以NcI交配设计和p(p-1)/2双列杂交设计抽样估计了我国玉米自交系总体和优良自交系亚总体各数量性状的基本遗传参数。结果表明,大多数数量性状遗传方差的主要分量是加性方差,显性方差较小。优良自交系亚总体各性状的遗传方差则普遍减小,说明其遗传基础更为狭窄。所以,为了不断地育出更好的自交系间杂种,迫切需要补充新的基因源。而现有的一些自交系和杂交种,则可用以合成综合种或复合种,再进行群体改良。这类群体由于加性变异丰富,在选择下将能产生较快的育种进展。 Based on the NcI mating design and the p (p-1) / 2 diallel crosses design sampling, the basic genetic parameters of the quantitative traits of maize inbred lines and elite inbred lines in China were estimated. The results showed that the major components of the genetic variance of most quantitative traits were additive variance and less dominant variance. The genetic variance of the traits in elite inbred lines generally decreased, which indicated that their genetic basis was more narrow. Therefore, in order to constantly breed better inbreds inbred lines, there is an urgent need to add new gene sources. Some of the existing inbred lines and hybrids can be used to synthesize synthetic or composite species, and then group improvement. Such groups due to additive mutation rich in choice will be able to produce faster breeding progress.