Chapter 5 Genetic Analysis of Apomixis - cimmyt

2 Gary H. T....i.....much food as it does today. In manydeveloping countries, more than half of thepeople are just entering or are still underreproductive age. Even if these people wereto have only two children per family, a neardoubling of total population is inevitable. Inaddition, economic growth will furtherincrease the demand for food.The challenge facing agriculture in the first halfof the 21st century is formidable. It mustprovide adequate nutrition for billions morepeople and contribute to their economicdevelopment, thereby stoking the desire tolimit family size. Furthermore, agriculturemust accomplish this without jeopardizing thecapacity of the natural resource base to meetthe needs of future generations. Currently,agriculture does not have the technologies todouble or triple food production in developingcountries, and so the threat arises that farmerswill irreparably damage the natural resourcebase in their efforts to feed growingpopulations-this scenario is alreadybecoming a reality in certain locations.Meeting the food challenge will demand thediscovery of new knowledge and thedevelopment of innovative technologies,which, combined with the broader adaptationand application of existing technologies, willallow greater intensification of production ona sustainable basis.Plant BreedingMany of the institutional structures andfinancial support systems needed to addressthe food challenge are already in place and canrightly claim an impressive record ofaccomplishment. International cooperation inplant breeding has been particularly successfulin producing improved crop varieties thatbenefit the developing world. When combinedwith appropriate management practices, thesemodem varieties have substantially increasedproductivity and contributed significantly tofood self-sufficiency and economicdevelopment in many countries of Asia andLatin America.In Asia, farmers have for centuries usedirrigation, organic fertilizer, and hand weedingon their small holdings. More recently, theyhave readily adopted modem varieties and,using their traditional intensive managementpractices together with purchased inputs, havein many locations pushed yield per hectareclose to the maximum potential. Modernvarieties of rice and wheat are now grown onnearly 70 percent of the area planted to thesecrops in Asia. Because many of these varietieshave short growing seasons, farmers canobtain two or three crops per year on fertileland under irrigation. Improved varieties havealso been produced for the poorer upland andseasonally flooded regions of Asia, howevertheir performance and rates of adoption havebeen less dramatic. During the past 20 years,the proportion of the Asian populationaffected by inadequate nutrition declined from40 to 19 percent. Nevertheless, Asia still hasthe greatest number of chronicallyundernourished people, 528 million, and thelargest projected increase in population (FAO1992; Bongaarts 1994; Lutz et al. 1997).In Latin America, modem varieties have madean enormous impact, however, due to thehighly skewed and inequitable distribution ofland ~n the region, it is primarily thecommercial farmers (who control most of thefertile land) that have adopted them.Production on the larger farms has increasedsignificantly and consumers have benefitedfrom lower prices. However, the majority ofLatin American farmers, who work smallholdings on less fertile land in the highlyheterogeneous hill regions, have not gleanedthe benefits offered by modem crop varieties.Developing improved varieties for them is adifficult task and only limited progress hasbeen made. No single elite breeding line is