干旱,半干旱地区作物育种的困惑与出路

粮食问题主要取决于一年生谷类作物产量。作物产量低而不稳的原因主要是病虫害及各种胁迫生境，其中干旱缺水为最大的产量限制因素，提高作物生产力的途径有二：其一是改善作物的生长环境，其二是通过育种手段选育在各肿胁迫环境中具有优良表现的基因型（品种）。矮秆化育种手段使水肥充裕区小麦产量有显著的提高，是通过提高收获指数获得的。干旱、半干旱地区育种却未能获得显著效果，要提高干旱、半干旱地区小麦育种的成效，对干旱

Dilemma and hopes of cereal crop breeding in arid and semi-arid areas

Productivity of crops is mainly decided by the seed production of annual cereals in arid and semi arid areas.Lower and unstable production of crop yield is constrained by pest and other stressing environments,in which limited water in the area is a main factor limited crop production.There are probably two ways to improve crop yield in the areas:one is to improve the environment where crop plant survive and grow,another way is to breed suitable genotypes,which are adaptable to the environment.The discovery of dwarfing genotype in favorable areas has made wheat productivity increased significantly throught the increase of harvest index.However,in arid and semi arid areas,breeding of crops has not attained such an efficient progress.It is believed that with further understanding on the relationships between evolution,drought tolerance and seed yield of crop plants,an efficient breeding way will be discovered in the areas.