黄瓜果形性状主基因+多基因混合遗传分析

Analysis of Mixed Major-gene with Polygenes Genetic Model for Fruit Shape Traits in Cucumber

本研究以长条形黄瓜‘二早子’为母本,短棒形黄瓜‘NC-76’为父本,及其构建的F1、F2共四个世代的遗传群体为研究材料,利用主基因+多基因混合遗传模型分析黄瓜果形的遗传特性。结果表明:在F2分离群体中,瓜长和果形指数两个性状均呈连续变异和正态分布,表明两性状均为多基因控制的数量遗传;瓜长性状的遗传符合2对加性-显主基因(B-2)模型,果形指数的遗传符合加性-显性-上位性多基因(C-0)模型;控制瓜长性状的两对主基因以加性效应为主,两者之间的加性效应相差不大,第一主基因存在负显性效应为-3.033,第二主基因显性正效应较小,为0.123,主基因遗传率为88.09%;控制果形指数性状为多基因遗传,遗传率为23.26%;瓜长受环境影响较小,而果型指数受环境影响较大,两者的环境方差占表现方差的比例分别为11.91%和76.74%。

In this study,genetic mechanism for fruit shape traits were discussed using a four-generation population(P1,P2,F1,F2) derived from cucumber cultivars‘erzaozi'(strip shape fruit)בNC-76'(short rod shape fruit) under the Mixed Major-gene with Ploygene Genetic Model.The results showed that two fruit shape traits grade values of F2 segregation population were continuous variation and normal distribution,it was proved that fruit length and fruit shape index were quantitatively genetic traits controlled by multiple genes.The inheritance of fruit length was appropriate for the model of two additive-dominance major genes(B-2),fruit shape index was appropriate for the model of additive-dominance-epitasis polygenes(C-0).The additive effects of two major genes controlling fruit length were little different,and the dominance negative effect value of the first major gene was-3.033,and the dominance effect value of the second major gene was 0.123.In F2 population,the heritability of major gene controlling fruit length was 88.09%,and the heritability of polygene controlling fruit shape index was23.26%.The environment factors had weak effects on fruit length,while that on fruit shape index had strong effects,the proportions of environmental variance in phenotypic variance were 11.91%,76.74%,respectively.