摘要
用质量－数量性状的混合分布遗传模型对２个水稻矮秆×高秆的Ｆ_２群体（组合１：Ｈ３５９／Ａｃｃ８５１８；组合 ２：Ｈ３５９／Ａｃｃ８５５８）的株高遗传进行了研究．结果表明：１）存在 １对主基因的分离，高秆对矮秆完全显性； ２）这对主基因的效应大小在两个组合中非常相近，说明这对主基因在不同遗传背景中效应稳定，与微基因之间无明显互作，这对于育种应用是有利的；３）两组合中由微基因分离引起的遗传方差大小相近，微基因的平均显性效应皆是减效方向，且数值上也相近，而平均加性效应则皆呈增效方向，但数值上相差很大，说明两组合中发生分离的微基因的数目可能相似，但微基因在双亲间的分布情况却大不相同；４）亲本表型方差（亦即环境方差）与亲本均值呈明显正相关关系，高秆的环境方差要比矮秆大得多，因而在不同主基因型中，微基因的遗传力表现不同，这在育种实践中应引起注意．
The mixture-distribution genetic model of qualitative-quantitative trait was applied to study the inheritance of plant height in rice using two F2 populations generated from crosses between a dwarf variety and two normal varieties (Combination I: H359/Acc8518, Combination Ⅱ: H359/Acc8558). Results were as follows : 1) There was a major locus segregating in the two populations and the normal allele was completely dominant over the dwarf allele. 2) The major locus showed very similar effects in the two combinations, indicating that the major locus had stable effects in different genetic backgrounds and had no apparent interaction with minor genes. 3) In the two combinations, the sizes of genetic variance due to the segregation of minor genes were very close, the average dominance effects of the minor genes were in the direction of decreasing the trait and quite similar in size, while the average additive effects of the minor genes were in the direction of increasing the trait, and their sizes were quite different. This suggested that the number of minor genes segregating in the two populations might be similar, but the distributions of minor genes between parents should be quite different. 4) The phenotypic variances of the parents (or the environmental variances) were positively proportional to the mean values of the parents. The environmental variances of normal genotypes were much greater than those of dwarf genotype. Hence, the minor genes showed different heritabilities in different major genotypes. Attention should be paid to this in practice.
出处
《生物数学学报》
CSCD
1999年第3期314-318,共5页
Journal of Biomathematics
关键词
水稻
株高
遗传
混合分布模型
Rice Plant height Qualitative-quantitative trait Inheritance Mixture distribution model
