Pyramiding of thermosensitive genetic male sterility (TGMS) genes and identification of a candidate tms5 gene in rice

Three thermosensitive genetic male sterility (TGMS) genes – tms2, tgms and tms5 – were pyramided using linked microsatellite markers. Three TGMS donors, Norin PL 12 (tms2), SA2 (tgms) and DQ200047-21 (tms5) were utilized in generating crosses from which two-gene and three-gene pyramids possessing the RM11 allele of Norin PL 12, RM257 allele of SA2 and RM174 allele of DQ200047-21 were selected. All selected progenies were male-sterile at sterility-inducing conditions. In addition, rice SF21 was identified as a candidate tms5 gene because of its complete linkage with RM174. The 4,200-bp region was amplified from the TGMS line M105S and the two ends were sequenced. In silico analysis of partial nucleotide sequences showed that the region is similar to the SF21 pollen-specific gene of Arabidopsis and Helianthus. The M105S tms5 sequence was also compared to the SF21 sequence from the International Rice Genome Sequencing Project (IRGSP) database.