SSR Mapping for 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, derived lines TTSW-5 from Tibetan triple spikelet wheat and common-spikelet wheat, Jian 3 and Chuanmai 55, were used to construct the F 2 populations for , phenotypic analysis and SSR genotyping. Genetic analysis of phenotypic traits showed that triple spikelet trait of Tibetan triple spikelet wheat are controlled by two independent recessive gene loci. One QTL linked to the triple spikelet trait was detected on the chromosome 2A by using F 2 population from TTSW-5/Jian 3 combination and SSR markers, the targeted locus was located within SSR markers, Xgwm275 and Xgwm122, the genetic distance between two markers is 6.6CM 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.