基于分子标记的油菜隐性核不育7-7365AB遗传模式探究

Analysis of Genetic Model for a Recessive Genic Male Sterile Line 7-7365AB in Brassica napus L. Based on Molecular Markers

【目的】利用分子标记和回交自交试验初步探讨甘蓝型油菜隐性细胞核雄性不育材料7-7365AB(Bnms 3ms 3ms 4ms 4RfRf/BnMs 3ms 3ms 4ms 4RfRf)育性的遗传模式。【方法】以纯合两型系7-7365AB为基本材料,分别构建了BnMs4位点和BnRf位点的近等基因系7-736512AB和7-7365AC,利用AFLP与BSA相结合的方法筛选与BnMs4连锁的分子标记,进行BnMs4的图谱定位;利用育性分离群体进行杂交、回交和自交,验证两基因之间的关系;利用2个基因紧密连锁的分子标记分析了176份材料的基因型。【结果】获得13个与BnMs4连锁的AFLP标记和4个SCAR标记,将该基因定位在N7连锁群的上端,与BnRf为同一个区段,并从图谱上获得CNU063、ENA06和sR4047这3个SSR标记,鉴定出了CNU063、ENA06、sR4047、SC25、SC916和SSR1这6个与BnRf共同的分子标记,它们分布于这2个基因两侧,且包含BnMs4和BnRf最短遗传图距分别为1.0cM和2.4cM。回交和自交试验证实BnMs4与BnRf并不是自由组合的遗传模式,而且几种基因型在176份材料中的分布频率也没有表现连锁不平衡现象。【结论】BnMs4和BnRf很可能属于复等位基因。

【Objective】 The genetic mode of the recessive epistatic genic male sterile （REGMS） line 7-7365AB （Bnms3ms3ms4ms4RfRf/BnMs3ms3ms4ms4RfRf） was studied by molecular marker technology and backcrossing, self-crossing experiments. 【Method】 Two near-isogenic lines, 7-736512AB and 7-7365AC, which correspond to the BnMs4 gene and BnRf gene derived from a homozygous two-type line 7-7365AB, respectively, were constructed. Combined with BSA method, AFLP markers linked to the BnMs4 gene were identified, four of which were converted to SCAR markers, and genetic mapping of BnMs4 using published linkage maps of Brassica napus was conducted. Well-designed self-crossing and backcrossing experiments were conducted between the male sterile and fertile individuals from the 2 near-isogenic populations. The markers were also used to screen 176 accessions of breeding materials. 【Result】 Thirteen AFLP markers and four SCAR markers were identified linked to the BnMs4 gene. The BnMs4 gene was located in the top of the N7 linkage group, and was in the same region as the BnRf gene located previously. Comparison of both mapping results, six markers, CNU063, ENA06, sR4047, SC25, SC916, and SSR1, were common between the BnRf gene and BnMs4 gene. They were located in flanking sides of the two genes. The identical two closest markers flanking the BnMs4 gene and BnRf gene had genetic distances of 1.0 cM and 2.4 cM, respectively. Backcrossing and self-crossing experiments confirmed that the relationship between the BnMs4 gene and BnRf gene might not be independent assortment. Moreover, the analysis of 176 accessions did not show linkage-disequilibrium between the two genes. 【Conclusion】 The BnMs4 gene and BnRf gene might be multiple alleles.