To identify genes associated with genic male sterility (GMS) that are useful for hybrid breeding in Brassica crops, we analyzed the “ms77B” strain, which is a spontaneous turnip GMS mutant derived from a cv. 77B population. Previously, we reported that the GMS phenotype of ms77B is caused by a single gene with sterility as the recessive trait. To identify the causative gene of GMS in ms77B, we performed bulked segregant and transcriptome analyses with high-throughput sequencing and identified BrEMS1 as the most likely candidate. BrEMS1 is a single-copy gene homologous to Arabidopsis thaliana EMS1/EXS, which is essential for anther development. The BrEMS1 gene of ms77B has a long insertion (1460 bp) in the coding sequence, and RNA sequencing revealed that the gene is not transcribed beyond the insertion site. The region that is not transcribed because of the insertion contains sequences that encode multiple leucine-rich repeats and a catalytic kinase domain. Furthermore, genotyping of an F2 population revealed a complete correlation between the insertion and the male sterility phenotype. Together, our results indicate that the male sterility phenotype of ms77B is due to a null mutation of BrEMS1, which is essential for anther development.

为了鉴定可用于甘蓝型作物杂交育种的与雄性不育相关的基因，我们分析了“ ms77B”菌株，该菌株是自简历中衍生的自发性萝卜GMS突变体。77B人口。以前，我们报道了ms77B的GMS表型是由具有不育作为隐性状的单个基因引起的。为了鉴定ms77B中GMS的致病基因，我们使用高通量测序进行了大量的分离子和转录组分析，并将BrEMS1确定为最可能的候选基因。BrEMS1是与拟南芥EMS1 / EXS同源的单拷贝基因，对花药发育至关重要。该BrEMS1ms77B基因在编码序列中有一个长插入（1460 bp），RNA测序表明该基因不会转录到插入位点之外。由于插入而未被转录的区域包含编码多个富含亮氨酸的重复序列和催化激酶结构域的序列。此外，F2人群的基因分型显示插入和男性不育表型之间的完全相关性。总之，我们的结果表明，ms77B的雄性不育表型是由于无效突变BrEMS1，这是花药发育至关重要。