Moricandia arvensis CMS 雄性不育和育性恢复的分子机理

Cytoplasmic male sterility (CMS) is currently the main way to take advantage of heterosis, and widely used in rice, corn, canola and vegetable. Moricandia arvensis CMS line is alloplasmic cytoplasmic male sterile in Brassica juncea, in this study, Moricandia arvensis CMS line and restorer line were used as materials and nearly isogenic lines population were construct by backcross. Through the mitochondrial genome sequencing and analysis, we try to clone ORF of Moricandia arvensis CMS. Meaning while, Map-based cloning strategy will be used to isolate the fertility restorer gene Rfm of Moricandia arvensis CMS, the candidate genes will be validated by complementation test. On this basis, the interaction betweeen sterility gene and restorer gene will be analysised through EMSAs and BiFC assays. This study will reveals the mechanism of male sterility and fertility restoration in heterologous cytoplasmic male sterility, which is helpful to develop new pollination control system by backcross in Brassica napus.

细胞质雄性不育（cytoplasmic male sterility,CMS)是目前利用杂种优势的主要途径，被广泛的应用于水稻、玉米和油菜等作物及蔬菜的育种中。Moricandia arvensis CMS是芥菜型油菜异源细胞质雄性不育材料，本研究以Moricandia arvensis CMS不育系和恢复系为材料，并构建了近等基因系群体。通过对线粒体基因组测序和分析，试图克隆Moricandia arvensis CMS不育基因，同时，利用图位克隆技术分离恢复基因，并对不育基因和恢复基因通过转基因验证。在此基础上，通过EMSAs和BiFC技术分析不育基因和恢复基因互作方式，探讨异源细胞质中的线粒体与细胞核之间的互作模式。本研究对于揭示异源细胞质雄性不育的机理具有重要意义，并为将Moricandia arvensis胞质转育到甘蓝型油菜加以利用提供理论支撑。

本研究一方面借助芥菜型油菜异源胞质不育系，将其胞质转移到甘蓝型油菜中创建新的胞质类型，此外我们对芥菜型异源胞质进行了线粒体基因组测序，比较了不同同核异质系间的序列特征和RNA编辑水平的差异，重点分析了其候选不育基因orf108的结构特征。研究结果包括如下：.1.通过对纯化后的线粒体进行2代和3代测序，拼接获得了5种芥菜型油菜异源胞质不育系的线粒体基因组。.2.与普通胞质芥菜型油菜线粒体基因组比较发现，5种异源胞质存在复杂的序列重组和倒位，差异SNPs和Indels集中在芥菜型油菜线粒体基因组的几个位点，有可能是重组热点区域；5种异源胞质同时包含不育基因orf108，但在不同胞质间具有一定的序列差异。.3.通过将芥菜型油菜异源胞质不育系与亲和性较好的甘蓝型油菜7-350进行不断的回交选育，我们成功将Brassica oxyrrhina、Diplotaxis catholica和Moricandia arvensis胞质转换到甘蓝型油菜核背景中。甘蓝型油菜Brassica oxyrrhina胞质败育彻底，具有明显的不育结构。这些不育系具有在育种中利用的潜力。