甜椒疫病抗性遗传及相关基因分子标记研究

Genetic and Molecular Marker Analysis of Resistance to Phythophtora capsici in Sweet Pepper

以高抗疫病的甜椒育种材料‘N1345’与高感疫病辣椒材料‘N1308’为双亲,构建了6个联合世代,运用植物数量性状主基因+多基因联合分离分析方法对N1345疫病抗性进行遗传分析,并对其F2群体进行EST-SSR与SSR连锁标记分析。结果显示,N1345对疫病抗性由2对加性—显性—上位性主基因控制(B-1-1),两主基因加性效应、显性效应均相等,主基因遗传率在B1、B2和F2世代分别为63.43%、82.32%和83.46%。筛选到E73、E318等2个EST-SSR标记与疫病抗性病级均呈显著负相关,相关系数分别为﹣0.6296、﹣0.5492,差异水平均为极显著(P<0.01),表明这2个标记与对疫病抗性基因紧密连锁。这2个标记在22份甜辣椒材料中分离一致,有6份材料抗、感表型与标记分离不一致。

Using the model of the major gene plus polygene of quantitative traits,a joint analysis of six-generations was performed from cross between a sweet pepper N1345 with high resistance to phythophtora blight and a highly susceptible hot pepper N1308.F2 population was analysed with EST-SSR and SSR molecular markers.It was showed that the resistance to Phythophtora blight of N1345 was controlled by two major genes（B-1-1）with equal additive and dominant effects.And the major genes heritabilities of B1,B2,F2 were 63.43%,82.32% and 83.46%,respectively.Two EST-SSR markers including E73 and E318 had significant minus correlation with desease indexes of Phythophtora capsici,with correlation coefficients–0.6296,–0.5492 separately（P 0.01）.It showed that the two markers were closely linked to genes of resistance to Phytophtora blight.Furthermore,the 2 EST-SSR markers had same speration in 22 pepper lines,and in 6 out 22 lines the resistance or susceptivity to Phythophtora wasn’t coincident with marker separation.