Long Weihua, Hu Maolong, Gao Jianqin, Sun Lijie, Zhang Jiefu, Pu Huiming
Key Lab of Cotton and Rapeseed (Nanjing) of Ministry of Agriculture/Institute of the Industrial Crops, Jiangsu Academy of Agriculture Sciences, 50# Zhongling St, Nanjing, Jiangsu, 210014, China.
Breed Sci. 2019 Jun;69(2):316-322. doi: 10.1270/jsbbs.18105. Epub 2019 May 18.
The Mutsu-Isuzu cytoplasmic male sterility (MI CMS) system is one of the three-line hybrid systems used in China. As we know, the hybrid system is tightly associated with the yield variation in F heterosis, while the restorer gene for the MI CMS () has not been finely mapped for further application in marker-assisted selection (MAS). In this study, the sets of near-isogenic lines (NILs) of in two different genetic backgrounds were hybridized with the genome-wide 60 K single-nucleotide polymorphism (SNP) chip of for screening the possible associated genomic region of . Through screening genotypes with SNP loci and sequencing the candidate loci, one 2.5 Mb physical region (covering three scaffolds) on chrA09 was identified as the candidate for the region. Then, the SSR markers for the target scaffolds were used to detect the recombination in an F population and narrowed the gene within the genetic distance of 0.52 cM, equivalent to a 350 kb physical segment. Moreover, the markers were tested to improve new elite restoration lines and to assess the percentage of hybrid seeds. Our results could potentially accelerate the map-based cloning of the gene to benefit rapeseed breeding.
水户-五十铃细胞质雄性不育（MI CMS）系统是中国使用的三系杂交系统之一。众所周知，杂交系统与杂种优势中F1的产量变异密切相关，而MI CMS的恢复基因（Rf）尚未进行精细定位，无法进一步应用于标记辅助选择（MAS）。在本研究中，将两种不同遗传背景下的Rf近等基因系（NILs）与甘蓝型油菜的全基因组60K单核苷酸多态性（SNP）芯片杂交，以筛选Rf可能的相关基因组区域。通过SNP位点筛选基因型并对候选位点进行测序，在A09染色体上确定了一个2.5 Mb的物理区域（覆盖三个支架）作为Rf区域的候选区域。然后，使用目标支架的SSR标记检测F2群体中的重组情况，并将Rf基因定位在0.52 cM的遗传距离内，相当于350 kb的物理片段。此外，对这些标记进行了测试，以改良新的优良恢复系并评估杂交种子的比例。我们的结果可能会加速Rf基因的图位克隆，从而有利于油菜育种。
