西藏三联小穗小麦中三联小穗性状控制基因的SSR分子标记定位

西藏三联小穗小麦是中国西藏地区一种独特的小麦地方品种,拥有特殊的三联小穗性状,超多的小穗数和小花数。分子定位控制三联小穗基因的基因座,发掘与之紧密连锁的分子标记,可为小麦高产育种提供分子标记辅助选择工具。本研究利用西藏三联小穗小麦的衍生系TTSW-5与普通穗型小麦,间3和川麦55,分别构建F2群体,成熟后进行穗部性状的表型分析和SSR基因型鉴定。性状表型遗传分析表明,西藏三联小穗小麦的三联小穗性状由两个独立遗传的隐性基因控制;通过SSR标记鉴定来自TTSW-5/间3组合的F2群体,在2A染色体上检测到1个与三联小穗性状相关的QTL,定位于SSR标记Xgwm275和Xgwm122之间,两标记间的遗传距离为6.6cM,该QTL的LOD值为6.19,可解释的表型变异值为33.1%,初步命名为qTS2A-1。我们推测qTS2A-1可能是控制三联小穗性状相关的主效QTL,SSR标记Xgwm275和Xgwm122可能可用于三联小穗性状的辅助选择。

SSR Mapping Locus Conferring on the Triple-spikelet Trait of the Tibetan Triple-spikelet Wheat(Triticum aestivum L.concv.tripletum)

Tibetan triple-spikelet wheat is an unique common wheat landrace in Tibet region of China,which has special triple spikelet trait with supernumerary spikelets and florets.Molecular mapping the control gene locus conferring on triple spikelet trait and mining the closely linked markers would be facilitate high-yield wheat breeding by marker-assisted selection approach.In this study,TTSW-5 derived lines from Tibetan triple spikelet wheat and two common-spikelet wheat,Jian3 and Chuanmai55,were used to construct the F2 populations for phenotypic analysis and SSR genotyping.Genetic analysis of phenotypic traits showed that triple spikelet trait of Tibetan triple spikelet wheat is controlled by two independent recessive gene loci.One QTL linked to the triple spikelet trait was detected on the chromosome 2A by using F2 population from TTSW-5/Jian3 combination and SSR markers,the targeted locus was located within two SSR markers,Xgwm275 and Xgwm122,the genetic distance between two markers is 6.6 cM with LOD value 6.19,which can be explained 33.1% phenotypic variation,The detected locus tentatively named as qTS2A-1.We speculated that qTS2A-1 locus might be one of dominant loci for controlling the triple spikelet trait,Therefore,SSR markers,Xgwm275 and Xgwm122,might be used as assisted selection markers for triple spikelet trait in high-yield breeding program.