青花菜与甘蓝近缘野生种‘B2013’杂交后代对根肿病抗性的遗传分析

Genetic Analysis of Clubroot Resistance in the Populations of Broccoli × Wild Cabbage Accession ‘B2013'

以高感根肿病的青花菜自交系‘93219’和高抗根肿病的甘蓝近缘野生种(Brassica macrocarpa Guss.)自交系‘B2013’为亲本配制的6个联合世代(P1、P2、F1、BC1、BC2和F2)群体为试材,采用主基因+多基因混合遗传模型对根肿病抗性进行了遗传分析。结果表明:青花菜×甘蓝近缘野生种‘B2013’后代对根肿病抗性的最适遗传模型为B-1模型,即由两对加性―显性―上位性主基因控制。BC1、BC2和F2世代主基因遗传率分别为81.22%、78.36%和80.00%,遗传变异平均值占表型变异的79.86%,环境变异平均值占表型变异的20.14%,表明抗病性以主基因遗传为主,同时受环境影响较大,应在早期世代进行选择,BC1、F2世代主基因选择效率较高。

Six generations(P1,P2,F1,BC1,BC2 and F2)derived from the crosses of broccoli inbred line‘93219'(high susceptible)and the wild cabbage accession inbred line(Brassica macrocarpa Guss.)‘B2013'(high resistant)were used to investigate the inheritance of clubroot resistance by using mixed major gene plus polygene inheritance model. The results showed that the clubroot resistance was controlled by two additive-dominant-epitasis major genes(B-1 model)in the joint analysis of the six generations. The major genes heritability of BC1,BC2 and F2 were estimated to be 81.22%,78.36% and 80.00%,the genetic variance and the environmental variance accounted for 79.86% and 20.14% of the phenotypic variance in each population respectively. It indicated that the clubroot resistance was dominated by major genes though the environmental factors had a great effect. In practical breeding,higher heritability of major genes can be favorable to an efficient selection in early generations,such as BC1 and F2 for resistance to clubroot in broccoli breeding plan.