Genetic diversity of Chinese cultivars in Brassica napus revealed by SSR markers | 我国近年审定的甘蓝型油菜品种的遗传多样性分析

chinois. 分析我国近年审定的甘蓝型油菜品种的遗传多样性。利用筛选出的24对SSR引物，对我国1999年以后审定的66份甘蓝型油菜品种及4份杂交组合的遗传多样性进行分析，以主成分分析、Shaanon指数、Simpson指数以及AMOVA分析揭示我国4大冬油菜区品种的变异程度。利用24对SSR引物共检测到104条清晰的谱带，其中86条呈多态性，多态性比率为84.61%；平均每对引物扩增出4.3条条带，片段长度在100～600 bp，多态性比率为50%～100%。70份甘蓝型油菜的遗传相似系数在0.40～0.93，平均为0.63。主成分分析结果显示，参试材料分布比较分散，并没有因来源地域相同而明显地聚在一起。在4大冬油菜区中，长江中游区品种Shaanon指数（1.593）和Simposon指数（0.732）最高，区内成对材料平均差异也最高（0.343 1）。不同大区油菜品种区内及区间分子方差分别为96.74％和3.26％。我国近年审定的冬油菜品种遗传多样性比较丰富；不同冬油菜区品种的变异以区内变异为主；长江中游区材料组内变异最为丰富，说明我国不同地区间材料交流比较频繁。

anglais. The study was done to reveal genetic diversity of 66 recently registered cultivars in Brassica napus from four winter-type rapeseed regions in China. Twenty-four pairs of SSR primer were chosen to analyze 66 B. napus cultivars registered after 1999 and four hybrid combinations in China. Principal component analysis, Shaanon index, Simpson index and AMOVA analysis were combined to reveal genetic structure of all tested varieties. In total, 104 fragments were detected with size ranged from 100 to 600 bp and 86 were polymorphism, the polymorphism rate was 84.61%. On average, each primer pair generated 4.3 polymorphic fragments with polymorphic rate ranged from 50% to 100%. The genetic similarity of 70 B. napus accessions ranged from 0.40-0.93, with average of 0.63. Principal component analysis revealed that all varieties scattered well in bi-plot, and accessions from the same geographic origin did not group together. Among four winter-type rapeseed regions, varieties from the middle of Yangtze valley had the highest values of Shaanon index (1.593), Simposon index (0.732), and average number of pairwise differences within population (0.343 1). AMOVA analysis indicated that the components of variation within populations and among populations were 96.74% and 3.26%, respectively. There existed considerable variance among recently registered B. napus cultivars in China. The component of variation within populations was dominant among populations. Varieties in middle of Yangtze valley possessed the richest genetic variation in the present investigation. The present investigation indicated that rapeseed genetic resources were extensively exchanged among different rapeseed regions in China.