GeneticResourcesand CropEvolution 43: 395---407,1996. (~) 1996 KluwerAcademicPublishers. Printedin the Netherlands

8/14/2019 GeneticResourcesand CropEvolution 43: 395---407,1996. (~) 1996 KluwerAcademicPublishers. Printedin the Nethe

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Genetic Resources and Crop Evolution 43: 395---407, 1996. 3 9 5(~) 1996 KluwerAcademic Publishers. Prin ted n the Netherlands.

G e o g r a p h i c v a r i a t i o n i n t e t r a p l o i d w h e a t (Triticum turgidum s s p . turgidumc o n v a r , durum) l a n d r a c e s f r o m t w o p r o v i n c e s i n E t h i o p i aLuci ano Pecetti t & Ardeshir B. Dama nia 2Intern ation al C enter fo r Agric ultur al Resea rch in the Dry Areas, P O. Box 5466, Aleppo, Syria; 1present address:Ist i tuto Sper imen tale per le Colture Foraggere, v iale Pia cenza 29, 200 75 Lodi, Italy; (2present address." Ge neticReso urces Con servation Program, Universi ty of Cali fornia, D avis, C ali fornia 95616-8602, USA )Received 14 M arch 1995; accepted 10 Octobe r 1995

K e y w ords: E t h i o p i a , g e n e t i c r e s o u r c e s , g e r m p l a s m e v a l u a t i o n , l a n d r a c e s , t e tr a p l o i d w h e a t , Trit icum turgidum s sp .turgidum c o n v . durum

A b s t r a c t

T h e r e i s c o n s i d e r a b l e w e a l t h o f g e n e t i c a l a n d m o r p h o l o g i c a l v a r ia t i o n i n t e tr a p l o i d w h e a t c o l l e c t e d f r o m E t h i o p i a b yp a s t e x p e d i t i o n s . S e v e r a l a u t h o r s h a v e s p e c u l a t e d o n t h e r e a s o n s f o r t h is c o n c e n t r a t i o n o f d i v e r s i t y s o f a r r e m o v e df r o m t h e c e n t r e o f o r i g i n o f w h e a t s i n W e s t A s i a . T h e p r e s e n t s t u d y r e p o r t s r e s u lt s o f e v a l u a t i o n c a r r i e d o u t o nm a t e r i a l c o l l e c t e d i n th e e a r ly 1 9 7 0 ' s f r o m E t h i o p i a . T h e l a n d r a c e s f r o m t h e tw o p r o v i n c e s S h e w a a n d T i g r a yw e r e f o u n d t o b e d is t i n c t ly d i f f e r e n t . T h i s d i v e r g e n c e w a s a t t ri b u t e d t o t h e d i ff e r e n c e s i n e n v i r o n m e n t a l c o n d i t i o n sb e t w e e n t h e m . W i d e d i f f e r en t i a ti o n a m o n g l a n d r a c es w i t h in e a c h p r o v i n c e w a s a l s o p r e s en t . T h e E t h i o p i a n f a r m e r ' sp r a c t i c e o f g r o w i n g c o m p o s i t e c u l t i v a r s in t h e f ie l d h a s r e s u l te d i n b u l k s a m p l e s o f E t h i o p i a n l a n d r a c e s c o n t a i n i n gs e v e r a l a g r o t y p e s . T h e p r o p o r t i o n o f t o t al v a r i a n c e d u e t o d i f fe r e n c e s a m o n g a g r o t y p e s w i t h in l a n d r ac e s w a s b yf a r t h e g r e a t e s t f o u n d i n t h i s s t u d y , f o l l o w e d i n m o s t c a s e s b y t h e v a r i a t i o n a m o n g l a n d r a c e p o p u l a t i o n s w i t h i np r o v i n c e s w h i c h e x c e e d e d , i n t u r n, t h e v a r i a t io n b e t w e e n p r o v i n c e g e n e p o o l s . T h e o p t i m a l s t r a t e g y f o r f u r t h e rg e r m p l a s m c o l l e c t io n s a n d i m p l i c at i o n s f o r i m p r o v e m e n t an d c o n s e r v a t i o n in l o c a l l y -b a s e d c o m m u n i t y g e n e b a n k sa r e d i s c u s s e d .

I n t r o d u c t i o n

E t h i o p i a n w h e a t s h a v e p r o v e d t o h a r b o u r a s u b s t a n -t ia l w e a l t h o f g e n e t i c v a r i a t i o n ( H a r l a n , 1 9 6 9 ) , p a r -t i c u l a r l y i n t e t r a p l o i d w h e a t f o r w h i c h t h e c o u n t r y i sc o n s i d e r e d t o b e a c e n t r e o f g e n e t i c d i v e r s i t y ( H a r l an ,1 9 7 1 ) . S e v e r a l e x p l o r a t i o n s h a v e r e s u lt e d i n th e e x t e n -s i v e c o l l e c t i o n o f c e r e a l g e n e t i c r e s o u r c e s f r o m t h i sl a n d . V a v i l o v ( 1 9 5 7 ) , S a k a m o t o & F u k u i ( 1 9 7 2 ) a n dP o r c e d d u e t a l. ( 1 9 7 5 ) r e p o r t e d t h e a b u n d a n c e o f m o r -p h o l o g i c a l l y d i f f e r e n t f o r m s o f t e tr a p l o id w h e a t t h e yc o l l e c t e d i n E t h i o p i a . L a r g e c o l l e c t i o n s o f t et r a p l o i dw h e a t f r o m t h i s c o u n t r y w e r e e v a l u a t e d ex-si tu, an dw i d e m o r p h o - g e n e t i c v a r i a ti o n w a s f o u n d ( J ai n e t a l. ,1 9 7 5 ; B e k e l e , 1 9 8 4 ; D o m i n i c i e t a l ., 1 9 8 8 ; A s i n s &Car bon e l l , 1989; T es f aye e t a l. , 1991; Pece t t i e t a l. ,1 9 9 2 a ) . S o m e o f t h e s e s tu d i e s a l s o p o i n t e d o u t t h eu n m i s t a k a b l e d i s t i n c t i v e n e s s o f t h e E t h i o p i a n m a t e r i -

a l s f r o m a n y o t h e r g e n e p o o l ( e . g . , D o m i n i c i e t a l . ,1988; Pece t t i e t a l , , 1992a) . Such a d i s t inc t iveness hasa l s o b e e n h i g h l i g h t e d b y V a v i l o v ( 1 9 5 7 ) , P o r c e d d u e ta l_ (1975) and Har lan (1992) .

T e t r a p l o i d w h e a t o c c u p i e s 6 0 % o f th e t o t a l w h e a ta r e a i n E t h i o p i a . I t i s tr a d i t io n a l l y g r o w n o n t h e h e a v yb l a c k s o i l s ( v e r t i s o l s) o f t h e h i g h l a n d s a t a l t it u d e s u s u -a l l y r a n g i n g b e t w e e n 1 8 0 0 a n d 2 8 0 0 m a s l , e x c l u s i v e l yu n d e r r a i n f e d c o n d i t i o n s ( T e s e m m a & B e l a y , 1 9 9 1 ) .A l m o s t a ll o f t h e w h e a t s g r o w n b y f a r m e r s a r e l an -d r a c e s , c o n s i s t i n g o f m i x t u r e s o f l i n e s w h i c h v a r y i nb o t a n i ca l f o r m a n d m o r p h o l o g i c a l c h a r a ct e r s ( S a k a m o -t o & F u k u i , 1 9 72 ; P o r c e d d u e t a l. , 1 9 7 5 ; T e s e m m a &B e l a y , 1 9 9 1 ) . M o r e t h a n o n e w h e a t s p e c i e s a r e o f t e ng r o w n a s m i x t u r e s i n t h e s a m e f i e ld . L o c a l f a r m e r s d oth i s to add var i e ty to the i r d ie t and to reduce the r i sko f l o s s e s d u e t o th e o u t b r e a k o f n e w p e s t s a n d d i s e a s e so r d u e t o u n u s u a l e n v i r o n m e n t a l c o n d i t i o n s ( B e k e l e ,


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3 9 61 9 84 ). T h e s e v a r i a b l e w h e a t f i e l d s a r e h a r v e s t e d a s aw h o l e a n d t h e f o l l o w i n g y e a r t h e s e e d s a re b r o a d c a s t a sa m i x t u r e , t h u s m a i n t a i n i n g t h e a b u n d a n c e o f v a r i a t i o ny e a r a f te r y e a r ( S a k a m o t o & F u k u i , 1 9 7 2 ) . T h e c o n -s i d e r a b l e d i v e r s i t y b o t h a m o n g a n d w i t h i n l a n d r a c e s( B e k e l e , 1 9 8 4 ) m a k e s t h e m i n t e r e s ti n g f r o m a b o t a n i -c a l a n d a b r e e d i n g p o i n t o f v i e w . A l t h o u g h a l o c a t io n -s p e c i f ic a d a p t a b i l i t y h a s b e e n o b s e r v e d f o r t h e E t h i o p i -a n t e t r a p l o i d c u l t i v a r s ( T e s e m m a , 1 9 9 1 ) , t h e p r e s e n c eo f g e n e r a ll y i m p o r t a n t f e a t u re s f o r c ro p i m p r o v e m e n th a s b e e n r e p o r t e d i n t h e s e l a n d r a c e s, s u c h a s s t e m r u s tres i s t ance , long coleopt i l e , shor t s t a ture , ea r ly matur i -ty , h igh pro te in content or adapta t ion to low so i l fe r t i l -i ty (Porceddu et a l . , 1975; Pecet t i e t a l . , 1992a).

V a r i o u s r e a s o n s w e r e a d v o c a t e d f o r th e o c c u r r e n c eo f a g r e a t d i v e r s i t y i n t h e E t h i o p i a n t e t r a p l o i d w h e a t ,s u c h a s i s o l a t i o n f r o m o t h e r w h e a t g e r m p l a s m , p r i m -i ti v e f a r m i n g s y s t e m s , h e t e r o g e n e o u s e n v i r o n m e n t s ,a n d n a t u r a l c r o s s - f e r t i l i z a t i o n d u e t o f i e l d m i x t u r e s( T e s e m m a & B e l a y , 1 9 9 I ) . K n o w l e d g e o n t h e p a t t e rno f v a r i a t io n f o r i m p o r t a n t m o r p h o - a g r o n o m i c tr ai ts i sn e e d e d f o r a p r o p e r m a n a g e m e n t a n d a b e t t e r e x p l o it a -t ion of th i s gen e pool ( J a in e t a l. , 1975; Beke le ,1984).

B e k e l e (1 9 8 5 ) t h o r o u g h l y d i s c u s s e d th e im p o r t a n c eo f a h i e r a r c h i c a l a p p r o a c h t o q u a n t i ta t i v e l y d e f i n e th ev a r i a t i o n i n a c e n t r e o f g e n e t i c d i v e r s i t y o v e r a r a n g e o fm i c r o c e n t r e s . S u b d i v i d i n g t h e v a r i a t i o n i n t o i t s c o m -p o n e n t s m a y a s s i s t i n g e n e t i c r e s o u r c e s c o n s e r v a t i o na n d u t i l i z a t i o n , b y d e t e r m i n i n g t h e r e l a t i v e c o n t r i b u -t i o n o f t h e d i f f e r e n t l e v e l s o f v a r i a b i l i t y t o t h e t o t a ld i v e r s i t y a v a i l a b l e in a n y o n e a r e a . T h i s w o u l d e n a b l ep l a n n i n g o f f u t u r e g e r m p l a s m s a m p l i n g , e st a b li s h m e n to f in-situ g e n e c o n s e r v a t i o n , o r u s e o f a p p r o p r i a t e g e n ep o o l s i n c r o p i m p r o v e m e n t f o r s p e c i f ic p l a n t a tt r ib u t e s( B e k e l e , 1 9 8 4 ; P o r c e d d u & D a m a n i a , 1 9 9 2 ) .

T h e p r e s e n t s t u d y i s a i m e d a t: i ) a s se s s i n g r e g i o n a la n d l o c a l p a t t e r n s o f p h e n o t y p i c v a r i a t io n f o r a w i d ea r r a y o f c h a r a c t e r s i n E t h i o p i a n t e t r a p l o i d w h e a t l a n -d r a c e s o r i g i n a t i n g f r o m m a n y d i f f e r e n t s i t e s ; a n d i i )i d e n t i f y i n g s o m e c o m p o n e n t s o f t h e e n v i r o n m e n t o fo r i g i n t h a t m i g h t c o n t r i b u t e t o t h e e x i s t e n c e o f s p e c i fi cf e a t u r e s i n t e t r a p l o i d l a n d r a c e s o f E t h i o p i a .

M a t e r i a ls a n d m e t h o d s

A c o l l e c t in g m i s s io n m o u n t e d b y t h e G e r m p l a s m I n s ti -tu te , Bar i , I t a ly , expl ore d the cent ra l and nor the rnh i g h l a n d s o f E t h i o p i a a n d c o l l e c t e d t e tr a p l o i d w h e a t(Triticum turgidum (L , ) The l l . s sp . turgidum c o n -

var. durum ( D e s f . ) M K ) s a m p l e s f o r m a n y s it e s, a sd e s c r i b e d b y P o r c e d d u e t a l . ( 1 9 7 5 ) . T h e s a m p l e sw e r e s u b s e q u e n t l y g r o w n a t t h e f i e l d s t a t i o n o f t h eG e r m p l a s m I n s ti tu t e n e a r B a r i. F r o m e a c h s a m p l e av a r i ab l e n u m b e r o f d i st in c t m o r p h o t y p e s w e r e i d en t i-f i ed o n t h e b a s i s o f a s e r i e s o f g r o s s l y d i a g n o s t i c m o r -phologica l t ra i t s , pa r t i cu la r ly of the sp ike and gra in( P. P e r r i n o , p e r s. c o m m . ) . M o r p h o t y p e s s i n g l e d o u t i ns u c h a w a y a r e a l s o t e r m e d ' a g r o t y p e s ' w i t h r e f e r e n c et o l a n d r a c e p o p u l a t i o n s ( B e l a y e t a i . , 1 9 9 3 ) , e m p h a -s i z i n g t h e i r a g r o n o m i c i n d i v i d u a l i t y w i t h i n t h e f a r ml a n d r a c e . A t o ta l o f 5 6 5 1 a g r o t y p e s f r o m 8 2 p o p u l a -t ions (= co l l ec t ion s i t e s ) were s ent for dupl i ca t ion tot h e I n t e r n a t i o n a l C e n t e r f o r A g r i c u l t u r a l R e s e a r c h i nt h e D r y A r e a s ( I C A R D A ) , A l e p p o , S y r i a.

T h i s p a p e r r e f e r s t o t h e e v a l u a t i o n o f o v e r 1 5 0 0a g r o t y p e s f r o m 3 3 s i te s g r o w n i n o n e s e a s o n a t I C A R -D A ' s r e s e a r c h s t a ti o n s w i t h i n t h e f r a m e w o r k o f t h ee v a l u a ti o n o f a w o r ld d u r u m w h e a t g e r m p l a s m c o l l e c -t ion (Pece t t i e t al ., 1992a) . A l l ag ro ty pes or ig ina te df r o m e i th e r o f t w o E t h i o p i a n a d m i n i s t r a ti v e p r o v i n c e s :S h e w a ( 1 2 1 2 a c c e s s i o n s f r o m 1 4 s i te s ) a n d T i g r a y 4 6 5a c c e s s i o n s f r o m 1 9 s i te s ) . G e o g r a p h i c r a n g e s o f th ec o l l e c t i n g s i t e s i n t h e t w o p r o v i n c e s a r e p r e s e n t e d i nT a b l e 2 . A l t h o u g h t h e c l o s e s t b o u n d a r i e s o f th e t w op r o v i n c e s a r e a b o u t 2 0 0 k m a p a r t, t h e g e o g r a p h i c c e n -t r e s o f th e t w o g r o u p s o f c o l le c t i n g s i t e s w e r e s e p a -r a t e d b y a b o u t 4 0 0 k m . B e s i d e s t h e g e o g r a p h i c s e p -a r a t i o n , t h e r e a r e s i g n i f i c a n t g e o l o g i c a l a n d c l i m a t i cd i f f e r e n c e s b e t w e e n t h e t w o p r o v i n c e s . T h e s o i l s inTigray a re s tony , sha l low and low in fe r t i l i t y , whi l et h o s e i n S h e w a h a v e b e t t e r f e r t i l i t y ; T i g r a y h a s l o w -e r e l e v a t i o n , w a r m e r c l i m a t e a n d l o w e r r a i n f a l l t h a nS h e w a ( A n o n y m o u s , 1 9 76 ; 1 9 8 4 ).

A w i d e r a n g e o f q u a n t i t a t i v e a n d d i s c r e t e c h a r a c t e r swas recorded , a s desc r ibed in Table 1 . A l l t ra i t s werer e c o r d e d u n d e r s e m i - a r id c o n d i t io n s a t th e I C A R D A ' sm a i n e x p e r i m e n t a l s ta t i o n o f T e l H a d y a , n o r t h e r n S y r -i a , e x c e p t d r o u g h t t o l e r a n c e , w h i c h w a s e v a l u a t e d a tt h e s t re s s fu l s i t e o f B r e d a , n o r t h e r n S y r i a , a n d S e p t o r i al e a f b l o tc h , o b s e r v e d u n d e r m o i s t a n d w a r m c o n d i -t io n s f a v o u r a b l e t o t h e p a t h o g e n d e v e l o p m e n t a t L a t -t a k i a , w e s t e r n S y r i a . F u r t h e r i n f o r m a t i o n o n t h e d a t ar e c o r d in g m e t h o d o l o g y c a n b e f o u n d in D a m a n i a e ta l . (1990, 1991) , Pece t t i & Annicchia r i co (1991) andP e c e t t i e t al. ( 1 9 9 2 a ) . A m o d i f i e d a u g m e n t e d d e s i g n( L i n & P o u s h i n s k y , 1 9 8 3 ) w a s u s e d a t B r e d a a n d T e lHadya , except for the d i sease nurse r i es in th i s l a t t e rl o c a t i o n _ D e t a i l e d i n f o r m a t i o n o n e x p e r i m e n t l a y - o u ta n d m a n a g e m e n t c a n b e f o u n d i n P e c e t t i e t a l. ( 1 9 9 2 a ,1 9 9 2 b ) . D i s e a s e n u r s e r i e s i n T e l H a d y a a n d L a t t a k i a


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3 9 7

Table 1. List o f quantitative and discrete characters recorded on a tetraploid wheat germplasm collectionfrom Ethiopia and the protocol of scoring usedQuantitative character Abb reviation U ni tHeading time DHE days from germinationMaturity time DM A days from germinationGrain-fil ling period GFP days (DMA less DHE)Plant height PLH cmGrain yield YLD t ha - 1Flag-leaf length FLL cmFlag-leaf width FLW cmFlag-leaf area FLA cm2Spike length SLE cmNo. of kernels per spikelet NKS countNo. of kernels per spike KSP countProtein content PRO %1000-kernel weight TKW gDiscrete character Abbreviation Sc or eEarly growth vigor EGV l(very low), 2, 3, 4, 5(very high)Productive tillering capacity TIL l(Iow), 3(intermediate),5(good)Flag-leaf attitude FAT l(erect), 5(semi-erect), 9(horizontal)Glum e colour (at maturity) GCO l(white). 2(yellow), 3(reddish), 4(grey), 5(black)Awn colour (at maturity) ACO l(white), 2(yellow), 3(reddish), 4(grey), 5(black)Glum e hairiness GLH l(absent), 3(low), 5(high)Spike density SDE l(very lax), 2, 3, 4, 5(very dense)Kernel colour KCO l(straw), 2(amber), 3(red-brown),4(purple)Drought tolerance DTO l(extremely bad), 2, 3, 4, 5, 6, 7, 8(very good)Yellow rust susceptibility YRU 1 resistant), 3, 5, 7, 9(very susceptible)Comm on bunt susceptibility BUN l(resistant), 2, 3, 4, 5, 6, 7, 8, 9(very suscept.)Septor ia leaf blotch suscep tibility SEP l(resistant), 2, 3, 4, 5, 6, 7, 8, 9(very susce pt.)

w e r e s o w n a s d e s c r i b e d i n P e c e t t i e t a l . ( 1 9 8 9 ) a n ds c r e e n e d u n d e r a r t i fi c i a l e p i p h y t o t i c c o n d i t i o n s w i t hl o c a l p a t h o g e n r a c e s .

M e a n v a l u e s o f t h e q u a n t i t a t i v e c h a r a c t e r s w e r ec o m p u t e d t o g e t h e r w i t h r a n g e s a nd C V s o f l a n d r a c ep o p u l a t i o n v a l u e s w i t h i n e a c h p r o v i n c e . A n a n a l y s i so f v a r i a n c e ( A N O V A ) w a s p e r f o r m e d , w h e r e t h e m e a ns q u a r e s o f t h e p r o v i n c e s w e r e t e s t e d a g a i n s t t h e p o o l e dm e a n s q u a r e s o f p o p u l a t i o n s w i t h i n p r o v in c e s , w h i l et h e la t t e r m e a n s q u a r e s a n d t h e m e a n s q u a r e s o f p o p u l a -t i o n s w i t h i n e a c h p r o v i n c e w e r e t e s t e d a g a i n s t th e m e a ns q u a r e s o b t a i n e d b y p o o l i n g o v e r p r o v i n c e s t h e w i t h in -p r o v i n c e e r r o r s u m o f s q u a re s a n d d e g r e e s o f f r e ed o m .T h e e s t i m a t e s o f t h e v a r i a n c e c o m p o n e n t s ' b e t w e e np r o v i n c e s ' , ' a m o n g p o p u l a t i o n s w i t h in p r o v i n c e s ' a n d' a m o n g a g r o t y p e s w i t h i n p o p u l a t i o n s ' w e r e c a l c u l a t -e d f o r a l l q u a n t i t a t i v e t ra i t s a c c o r d i n g t o t h e f o r m u l a e

r e p o r t e d b y S t e e l & T o r r i e s ( 1 9 6 0 , p . 1 2 5 ) f o r a h i e r a r -c h i c a l A N O V A w i t h u n e q u a l s u b - s a m p l e n u m b e r s .

A c a n o n i c a l d i s c r i m i n a n t a n a l y s is , r e p e a t e d l y u s e di n g e r m p l a s m e v a l u a t i o n s ( e. g , P o r c e d d u , 1 9 7 6 ; S p a g -n o l e t t i Z e u l i & Q u a l s e t , 1 9 8 7 ; P e e t e r s , 1 9 8 8 ) , w a su n d e r t a k e n t o a s s e s s o n a m u l t i v a r i a t e b a s i s d i f f e r -e n c e s , a n d , h e n c e , d i s t i n c t i v e n e s s b e t w e e n t h e tw op r o v i n c e t e t ra p l o i d g en e p o o l s . A g r o t y p e v a l u e s f r o m1 4 p o p u l a t i o n s in S h e w a a n d 1 3 i n T i g r a y ( f o r w h i c h al a r g e n u m b e r o f c o m p l e t e c a s e s w a s a v a i l a b l e f o r t h ea n a l y s i s ) w e r e u s e d f o r a l l q u a n t i t a t i v e t r a it s . H o w -e v e r , g r a i n - f i l l i n g p e r i o d a n d f l a g - l e a f a r e a , d e r i v e db y c o m p u t a t i o n s f r o m o t h e r re c o r d e d c h a r a c t e r s w e r en o t i n c l u d e d a s o r i g i n a l v a r i a b l e s i n t h e a n a l y s i s . Aw e i g h t w a s a t t r i b u t e d to e a c h a c c e s s i o n i n v e r s e l y p r o -p o r t i o n a l to t h e n u m b e r o f a g r o t y p e s o f i t s p o p u l a t i o no f o r i g i n , t o a v o i d b i a s d u e t o t h e d i f f e r e n t s i z e o f t h e


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39 8

Table 2. Summ ary statistics for 13 morphometric traits recorded on 14 landrace populat ions from Shewa and 19populat ions from Tigray provinces, together with some geographic and climatic variables o f the sites of origin of thepopulations

SHEWA TIGRAYCharacter Mean min max CV% Mean min max CV%Heading time (dd.) 148.1 146.4 149,8 0.8 143.1 139.0 149.0 1.9Maturity time (dd.) 186.0 183.3 190.3 1.1 182.3 175.6 189.6 2.0Grain-filling period (dd.) 38 0 35.7 40.5 4.1 39 1 36.0 41.4 3,8Plant height (cm) 90.9 85.4 96.8 3.6 91.2 75.8 109.6 9,0Grain yield (t ha - t ) 2.67 2.23 3.13 10.4 1.88 0.60 2.65 27.7Flag-leaf length (cm) 28.0 26.2 29.1 2.5 27. l 24.6 29,4 4.9Flag-leaf width (cm) 1.7 1.5 1,9 4.9 1.7 1.3 1.9 8.8Flag-leaf area (cm?) 35.7 32.2 40,2 6.3 34.6 24.8 41.3 12,5Spike length (cm) 10.5 9,9 11.3 4.2 9.7 8,3 11,7 9.0No. of kernels per spikelet 2.2 2,0 2.4 5.5 2,4 2.0 2.9 10.8No, of kernels per spike 37.7 33.0 45,1 8.0 32.4 23.1 41.1 14.8Protein content (%) 14.2 13.3 14.9 3.5 13,6 12.5 14,5 4.31000-kernel weight (g) 33,8 31.7 36.0 4,3 37.7 30.8 42.5 9,4Latitude (N ) 9461 9241 956 1,6 1340 1 1250 ~ 142 21 3.0Longitude (E) 38 561 38 04 61 390071 0,4 39251 38571 390351 0.5Altitude (m asl) 2707,1 2100 2900 l 1,0 2237.7 1940 2650 8.5Annual rainfall (mm) 1246,4 1050 1400 8.1 618.5 500 850 16.4Mean daily min T (C) 5,2 5.1 5.3 1.6 11,0 7.0 12.7 15.4Mean daily max T (C) 21,4 21.2 22.3 2,1 23.4 22.5 25.0 3 8

v a r i o u s p o p u l a t i o n s . T h e i n f l u e n c e to th e e n v i r o n m e n to f o r i g i n o n t h e v a r i a t io n a m o n g l a n d r a c e p o p u l a t i o n sw a s a s s e s s e d c o m p u t i n g t h e c o r r e l a t i o n c o e f f i c i e n t sb e t w e e n s o m e c l i m a t i c v a r i a b l e s ( t o t a l r a i n f a l l , a v e r -a g e d a il y m a x i m u m t e m p e r a t u r e , a n d a v e r a g e d ai lym i n i m u m t e m p e r a t u r e ) o f t h e c o l l e c t i n g s i t e s [ e x t r a p -o l a t e d f r o m t h e r e c o r d s o f t h e n e a r e s t m e t e o r o l o g i c a ls t a ti o n ( s ) ] a n d t h e p o p u l a t i o n m e a n v a l u e s o f t h e fi r stt h r e e c a n o n i c a l v a r i a b l e s . T h e u s e o f s u c h c o r r e l a t io n sb e t w e e n e n v i r o n m e n t a l v a r i a b l e s a n d p a t te r n o f v a r i a -t i o n w a s p r o p o s e d b y A n n i c c h i a r i c o ( 1 9 9 2 ) i n a s t u d yo n th e g e n o t y p e e n v i r o n m e n t i n t e r a ct i o n , a n d h a sb e e n a p p l i e d t o d u r u m w h e a t i n a w i t h i n - c o u n t r y v a r i -a t i o n a s s e s s m e n t ( P e c e t t i & N a c h i t , 1 9 93 ).

T h e f r e q u e n c y d i s t r i b u t i o n o f t h e s c o r e d v a l u e sr e c o r d e d f o r t h e d i s c r e t e v a r i a b l e s w a s d e t e r m i n e d f o re a c h p r o v i n c e . H o m o g e n e i t y o f s c o r e f r e q u e n c y d i st ri -b u t i o n b e t w e e n p r o v i n c e s w a s t e s t e d b y t h e P e a r s o n ' sc h i - s q u a r e .

T h e S h a n n o n - W e a v e r d i v e r si t y i n d e x ( H s) w a sc o m p u t e d t o a s s e s s t h e o v e r a l l p h e n o t y p i c d i v e r s i t yw i t h i n p r o v i n c e s a s w e l l a s f o r e a c h c h a r a c t e r . T h i sp a r a m e t e r h a s b e e n u s e d e x t e n s i v e l y i n e v a l u a t i n g

g e n e t i c r e s o u r c e s t o m e a s u r e p h e n o t y p i c d i v e r s i t y f o rd i sc re te t ra i t s bo th among (e .g . J a in e t a l_ , 1975) andw i t h i n c o u n t r y g e n e p o o l s ( e _ g . N e g a s s a , 1 9 8 6 ) . Ah i e ra r c h ic a l A N O V A o f t h e H ' i n d e x o v e r c h a r a c te r swas ca r r i ed out , a s ind ica ted by Ja in e t a l . (1975) , toa s se s s d if f e r en c e s b e tw e e n p r o v i n c e s a n d a m o n g p o p -u l a t i o n s w i t h i n p r o v i n c e s f o r t h e l e v e l o f p h e n o t y p i cdivers i ty .

R e s u l t s a n d d i s c u s s i o n

S u m m a r y s ta t is ti c s ( m e a n , m i n i m u m , m a x i m u m a n dC V ) o f t h e m o r p h o - p h y s i o l o g i c a l c h a r a c te r s a n d o f t h eg e o g r a p h i c a n d c l i m a t i c c o l l e c t i n g v a r i a b l e s f o r t h el a n d r ac e p o p u l a t i o n s f r o m t h e t w o E t h i o p i a n p r o v i n c e sa r e r e p o r t e d i n T a b l e 2 . L a n d r a c e s f r o m T i g r a y o r i g -i n a t e d a t s i t e s s i t u a t e d a t l o w e r a v e r a g e a l t i t u d e a n dw i t h l e s s f a v o u r a b l e c l i m a t i c c o n d i t io n s , p a r t i c u l a r l y i nt e r m s o f r ai n f a l l a n d m i n i m u m d a i l y t e m p e r a t u r e , t h a nl a n d ra c e s f r o m S h e w a . F o r t h e se t w o c l i m a t ic p a r a m -e t e r s , t h e c o l l e c t i n g s i t e s i n T i g r a y w e r e r e m a r k a b l ym o r e v a r i a b l e th a n t h o s e i n S h e w a , a s i n d i c a t e d b y t h e


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r e spe c t ive C V s ( Ta b le 2) . S uc h a n e nv i r on m e n ta l va r i-a t i on m a y ha ve c o n t r ibu t e d to t he h ighe r c oe f f i c ie n t o fva r i a t i on in T ig r a y tha n in S he w a f o r a lm os t a l l t r ai ts( Ta b le 2 ). S im i l a rly , B e ke le ( 1984 ) f oun d d i f f e r e nc e so f C V s a m ong E th iop ia n r e g ions , a t t ri bu t ing the m tod i f f e r e n t e nv i r o nm e n ta l c ond i t i ons w i th in e a c h r e g ion .D e sp i t e t he l ow e r num be r o f a g r o type s s ing l e d ou tpe r popu la t ion in t he ge r m p la sm o f T ig r a y ( P. P e r r ino ,pe r s . c om m . ) , a h ighe r va r i a b i l it y w i th in popu la t ionsin T ig r a y tha n in S he w a w a s a l so a ppa r e n t . I nde e d ,the a ve r a ge w i th in - popu la t ion C V w a s h ighe r i n t hef o r m e r p r ov in c e f o r m os t t r a it s ( da t a no t show n) . I t i sw e l l e s t a b l i she d tha t t he va r i a t i on a m ong c r op s t r a in si s ge ne r a l ly g r e a t e r i n s t r e s se d e nv i r onm e n t s t ha n inf a vou r a b le one s ( B e ke le , 1984 ) , p r ov id ing in t he f o r -m e r d i f f e r e nc e s f o r s e l e c t ion to a c t, t hus c on t r ibu t ing tothe a da p ta t i on to t he d i f f e r e n t g r ow ing c ond i t i ons .

A c c o r d ing to t he A N O V A p r e se n te d in Ta b le 3 ,t he p r ov in c e m e a n va lue s r e po r t e d in Ta b le 2 d i f f e r e ds igni f icant ly (p _< 0 .05) fo r heading and m atur i ty t ime ,g r a in y i e ld , num be r o f ke r ne l s pe r sp ike , a nd 1000 -ke r ne l w e igh t . T he g e ne poo l f r om T ig r a y w a s e a r li e r,ha d low e r y i e ld po te n t i a l unde r m od e r a t e ly fa vou r a b lecondi t ions , had shor te r sp ikes , le ss ke rne ls pe r sp ike ,a nd he a v ie r ke r ne l s t ha n the ge ne poo l f r om S he w a .

Tw o c u l t i va r s a da p te d to t he e nv i r onm e n t o f e va l -ua t ion w e r e u se d a s c on t r o l s in t he e xpe r im e n t , na m e -ly t he l oc a l l a nd r a c e 'H a u r a n i ' a nd the I C A R D A 'sim pr o ve d va r i e ty ' S ha m 1 ' . The se c u l t iva r s a re c ons id -e red to be re la t ive ly ea r ly in heading and matur i ty . Inth i s e xpe r im e n t , bo th o f t he m he a de d , on a ve r a ge , 140da ys a f t e r ge r m ina t ion , a nd m a tu r e d in 182 days . 'H a u -rani ' i s a ta ll landrac e (averag e p lant he igh t 112 cmin th i s e xpe r im e n t ) , w i th good y i e ld unde r t he g ive nc ond i t i ons ( 3 . 39 t ha - l ) , c om pa c t sp ike ( 6 . 1 c m ) a ndlow nu m b e r o f ke r ne l s pe r sp ike ( 39 .2 ) . ' S h a m 1 ' i sa s e m i - dw a r f va r i e ty ( p l a n t he igh t 88 c m ) , w i th ve r yh igh y i e ld po te n t i a l ( 4 .77 t ha - l ) , m e d ium sp ike l e ng th( 8.1 c m ) a nd h igh ke r ne l num be r ( 50 . 0 ). Em p i r i c a l lyc om pa r e d w i th t he se a da p te d c u l t iva r s , t he E th iop iange ne poo l a p pe a r e d , on the a ve r a ge , t o be c ons t i t u t e dby low y i e ld ing m a te r i a ls , w i th l ong sp ikes , l ow ke r ne lnum be r a nd r a the r sho r t s t a tu r e .

Te se m m a e t a l. ( 1993 ) s t a t ed tha t t he y i e ld po te n -t i al o f l a nd r a c e g e no ty pe s c a n be r e a l i z e d on ly i f t he yare tes ted a t or near the i r or ig ina l co l lec t in g s ites . T hisi s pa r t ic u l a r ly t r ue f o r t he E th iop ia n m a te r ia l s , w h ic he vo lve d unde r spe c i f i c e nv i r onm e n ta l a nd a g r onom -ic c ond i t i ons ( Te se m m a & B e la y , 1991 ) . The y i e ldl e ve l o f t he E th iop ia n ge r m p la sm e va lua t e d in S y r i a ,t hough low e r t ha n tha t o f a da p te d c u l t iva r s , w a s h ighe r

3 99tha n the one r e c o r de d f o r E th iop ia n l a nd r a c e s g r ow nat the i r si te s of or ig in , us ing a s imi la r p lo t s ize ands t a nda rd a g r onom ic p r a c t i c e s ( Te se m m a e t al ., 1993 ) .The longe r c yc l e re c o r de d in S y r i a t han in E th iop ia onE th iop ia n l a nd r a c e s ( pe r ha ps due to s low e r g r ow th r a t ec a use d by low e r w in t e r t e m pe r a tu r e in S y r i a ) c ou ld bethe reason for the h igher y ie ld in the former country_The ou t s t a nd ing va r i a t i on a m ong a g r o type s f ound inbo th p r ov inc e s ( da t a no t show n) sugge s t s t ha t t he ide n -t i fi c a ti on o f e x t r e m e va r i a n t s f o r im po r t a n t a g r ono m ict ra it s, to be used in breed ing prog ram me s, mi ght beposs ib le .

F ive a g r o type s e xc e e d ing 5 t ha - 1 o f g r a in y i e ldw e r e f ound in t he ge ne poo l f r om S he w a , a nd tw oin tha t f rom Tigray . S r ivas tava e t a l . (1988) repor t -e d 10 t et r a p lo id w he a t a c c e s s ions ( = a g r o type s ) f r oma n E th iop ia n c o l l e c t ion w h ic h ou ty i e lde d ' S ha m 1 'i n a n e nv i r onm e n t ve r y s im i l a r t o t he p r e se n t one .O ne a g r o type f r om T ig r a y , s e l e c te d on the ba s i s o f i tsd r ough t t o l e r a nc e in S y r i a , y i e lde d c ons i s t e n t ly w e l lf o r t h r e e s e a sons i n a d i f f e r e n t M e d i t e r r a ne a n e nv i r on -me nt in S ic i ly (Pece t t i e t al ., 1994) . Com par in g thee a r li ne s s o f t he ge ne poo l f r om T ig r a y ( Ta b le 2 ) a ndtha t o f ' S ha m 1 ' a nd 'H a u r a n i ' p r e v ious ly m e n t ione d ,the se E th iop ia n m a te ri a l s s e e m r a the r su i t ed t o e sc a pethe t e r m ina l d r ough t a nd he a t s t r e s s o f t he M e d i t e r -r a ne a n e nv i r onm e n t s .

B e s ide s t he a l r e a dy m e n t ione d d i f f e r e nc e s be tw e e nthe tw o p r ov inc i a l ge ne poo l s , t he A N O V A r e po r t -ed in Table 3 shows tha t h ighly s igni f icant va r ia -t ion (p < 0 .001 in a l l but on e case ) occur red for a l lm or phom e t r i c c ha r a c t e r s a m ong popu la t ions ( on thew ho le ) w i th in p r ov inc e s . I n m os t c a se s , s i gn i f i c a n tc o r r e l a ti ons e x is t e d ( da t a no t show n) be tw e e n pop u-l a t i ons m e a n va lue s o f t he a g r onom ic t r a i t s a nd thec l imat ic col lec t ing var iables . This f inding sugges tedtha t t he m or ph o - phys io log ic a l va r i a t ion a m ong l a n -d r a c e popu la t ions a c ros s t he tw o p r ov inc e s w a s m os t lya t t r ibutable to c l imat ic va r ia t ion among s i te s of or i -g in . A w ide d i f f e r e n t i a ti on a m o ng l a nd r a c e popu la -t i ons w a s a l so p r e se n t w i th in e a c h p r ov in c e ge ne poo l(Table 3) . This va r ia t ion seemed most ly re la ted to thec l im a t ic va r i a t i on w i th in t he S he w a p r ov inc e , a s sug -ge s t e d a ga in by the c o r r e l a t i on c oe f f i c i e n t s be tw e e npopu la t ion m e a n va lue s o f t he r e c o r de d t r a it s a nd c l i -m a t i c pa r a m e te r s ( da t a no t show n) . C onve r se ly , t hesa m e c o r r e l a ti on c oe f f i ci e n t s w e r e m uc h low e r f o r t hepopula t ions col lec ted in Tigray , indica t ing tha t in th isp r ov inc e o the r e nv i r onm e n ta l ( o r a g r onom ic ) f a c to r sbe s ide s t he c l im a t i c one s m igh t a c c oun t f o r t he va r i a-t ion of the landraces .


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4

Table3Ayovao1mpmcc

ebwawhnponoomoEhoaeodw

a

TFesgce

hsw

ohoohaumsvueh

hvuhbo

onhTeossFcea

aoau

sTe

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ovaod

Mes

D

DMA

G

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FWaF

S

N

K

P

TW

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14

2

2

1

1

1

In

2

1

5

5

3

1

Pepao

whnpon

31

2

1

8

6

3~

6

4

1

1

6

1

2

Paon

Sw

11

4

2

8

9

3

7

4

2

1

8

1

1*

Tg

11

1

3

8

4

4

6

4

1

1

4

4

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1

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4

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8

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nnsgc*p_00*p~00*p_00


7/13

401

Tab /e 4 . Var i ance e s t im a tes ( a 2 ) f o r t he com pon en t s ' b e tw een p r ov inc es ' , ' am ongp o p u l a t io n s w i t h in p r o v i n c e s ' a n d ' a m o n g a g r o t y p es w i t h i n p o p u l a t i o n s ' , e x p r e s s e das pe r cen t ag e o f the t o ta l phen o typ i c va r i ance i n a h ie r a r ch i ca l ANO VA o f 13m or p hom et r i c t r a it s .

C h a r a c t e r B e t w e e n A m o n g p o p u l a ti o n s A m o n g a g r o t yp e sp r ov inces w i th in p r ov inces w i th in popu la t i ons

Days t o head ing 34 .9 13 .5 51 .6Day s to matu r i ty 8 .1 10.9 81.0Gr a in - f i l l ing pe r iod 0 .8 7 .2 92 .0Plant heig ht 0 .1 8 .1 91.8Grain yield 19.6 12.2 68.2F lag - l ea f l eng th 2 .1 7 .3 90 .6F lag - l ea f w id th 0 .1 23 .0 76 .9Flag - lea f area 0 .1 17.5 82.4Spike length 6 .9 11.5 81.6No. kerne ls/spik elet 2 .9 12.2 84.8No. kern els/sp ike 7 .1 10.1 82.8P r o t e in con t en t 4 .0 14 .5 81 .51000-kernel we ight 10.6 19.0 70.4

W he n the t o t a l phe no typ ic va r i a nc e w a s pa r t i -t i one d a m ong i t s h i e r a r c h i c a l c om pone n t s ( be tw e e npr ov inc e s , w i th in p r ov inc e s a nd w i th in popu la t ions ) ,w i th no e xc e p t ion s t he h ighe s t c on t r ibu t ion to t he va r i-a t i on w a s t he one due to t he c om po ne n t o f l ow e s to r de r , v i z . a m on g a g r o ty pe s w i th in popu la t ions ( Ta b le4 ) . B e ke le ( 1984 ) f oun d the sa m e o r de r o f m a gn i tudepa r t i t ion ing the t o t a l va r ia nc e f o r m o r pho log ic a l c ha r -a c t e rs i n E th iop ia n t e t r a p lo id l a nd r a c es : w i th in popu -l a t ions > a m o ng popu la t ions > a m on g r e g ions . The ser e su lt s , f a r f r om b e ing su r p r i s ing , c on f i r m tha t la n -d r a c e popu la t ions a r e h igh ly he t e r og e ne ou s p l a n t c om -m un i t i e s i nc lud ing a num be r o f ge no type s d i f f e r ingf o r m o r p h o - a g r o n o m i c fe a tu r e s. T h e p r e s e n c e w i th -in l a nd r a c e popu la t ions o f d i f f e r e n t ge no ty pe s a b l e t oc ope w i th d i f f e r e n t t ype , t im e a nd se ve r i t y o f s t r e s smight account for the i r y ie ld s tabi l i ty , pa r t icu la r ly inharsh env iron me nts (Ceccare l l i e t al ., 1987) . In con -t r a s t , E l ings ( 1991 ) f ound tha t phe no typ ic va r i a t i ono f S y r i a n du r um w he a t l a nd r a c e s c ou ld be a t t r i bu t e da lm os t e n t i r e ly t o d i f f e r e nc e s a m on g l a nd r a c e popu la -t i ons w he r e a s w i th in - popu la t ion va r i a ti on w a s l ow .

T h e v a r i a n c e e s t i m a t e o f t h e c o m p o n e n t ' a m o n gpopu la t ions ' w a s a lw a y s l a r ge r t ha n the e s t im a te o f t hec o m p o n e n t ' b e t w e e n p r o v i n c e s ' w i t h t w o r em a r k a b l ee xc e p t ions , v i z . he a d ing t im e a nd g r a in y i e ld ( Ta b le4 ) . The se tw o c ha r a c t e r s w e r e t hose show ing the h igh -e s t c o r r e l a t i on c oe f f i c i e n t s w i th t he c l im a t i c c o l l e c t ing

var iables (da ta not show n) . I t is , the re fo re , ev id ent tha tthe la r ge d i f fe r e nc e s be tw e e n S h e w a a nd T ig r a y f o r t hec l im a t ic f e a tu r e s o f t he s i te s o f o r ig in i s r e spons ib l e f o rthe g r e a t d i f fe r e n t i a t ion o f he a d ing t im e a nd g r a in y i e ldbe tw e e n the p r ov inc e s . Th i s r e su l t m igh t ha ve im po r -t a n t im p l i c at ions f o r f u tu r e ge r m p la sm c o l l e c t ions . Tosa m ple t he g r e a t e s t d ive r s i t y w i th in t he c ou n t r y f o r e a r -l ine s s o r y i e ld po te n t i a l i t w ou ld be im po r t a n t i nde e d toe xp lo r e a s m a ny ge og r a ph ic a l ly a nd c l im a t i c a l ly d is -t inc t r egions as poss ib le , r a the r than col lec t ing exten-s ive ly w i th in i nd iv idua l p r ov inc e s .

The ob se r va t ions sugge s t e d by the un iva r i a t e a na l -y s i s w e r e sum m a r i z e d by the c a non ic a l d i s c r im ina n ta na ly s is , t he r esu l t s o f w h ic h a r e r e po r t e d in Ta b le5 a nd g r a ph ic a l ly r e p r e se n te d in F igu r e 1 . A p r opo r -t i on o f 88 . 3% o f a g r o type s f r om S he w a a nd 83 . 4%f r om T ig r a y w e r e c o r r e c t ly c la s s i fi e d a s be long in g tothe i r a c tua l p r ov inc e o f o r ig in , on the ba s is o f a c r o s s -va l ida t ion c lass i f ica t ion per formed us ing a d isc r imi-na n t f unc t ion c om pu te d f r om the o the r obse r va t ions inthe da t a s e t. Th e r e f o r e , the d i s t i nc t ion be tw e e n the tw opr ov in c e ge ne poo l s w a s ve r y c l e a r. The pe r c e n t o f m i s -c lass i f ied access ions w as s l ight ly h ighe r in Tigray thanin S he w a . J a r a da t ( 1991 ) f ound tha t the c o r r e c t c l a s -s i fi c a ti on in a d i s c r im ina n t a na ly s i s o f du r um w he a tl a nd r a c e ge no type s f r om Jo r da n w a s h ighe s t i n t he d r i -es t d is t ric ts of co l lec t ion . Tha t was not the case in thep r e se n t s tudy , a s S he w a ha s m or e f a vou r a b le c lim a t i c


8/13

4 0 2

Table 5, Eigenvalues,proportionand cumulativevariance of the first threecanonical variables (CAN -) and co rrelation coefficientsof the CANs w ithboth the original variables and som e climatic features of the sites of originof tetraploid wheat landrace populations from EthiopiaC AN - I C A N - 2 C A N - 3

Eigenva lue 2 18 0.56 0.31Propo rtion of total variance 0.54 0.14 0.07Cum ulative varianc e 0.54 0.68 0.75Correlation coefficientwith:Heading time 0.64"* 0.63** -0 ,1 4Maturity time -0 .3 2 0.45* 0.08Plant height 0.11 0.20 -0,3 8*Grain yield -0 .2 4 0.14 0.46*Flag-leaf length -0 .18 0.21 -0. 31Flag-lea f width 0.20 0.74*** 0.14Spike length 0.41" 0.05 0.25No, kerne ls/spikelet 0.33 0.41 * 0.11No. kernels/spike -0 .0 9 0.20 0.13Protein content 0.16 0.24 -0 .5 9 *~'1000-kernel weig ht 0.64** 0.51"* 0.04An nual rainfall 0.94*** 0.20 0.02Mean daily rain T 0.91"** -0.21 -0. 02Mean daily max T 0.72 **~ -0 .2 3 0.27

*: p ~ 0.05; "* :p


9/13

C A N 210.00

2 .33

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- 13.008 . 5

- 8 . 5 - 1 8 . 5

ob I

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403

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o = S h e w aD = " lqgray

F i g . 1 . S c a t t e r d i a g r a m s o f t h e fi r st th r e e c a n o n i c a l v a r i a b l e ( C A N - ) m e a n v a l u e s o f t e tr a p l oi d w h e a t l a n d r a c e p o p u l a t i o n s f r o m t w o p r o v i n c e si n E t h i o p i a .

w hi t e g lum e s p r e va i l e d in S he w a , w h i l e T ig r a y show e dh ighe r f r e que nc y o f g r e y g lum e s . T e s f a ye e t a l. ( 1991 )r e po r t e d a s im i l a r t r e nd f o r g r e y g lum e s in T ig r a y ,a n d a m u c h h i g h e r f r e q u e n c y o f b l a ck g l u m e s i n b o thp r ov in c e s t ha n in t h i s s tudy . I t i s a s sum e d tha t none o fthe se he a d c o lou r s ha s a n a da p t ive a dva n ta ge f o r t hep la n t o r t he popu la t ion a s a w h o le ( Ze ve n , 1983 ). Thea w n c o l o u r f r e q u e n c y p a r a l le l ed t h a t o f g l u m e c o l o u r( Ta b le 6 ) . G la b r ous g lum e s w e r e by f a r the m os t c om -m on in bo th p r ov inc e s , a l t hough T ig r a y ha d a m uc hh i g h e r p r o p o r t i o n o f a g r o t y p e s w i th p u b e s c e n t g l u m e stha n S he w a . Th e a da p t ive s ign i f i c a nc e o f t h is c ha r a c t e ris not c lea r ( Ja in e t a l ., 1975) , even thoug h i t s ro le inc on t r o l l i ng s e e d d i s e a se s a nd in se c t s ha s be e n spe c u la t-e d ( W a r ha m , 1988 ) . T ig r a y show e d h ighe r f r e que nc yo f t ype s w i th pub e sc e n t g lum e s a nd w i th t o l e r anc e s t oc om m on bun t ( Ta b le 6 ) . H ow e ve r , t he r e i s no d i r e c tp r o o f f o r a c a use - e f f e c t r e l a t ionsh ip be tw e e n the se tw ocharac te r s .

A l though be ing the m os t f r e que n t i n bo thp r ov inc e s , t he r e d - b r ow n ke r ne l c o lou r r e p r e se n te dm o r e tha n 80% o f t o t al a g r o type s in S he w a , bu t on ly40% o f t he t o t a l in T ig r a y w he r e t he t h r e e o the r ke r-n e l c o lo u r s w e r e m u c h m o r e c o m m o n t h an i n S h e w a .

B e ke le ( 1984 ) a l so f ound tha t b r ow n ke r ne l c o lou rw a s p r e dom ina n t i n t e t r a p lo id l a nd r a c e s. P u r p l e s e e dsin c u l t iva t e d t e t r a p lo id w he a t s a r e e nde m ic to E th io p ia( Ze ve n , 1991 ) w h ic h i s l i ke ly t o be t he c e n t r e o f o r ig infor th is charac te r (Ja in e t al ., 1975) . Our da ta sugg es ta c l i na l va r i a ti on f o r t he f r e qu e nc y o f pu r p l e ke r ne l sin t he c oun t r y , w i th a h ighe r p r opo r t i on in d r i e r e nv i -r onm e n t s . Th e s a m e t r e nd d id no t a ppe a r i n t he r e su l tso f N e ga s sa ( 1986 ) a nd T e s f a ye e t al . ( 1991 ) . H ow e v-e r , in t he f o r m e r c a se t he num be r o f s a m p le s t e s t e dwas ra the r l imi ted , whereas in the la t te r s tudy envi-r onm e n ta l d i f f e r e nc e s a m ong the s it e s o f o r ig in o f t hepopu la t ions e xa m ine d w e r e p r oba b ly le s s m a r ke d tha nin t he p r e se n t e va lua t ion . N e ga s sa ( 1986 ) quo te d a na s soc i a ti on be tw e e n the pu r p l e s e e d c o lou r a nd d i s e a ser e s i s ta nc e in t e t r a p lo id e n t r i e s f r om sou the r n E th iop ia ,and an invar iable assoc ia t ion of th is charac te r wi thg r e y c o lou r a nd ve r y poo r r he o log ic a l p r ope r t i e s i n t heflour.

A s r e ga r ds t he s c o r e d c ha r a c t e rs be a r ing a g r e a t e ra g r onom ic s ign i f i c a nc e , t he ge r m p la sm f r om S he -w a pos se s se d m or e h igh - t i l l e r ing a g r o type s , a nd l e s sa c c e s s ions su sc e p t ib l e o r ve r y su sc e p t ib l e t o ye l lowr us t a nd S e p to r i a l e a f b lo t c h , w h i l e t he ge ne poo l f r om


10/13

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Table6F

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eowch

c

eohm

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eF

a

aoasdnosTe1

C

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TG

1

2

3

4

5

6

7

8

9

1

2

3

4

5

6

7

8

9

FA G A G K T D Y S B

30

56

1458244301

165810551

90

07

13

45768

64

0

37

66

93

3919252117552201

04

5

74

17

1

0

0830113534123000

300118284616222325

13 24

642210

26551511

82

00

10214722

34

48

37 02 000005

58083158

64 0 13 1

8

13

48

631014292194

11

48

60

12

18

43254128

5002

8412242114

c

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Documents

GeneticResourcesand CropEvolution 43: 395---407,1996. (~) 1996 KluwerAcademicPublishers. Printedin the Netherlands