Chapter 30
Creating Value with Agricultural Biotechnology Developing World Applications Peter S. Carlson Crop Genetics International Corporation, 7170 Standard Drive, Hanover, MD 21076 Agricultural Biotechnology in the Developing World
In the absence of real world examples or concrete results, the potential utilization of plant biotechnology in agriculture, particularly in the developing world, is like a Rorschach ink blot test; the viewer experiences subjective rather than objective reality. The problem is particularly acute in attempts to divine the utility of new technologies in altering the productivity of small holding, primarily marginal farmers in the developing world. Plant genetics in actual fact, will probably not play a major role in changing the condition of such indivviduals when compared to political and economic forces. However, the role of plant genetics appears real and not inconsequential: improve seeds of planting materials are an often cited need for these farmers. Improved seed probably holds as much potential for helping small farmers as any other single agronomic input. What types of genetic alterations are appropriate for the needs of developing world agriculture? Certainly, the agronomic situation of the small, marginal farmer is different from that of the large commercial farmer common in the developed world. It is impossible to transfer standard developed world farming technologies if there is not the ready availability of chemical and physical means to manipulate the environment. Additionally, the economic (e.g., market price, access to credit) and politiccal (e.g.,, land tenure arrangements) constraints are beyond immediate control. Small farmers have responded with a diversity of solutions to their individual situations. It appears as if there is one central theme in a l l of the various viable solutions: to develop a defensive stance. In agronomic terms this may mean a diversity of crops for home consumption and for the market. In biological terms this implies genetic variability. Some risk is 0097-6156/88/0362-0361 $06.00/0 © 1988 American Chemical Society
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acceptable, but not too much. Some harvest i s p r e f e r a b l e t o no harvest, and when there i s l i t t l e c o n t r o l over the environment, or l i m i t e d agronomic i n p u t s , the g e n e t i c composition of the crop becomes an important c o n s i d e r a t i o n . T h i s defensive stance may a l t e r the p l a n t breeder's s t r a t e g y : i n c r e a s i n g y i e l d , while c o n t i n u i n g t o be an e s s e n t i a l breeding o b j e c t i v e , becomes of secondary importance when compared with s u r v i v a l and adequate l e v e l s of production under the e n t i r e range of p o s s i b l e environmental ( p h y s i c a l , chemical, and b i o l o g i c a l ) c o n d i t i o n s . Hence, a major concern f o r crop improvement must be to maintain and increase the range of g e n e t i c v a r i a b i l i t y which permits a crop species t o s u r v i v e and be productive under widely d i f f e r e n t conditons. The production and a n a l y s i s of g e n e t i c v a r i a b i l i t y and i t s i n c o r p o r a t i o n i n t o adapted v a r i e t i e s i s an appropriate goal t o a i d these farmers. The ingèrent strength of conventional p l a n t breeding techniques and new b i o t e c h n i c a l manipulations f o r the small farmer i s t h a t they are p o t e n t i a l l y s c a l e n e u t r a l , p o l i t i c a l l y n e u t r a l , r e l a t i v e l y inexpensive f o r the farmer, andd can i n v o l v e few t i e s with commerical networks. These q u a l i t i e s make p l a n t improvement programs and t h e i r r e s u l t s a c c e s s i b l e t o small farmers and acceptable t o governmental agencies and i n t e r n a t i o n a l developmental e f f o r t s . While the crop improvements provided by the "green r e v o l u t i o n " have not always been of t h i s nature, there i s no reason why the technologies of breeding and g e n e t i c s cannot accomplish these g o a l s . Commerical i n c e n t i v e i s the d r i v i n g f o r c e behind the development and a p p l i c a t i o n of biotechnology i n the developed world. I doubt t h i s engine w i l l work i n l e s s developed c o u n t r i e s p r i m a r i l y because the f i n a n c i a l o p p o r t u n i t i e s do not balance the science and market r i s k s . The burden of a p p l i c a t i o n must be shouldered by the p u b l i c s e c t o r . T h i s task demands uncommon wisdom and forethought i n formulating p o l i c y . I base my c o n c l u s i o n on the f o l l o w i n g c o n s i d e r a t i o n s : 1.
Science does not e x i s t i n a vacuum; economic, s o c i a l and p o l i t i c a l f o r c e s determine which technologies are u t i l i z e d . Inexpensive, proven technologies a r e , under o r d i n a r y c o n d i t i o n s , p r e f e r r e d by the market. Biotechnology i s i n many i n s t a n c e s n e i t h e r an i n expensive nor proven methodology f o r crop improvement.
2.
C u r r e n t l y u t i l i z e d a g r i c u l t u r a l technologies work. In the developed world, the food machine i s n ' t broken! In f a c t , the machine i s running too f a s t a l r e a d y . The world s u f f e r s from massive overproduction of f o o d s t u f f s and d e c l i n i n g p r i c e s f o r such products. What needs f i x i n g i s the production/delivery/market i n f r a s t r u c t u r e i n nations experiencing famine, and
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n a l ecological policies to reverse the d e s e r t and s h r i n k i n g t r o p i c a l jungles. p o l i c y using biotechnology to increase c o u n t r y f o o d o u t p u t m i g h t make a b a d worse.
3.
The use o f b i o t e c h n o l o g y t o c r e a t e n o v e l c r o p v a r i e t i e s i s generally not a business with attractive r e t u r n on investment. N o m a t t e r how c a r e f u l l y c r a f t e d t h e p a t e n t p r o t e c t i o n may b e , a s a p r a c t i c a l m a t t e r f o r many c r o p s t h e f a r m e r ' s f i e l d i s a g e n e t i c Xerox machine.. The onetime s a l e by the biotechnology b r e e d e r o f a new v a r i e t y c a n n o t s u p p o r t a p r i c e s t r u c t u r e adequate to cover research c o s t s . The e x t r a e f f o r t t o h y b r i d i z e a new v a r i e t y t o c r e a t e a "repeat sales" o p p o r t u n i t y i s s u b s t a n t i a l . Seen i n t h i s c o n t e x t , a g r i c u l t u r a l b i o t e c h n o l o g y may b e a n "orphan technology."
4.
The farmer i s a p r i c e and r i s k s e n s i t i v e consumer, and i s extremely r e l u c t a n t to i n c r e a s e the p o r t i o n of his costs devoted to p l a n t i n g materials at the beginning of the growing season. Biotechnology is an e x p e n s i v e u n d e r t a k i n g and an a d d i t i o n a l c o s t i n varietal production. The added v a l u e c r e a t e d by b i o t e c h n o l o g y m a n i p u l a t i o n s w i l l n o t be r e i m b u r s e d by the market.
5.
Technology t r a n s f e r i s not a generic e x e r c i s e . Mani p u l a t i o n s which ahve been d e f i n e d f o r use w i t h tomatoes w i l l n o t be d i r e c t l y a p p l i c a b l e t o bananas. Goals f o r the improvement o f c o r n are i n a p p r o p r i a t e for cassava. Agronomic goals f o r r i c e production i n Japan are wholly d i f f e r e n t from those i n I n d i a . I n t h i s l i g h t , t h e q u e s t i o n o f who "owns" o r " c o n t r o l s " new t e c h n o l o g y i s a b s u r d . The u n d e r l y i n g s c i e n c e o f b i o t e c h n o l o g y can not and w i l l n o t be effectively protected. A d d i t i o n a l l y , the developing w o r l d has a c c e s s t o the w o r l d p a t e n t l i t e r a t u r e and i s u n d e r l i t t l e o r no c o n s t r a i n t t o a b i d e by intellect u a l p r o p e r t y laws i n f o r c e i n the developed nations. Private i n d u s t r y i n the developed nations w i l l not undertake work aimed a t m o d i f y i n g t r o p i c a l c r o p species i n the absence of p r o t e c t i o n and a c l e a r r e t u r n on investment.
6.
The i n f o r m a t i o n b a s e f o r t r o p i c a l c r o p s i s much smaller than that f o r the annual temperate species making t e c h n i c a l a p p l i c a t i o n s more d i f f f i c u l t . Crop productivity or crop y i e l d is a quantity often expressed i n bushels per acre, tons per acre, kilograms p e r h e c t a r e , o r j i n p e r mu. This notation is a physical description of a b i o l o g i c a l endpoint, f o r p r o d u c t i v i t y i s t h e sum o f t h e biological
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components which r e s u l t i n a p o p u l a t i o n of mature p l a n t s . Although t h i s expression i s o f t e n a s a t i s f a c t o r y one f o r farmers, ecconomists, or s t a t i s t i c s i a n s i t hides the extent of our b i o l o g i c a l ignorance. Not enough i s known about the u n d e r l y i n g b i o l o g y which d i r e c t l y or i n d i r e c t l y determines crop y i e l d . Furthermore, what i s known i s inadequate f o r our needs. Contemporary r e s e a r c h e f f o r t s have r e v e a l e d and w i l l continue t o r e v e a l new methods f o r g e n e t i c manipulation with higher p l a n t s . These new methods, should be of d i r e c t u t i l i t y t o p l a n t breeders and agonomists i n the developing world. To adequately u t i l i z e the techniques, i t i s important t o have a c l e a r biochemical d e s c r i p t i o n of what needs t o be a l t e r e d . What are the b i o l o g i c a l l i m i t a t i o n s of p l a n t growth and p r o d u c t i v i t y , and how does t h i s b i o l o g y i n t e r a c t with the environment? Defined g e n e t i c a l l y , encoded processes can be g e n e t i c a l l y manipulated while kilograms per hectar cannot. I n t e r n a t i o n a l a g r i c u l t u r a l biotechnology l a b o r a t o r i e s l o c a t e d i n the developing world should focus t h e i r e f f o r t on the extension and a p p l i c a t i o n of e x i s t i n g t e c h n o l o g i e s t o t r o p i c a l crop s p e c i e s and the p a r t i c u l a r needs of t r o p i c a l a g r i c u l t u r e . The extension andd a p p l i c a t i o n of e x i s t i n g t e c h n o l o g i e s i s , a t the c u r r e n t time, a more important and c l e a r e r g o a l than the i n v e n t i o n of new s c i e n c e . I t i s the s t r a t e g y t h a t the CGIAR I n s t i t u t e have s u c c e s s f u l l y u t i l i z e d . An Example of Biotechnology Extension and
Application
The u t i l i z a t i o n of p l a n t t i s s u e and c e l l c u l t u r e techniques i n p l a n t improvement may w e l l have i t s g r e a t e s t impact i n those crop s p e c i e s whicch are c l o n a l l y propagated, e.g., bananas, sugar cane, yams, cassava, potatoes, t r e e s p e c i e s , e t c . P r o l i f i c plantlet production from meristems and other t i s s u e sources f a c i l i t a t e s r a p i d propagation of p l a n t s with e l i t e genotypes i n crop s p e c i e s not e a s i l y propagated v i a seeds. Meristem c u l t u r e techniques a l s o provide the b a s i s f o r e l i m i n a t i o n of systemic diseases from p l a n t i n g m a t e r i a l s . 1
P l a n t s regenerated from longer term c a l l u s or suspension c u l t u r e s o f t e n show an i n c r e a s e d g e n e t i c v a r i a t i o n which has been reported t o be of value t o breeding programs i n p e r e n n i a l crop s p e c i e s . Genetic v a r i a t i o n produced d u r i n g t i s s u e c u l t u r e of sugar cane has r e s u l t e d of s e v e r a l new d i s e a s e r e s i s t a n t clones r3,4. S i m i l a r v a r i a t i o n r e s u l t i n g from the c u l t u r e of potato p r o t o p l a s t s i s now being u t i l i z e d by breeders as a source of disease r e s i s t a n c e and greater a d a p t a b i l i t y t o environmental extremes5. The i n c r e a s e i n g e n e t i c v a r i a b i l i t y due t o passage of c e l l s through 2
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t i s s u e c u l t u r e has a l s o been d e s c r i b e d i n other crops such as r i c e , o a t s , wheat, l e t t u c e and tomatoes^. The primary a p p l i c a t i o n of i n c r e a s e d g e n e t i c v a r i a b i l i t y r e s u l t i n g from t i s s u e c u l t u r e has been the recovery of new genotypes with i n c r e a s e d t o l e r a n c e t o p l a n t d i s e a s e s ^ . Tissue c u l t u r e v a r i a t i o n i s superimposed d i r e c t l y upon e x i s t i n g q u a l i t i e s of a c u l t i v a r . T h i s t h e o r e t i c a l l y allows the i n t r o d u c t i o n of a l t e r a t i o n s i n s i n g l e t r a i t s without the segregation of a v a s t a r r a y of a l l e l e s as i n a sexual cross2,6. Passage of p l a n t t i s s u e s throgu i n v i t r o c u l t u r e combined with s e l e c t i o n s of the r e s u l t i n g genotypes f o r t h e i r response t o p l a n t pathogens c o n s t i t u t e s a method f o r improving a w e l l adapted or s u c c e s s f u l v a r i e t y by the a d d i t i o n of s i n g l e disease response c h a r a c t e r i s t i c s . Bananas and Black Sigatoka Bananas are an unusual agronomic crop s i n c e o n l y clones s e l e c t e d from nature are c u r r e n t l y c u l t i v a t e d . Commercial banana clones are v e g e t a t i v e l y propagated, parthenocarpic t r i p l o i d s and are s e x u a l l y s t e r i l e . Consequently, the standard techniques of p l a n t breeding based upon sexual crosses can not be u t i l i z e d f o r banana improvement7. Only two major clones (Gros M i c h e l and Cavendish) have been acceptable f o r the export t r a d e ? , and are important sources of export income f o r a number of developing n a t i o n s . D i p l o i d bananas, which are s e x u a l l y f e r t i l e , , are not grown f o r export s i n c e t h e i r f r u i t s i z e and p l a n t v i g o r are u n s u i t a b l e . No crop species b e t t e r i l l u s t r a t e s the b i o l o g i c a l dangers of a g e n e t i c monoculture than bananas. Panama d i s e a s e , or f u s a r i a l w i l t (caused by Fusarium oxysporum Cubense), became a s e r i o u s problem i n Gros M i c h e l i n the 1940's and by 1955 had made c u l t i v a t i o n of t h i s c u l t i v a r u n p r o f i t a b l e . Approximately 100,000 acres of bananas were destroyed or abandoned i n c e n t r a l America because of t h i s disease8. Cavendish clones r e s i s t a n t t o Panama disease were s u b s t i t u t e d f o r Gros M i c c h e l d u r i n g the 1950's and I960's c r e a t i n g a new monoculture of the v a r i e t y . There are s e v e r a l d i f f e r e n t Cavendish subclones which vary i n height but are a l l e s s e n t i a l l y g e n e t i c a l l y i d e n t i c a l ^ . No known n a t u r a l or s e l e c t e d clones e x i s t as p o s s i b l e commercial a l t e r n a t i v e s t o the cavendish c u l t i v a r s l O . The Cavendish c u l t i v a r s are s u s c e p t i b l e t o a d e s t r u c t i v e and c o s t l y d i s e a s e . Since 1933, Sigatoka l e a f spot or Yellow Sigatoka (cause by Mycosphaere11a musicola), has been a p o t e n t i a l l y s e r i o u s disease i n the C e n t r a l and South American r e g i o n s . However, r o u t i n e
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and i n e x p e n s i v e c o n t r o l m e a s u r e s were a b l e t o c o n t a i n t h e s p r e a d and m o d e r a t e t h e d e s t r u c t i v e n e s s o f t h i s pathogenll. B l a c k l e a f s t r e a k , a more s e v e r e s t r a i n o f M. m u s i c o l a , was p r e s e n t i n t h e P a c i f i c regiron f o r many y e a r s , b u t was n o t f o u n d i n W e s t e r n H e m i s p h e r e ! . In 1972, a more v i r u l e n t S i g a t o k a l e a f s p o t p a t h o g e n , a p p a r e n t l y c a u s e d by a m u t a t i o n o r s e x u a l r e c o m b i n a t i o n of m u s i c o l a , was i d e n t i f i e d i n H o n d u r a s l 3 . T h i s new f u n g a l l e a f s p o t p a t h o g e n , termed B l a c k S i g a t o k a ( M y c o s p h a e r e l l a f i j i e n s i s v a r . d i f f o r m i s ) has g r e a t l y i n c r e a s e d d i s e a s e c o n t r o l c o s t s andd c u r r e n t l y threatens t h e e x p o r t banana i n d u s t r y i n t h e A m e r i c a s . Since the o r i g i n a l e p i d e m i c i n Honduras i n 1 9 7 3 - 7 4 , t h i s d i s e a s e h a s s p r e a d t h r o u g h o u t c e n t r a l and S o u t h A m e r i c a and t h e Caribbean Basin r e g i o n . 2
New g e n e t i c v a r i a t i o n i s n e e d e d i n C a v e n d i s h c u l t i v a r s to p r o t e c t t h i s i n d u s t r y against another devastating epidemic. Genetic resistance to Black S i g a t o k a i n Cavendish c u l t i v a r s would a l s o reduce production costs. Sources of genetic r e s i s t a n c e to B l a c k S i g a t o k a have been i d e n t i f i e d i n s e v e r a l s e l e c t e d c l o n e s o f t h e d i p l o i d banana s p e c i e s Musa a c u m i n a t a ^ . However, t h i s g e n e t i c r e s i s t a n c e c a n n o t be i n c o r p o r a t e d i n t o Cavendish v a r i e t i e s because of s e x u a l sterility!5. An a l t e r n a t i v e method f o r g e n e t i c m a n i p u l a t i o n o f C a v e n d i s h c l o n e s w o u u l d be t o i n d u c e s o m a t i c m u t a t i o n s f o r B l a c k S i g a t o k a r e s i s t a n c e by u s i n g i o n i z i n g r a d i a t i o n and o t h e r mutagens on p l a n t l e t s , f o l l o w e d by s e l e c t i o n o f increased disease tolerance. However, s e v e r a l a t t e m p t s a t u s i n g m u t a t i o n b r e e d i n g methods t o r e c o v e r B l a c k S i g a t o k a t o l e r a n t s u b c l o n e s o f C a v e n d i s h bananas h a v e n o t been s u c c e s s f u l ! 5 . 4
Genetic variation occuring i n tissue culture holds promise as a u s e f u l t e c h n i q u e f o r r e c o v e r i n g B l a c k Sigatoka r e s i s t a n t Cavendish c l o n e s . The u s e o f t i s s u e culture i s a r e a l i s t i c a l t e r n a t i v e because: 1.
G e n e t i c v a r i a t i o n c c c u r i n g i n c e l l and t i s s u e c u l t u r e i s a proven technique f o r the production of d i s e a s e r e s i s t a n t o r t o l e r a n t genotypes i n a range of crop species ,3,4,5,6. 2
2.
E v e n t h o u g h o u r knowledge o f b a n a n a t i s s u e c u l t u r e i s n o t c o m p l e t e , t h e r e h a s been some p r o g r e s s o v e r t h e last several yearslS. I t i s now p o s s i b l e t o r e g e n e r a t e l a r g e numbers o f p l a n t s f r o m c a l l u s c u l t u r e s o f C a v e n d i s h bananas and t o i d e n t i f f y s o m a c l o n a l variants w i t h i n t h i s population of regenerated plants 0. we c a n e x p e c t t h e r e m a i n i n g m a j o r p r o b l e m , t h a t o f p l a n t l e t r e g e n e r a t i o n , f r o m s u s p e n s i o n and p r o t o p l a s t c u l t u r e s , t o be d e f i n e d w i t h i n s e v e r a l y e a r s i f an i n t e n s i v e e f f o r t i s initiatedl9. 2
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3.
The B l a c k S i g a t o k a fungus appears t o produce a t o x i n . R e l a t e d f u n g i i n the genus C e r c o s p o r a produce a p h y t c t o x i n , C e r c o s p o r i n , w h i c h can r e a d i l y be isolated and p o t e n t i a l l y used as a d i r e c t s e l e c t i v e agent for increased disease resistance or tolerance20,21,22,23.
4.
Resistance to Black Sigatoka i n w i l d d i p l o i d banana s p e c i e s i s c o n t r o l l e d by one o r o n l y s e v e r a l genes. This r e l a t i v e l y simple genetic system i s w e l l suited f o r m a n i p u l a t i o n by t i s s u e c u l t u r e techniques* . 0
Several different selection s y s t e m s c o u l d be employed to produce Black Sigatoka r e s i s t a n t banana clones: 1.
A l a r g e number o f p l a n t s c o u l d be r e g e n e r a t e d f r o m c a l l u s c u l t u r e s and examined f o r t h e i r r e a c t i o n to Mycosphaere1la f i j i e n s i s v a r d i f f o r m i s by d i r e c t inoculations. Techniques f o r greenhouse inoculations have been e s t a b l i s h e d " , i f insufficient varia b i l i t y i s produced by passage through c u l t u r e , c h e m i c a l a n d p h y s i c a l mutagens c o u l d be e m p l o y e d . This approach i s currently a v a i l a b l e ! 9 .
2.
The p h y t o t o x i c c h e m i c a l o r c h e m i c a l s produced by M. f i j i e n s i s v a r d i f f o r m i s c o u l d be u s e d as a s e l e c t i v e agent i n t i s s u e c u l t u r e to recover r e s i s t a n t c e l l s and c a l l i . These r e s i s t a n t calli c o u l d be r e g e n e r a t e d i n t o p l a n t s and examined f o r t o l e r a n c e by d i r e c t i n o c u l a t i o n w i t h t h e disease fungus.
3.
C e r c o s p o r i n , a phytotoxin produced by a r e l a t e d f u n g u s , i s known t o a c t by p r o d u c i n g s i n g l e t oxygen a n d s u p e r o x i d e r a d i c a l s when e x p o s e d t o light 5,26. The B l a c k S i g a t o k a t o x i n appears t o a c t i n a s i m i l a r fashion21. Tobacco c e l l s r e s i s t a n t to a superoxide r a d i c a l p r o d u c e r , t h e h e r b i c i d e p a r a q u a t , show a slight increase i n tolerance to Cercosporin. S e l e c t i o n o f banana c e l l s which are r e s i s t a n t to paraquat followed by r e g e n e r a t i o n of e n t i r e plants and examination o f the r e a c t i o n o f these s e l e c t i o n s t o C e r c o s p o r i n and t o M ^ f i j i e n s i s var difformis by d i r e c t i n o c u l a t i o n c o u l d be a c c o m p l i s h e d . A s i m i l a r p r o t o c o l c c o u l d be e s t a b l i s h e d w i t h a g e n t s t h a t produce s i n g l e t oxygen r a d i c a l s . 2
4.
C o n d i t i o n a l l e t h a l mutants (temperature sensitive) o f M ^ f i j i e n s i s v a r d i f f o r m i s c o u l d be p r o d u c e d f o r use i n c o - c u l t u r e s e l e c t i o n systems. Banana suspension and c a l l u s c u l t u r e s c o u l d be c o - c u l t u r e d w i t h c o n d i t i o n a l l e t h a l mutants o f the pathogen can attack the plant c e l l s . Growth of the pathogen
368
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could then be halted by s h i f t i n g the c o - c u l t u r e s t o non-permissive c o n d i t i o n s . Banana c e l l s and c a l l i able t o r e s i s t i n f e c t i o n by the pathogen and s u r v i v e i n t i s s u e c u l t u r e could be regenerated i n t o p l a n t s and examined f o r p l a n t l e t r e s i s t a n c e by d i r e c t inoculation. 5.
Black Sigatoka r e s i s t a n t d i p l o i d banana s p e c i e s could be e s t a b l i s h e d i n c a l l u s and suspension c u l t u r e and the response of these t i s s u e c u l t u r e s t o M. f i j i e n s i s var d i f f o r m i s and i t s t o x i n c o u l d be analyzed. The c h a r a c t e r i z a t i o n w i l l be u t i l i z e d t o develop s e l e c t i v e systems not obvious from our current knowledge of the host-pathogen i n t e r a c t i o n s .
6.
P r o t o p l a s t f u s i o n could be attempted between the Cavendish v a r i e t y and r e s i s t a n t d i p l o i d banana s p e c i e s . T h i s approach would c o n s t i t u t e a l a s t r e s o r t s i n c e p r o t o p l a s t t e c h n o l o g i e s appear more remote with t h i s genus than do suspension c u l t u r e methodologies.
Once Black Sigatoka t o l e r a n t p l a n t l e t s have been recovered, e v a l u a t i o n of y i e l d and other agronomic c h a r a c t e r i s t i c s of the s e l e c t e d subclones would be undertaken. Subclones which maintain the c h a r a c t e r i s t i c s of the p a r e n t a l Cavendish c u l t i v a r and demonstrate r e s i s t a n c e or t o l e r a n c e t o Black Sigotoka wculd then be chosen f o r mass production v i a r a p i d shoot t i p propagation. T h i s type of technology extension i s u n l i k e l y t o be undertaken by a p r i v a t e company f o r the f o l l o w i n g reasons : 1. 2. 3.
The p r o j e c t r e q u i r e s tremendous up f r o n t r e s e a r c h c o s t s with no guaranteed success. There are no ready customers w i l l i n g t o pay the p r i c e f o r an improved CCavendish c l o n e , or f o r the research c o s t s . An improved Cavendish clone represents a one-time s a l e since i t i s not l e g a l l y p r o t e c t a b l e .
Consequently, t h i s p r o j e c t appears i d e a l f o r execution i n a p u b l i c o s e c t o r l a b o r a t o r y i n the d e v e l oping world. I t i s important t o r e a l i z e t h a t bananas have enormous importance i n the developing world beyond the export value of the crop. Of the approximately 12 b i l l i o n bananas produced annually, 80% are consumed l o c a l l y i n the domestic market of the producing country. Domestic consumption i s p r i m a r i l y of a l a r g e number of v a r i e t i e s d i f f e r e n t from the Cavendish produced f o r
30. CARLSON
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export. The m a j o r i t y o f these l o c a l cooking banana and p l a n t a i n v a r i e t i e s are a l s o s u s c e p t i b l e t o Black Sigatoka, t h r e a t e n i n g an important developing world food source. Once proven methodologies and manipulations have been d e f i n e d f o r recovery o f Musa sp t o l e r a n t t o Black Sigatoka, they could be r a p i d l y t r a n s f e r e d t o r e g i o n a l or n a t i o n a l l a b o r a t o r i e s f o r use with l o c a l l y adapted and accepted c u l t i v a r s . Although t h i s banana p r o j e c t i s presented only as an example, i t embodies c r i t e r i a a p p r o p r i a t e f o r emphasis i n developing world i n s t i t u t i o n . These c r i t e r i a i n c l u d e : 1. 2. 3. 4. 5.
A c l e a r developing world need t h a t cannot, o r w i l l not, be f i l l e d by e x i s t i n g i n s t i t u t i o n s . Minimal r e s u l t i n g s o c i a l d i s r u p t i o n o r impact. T e c h n i c a l f e a s i b i l i t y by extension o f e x i s t i n g technologies. A r e l a t i v e l y short horizon time. D e f i n i t i o n o f r o u t i n e manipulations t r a n s f e r a b l e t o r e g i o n a l o r n a t i o n a l e f f o r t s throughout the develop i n g world.
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RECEIVED September
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