不结球白菜(Brassica campestris ssp. chinensis Makino)种质资源SRAP遗传分化分析

利用SRAP分子标记分析了国内外64份不结球白菜种质资源的DNA遗传多样性和遗传分化。21对引物组合共检测出215个位点，其中112个为多态性位点，多态性比率达52.09%，平均每对引物组合产生10.24个位点和5.33个多态性位点。不结球白菜各类型中普通白菜的Nei’s基因多样性指数（0.1410）和遗传丰富度[(190) 88.37%]最高；各生态区域中江淮流域不结球白菜的Nei’s基因多样性指数（0.1451）和遗传丰富度[(185) 86.05%]最高；国内的Nei’s基因多样性指数(0.1293)和遗传丰富度[(188) 87.44%]分别高于国外。遗传变异估算表明，不结球白菜遗传分化系数58.22%，大部分变异存在于种群间；基因流为0.4031，说明群体间基因流动较少，遗传分化程度较高。以遗传相似系数0.872为截值，可把不结球球白菜分为Ⅵ个类群。

Genetic Differentiation of Non-Heading Chinese Cabbage (Brassica campestris ssp. Chinensis Makino) Germplasm Based on SRAP Markers

The genetic diversity and differentiation were assessed in 64 accessions of non-heading Chinese cabbage from all the world by SRAP(Sequence-related amplified polymorphism) markers.Two hundred and fifteen loci were detected by 21 pairs of SRAP primers.Among them,112 were polymorphic,the polymorphic rate was 52.09%,and 10.24 loci and 5.33 polymorphic loci were amplified by each pair primer an average.The Nei's gene diversity index and Genetic richness of B.compestris var.communis were 0.1410 and(190) 88.37% respectively,the highest among different types of non-heading Chinese cabbage,and 0.1451 and(185) 86.05% respectively in Jianghuai Plain,the highest among all the regions ecological regions.These two indices were respectively 0.1293 and(188) 87.44% higher in domestic cabbage than in the foreign cabbage.The measurement of genetic variation showed that the coefficient of genetic differentiation was 58.22%.Most of the genetic variation existed among populations.The gene flow(0.4031) was less among populations,indicating that the degree of genetic differentiation was higher.Six groups were clustered according to genetic similarity coefficient of 0.872.