甘蓝型油菜角果数突变体基因的定位及候选基因分析  

Mapping and candidate gene analysis of silique number mutant in Brassica napus L.

作　　者：赵改会 李书宇[2] 詹杰鹏[1] 李晏斌 师家勤[1] 王新发[1] 王汉中[1] ZHAO Gai-Hui;LI Shu-Yu;ZHAN Jie-Peng;LI Yan-Bin;SHI Jia-Qin;WANG Xin-Fa;WANG Han-Zhong(Oil Crops Research Institute,Chinese Academy of Agricultural Sciences,Wuhan 430062,Hubei,China;Crop Research Institute,Jiangxi Academy of Agricultural Sciences,Nanchang 330200,Jiangxi,China;Wuhan Agricultural Technology Extension Center,Wuhan 430400,Hubei,China)

机构地区：[1]中国农业科学院油料作物研究所,湖北武汉430062 [2]江西省农业科学院作物研究所,江西南昌330200 [3]武汉市农业技术推广中心,湖北武汉430400

出　　处：《作物学报》2022年第1期27-39,共13页Acta Agronomica Sinica

基　　金：江西省自然科学基金项目(20202BABL205016);湖北省自然科学基金重点(杰青)项目(2018CFA075);优质高产多抗油菜新品种选育项目(2018ABA087);国家现代农业产业技术体系建设专项(CARS-13)资助。

摘　　要：角果数是油菜单株产量重要的构成因子之一,其优异等位基因的发掘和利用对产量的提高至关重要。油菜中已定位到上百个角果数QTL,但大多数效应不大且不稳定,难以进行精细定位或克隆。本研究前期发掘到一个油菜突变体(No.7931),其花序顶端在分化出约十朵花后即停止生长,因而成熟期角果极少。利用该少角果突变体和多角果品系No.73290构建F2分离群体,从中挑选角果数极端单株各30株进行BSA-seq,在C02染色体检测到3个关联区间:0~1.1 Mb、4.7~6.2 Mb、11.5~12.4 Mb。该候选区间在油菜参考基因组DarmorV8.1中有522个注释基因,存在SNP或Indel差异且有同源注释的基因235个。在花芽分化初期,选取两亲本(No.73290和No.7931)的茎尖分生组织进行RNA-seq,总共鉴定到8958个差异表达基因(DEGs)。这些DEGs显著富集于20个生物学通路,包括碳代谢、翻译、氨基酸代谢(和花芽分化高度相关)等,其中99个位于关联区间。结合基因功能注释以及序列和表达差异分析确定了9个候选基因(BnaC02g00490.1D2、BnaC02g01030.1D2、BnaC02g01120.1D2、BnaC02g00270.1D2、BnaC02g02670.1D2、BnaC02g08680.1D2、BnaC02g08890.1D2、BnaC02g09480.1D2和BnaC02g10490.1D2),它们主要参与花序分生组织特性的维持和花器官的发育。上述研究结果为后续油菜角果数基因的精细定位和克隆奠定了坚实的基础。The silique number is one of the important components of yield per plant in oilseed rape(Brassica napus L.)and the exploitation and utilization of its excellent alleles are essential to increase yield.More than hundreds of silique number QTLs have been mapped in oilseed rape,but they are difficult to be fine-mapped or cloned because of their moderate and unstable effects.A oilseed rape mutant(No.7931)was detected in previous study and it had few siliques at mature stage due to the stop growth after differentiation about 10 flowers on the top of inflorescence.A F2 segregating population consisting of 3400 individuals was con-structed using this mutant and another more-silique lines No.73290.Among them,we performed BSA-seq on 30 individuals with extreme more-or less-siliques and detected three associated intervals of 0-1.1 Mb,4.7-6.2 Mb,and 11.5-12.4 Mb on the C02 chromosome.These genomic intervals contained a total of 522 annotated genes in the reference genome DarmorV8.1,among which 235 genes had functional annotation and SNP/InDel variation.At the early stage of flower bud differentiation,the shoot apical meristems of two parents were subjected to RNA-seq,and a total of 8958 differentially expressed genes(DEGs)were de-tected.These DEGs were significantly enriched into 20 pathways,including carbohydrate metabolism,translation,and amino acid metabolism(highly associated with flower bud differentiation)and so on,among which 99 were located in the associated intervals.By the integration of gene functional annotation as well as sequence and expression variation analysis,a total of nine candidate genes(BnaC02g00490.1D2,BnaC02g01030.1D2,BnaC02g01120.1D2,BnaC02g00270.1D2,BnaC02g02670.1D2,BnaC02g08680.1D2,BnaC02g08890.1D2,BnaC02g09480.1D2,and BnaC02g10490.1D2)were identified,which were mainly involved in the maintenance of inflorescence meristems and the regulation of flower development.The above results lay the foundation for the following fine-mapping and cloning of the silique number mutant gene in oilseed rape.

关 键 词：油菜 角果数突变体 花芽分化 BSA-seq RNA-SEQ 

分 类 号：S565.4[农业科学—作物学]