欢迎访问《麦类作物学报》编辑部网站

为揭示中国节节麦的遗传多样性并发掘可能具有独特变异的节节麦种质资源，采用ISSR标记对75份中国节节麦的遗传多样性进行分析。结果表明，筛选出的9条ISSR引物共检测得到155个位点，多态性位点（138个）百分率为89.31%。Nei’s多样性指数（H_e）、Shannon’s信息指数（I）、基因分化系数（G_st）和基因流（N_M）分别为0.273 4、0.415 2、0.138 5和3.11，表明中国节节麦有较高的遗传多样性，群体间有中等程度的遗传分化。基于简单相似系数的UPGMA聚类分析表明，除5份河南和陕西节节麦聚类形成独立的分支Group 2 (T078、T102和SC1) 和Group 3(SX38和T006)外，绝大多数节节麦均聚类形成较大的分支Group 1，且在Group 1中，除4份节节麦（T002、T023、XJ6和XJ49）外，绝大多数节节麦均依据地理分布分别形成了黄河流域节节麦亚组和新疆节节麦亚组，在遗传距离约0.77处，又可依次分为河南、陕西和新疆节节麦小分支。二维主成分分析、群体的遗传一致度和分子变异分析也表明了类似的结果，同属于黄河流域节节麦亚组的河南、陕西节节麦遗传一致度（S=0.971 8）较高，群体内个体差异是中国节节麦变异的主要原因，但两大亚组和三居群的遗传差异分别占总变异的18.57%和10.38%。可见，不同节节麦的地理分布和生境差异，是导致中国节节麦居群遗传分化的主要原因，而聚类分析中单独形成独立分支Group 2和Group 3的5份黄河流域节节麦，可能是具有独特遗传变异的种质资源。

英文摘要:

In order to reveal the genetic diversity of _{Aegilops tauchii} accessions native to China extensively and screen some beneficial wild resources with individual genetic variation,ISSR markers were used to assess the genetic diversity of 75 Chinese _{Aegilops tauchii} accessions. Nine ISSR primers produced 138 (89.31%) polymorphic bands out of 155 bands in total. Genetic parameters including average number of effective alleles (N_e=1.471 5),Nei’s gene diversity (H_e=0.273 4),Shannon’s information index (I=0.415 2),and gene differentiation coefficient (G_st=0.138 5) revealed a high level of genetic diversity and middle level of gene flow maintained in Chinese _{Aelilops tauchii} populations.A dendrogram constructed on the basis of cluster analysis of similarity simple coefficient clustered all the samples in three main groups 1,2 and 3. Although most of accessions except for T002,T023,XJ6 and XJ49 were placed into group 1 with two subgroups (sub 1 and sub 2),regarding to their different locations (Yellow River basin and Yili River Valley in Xinjiang). There were still five accessions from Henan and Shaanxi provinces clustered in group 2 (T078,T102 and SC1),and group 3 (SX38 and T006). The further two-dimensional principal coordinates analysis (PCoA),the analysis on the genetic distance and similarity among Henan,Shaanxi and Xinjiang populations and the analysis of molecular variance (AMOVA) also confirmed the results that the genetic similarity of Henan and Shaanxi was highest among the three populations. 18.57% of the variance was due to the differences between Yellow River basin and Yili Valley,and 10.38% of the variance was due to differences among populations of Henan,Shaanxi and Xinjiang and the remaining 71.05% was due to differences within populations. Thus,it was suggested that the high genetic diversity of Chinese _{Aegilops tauchii} was attributable to geographic isolation,and the five accessions constituted two independent groups 2 and 3 maybe the beneficial wild resources with individual genetic variations.

查看全文查看/发表评论下载PDF阅读器

关闭