Genetic analysis, molecular tagging and mapping of the thermo-sensitive genic male-sterile gene (wtms1) in wheat

A thermo-sensitive genic male-sterile (TGMS) wheat line (Triticum aestivum L.) BNY-S was obtained from the spontaneous mutant of BNY-F. Its fertility was decided by the temperature during the differentiation stage of the spikelets. BNY-S was completely sterile when the temperature was lower than 10°C during the differentiation stage of the spikelets, but fertile when the temperature was higher than 10°C. Genetic analysis indicated that the sterility of BNY-S was controlled by a single recessive gene, which was named as wtms1. An F2 population, consisting of 3,000 individuals from the cross between BNY-S and Lankao 52-24, was used for genetic analysis and statistical analysis of the TGMS and, out of them, 158 sterile and 93 fertile extremes were present for molecular tagging and mapping of the wtms1 gene. SSR (simple sequence repeat) and AFLP (amplified fragment length polymorphism) techniques combined with BSA (bulked segregant analysis) were used to screen markers linked to the target gene. As a result, wtms1 was preliminarily mapped on chromosome 2B according to SSR analysis. In AFLP analysis, 14 polymorphic AFLP loci were identified with a linkage relation to the wtms1 gene. Then linkage analysis using the F2 population showed that three of them, E: AAG/M: CTA163, E: AGG/M: CTC220 and E: ACA/M: CTA160, were linked to the wtms1 gene relatively close to a genetic distance of 6.9 cM, 6.9 cM and 13.9 cM, respectively. Finally, the wtms1 gene was mapped between the SSR marker Xgwm 374 and the AFLP marker E: AAG/M: CTA163 with the distance of 4.8 cM and 6.9 cM, respectively. A partial linkage map was constructed according the SSR and AFLP data.