春性与半冬性甘蓝型油菜的SSR标记多样性分析比较

Genetic diversity comparison between spring and weak-winter Brassica napus cultivars using single-locus SSR markers

通过42个单位点SSR标记分析59个甘蓝型油菜品种,比较春性和半冬性甘蓝型油菜品种间的遗传差异。结果表明,不同位点上存在2～6个等位基因,平均每位点检测到4.29个等位基因。不同位点的遗传多样性指数在0.40～0.70之间,所有供试位点平均遗传多样性指数为0.50,表明甘蓝型油菜品种资源中存在丰富的遗传变异。春性和半冬性油菜品种间的等位基因总数相差不大,主要等位基因的类型和频率存在明显的差异,而且春性和半冬性品种中分别存在相当数量的特异稀有等位基因。春性和半冬性油菜品种在27个位点上的遗传分化水平很小,仅在2个位点上存在明显的遗传分化,这些分化主要是由品种的春化特性差异造成。聚类分析表明春性和半冬性品种之间存在广泛的亲缘关系。

42 single-locus SSR markers were used to analyze the genetic diversity of 59 spring and weak-winter rapeseed （Brassica napus L.） cultivars. The results indicated that the allele number varied from 2 to 6 with an average of 4.29 alleles each. The diversity index varied from 0.40 to 0.70 with an average of 0.50. It indicated abundant genetic variation in the germplasm. The difference of total number of alleles was not statistically significant between spring and weak-winter cultivars. Distinct types of major alleles were observed in the spring and weak-winter cultivars,and their corresponding allele frequencies were significantly different between the spring and weak-winter cultivars. Uncommon alleles were identified. Little genetic differentiations were detected between the spring and weak-winter cultivars at 27 loci. 2 loci had significant differentiations,which were caused by vernalization. Cluster analysis could not completely separate the spring and weak-winter cultivars,which suggested that they have broad genetic relationship. The present results would provide valuable guidance for germplasm collection and genetic breeding in B.napus.