Chapter 5 Genetic Analysis of Apomixis - cimmyt

Chapter 1Feeding the World in the 21st Century:Plant Breeding, Biotechnology, and thePotential Role of ApomixisGARY H. TOENNIESSENAsurplus of food in many of the world'swealthier countries has led to a certaincomplacency there about future supplies andavailability. But for the vast majority of theworld's people, who live in poorer developingcountries faced with growing populations andincreasing demand for food, concern ratherthan complacency is the order of the day. Forthe nations of the South, the task of feedingtheir future generations presents a critical andformidable challenge for agriculture over thenext half century or longer.Population ProjectionsFortunately, there are reasons to be optimisticthat an end to population growth is finally insight, albeit at some distance (Lutz et al. 1997).The rate of world population growth peakedaround 1970 and has been steadily decliningsince then. As societies have moved fromdependence on subsistence agriculture tomore intensive agriculture and more modemeconomies-in the process providingimproved nutrition and health care andexpanded educational opportunities to theirgirls and boys-desired family size hasdropped. A family planning revolution in thedeveloping world, under way now for morethan two decades, has lowered the averagenumber of children in a family from six tothree, which is reflected in a respective declinein annual population growth from 2.5 toaround 1.8 percent (United Nations 1997).Contraceptive use by women of child-bearingage in developing countries has risen fromabout 10 percent to more than 50 percentduring the last three decades; and it isestimated that there are at least an additional100 million women who wish to regulate theirfertility, but who are not now usingcontraceptives. Ifeffective family planning andreproductive health services were provided toall those wishing to use them, demographersnow predict that replacement level fertilitycould be reached as early as 2020 and that theworld's population would stabilize at 8-11billion people near the middle of the 21stcentury (Bongaarts 1994; Lutz et al. 1997).Although the task of curbing populationgrowth will be arduous, generally speakingthe agencies and institutions that providefamily planning services have the technicalknow-how required to achieve this goal; nowthey are working on mol5ilizing the necessaryfinancial resources and political commitments.To complement this effort, the agriculturalsector must provide the basic nutrition andeconomic growth needed to fuel the desire forsmaller families and the requisite familyplanning services, until the time thatreplacement level fertility is reached.These encouraging population trends will,over the long term, be good for agriculture, asthey imply that sometime during the nextcentury the ever-increasing demand forgreater food production should finallystabilize. The downside is that even giventhese positive trends, the developing worldwill need to produce two to three times as