苦荞粒形相关性状的遗传分析

利用籽粒大小差异较大的2个苦荞品种的杂交后代开展了与产量具有密切关系的粒形相关性状的遗传规律及其性状间的相关性分析。结果表明,F₂和F₃群体的粒长、粒宽、长宽比和千粒重表现值范围都超过亲本的表现值,并且粒长、粒宽和长宽比的变异系数均小于10%,千粒重的变异系数大于10%。另外,粒长、粒宽、长宽比和千粒重的加性方差均大于显性方差,广义遗传率在F₂和F₃代中分别为0.77~0.82和0.82~0.85,固定遗传率都达到0.80以上。粒形性状间的相关性分析结果表明,粒长、粒宽和千粒重相互间都存在极显著的正相关,粒宽和千粒重,粒长和长宽比的遗传相关系数较大。以上结果表明,具有较高遗传率的粒形相关性状可以在后代早期进行选择,但由于这些性状是数量性状而且受多个基因的控制,因此建议继续繁殖后代到基因型稳定,同时考虑性状间的相关性选拔最为有效。

Genetic Analysis of Grain Shape Related Traits in Tartary Buckwheat

In this study, we used the hybrid offspring of two tartary buckwheat varieties with large difference in grain size to carry out the genetic parameter of grain-related traits closely related to yield and the phenotypic and genetic correlation among grain-related traits. The results showed that grain length, grain width, length-width ratio and 1000-kernel weight of F₂ and F₃ populations were all higher than that of their parents, the coefficient of variation of grain length, grain width and length-width ratio was less than 10%, and the coefficient of variation of 1000-kernel weight was more than 10%. In addition, the additive variance of grain length, grain width, length-width ratio and 1000-kernel weight were higher than that of the dominant variance. The broad sense heritability was from 0.77 to 0.82 and from 0.82 to 0.85 in F₂ and F₃ generations, respectively, and the true sense heritability was over 0.80. The correlation analysis between grain shape traits showed that there were significant phenotypic positive correlations among grain length, grain width and 1000-kernel weight, and the genetic correlation coefficients of grain width and 1000-kernel weight, grain length and aspect ratio was large. The above results indicated that grain shape related traits with high heritability could be selected in early generations, but since these traits were quantitative traits and controlled by multiple genes, it was suggested that the offspring should continue to be propagated until the genotype was stable, it is most effective to select the characters with the correlation among them.