在自花授粉作物品种改良中,传统的育种方法(即系谱法和回交法)是十分有效的,尤其适合于由少数基因控制的性状改良。但是,在数量性状方面,由于多基因作用的类型,连锁,群体大小,以及环境效应的影响,这种传统的育种方法的效果受到了限制。Jensen(1970)提出了常规育种方法的三大局限性。(1)限制在较小的基因库内,(2)连锁区 In breeding self-pollinated varieties, traditional methods of breeding (ie, both the pedigree method and the backcross method) are very effective and are particularly suitable for the improvement of traits controlled by a few genes. However, in quantitative traits, the effectiveness of this traditional breeding method has been limited due to the types of polygenic effects, linkage, population size, and environmental effects. Jensen (1970) proposed three major limitations of conventional breeding methods. (1) restricted to smaller gene pools, (2) linkage regions