陆地棉纤维品质相关QTL定位研究

 【目的】以湘杂棉2号和中棉所28两个具有共同亲本的陆地棉强优势杂交种的F2为作图群体,构建覆盖率较高的遗传图谱,发掘稳定的纤维品质相关QTL,为标记辅助选择提供依据。【方法】利用SSR标记和JoinMap3.0软件构建陆地棉连锁图,利用Win QTLCart 2.5的复合区间作图法分别对2群体6个纤维品质相关性状在F2和F2:3中进行QTL定位。【结果】利用包含245个多态位点、全长1 847.81 cM的遗传图谱检测纤维品质QTL。中棉所28群体在多环境平均值的联合分析中检测到22个QTL,三环境分离分析中检测到39个QTL;湘杂棉2号群体分别检测到18个和51个QTL。在A3、D2、D9等染色体上有QTL成簇分布现象,并在2个群体中发现一些不受环境影响,稳定遗传的QTL。纤维长度、纤维强度、麦克隆值和伸长率4个性状在2个群体中发现有8对共同QTL。【结论】这些稳定遗传的QTL可以用于分子标记辅助纤维品质改良的育种选择。

QTL Mapping for Fiber Quality Properties in Upland Cotton (Gossypium hirsutum L.)

Objective] In this paper,two F_2 mapping populations were respectively assembled by using the parents of CR128 hybrid (CRI12 and 4133,their corresponding population named as Popl ) and the parents of XZM 2 hybrid (CRI12 and 8891,their corresponding population named as Pop2),to construct linkage map with higher genome coverage,to map QTLs related with fiber qualities,and further to provide information for molecular marker-assisted breeding.Method]The linkage map was constructed with SSR markers by JOINMAP 3.0 software.The QTLs for 6 fiber quality properties in F_2 and F_(2:3) populations were mapped by the composite interval mapping method (CIM) using Win QTLCart 2.5.Result]A joinmap was integrated with 245 loci and covered 1847.81 cM.Based on this,QTLs related with fiber qualities were further detected.In detail,39 QTLs were identified in three environments in separate analysis and 22 QTLs in the joint analysis in Pop1.Similarly,51 and 18 QTLs were identified in Pop2,respectively.QTLs were clustered on chromosomes A3,D2 and D9,and some stably heritable QTLs were also discovered by integrating analysis in different environments.Of them,8 QTLs for the 4 traits could be found simultaneously in the two populations,and more 4 QTLs for fiber strength,micronaire,and fiber elongation were offered by CRI12.Conclusion]These stably heritable QTLs could be used for the molecular breeding of fiber quality traits in upland cotton.