SSR和SRAP标记研究油菜杂交种骨干亲本的遗传多样性

用SSR和SRAP两种分子标记方法研究51份甘蓝型油菜杂交种亲本系的遗传多样性，并对两种分子标记研究结果进行比较。结果发现，在51份材料中，45对SSR引物共扩增出194条多态性条带，平均每对引物为4.3条，25对SRAP引物共扩增出197条多态性条带，平均每对引物为7.9条。UPGMA聚类分析表明，SSR和SRAP标记都可将51份亲本材料划分为五大类群，本所选育的玻里马细胞质雄性不育系（Polima CMS）的主要保持系和恢复系都聚在同一类群的不同亚群中。根据系谱资料分析发现，SRAP标记划分的类群与系谱资料更为接近，SRAP标记更适用于遗传关系较近材料的遗传多样性分析。SRAP标记揭示的亲本间遗传距离要大于SSR标记揭示的遗传距离。两种不同标记方法揭示出油菜亲本遗传多样性的差异主要是由不同的标记方法揭示的标记位点等位基因变异数不同造成的。

Genetic Diversity of Parental Lines of Rapeseed Hybrids Based on SSR and SRAP Markers

The genetic diversity of 51 parental lines used for hybrid production and breeding in Brassica napus L. was studied by SSR and SRAP markers, and the results of these two maker systems were compared. One hundred and ninety-four polymorphic fragments were detected using 45 SSR primer pairs, with an average number of polymorphic fragments per primer pair of 4.3. Whereas 197 polymorphic fragments were detected using 25 SRAP primer pairs, with an average number of polymorphic fragments per primer pair of 7.9. The 51 parental lines could be divided into five groups based on either SSR or SRAP markers by UPGMA cluster analysis. The main maintainer lines and restorer lines of Polima CMS were classified into the same group but different sub-groups. The groups classified by SRAP markers were more in accord with pedigree information than SSR markers.The SRAP markers were more effective in genetic analysis of closely related lines. The genetic distance calculated based on SRAP markers was larger than that on SSR markers. There is difference between the genetic diversity evaluated by SRAP and SSR markers, even though the same number of polymorphic fragments was used for evaluation. This difference may be caused by different numbers of variation alleles of the same gene detected by different primer sequences.