中文摘要：

根据同源序列法克隆的NsaCMS候选恢复基因PPR6J8的序列，采用PCR方法在NsaCMS不育系、恢复系、原始体细胞杂交亲本以及其他甘蓝型油菜品种中共克隆出22个同源序列。序列分析表明，野芥亲本野油18、甘蓝型油菜亲本中双4号各含有2个同源序列，而NsaCMS4个恢复系则分别含有3、1、1、1个同源序列。恢复系中候选恢复基因的序列与野芥亲本野油18的同源序列的一致性在93％以上，其中恢1、恢3和恢4中至少有一个同源序列与野油18的第1个同源序列完全相同，恢2中的同源序列与野油18的第2个同源序列完全相同；但与甘蓝型油菜的同源序列一致性均低于80％，说明候选恢复基因来源于新疆野芥，而不是甘蓝型油菜。除了原来的P尸R618外，获得了3个来源于恢复系的新候选恢复基因。候选恢复基因在序列上与萝卜和矮牵牛的恢复基因一致性较高。半定量RT-PCR分析表明，候选恢复基因在恢复系多个组织中都有表达，但在根、茎中表达量特别少。其表达量随着营养器官到生殖器官的发育逐渐升高，最高的是在1．5—2．5mm的花蕾中，即雄性败育关键时期。但不育系中的同源基因在茎中的表达量则相对高于其他组织。

英文摘要：

Nsa cytoplasmic male sterility （CMS） is a novel CMS system developed by somatic hybridization between Brassica napus and Sinapis arvensis. Cloning of the restorer genes for Nsa CMS is important for both the development of better restorers and the mechanism understanding of fertility restoration. A candidate restorer gene named PPR618 of Nsa CMS was cloned based on homologue sequencing strategy previously. In this study, based on the sequence information of PPR618, 22 homologous se- quences were identified in Nsa CMS male sterile line, Nsa CMS restorer lines, the original fusion parents which gave rise to Nsa CMS and several other B. napus lines as well as one B. oleracea and one B. rapa accessions. Sequence analysis showed that there were two PPR618 homologues in each of the fusion parental lines, S. arvensis var. Yeyou 18 and B. napus var. Zhongshuang 4, whereas there were three, one, one, and one PPR618 homologues in the four restorers, Hui 1, Hui 2, Hui 3, and Hui 4, respectively The identity of the homologous genes in restorers was above 93% to those in Yeyou 18, but less than 80% to those in Zhong- shuang 4, implicating the candidate restorer genes of Nsa CMS originated from S. arvensis. Both homologues in S. arvensis were found in the restorers, one in Huil, Hui 3, and Hui 4, the other in Hui 2. Besides PPR618, three new candidate restoring genes were identified. The homologous genes from restorers were also found to have relations with the restoring genes for CMS system of radish and petunia. Semi-quantitative RT-PCR results showed that the candidate restoring gene expressed in all tested organs. The gene expression gradually increased along with the developmental process from vegetative to reproductive stages, peaked in the bud of 1.5-2.5 mm in diameter, and slumped in roots and stems. In contrast, the highest expression of homologous gene in male sterile line was detected in stems.