盐胁迫下调控小麦苗期性状的QTL分析

【目的】定位盐胁迫下调控小麦苗期性状的QTL位点，为分子标记辅助选择小麦耐盐性状提供基因位点和连锁标记。【方法】以小偃54×京411重组自交系群体为材料，在盐胁迫条件下检测调控小麦苗期MRL、 RDW、SDW和TDW及其相对性状的QTL位点。【结果】共检测到调控小麦苗期4个性状及其相对性状的25个QTL位点，分布在1A、2A、2D、3A、4A、4B、5B、5D、6B、7A和7B共11条染色体上，贡献率在4.4%—25.5%。其中有15个QTL位点成簇分布于3A、4A、4B、5B、5D染色体的5个遗传区间，其余10个QTL位点各自分布于不同的染色体区段。检测到的5个贡献率大于10%的位点分别位于3A染色体的Xgwm497.1—Xcfa2193和4A染色体的Xbarc78—Xgwm350.1。【结论】多数调控小麦耐盐性的QTL位点成簇分布于3A、4A、4B、5B和5D染色体上，3A染色体的Xgwm497.1—Xcfa2193和4A染色体的Xbarc78—Xgwm350.1携带所有5个贡献率在10%以上的QTL位点。

QTLs Analysis of Wheat Seedling Traits under Salt Stress

【Objective】The present study is aimed to identify QTLs associated with seedling traits under salt stress in common wheat(Triticum aestivum L.) and provide target loci and linked molecular markers for marker assisted selection of wheat salt tolerant-related traits.【Method】A hydroponic culture was carried out to evaluate wheat seedling traits(RDW,MRL,SDW,TDW) under control(CK) and salt stress(ST) conditions by using a recombinant inbred line(RIL) population derived from two Chinese wheat varieties Xiaoyan 54 and Jing 411.The relative values of each trait(ratio of ST/CK) were also calculated.【Result】 A total of 25 QTLs for 4 traits were detected distributed on chromosomes 1A,2A,2D,3A,4A,4B,5B,5D,6B,7A and 7B,and explained phenotypic variation ranging from 4.4% to 25.5%.Fifteen out of 25 QTLs detected in this research located on 5 genetic intervals in clusters on chromosomes 3A,4A,4B,5B,and 5D and each of the other 10 loci located on different genetic intervals.A total of 5 major QTLs(explained phenotypic variation more than 10%) located on two major chromosome regions(Xgwm497.1-Xcfa2193 and Xbarc78-Xgwm350.1) on chromosomes 3A and 4A,respectively.【Conclusion】 Most QTLs for wheat salt tolerance detected in present paper clustered on chromosomes 3A,4A,4B,5B and 5D.Five major QTLs located on two chromosome regions(Xgwm497.1-Xcfa2193 and Xbarc78-Xgwm350.1) on chromosomes 3A and 4A,respectively.These chromosome regions may have a potential in the practice of marker assisted wheat breeding for improving salt-tolerance.