双列杂交设计的主-微位点组遗传分析方法研究

数量性状遗传研究通常以双亲本杂交后代为对象，而作物育种中常涉及多个具有优良性状的亲本作为有利基因的供体，因此有必要研究多个材料间的遗传关系，以便从中选择最佳亲本组合，这对杂种品种选育尤其重要。本研究在以往位点组分析方法的基础上，将其扩展为主基因＋多基因遗传模型框架下双列杂交设计的主－微位点组遗传分析方法，将微位点组从原来的剩余部分中分离出来。该方法针对双列杂交设计的主位点组和微位点组及其与环境互作的统计遗传模型提出了主位点组检测与效应估计和微位点组效应估计的逐步选入回归法；因模拟实验发现逐步选入回归法的F测验有偏，提出了F测验的调整方法。利用模拟方法评估了遗传率、主位点组个数、增效基因型频率、主位点组间相似性和微基因效应等因素与方法功效的关系。然后通过模拟实验数据和油菜实际试验数据的分析验证了所提方法的应用效果。本研究建立的双列杂交设计的主－微位点组遗传分析方法为杂种品种的亲本选配提供了方法和理论依据。

A Genetic Analysis Method of Major-Minor Locus Groups in Diallel Cross Design

Studies on inheritance of quantitative traits are usually based on two-way crosses, while in plant breeding, knowledge on inheritance of traits among a group of parental materials is needed since elite genes or QTLs are scattered in different materials. It is especially true in breeding for hybrids. Based on our previous studies on major locus group analysis among a set of parents, we aimed at extending the analysis to major-minor locus groups in diallel cross experiment. The statistical method was derived from a forward stepwise regression for identifying major locus groups and estimating their genetic effects as well as the estimation of genetic effect of collective minor locus groups. In which the procedure of adjusting F criterion was raised since biased F-test was found in a simulation study. Then the procedure was used to evaluate the relationship between its power and some factors, including heritability value, number of major locus groups, genotypic frequency with increment alleles, similarity among major locus groups and effect of collective minor locus groups. A simulated diallel cross experiment was used to demonstrate the effectiveness of the procedure. A diallel cross experiment on days to flowering of rapeseed was given to show the statistical steps and its utilization. The procedure of major-minor locus group analysis in diallel crosses based on major gene plus polygene inheritance model provides a way to analyze the genetic constitution of a group of parental materials for obtaining the best hybrid combinations.