黄瓜抗黑星病不同基因源的遗传分析

Genetic Analysis of Resistance to Cladosporium cucumerinum from Different Gene Sources in Cucumber

基于苗期人工接种鉴定结果,获得2份抗黑星病黄瓜材料(HX1,Cucumis sativus var.sativus,DI=5;HX5,C.sativusvar.xishuangbannesis,DI=38.7)和1份感病材料(HX8,C.sativus var.sativus,DI=80)。利用上述3份材料构建了2个组合(HX1×HX8,HX5×HX8)的6世代群体(P1、P2、F1、F2、B1和B2),并分别进行黑星病苗期人工接种鉴定。采用主基因+多基因联合遗传分析方法进行遗传分析,结果表明2份材料抗黑星病的遗传规律不同。组合HX1×HX8的F1单株表现为抗病,而组合HX5×HX8的F1单株基本表现为感病。HX1对黑星病的抗性符合两对加性-显性-上位性主基因+加性-显性多基因混合遗传模型(E_1模型),HX5的抗性遗传符合加性-显性多基因模型(C模型)。在组合HX1×HX8中,两对主基因的加性效应均大于显性效应,B1、B2和F2群体的主基因遗传率分别为72.51%、98.19%和96.91%,多基因遗传率均为0,表明HX1对黑星病的抗性以主基因遗传为主;HX5对黑星病的抗性遗传以多基因的显性效应为主。

Based on the resistance identification of scab at seedling stage in cucumber,two lines resistant to Cladosporium cucumerinum （ HX1, Cucumis sativus var. sativus, DI = 5 and HX5, C. sativus var. xishuangbannesis, DI = 38.7） and one susceptible material （ HX8, C. sativus var. sativus, DI = 80） were obtained. Six generations （ P1, P2, F1, F2 ,B1 and B2）of two combinations（HX1 × HX8 and HX5 × HX8）were used as genetic populations and resistance identification of scab at seedling stage were performed. The genetic characteristics of scab resistance were analyzed with a mixed model of major genes plus poly-gene. The results showed that the inheritance of scab resistance of the above two gene sources was different. The plants of F1 generation of HX1 × HX8 combination expressed resistant while those of HX5 × HX8 combination were susceptible. The inheritance of HX1 agreed to a mix genetic model of two major genes with additive-dominance-epistatic effects plus poly-genes with additive-dominance effects（E_1 model）and that of HX5 was fitted to poly-gene（C）model. For high resistance material HX1 ,the additive effect of two major genes was larger than dominant effect. Heritabilities of the major genes in F2 ,B1 and B2 were estimated to be 96.91% ,72. 51% and 98.19% , respectively. Poly-gene heritabilities of three generations were all 0,indicating that scab resistance in HX1 was controlled by major gene. For resistance material HX5 ,the heritability was mainly dominant effect of poly-gene.