近几十年来,两种主要粮食作物——玉米和高粱的产量有了很大提高。这是由于采用大面积杂交技术,把两个不同的品系或品种进行杂交获得了性状比两个亲本更加优良的杂交种子的原故。当前,另一种主要粮食作物——小麦,也将发生这样的变化。遗传育种的基础是杂种优势,杂交品种的后代比同种繁殖的后代具有较大的生活力。杂交种 In recent decades, the production of two major food crops, maize and sorghum, has greatly increased. This is due to the hybridization of two different strains or varieties using large-area hybridization techniques to obtain hybrid seeds with better traits than the two parents. Currently, another major staple crop, wheat, will see such a change. The basis of genetic breeding is the heterosis, the offspring of hybrid varieties have greater viability than the offspring of the same species. Hybrids