大白菜叶柄黑点症抗性相关候选基因的挖掘

Mapping of Chinese Cabbage Genes Related to Petiole Black Spot Resistance

大白菜叶柄黑点症是严重影响大白菜商品性的一种生理性病害。本研究以抗大白菜叶柄黑点症品系(韩春娃C8-1)和感叶柄黑点症品系(韩春娃-4-2-3-4)为亲本,构建F2群体,通过高N水平水培处理,筛选出高抗叶柄黑点症和高感叶柄黑点症的植株各20株,构建两个极端性状混池DNA文库,通过BSA-Seq技术,对大白菜叶柄黑点症抗性相关候选基因进行挖掘。对于502662个高质量的SNP位点和173111个高质量的InDel位点,利用ED和Index方法对这些SNP和InDel位点分别进行关联分析,取所有结果的交集,得到1个包含295个编码基因,位于第1染色体的候选区域,与叶柄黑点数性状紧密关联;对这295个基因进行进一步的功能注释,NR、Swiss-Prot、GO、KEGG和COG数据库共注释到292个基因,其中存在133个非同义突变基因,30个移码突变的基因。候选区域内编码基因的深度注释有助于功能基因的进一步分离,为大白菜叶柄黑点症抗性相关基因的精细定位及克隆提供理论依据。

Chinese cabbage petiole spot is a physiological disease that seriously affects the commodity value of Chinese cabbage.In this study,the F2 population was constructed using the petiole spot resistant strain(Han Chunwa C8-1)and the petiole spot susceptible strain(Han Chunwa-4-2-3-4)as parents.20 plants with high resistance to petiole spot and 20 plants with high susceptible to petiole spot were selected to construct the two pools of extreme trait mixed pool DNA libraries.The candidate genes related to petiole spot resistance of Chinese cabbage were analyzed by BSA-Seq technology.From 502662 high-quality SNP loci and 173111 high-quality InDel loci,one candidate regions were obtained closely related to the target traits by both SNP-index and ED methods.It was located on chromosomes 1,and contained 295 coding genes.Furthermore,total 292 genes were annotated by NR,Swiss-Prot,GO,KEGG and COG databases.Among them,there were 133 non-synonymous mutation genes and 30 frame shift mutation genes.Functional annotations of these candidate genes are helpful for further gene isolation and provide theoretical basis for fine mapping and cloning of the genes related to petiole spot resistance in Chinese cabbage.