小麦RIL群体遗传连锁图谱的构建及其多态性分析

Construction of genetic linkage map and marker polymorphism analysis in wheat RIL population

以普通小麦重组近交系(recombinant inbred lines,RIL)‘Q9086×陇鉴19’为作图群体,利用SSR标记构建小麦遗传连锁图谱.结果表明:通过选用2 187对SSR引物筛选出RIL群体双亲表现多态性的引物共405对,多态性频率为18.52%.不同类型SSR标记多态性频率从小到大依次为Xpsp(4.4%)<Xgdm(9.0%)<Xbarc(18.0%)<Xwmc(22.7%)<Xgwm(23.6%).通过χ2检测(P<0.05),有201个SSR标记表现为偏分离,偏分离频率为37.53%,80%偏向母本‘Q9086’,其偏分离位点主要分布在A基因组上.共有358对SSR引物的413个标记被定位在小麦21条染色体上,群体的遗传连锁图总长度为3 209.6cM,平均每条染色体连锁图长152.8cM,平均2个标记的距离为7.8cM.

The recombinant inbred lines（RILs）（＇Longjian19×Q9086＇） of wheat were as donors,and a genetic linkage map was constructed by SSR markers.The results showed that total of 405 pairs SSR markers were available with showing SSR polymorphism differences between two parents of RILs from 2 187 pairs SSR originally selected.The polymorphism frequency was 18.52%.The polymorphism frequency of SSR showed,in turn,Xpsp（4.4%）Xgdm（9.0%）Xbarc（18.0%） Xwmc（22.7%）Xgwm（23.6%）.Through the χ2 test（P0.05）,201 SSR,mainly distributed on A genome,showed the significantly segregation distortion with 37.53% of segregation percentage,and 80% of segregated distortion SSR markers resulted from female parent ＇Q9086＇.Total of 413 SSR markers from 358 pairs SSR markers were mapped on 21 chromosomes of wheat.The linkage genetic map was covered 3 209.6 cM.The average length per every chromosome was 152.8 cM,and the interval distances between two SSR markers were average 7.8 cM on the linkage map.Therefore,The SSR markers of the genetic linkage map were characteristic of abundance,segregation distortion,adequate density and covering the whole chromosomes in wheat,indicated that the genetic map would suit for the further QTL mapping for drought-tolerant traits in wheat.