Genetic analysis and chromosome mapping of a thermo-sensitive genic male sterile gene in wheat

BS20-T is a thermo-sensitive genic male sterile (TGMS) wheat line (Triticum aestivum L.) used in hybrid wheat breeding in northern China. BS20-T was crossed with common wheat variety ZN7. F1 plants were highly fertile. The segregation ratio of male fertile and male sterile individuals in F2 and BC1F1 plants were close to 3:1 and 1:1, respectively. Other crosses of BS20-T also segregated for a single gene. Bulked sergeant analysis with SSR markers indicated the sterility gene was located on chromosome 2BL. It was named tmsBS20T. Screening of 162 extremely sterile and 30 extremely fertile F2 plants with linked markers indicated flanking by gwm403 and gwm374 with genetic distances of 2.2 and 4.5 cM, respectively. tmsBS20T was transferred into several common wheat varieties by using traditional hybridization combined with marker assisted selection with these two markers. Further identification of derived TGMS lines is ongoing.