大白菜耐热性QTL定位与分析

 应用352个标记位点的大白菜AFLP和RAPD图谱，采用复合区间作图的方法对控制大白菜耐热性的数量性状基因位点(QTL)进行定位和遗传效应研究。用苗期热害指数进行耐热性表型鉴定，共检测到5个耐热性Q几位点，分布于3个连锁群上。ht-1、ht-3和ht-5表现为增效加性效应，ht-2和舡4表现为减效加性效应。ht一2对大白菜耐热性的遗传贡献率最大，其次是ht-5。发现了与5个 I8紧密连锁的侧连分子标记，它们与Q几间的距离为0．1 2．4 cM。这为大白菜耐热性分子标记辅助选择提供了理论基础。关键词：中图分类号：

Mapping and Analysis QTL Controlling Heat Tolerance in Brassica campestris L.ssp.pekinensis

An AFLP and RAPD genetic map with 352 markers was employed in mapping and analysis QTL controlling heat tolerance in Brassica campestris L.ssp. pekinensis ,using composite interval mapping method.Heat damage index in seedlings was used as phenotypic value to detect quantitative trait loci.Five QTL were mapped in three linkage groups.Three loci including ht 1,ht 3 and ht 5 showed positive additive effect,while ht 2 and ht 4 showed negative additive effect.Out of the five QTL,pbenotypic variation explained by ht 2 was the biggest one,and then ht 5.The distance from the nearest flanking markers to QTL ranged from 0 1 cM to 2 4 cM.These markers provided useful information for molecular marker assistant selection of heat tolerance in breeding programmes of Chinese cabbage.