番茄遗传图谱构建和抗晚疫病基因Ph-2的QTL分析

Construction of Genetic Linkage Map and QTL Analysis of Phytophthora infestans Resistant Gene Ph-2 in Tomato

以含有抗番茄晚疫病(Phytophthora infestans)基因Ph-2的樱桃番茄(Solanum lycopersicum var.cerasiforme)W.Va.700为父本,感病的普通番茄(Solanumlycopersicum)优良品系04957为母本,构建的260个F2单株为图谱构建群体,通过接种番茄晚疫病病原菌生理小种T1,对Ph-2基因进行了抗病性鉴定和遗传分析。结果表明,抗性基因Ph-2对生理小种T1的抗性呈正态分布,属于数量性状遗传。进一步应用RAPD、SSR和AFLP的方法构建了包含12个连锁群,长度1154.85cM,平均图距9.47cM的分子遗传图谱。检测到5个与抗性基因Ph-2相关的QTL(quantitative trait loci)位点,其中QPh2-1、QPh2-2、QPh2-3和QPh2-4,位于第3连锁群上,表型变异分别为26.95%、16.63%、16.24%和6.69%;QPh2-5位于第1染色体上,与OPK14的距离为0.76cM,表型变异为33.87%;QPh2-2、QPh2-3和QPh2-4为减效QTL。

In this paper,a set of 260 F2 progeny was obtained by crossing the Phytophthora infestans resistant cultivar W.Va 700（Solanum lycopersicum var.cerasiforme） carrying Ph-2 gene（resistant to race T1） with the susceptible cultivar line 04957（S.lycopersicum） for constructing the genetic map,and plants were inoculated using Phytophthora infestans T1 for disease resistance identification.The results showed that the resistance to race T1 was in accordance with normal distribution,and the resistance of Ph-2 gene was quantitative character：A genetic map with 12 linkage groups was constructed by RAPD,SSR and AFLP methods.The map covered 1 154.85 cM map distance,the average map distance was 9.47 cM.Five QTL（quantitative trait loci）,designed as QPh2-1,QPh2-2,QPh2-3 and QPh2-4,were linked to Ph-2 gene in the third linkage group.The explainable phenotypic variation of them were 26.95%,16.63%,16.24% and 6.69% respectively.QPh2-5 was detected on chromosome 1,it was 0.76 cM away from molecular marker OPK14,its explainable phenotypic variation was 33.87%.The genetic effects of QPh2-1 and QPh2-5 were additive and dominant seperately.