家系间数量性状主基因效应的分析

Analysis of the Effects of Major Genes on Quantitative Traits between Families

具有主基因差异的纯系杂交,其后代家系按主基因型表现为不同类型。本文以似然函数法分析F_3家系资料,提出家系主基因型鉴别,主微基因效应和互作以及主基因显性度的估计和测验方法。应用于籼稻株高和直链淀粉含量两组资料的分析,结果表明,家系间的分离比均符合一对主基因的理论比。两对主基因的增值基因均表现不完全显性,高杆基因对半矮杆基因的显性度估计为0.67,高直链淀粉含量基因对低直链淀粉含量基因估计为0.32。半矮杆基因与遗传背景的互作,测验结果不显著。

Families derived from a cross between two inbred lines with major gene difference on quantitative traits could be identified for their genotypes. In this paper likelihood method is used to analyse F3 families from such cross. The method is proposed for genotype identification, estimation of major gene and polygene effects and the degree of dominance of the major genes. The method is applied to two sets of data about the plant height and the grain amylose content of indica rice, In both cases one major gene segregation is accepted. Alleles of both major genes with increasing effects show incomplete dominance with the degree of dominance 0.67 for plant height and 0.32 for amylose content. Interaction between major gene and polygenic background is not found for plant height and cannot be tested for amylose content due to the limited sample size per family.