of Stem Thickness and Plant Height. The materials used f o r t h i s a s s o c i a t i o n were s e l e c t i o n s from Rogers (24) a l f a l f a . 75 plants were se l e c t e d at random and a e h i square run on these. The stem thickness was given 3 designations, t h i n , medium, and t h i c k f the height was also d i v i d e d i n t o 3 categories, 25 inches and l e s s , 25-30 inches, and 30 inches and more. Table 5 gives the d i s t r i b u t i o n . Table 5 Plant He ight(Inches) 0 - 2 5 25- 30 30 & over T o t a l Stem. Thin 18 (8.9) 3 (7.5) 0 (4.48) 21 t h i c k n Medium 13 (14.9) 18 (12.6) 4 (7.4) 35 Thick 1 (8.1) 6 - (6.8) 12 (4) 19 T o t a l 32 27 16 75 The c h i square at the 5% l e v e l of p r o b a b i l i t y and 4 degrees of freedom was 9.49 which would i n d i c a t e avery strong a s s o c i a t i o n between thickness of stem and p l a n t height. However, i t might be p o s s i b l e to s e l e c t a t a l l growing pl a n t w i t h a t h i n g stems Burton (5) found a strong a s s o c i a t i o n between'height and number of stemso 3 4 7 . A s s o c i a t i o n of Height and Spread, Materials used were random s e l e c t i o n s from the progengy i n v o l v i n g 5 0 0 plants. Awere taken by the Department of Agronomy i n the e a r l y summer. K i r k ( 1 7 ) and Armstrong and White ( 1 ) found a p o s i t i v e c o r r e l a t i o n between these 2 characters. Table 6 gives the d i s t r i b u t i o n . Table 6 2 t * 1 5 • • » • • • • • • . • • • • » a • » ft 1 3 3** 1 3 * • » • • • • • « « • • . . . f . 0 3 4.** 3 • . . " ^ , 3 0 5 ™ ^ 1 . . . . / » » 1 6 7 • » . . . 1 5 7 * * ^ • * . • ^ . 3 5 • . . . . 2 4 1 0 * ^ 1 9 • - , 0 7 1 1 * * 1 5 • • . ^ , 2 3 1 2 * " * 1 1 * e » * 9 « * * 9 0 V . . . f . 2 6 1 3 ™*2yL, • • • • • 2 3 1 4 ~ * 2 3 * • • • » • • • « » - • » • • • * ^ » 2 4 The c o r r e l a t i o n i s p o s i t i v e but low though i n some l i n e s the a s s o c i a t i o n i s q u i t e strong. I t should therefore be pos s i b l e to s e l e c t "tatfe growing plants which are spreading. 35 The stage of growth at which these c o r r e l a t i o n s are taken i s important. The above mentioned pla n t s were r e l a t i v e l y mature, e a r l i e r c o r r e l a t i o n s may have been b e t t e r , 8. A s s o c i a t i o n of Flower Abundance and Raceme Supporting Ovules. I t was thought that the flower abundance would have a considerable e f f e c t on seed.development. The f o l l o w i n g studies deal w i t h the e f f e c t of flower abundance on various c h a r a c t e r i s t i c s a f f e c t i n g seed y i e l d . Table 7. FLower Abundance Racemes % Remaining, 0-50 50-80 80-100 i i i * Total' Poor ' (2.63) 13 1 (11- 37) ! (6.1) J 20 F a i r 3 (3.4) -15 (16.9) 12 (9.1) 30 Qbod 7 (3.4) | . 15 I (14.2) 1 i 4 1(7.8) ! 26 .Total. 10 ] •' 43 ' 23 i 76 The flower abundance was d i v i d e d i n t o 3 categories, poor f a i r , andgood and the percentage of flowers remaining were 36 divided into 3 classes according to percentage 0-50%, 50-80%, 80-100%. There i s no a s s o c i a t i o n "between the flower abundance, and the number of racemes remaining. The c h i square at the5% l e v e l of s i g n i f i c a n c e i s 9.49 which indic a t e s ho r e l a t i o n s h i p . 9. A s s o c i a t i o n of Foliage Color and Flower Abundance. Rogers a l f a l f a (24) was used f o r t h i s c o r r e l a t i o n . The f o l i a g e c o l o r was d i v i d e d into l i g h t and dark and the flower abundance into 3 classes poor, f a i r and good. Table 8 Foliage Color Flo Poor wer Abunc | F a i r lance Good Tota l Dark Green 10 ' (12.0) 18 (17.7) 19 ( 17.1) 47 Light Green 9 (6.9) 10 (10.2) 8 (9.8) 27 T o t a l 19 28 27 : 74 .: As would be expected there was no r e l a t i o n s h i p i n t h i s a s s o c i a t i o n . The c h i square f o r 2 degrees of freedom at the 5% l e v e l of p r o b a b i l i t y i s 5;»99"e Here again the p o s s i b i l i t y of the e f f e c t of a boron d e f i c i e n c y must not be overlooked. 37 10. As s o c i a t i o n of Flower Abundance and Flower F a l l . \ In some cases there were a large number of flowers that f e l l e a r l y i n development I.e. long before pods had begun to form. In Table 9 the flower abundance i s d i v i d e d i n t o 3 classes poor, f a i r and good, and the amount of flower f a l l i n t o 3 classes 0-50,50-80 and 80 and over. Table 9 Slower ibundance Amount of 0- 50 Flower 1 50-80 ? a l l -80- . T o t a l Poor (2.63) 13 (11.3) 7 (6.1) 20 Fair 3 (31.9) 15 (16.9) 12 (9.1) 36 3ood 7 (3.4) 15 (14.7) ' 43 4 £7.8) 26 Total 10 ,23 76 M a t e r i a l s used were random s e l e c t i o n s from the -F4 progeny.' The c h i square at the 5% of p r o b a b i l i t y and 4 degrees of freedom i s 5.81 which would i n d i c a t e no a s s o c i a t i o n . 38 FLOWER COLOR, OTHERITANCE S!32UDIES. Flower Color Inheritance Studies i n A l f a l f a . The flower colors have been placed i n 15 c a t e g o r i e s A l  though the v a r i e g a t l s j % colors are predominately blue or purple there appeared variegated flowers which wens b a s i c a l l y yellow or green or a mixture of t h i s w i t h blue and purple»: The m a t e r i a l used was the F Q of the o r i g i n a l 7 hybrids. Table 1 gives t h e i r d i s t r i b u t i o n . T h e ' f i r s t column indi c a t e s the h y b r i d from which the plants were derived. Table 1 H # 7 # 56 # 68 # 71 # 156 # 190 0 ) H ft PM 2 3 3 1 1 0 ) m > H ft 3 PM > CD H ,Q I Q) H ft 3 6 2 1 ' CD H ft Sh P4 I CD H cd PM 1 2 CD CO d) »r! O HI ft 1h 13 13 20 2 6 8 o a) •H 3 4 0) •a 1 1 1 1 CD H I P» o H H > CD H ft ft H o H H iS I ci CD cis 3 2 8 18 o i—l H 12 1 5 13 12 3 -d CD -P cS hQ CD •rt 4-3 0) H ft & P-t The designation of a c t u a l colors presented a great d i f f i c u l t y . Some plants weas-different c o l o r s during the various stages of 39 t h e i r blooming p e r i o d . > A large number of r a t i o s were t r i e d but none f i t t e d , , Color inheritance Is probably f u r t h e r complicated due to the p o l y p l o i d nature of the m a t e r i a l . . In table 2 the color classeswere cut down to 3. The flowers wer b a s i c a l l y purple, green or yellow and were c l a s s  i f i e d on that b a s i s . Table 2 Parent Plant — — — , Pnrple & Blue f — — 1 1 Green i '• Yellow. #7 21 • 0 12 #56 30 ' I #68 17 8 • #71 7 . • i s . ; . ! ^ #156 10 12 #190 8 ; 20 •. .3 , Lepper and Qdlqnd^ (20) put flower color Inheritance i n a l f a l f a on a 3 f a c t o r b a s i s . Their hypothesis was not d i s  proved. However, "pure yellow" occurs much l e s s f r e q u e n t l y than expected. Out of 185 Fg p l a n t s , whites and yellows are not recovered a t a l l . They are recovered f a i r l y f r e q u e n t l y i n l a t e r generations. P o l l i n a t i o n c o n t r o l may not have been s a t i s f a c t o r y . E i t h e r some cr o s s i n g may have taken place or the 40 numbers of progeny received were not s u f f i c i e n t f o r accurate conclusions. The hybrids are p o l y p l o i d and therefore not l i k e l y to y i e l d many yellows and whites t i l l l a t e r generations. The general segration d i s t r i b u t i o n , however, suggests an inheritance pattern i n v o l v i n g s e v e r a l p r i n c i p a l mendelian factors', with f a c t o r s f o r purples and blues e p i s t a t i c to those f o r yellow and white. 41 DISCUSSION The r e s u l t s obtained from t h i s work are of i n t e r e s t i n r e l a t i o n to the p r a c t i c a l bearing, which they may have on the problem of a l f a l f a improvement. When s e l e c t i o n i s desired for. a ce r t a i n , character j i t i s often d e s i r a b l e to determine, i f p o s s i b l e , which other characters of the. p l a n t , i f any, are associated w i t h i t . By s e l e c t i n g f o r o n e r ; f t may be, poss i b l e to secure the other a l s o . However, i n crop improvement work a breeding program must go hand i n hand wi t h c o r r e l a t i o n s t u d i e s . I t i s p o s s i b l e to generalize On the p o s s i b i l i t i e s of inbreeding and hybridyktlon as a means of improving a l f a l f a . As i n most normally cross f e r t i l i z e d crops there i s a reduction of v i g o r upon Inbreeding. However, some l i n e s showed no l e s s  ening of v i g o r upon s e l f - f e r t i l i z a t i o n , which seems to i n d i c a t e that the d i f f e r e n t i a l e f f e c t of s e l f - f e r t i l i z a t i o n i s due to the genetic c o n s t i t u t i o n . In t h i s i n v e s t i g a t i o n emphasis has been placed upon seed production. At present the major problem i s to develop a vigorous p l a n t which i s also a good seed y-ielder. An abundance of flowers would appear to have some bearing on the f i n a l seed production. Many f a c t o r s both genetic and environmental a f f e c t these c h a r a c t e r i s t i c s of the p l a n t . High and low f e r t i l i t y and v i g o r are apparently inherited,, However, environmental conditions must be s a t i s f a c t o r y before a plant w i l l f u n c t i o n to i t s optimum. I t i s hoped that the c o r r e l a t i o n e s t a b l i s h e d , both p o s i t i v e and negative, between seed y i e l d 42 and other c h a r a c t e r i s t i c s w i l l prove of help i n future a l f a l f a improvement work. Pigmentation does not appear to have any e f f e c t on any of the characters studied. Both flower c o l o r and the degree of pigmentation of the leaves y i e l d e d no d e f i n i t e a s s o c i a t i o n s . Leaf spot was the only disease of which there was any evidence*Other than its•appearance on the leaves i t d i d not appear to have any e f f e c t e i t h e r morphologically or physio l o g i c a l l y . In some of these studies s u f f i c i e n t numbers were a v a i l  able but i n others due to the l a c k of time and f a c i l i t i e s , the number of samples taken were few. I t should therefore be cautioned that i n these "cases where l i m i t e d numbers were used conclusive r e s u l t s are impossible. Further work may y i e l d d i f f e r e n t conclusions. CONCLUSIONS • S e l e c t i o n w i t h i n s e l f f e r t i l i z e d l i n e s appears to provide a primary' mode of attack f o r the breeding of improved v a r i e t i e s of a l f a l f a . As i n d i c a t e d ' i n these and other studies there i s a general reduction of v i g o r lipon s e l f p o l l i n a t i o n . However, a few plants r e t a i n t h e i r good c h a r a c t e r i s t i c s even upon s e l f - i n g . When superior inbred strains.have been obtained which are vigorous enough to replace the heterogenous v a r i e t y now grown, the breeding program beSmes r e l a t i v e l y simple,, These studies show that there i s a general reduction of seed y i e l d , p l a n t y i e l d and plant height between the F^ and F2. But a few plants tend to r e t a i n the good q u a l i t i e s of the parent. Seed y i e l d was s t u d i e d i n some d e t a i l and i t was shown that high y i e l d i n g plants had a greater number of t w i s t s per pod. Open p o l l i n a t i o n and good weather had a b e n e f i c i a l e f f e c t on the amount of seed s e t . The abundance of flowers seemed to be an i n d i c a t i o n of f i n a l seed y i e l d i . e . an abundance of flowers would give a good seed-set. However, due to the small number of samples involved and some d i f f i c u l t i e s encountered i n the f i e l d , t h i s r e s u l t can by no means be taken as absolute. Leaf spot and flower c o l o r , on the other hand, gave no assoc i a t i o n w i t h seed y i e l d at a l l . S e l f f e r t i l i z a t i o n tended to decrease the seed y i e l d . Whether handling of the racemes i n the processes e f f e c t i n g f e r t i l i z a t i o n increased or decreased the f i n a l seed y i e l d , i s uncertain. These r e s u l t s i n d i c a t e that flov/er abundance i s no i n d i c a t i o n of alisuperiorcplan'ti'il.Associations of t h i s character w i t h 44 f o l i a g e color. ? l e a f spot and percentage of ovules developing on the raceme gave no p o s i t i v e results» The stem, on the other hand,' i s a f a i r l y r e l i a b l e i n d i c  a t i o n of a superior p l a n t . Correlations between the height of the stem and stem width, plant y i e l d and spread a l l gave p o s i t i v e r e s u l t s . Leaf spot d i d not appear to hinder the a c t i v i t y of the plant at a l l . There was no a s s o c i a t i o n between l e a f spot and flower abundance, l e a f color or percentage of ovules developing.on the raceme. Several uns-uccessful attempts were made to reach some conclusion regarding the mode of flower c o l o r i n h e r i t a n c e . Various workers have suggested hypothesis f o r flower c o l o r inheritance of a l f a l f a but the author was unable to f i t any of these to her r e s u l t s . I t i s hoped that t h i s work w i l l contribute something to future a l f a l f a improvement work. I t was unfortunate that i n some cases data was very l i m i t e d . These r e s u l t s can only be used as i n d i c a t i o n s . However, f u r t h e r i n v e s t i g a t i o n using l a r g e r numbers may contribute some d e f i n i t e conclusion. SUMMARY 4 5 I There was a s i g n i f i c a n t a s s o c i a t i o n between pod shape and number of seeds per pod f o r s e l f p o l l i n a t i o n m a t e r i a l , 2. There was a h i g h l y s i g n i f i c a n t c o r r e l a t i o n between number of seeds per pod and pod shape i n the open p o l l i n a t e d m a t e r i a l , 3 Low seed y i e l d i n g plants tend t o have s t r a i g h t podsf high seed y i e l d i n g plants tend to have twisted pods, 4 There i s probably some a s s o c i a t i o n between many flowers w i t h a large seed s e t but data are too scanty to put much r e l i a n c e on i t , 5 There i s a. s i g n i f i c a n t d i f f e r e n c e i n seeds (a) per pod between s e l f and open p o l l i n a t e d racfmes, (b) there i s a s i g n i f i c a n t c o r r e l a t i o n between pods w i t h abundant seed inboth open p o l l i n a t e d and s e l f p o l l i n  ated, 6 There i s no a s s o c i a t i o n between flower c o l o r and seed y i e l d , 7 Comparisons between seed y i e l d of successive years showed a d e c l i n e . However, a good seed y i e l d e r tended to remain good seed y i e l d e r s , 8 There are d i s t i n c t l y more high y i e l d i n g plants than ex pected i n a normal d i s t r i b u t i o n curve, 9 Comparisons of seed y i e l d , plant y i e l d and plant height between the F-j_ and Fr, showed a reduction i n general, 1 0 There i s no a s s o c i a t i o n of flower abundance and floxver c o l o r . 4 6 11 There i s no a s s o c i a t i o n between, l e a f s p o t t i n g incidence and flower abundance, 12 There i s no a s s o c i a t i o n between flower abundance and the percentage of ovules developing on the racemes, 13 There i s no a s s o c i a t i o n between flower abundance and flower f a l l , 14 There i s no a s s o c i a t i o n between flower abundance and l e a f dolor* 15 There i s a strong c o r r e l a t i o n between stem thickness and stem height, 16 There i s a p o s i t i v e c o r r e l a t i o n between plant height and plant y i e l d . The p o s i t i v e c o r r e l a t i o n i s high but not absolute, 17 There i s a c o r r e l a t i o n between pla n t height and spread. 18 There Is no a s s o c i a t i o n between l e a f s p o t t i n g incidence and l e a f c o l o r , 19 There i s no a s s o c i a t i o n between l e a f s p o t t i n g incidence and the percentage of ovules developing on the racemes, 20 Ho conclusions were a r r i v e d at regarding the mode of flower color i n h e r i t a n c e . 46 1, Armstrong, J.M.' and White, W. J . Factors A f f e c t i n g Seed S e t t i n g i n A l f a l f a : Jour of A g r i c . Science, V o l , 25 - 1935, 2, Bolton, J.L. and F r y e r , J.M. In t e r p l a n t V a r i a t i o n s i n Certain Seed S e t t i n g Processes i n A l f a l f a s Sex. A g r i c , V o l , 18 - 1937, 3, Brink, R.A, and Cooper, D.D. Somatoplastic S t e r i l i t y i n M, s a t i v a : S c i , News Serv i c e , V o l , 90, 4, Brink, R..A. and Cooper, D.C. P a r t i a l and S e l f Incompatability and the Collapse of F e r t i l e Ovules as Factors A f f e c t i n g Seed Formation i n A l f a l f a : Jour, A g r i c , Research, Vol,.60 - 1940 5, Burton, G.W. ' A l f a l f a Inheritance Studies i n New Jersey: Am, Soc. Agroa. Jour,, V o l , 27 - 1935 6, Carlson, J,W. A r t i f i c i a l T r i pping of Flowers i n A l f a l f a i n R e l a t i o n to Seed Production? Jour, of Am. Soc, Agroa,, V o l , 22 1930. 7, Clarke, A.E. and Fryer, J.M, s Seed S e t t i n g i n A l f a l f a : S c i . A g r i c . , V o l . 11 - 1930 8, Cooper, D.C. ' Embryo M o r t a l i t y i n R e l a t i o n to Seed Formation i n A l f a l f a s Am, Jour, of Bot., V o l . 24, 1937. 9^ Dwyer, R.E.P, Lucerne Breeding Technique - A New System of Close Breeding: Herbage Reviews, V o l . 4- 1936 10, Englebert, V. A Study of Various Factors Influencing Seed Production i n A l f a l f a s S c i . A g r i c . , V o l . 12 - 1931. 11, F a r l e y , H. A C y t o l o g i c a l Study of U. B. C. A l f a l f a s M.S.A. Thesis 1936 - unpublished. 12, Freeman, G.F. P h y s i o l o g i c a l C orrelations and C l i m a t i c Reactions i n A l f a l f a Breedings Am. Nat., V o l . 48 - 1941, 13, G r i z z a r d , A.L. and Matthews, E. M. E f f e c t s of Boron on Seed Production of A l f a l f a s Jour. Am. Soc. Agron., V o l . 34 -1942 14.. Hay, W.D. D o e s . . A r t i f i c i a l Tripping of- A l f a l f a Blossoms Increase Seed S e t t i n g ! S c i . A g r i c , V o l . 5, 1924, .15. Hut chins on ? A. H, and Farley., H. • ' Seed Development i n Medicago Hybrids| Normal Ovule Canadian Jour. Research, V o l , 19, 1941, 16. Jones, F.R. Evidence of Resistance i n A l f a l f a , Red Clover and Sweet Clover to Certain Fungus Parasites? Phyt., V o l . 31- 1941. 17* K i r k , L.E. S e l f F e r t i l i t y i n R e l a t i o n to Forage Crop Improvement! Sc. A g r i c , V o l , 8 - 1927 18, Ledingham, G. F. G y t o l o g i c a l and Developmental Structures of Hybrids Between M. s a t i v a and a D i p l o i d M. Falacata: Genetics, V o l . 25- 1040. 19. Lejeune, C.J. and Olson, P.J. Seed S e t t i n g i n A l f a l f a 5 Sc. A g r i c , V o l . 20 - 1939. 20. Lepper, R. and Odland, T.E. Leaf Mutation i n A l f a l f a : Journ. Am. Soc. Agron. 9 V o l . 31 - 1937. 21, Lepper, R and Odland, T.E. Inheritance of Flower Color i n a l f a l f a : Journ. Am. .Soc Agron., V o l . 31- 1937. '22. McVicar, R. F. ' Inheritance of Seed Colour i n A l f a l f a : S c A g r i c V o l , 15 - 1934. 23. Moe, G.G. • Inherantance Studies of A l f a l f a s 1928 Thesis - Unpublished. 24. Rogers, C.B. W. Rhizome Studies of A l f a l f a s M.S.. A. Thesis - 1941 Unpublished. 25. Southworth, W» Influences Which Tend to A f f e c t Seed Production i n A l f a l f a and an Attempt to Raise High Seed Producing S t r a i n s by Hybridizations S c A g r i c . , V o l . 9 - 1928. 26. Stewart, G. A b n o r m a l i t i e s i n Inbred A l f a l f a and Surgar Beets 1 Jour, of Hereditary, V o l . 25, 1934. 27. Stewart, G« The E f f e c t s of Inbreeding on V a r i a b i l i t y i n A l f a l f a s Jour. A g r i c . Reasearch, V o l . 49- 1934 s 28. Tysdal, H. M. Is Tripping Necessary f o r Seed S e t t i n g i n A l f a l f a s Jour. Am. Soc. Agron., V o l . 32s 1940. 29. Tysdal, HvR. and Clark, I . ' = Improvement of A l f a l f a Seed Production by Inbreedings Jour. Am. Soc. Agron., V o l . 26-1934. 30. Tysdal, H.R. And Westover. A l f a l f a Improvements U. S. A g r i c . Year Book - 1937. 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Country Views Downloads
United States 15 4
China 4 13
Canada 4 4
Russia 2 0
France 1 0
Japan 1 0
City Views Downloads
Unknown 7 18
Ashburn 6 0
Shenzhen 4 13
Fairview, Alberta 3 0
Kansas City 3 0
University Park 1 0
Brookings 1 0
Sylvan Lake 1 1
Tokyo 1 0

{[{ mDataHeader[type] }]} {[{ month[type] }]} {[{ tData[type] }]}
Download Stats

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0105658/manifest

Comment

Related Items