Male sterile lines are important for hybrid seed production in Brassica rapa. In our previous study, we obtained a multiple-allele inherited male sterile line of Chinese cabbage. To identify the male sterile gene Ms in B. rapa, we used B. rapa L. var. chinensis (‘AB03’; MsMs) and B. rapa var. purpuraria (‘AB04’; Ms^fMs^f) as parents to construct an F₂ segregating population, and mapped the Ms gene on chromosome A07 between single sequence repeat (SSR) markers SSRY17 and SSRY22, which flank the gene at genetic distances of 0.11 cM and 0.31 cM, respectively. The interval between the two markers was 231.3 kb and comprised 21 genes. Whole-genome resequencing and sequence comparison revealed that only one gene, Bra015018, harbored an insertion–deletion (InDel) in an exon in the mapped interval. This InDel led to premature termination of translation due to generation of the stop codon TGA. Bra015018 was homologous to AT1G34355, which encoded a forkhead-associated (FHA) domain-containing protein that was related to plant growth and floral development. Genotyping revealed that male sterility was fully co-segregated with the InDel. qRT-PCR analysis showed that Bra015018 was specifically expressed in the stamen. Consequently, we predicted that Bra015018 was a candidate gene of Ms.

雄性不育系对于甘蓝型油菜杂交种子的生产很重要。在我们之前的研究中，我们获得了多等位基因遗传的大白菜雄性不育系。为了识别雄性不育基因女士在芜菁，我们用芜菁L.变种。中华（' AB03 '; MsMs）和B. rapa var。以Purpuraria（'AB04'; Ms ^f Ms ^f）为父母构建F ₂隔离种群，并绘制Ms图在单序列重复（SSR）标记SSRY17和SSRY22之间的A07染色体上，该基因位于基因的侧翼，遗传距离分别为0.11 cM和0.31 cM。这两个标记之间的间隔为231.3 kb，包含21个基因。全基因组重测序和序列比较显示，只有一个基因Bra015018在所映射的间隔中的外显子中具有插入缺失（InDel）。由于终止密码子TGA的产生，该InDel导致翻译的过早终止。Bra015018与AT1G34355同源，它编码与植物生长和花发育有关的含叉头相关（FHA）域的蛋白质。基因分型显示，男性不育症与InDel完全隔离。qRT-PCR分析表明，Bra015018在雄蕊中特异性表达。因此，我们预测Bra015018是Ms的候选基因。