两种选择方法对玉米群体遗传组成的效应

EFFECTS OF ALTERNATIVE SELECTION PROCEDURES ON GENETIC COMPONENTS OF MAIZE(Z.mays L.)POPULATION

用TTC法分析了玉水 G 综合种原始群体及其经过两轮全姊妹轮同选择与四轮混合选择改良的两个衍生群体10个数量性状的遗传组成。结果发明,Co 群体各性状均具有较大的遗传变异,其遗传组成以加性分量力主;许多性状的显性和上位性分量也具有显著作用。Co 群体经过改良后,在多数性状上基因的累加作用进一步增加,而等位基因及非等位基因的互作效应则减小。所采用的两种改良方法对群体多数性状遗传组成的选择效应基本相同。

Two cycles of full-sib recurrent selection and four cycles of mass selection were completed in a maize population G Symthetic′.Genetic components of the original popu- lation and its improved populations(C2A2 and MAS4)for 10 quantitative traits were stud- ied with triple test cross(TTC)design.Greater genetic variation was found in the Co copulation for all traits,and additive variance was a dominant genetic component; dominance and cpistasis were also significant for a lot of traits.Whilc the original popula- tion was beng improved,additive effect of genes was further increased for most traits, whereas effects of allelic and non-allelic interactions were gradually reduced.Both selection methods showed similar effects on genetic components for most traits.