采用SSR标记和表型性状聚类对杂交粳稻亲本的遗传多样性研究

Genetic Diversity of Parental Lines in Japonica Hybrid Rice Based on Cluster Analysis of SSR Markers and Phenotypic Characters

以20个新育成的粳稻BT型不育系和10个恢复系为材料,采用SSR分子标记和表型性状2种聚类方法对杂交粳稻亲本的遗传多样性进行比较研究,并分析这些亲本的遗传差异。结果表明,64对SSR引物在30个亲本中共检测到185个多态性片段,平均每对引物为2.9个,以第11染色体上的平均等位基因数目最多,每个SSR位点的多态性信息含量指数(PIC值)变化范围为0.064～0.844。利用SSR分子标记将30个亲本材料划分为7大类群,其中所有不育系被划分为一群,分类结果与系谱分析基本吻合。表型聚类以10个农艺性状为依据,将供试材料划分为4大类群,不育系和恢复系被聚到不同的类群,群内差异不大。同表型性状聚类相比,SSR分子标记聚类能更准确的揭示亲本之间的遗传差异,是研究亲本遗传多样性的一种较好方法。

The genetic diversity among 20 new japonica male sterile lines and 10 restorer lines was studied using two methods of cluster analysis based on the simple sequence repeat （SSR） markers and phenotypic characters. The results indicated that 64 pairs of SSR primers could produce 185 steady polymorphic bands among 30 parents averaging 2.9 bands for each pair of primers. Chromosome 11 showed the greatest value in average allele number. The polymorphic index content （PIC） values varied from 0. 064 to 0. 844. 30 parents were divided into seven groups based on SSR marker cluster analysis, which was coincident with the genetic groups determined by their pedigree analysis. On the basis of phenotypic character cluster analysis, they were divided into four groups and male sterile lines and restorer lines were classified into different groups and there existed limited difference within the same group. The results indicated that SSR marker cluster analysis could be a better method to study the genetic diversity of parental lines, because it could detect the genetic difference of parental lines more detailedly than phenotypic character cluster analysis.