黄瓜霜霉病抗性遗传分析

摘要

Six generation of P1,P2,F1,B1,B2,F2 derived from a crossing between parent ‘ILl12’,a susceptible to downy mildew (DM),and parent‘ HNAU0023 ’,a high resistant to DM,were used for genetic analysis of downy mildew resistance(DMR) in cucumber by SEA-G 6.The results showed that the best model was "E-0 model","two pair of additive-dominant-epistasis major gene+ additive-dominance-epistasis interaction polygene".The additive effects of two major genes were 13.05;dominance effect of the major gene were-30.34,-15.88.Heritability of the major gene in B1,B2,F2 population was 68.63％,76.36％,87.15％;Heritability of the polygene was 0,7.25％,0.Heritability of the major gene was higher than the polygene,obviously.Therefore,in the breeding of resistance to cucumber downy mildew,major gene should be high priority.%以华北型黄瓜霜霉病抗病自交系‘HNAU0023’、霜霉病感病自交系‘IL112’通过自交、杂交、回交所构建的P1、P2、F1、F2、B1、B26个世代作为研究材料,使用6世代联合分离分析软件(SEA-G 6)对黄瓜霜霉病抗性进行遗传分析.结果表明,抗性遗传的最佳模型为E-0模型,即“2对加性-显性-上位性主基因+加性-显性-上位性多基因”混合遗传模型.2对主基因加性效应相同,均为13.05;显性效应为负值,分别为-30.34、-15.88.B1、B2、F2的主基因遗传率分别为68.63％、76.36％、87.15％,多基因遗传率分别为0、7.25％、0,各分离世代主基因遗传率明显大于多基因遗传率.因此,在黄瓜霜霉病抗性育种中应优先考虑主基因.