烟草白粉病抗性基因的遗传分析

以烟草抗白粉病品种台烟7号为母本，感病品种NC89为父本，构建6个世代的群体，利用主基因 多基因混合遗传模型的分离分析方法，研究烟草白粉病的抗性遗传规律。结果表明，烟草白粉病抗性的遗传是由两对加性-显性-上位性主基因 加性-显性-上位性多基因（E-0模型）控制的。B1、B2和F2世代主基因的遗传率分别为88.05%、32.62%、84.43%，主基因遗传率很大，说明可以在抗病育种早期进行选择；B1、F2世代多基因遗传率均为0.00%，说明烟草白粉病的发生受一定环境影响。

The Genetic Analysis of the Resistance to Tobacco Powdery Mildew

Six populations (P1,P2,F1,B1,B2 and F2) were constructed from the resistant variety Taiyan 7 as the female parent and the susceptible variety NC89 as the male parent. The inheritance of the tobacco powdery mildew was investigated by the mixed major-gene plus polygene inheritance model. It was found that the inheritance of the resistance to tobacco powdery mildew was fit to a mixed genetic model of two major genes with additive-dominant-epistatic effects plus polygenes with additive-dominant-epistatic effects(the E-0 model).The heritability of major gene in B1, B2 and F2 was 88.05%, 32.62% and 84.43%, respectively. Because of the high heritability of the major gene, the selection of resistant plant could be carried out in the early breeding for disease resistance. Both of the polygene heritabilities in B1, F2 were 0.00%,which showed that the environmental effect should also be taken into consideration for the outbreak of tobacco powdery mildew.