小麦穗颈长的遗传和育种价值

Inheritance of Neck Length of Spike and Its Breeding Value in Wheat

以8个小麦品种双列杂交的F1及其亲本为材料,研究了小麦穗颈长的遗传。结果表明,穗颈长的遗传符合加性———显性模型,基因作用以加性效应为主,高值对低值为显性,显性程度为部分显性。控制穗颈长的增减效等位基因频率在亲本间的分配比率有极显著差异,增效基因多于减效基因。穗颈长可能受4对主效显性基因控制,狭义遗传力高,早代选择有效。穗颈长与株高呈显著遗传正相关,与每穗粒数、千粒重、单穗粒重和单株产量呈微弱遗传正相关。

A set of F1 diallel crosses involving the eight wheat cultivars were analyzed for the inheritance of neck length of spike . The results showed that the inheritance of neck length of spike fit in with the additive dominance model, mainly controlled by the additive genetic effects. The high value was relate to the dominant genes and low value was related to the recessive ones. The degree of dominance was partial dominance. There was significant difference on the frequency distribution of additive and reducing alleles, and the additive alleles were predominant. Neck length of spike might be controlled by four pairs of major dominant genes, with higher narrow sense heritability, which indicated that it could be selected in the earlier generations. The genetic correlation of between neck length of spike and plant height was significantly positive, and that of between neck length of spike and grain number per spike,1000-kernel weight, kernel weight per spike and grain yield per plant was slightly positive. 