本文给出了显性与超显性模型下加性方差的分剖公式,为研究选择作用下基因间关系的变化提供了有力的方法。并模拟研究了群体大小、连锁强度与遗传力水平对遗传方差变化的影响。小群体中遗传方差在世代间波动很大;大群体中则稳定下降、波动较小。选择作用下平衡加性方差下降很快,特别是高遗传力性状。紧密连锁在小群体中一方面降低选择反应,一方面维持了更多的加性方差,从而使得预测长期选择反应甚为困难。 In this paper, the formulas for dividing the additive variance in dominant and super-dominant models are given, which provides a powerful method for studying the changes of the relationships between genes under selection. The effects of population size, linkage intensity and heritability on genetic variation were also studied. The genetic variances in small groups fluctuated greatly from one generation to another; while in larger ones, the genetic variance decreased steadily and fluctuated less. Under the action of choice, the equilibrium additive variance decreases rapidly, especially in high heritability traits. Tight linkage in a small population reduces the choice reaction on the one hand and maintains more additive variance on the other hand, making it difficult to predict long-term choice responses.