不结球白菜品种(系)遗传多样性与亲缘关系的SSR分析

Analysis of Genetic Diversity and Relationship of Pakchoi Accessions Based on SSR Markers

利用具有多态性的31对SSR引物,对国内外191份不结球白菜的遗传多样性及亲缘关系进行了分析。引物平均多态性信息含量(PIC)为0.34;供试不结球白菜品种(系)的平均期望杂合度(He)为0.41,Shannon's信息指数(I)为0.65;遗传分化系数(Gst)为0.20,说明80%的遗传多样性来自品种(系)之间的差异。不同生态区域的遗传多样性具有差异:国内高于国外,且江淮流域最高。利用UPGMA法作图,将供试的191份品种(系)聚为六大类,同时Structure种质遗传结构分组结果与UPGMA法聚类结果基本吻合,两种分析方法均说明了类群划分与地理分布有一定相关性。研究结果表明不结球白菜品种(系)具有丰富的遗传多样性,大部分品种(系)的亲缘关系聚类是按照地理来源及种质遗传背景进行,本研究为不结球白菜育种研究提供了参考。

Thirty one pairs of SSR primer were used to analyze the genetic diversity and relationship among 191 cultivars （strains） ofPakchoi （Brassica rapa L. ssp. chinensis Makino）, in order to provide some molecular information to support the effective Pakchoi breeding. The average value ofpolymorphism information content （PIC） was 0.34; The average value of expected gene heterogeneity （He） and Shannon＇s information index of tested Pakchoi accessions were 0.41 and 0.65, respectively. The coefficient ofgene differentiation （Gst） was 20%, indicating 80% of the genetic variation existed within populations. Genetic diversity of tested cultivars and strains from Jianghuai Plain was the highest among different ecological areas. In addition, genetic diversity of cultivars from China was higher than those of Japan and South Korea. The 191 accessions could be separated into 6 groups by UPGMA （unweighted pair group method with arithmetic average） analysis. Meanwhile, the result of grouping germplasm genetic structure by STRUCTURE was basically consistent with that of UPGMA clustering, two methods both showed that species divided had certain correlation with geographic distribution. The result showed that the genetic diversity of 191 tested Pakchoi cultivars （strains） was relatively abundant, and most of them were clustered based on geographic origin and genetic background. This study provided reference for Pakchoi breeding research.