Molecular mapping of dominant male sterile gene in the Brassica napus line Shaan-GMS by BSA-Seq and candidate gene association analysis

Shaan-GMS is a spontaneous dominant genic male sterile (GMS) line in Brassica napus, and its male sterility is genetically controlled by a single gene with three alleles of different dominant relationships (Mf > Ms, Ms > ms). Here, whole genome resequencing was performed on the homozygous (MsMs*MfMs) and heterozygous (Msms*msms) two-type lines of Shaan-GMS, respectively, for localizing male sterile gene. BSA-Seq of both two-type lines detected one candidate gene BnaA08g26080D on the chromosome A08 in common. By integrating the genetic maps of Mf/Ms and Ms/ms locus, the fertility locus of Shaan-GMS was located in the overlapping region on the A08 chromosome containing 14 genes. Among them, five genes of interesting were sequenced. As a result, two genes (BnaA08g25920D and BnaA08g25870D) showed DNA sequence variation among male sterile plants (MsMs), fertile plants (msms), and restorer plants (MfMf) of Shaan-GMS. The candidate gene association analysis indicated that DNA variations in the BnaA08g25870D had no relationship with male fertility in a panel of 88 rapeseed lines, therefore, BnaA08g25920D is the candidate for the male sterile gene. This study lays a foundation for molecular cloning of male sterile gene in Shaan-GMS, and the developed molecular markers and the identified restorer lines will be useful for developing new hybrid varieties based on the dominant GMS system.