利用EST-SSR标记构建中国老芒麦品种DNA指纹图谱及种质遗传多样性

本研究利用EST-SSR分子标记,对国内的52份老芒麦(Elymus sibiricus)材料进行遗传多样性的研究,并构建了7个老芒麦品种及栽培材料的DNA指纹图谱。20对EST-SSR引物共产生204个条带,平均每对引物扩增出10.2条带,176(86.27%)条带为多态性条带,表明供试材料具有较高水平的多态性。同时,引物Elw404和Elw195构建的指纹图谱较为容易地将品种和栽培材料与其他材料区别开。分子方差分析(AMOVA)表明,老芒麦地理区域内(73.94%)的遗传变异远高于地理区域间(26.06%)。结构分析将52份材料分为5组,主成分分析(PCoA)结果与之相似。与品种及栽培材料相比,野生材料具有更高的遗传多样性多态性条带数(NPB)为174,多态性百分比(PPB)为85.29%,香农多样性信息指数(I)为0.296 6,Nei’s基因多样性(H)为0.179 8,观察等位基因数(Na)为1.852 9],可作为重要的遗传资源用于后续的育种工作。本研究结果表明,EST-SSR分子标记可以有效地评价老芒麦种质遗传多样性及进行品种鉴定。研究结果为制定老芒麦种质原位和非原位保护策略提供参考。

EST-SSR marker based DNA fingerprinting for cultivar identification and genetic diversity analysis of Elymus sibiricus germplasm in China

In this study,EST-SSR markers were used to analyze the genetic diversity of 52 Elynus sibiricus accessions,and to construct DNA fingerprinting profiles of seven E.sibiricus cultivated accessions and cultivars in China.A total of 204 bands were generated from 20 EST-SSR markers with an average of 10.2 bands per marker.Of the total,176 (86.27％) bands were polymorphic,indicating that the tested materials possessed a high level of polymorphism.The primers Elw404 and Elw195 could distinguish the seven cultivated accessions and cultivarsfrom other wild materials.Analysis of molecular variance showed that genetic variation was greater within geographical regions (73.94％) than between them (26.06％).Structure analysis suggested that the 52 accessions were clustered into five groups;a similar result was obtained using principal coordinate analysis.Compared with cultivars and cultivated accessions,wild accessionsnumber of polymorphic bands=174,percentage of polymorphic bands (PPB)=85.29％,Shannon's information index (Ⅰ)=0.296 6,Nei's genediversf ty (H)=0.179 8,observed number of alleles (Na)=1.852 9] possessed higher genetic diversity,suggesting that wild accessions could be used as important genetic resources for future breeding programs.Furthermore,ex situ and in situ conservation strategies were suggested for E.sibiricus germplasm.The results of the present study showed that EST-SSR markers provided an efficient means of assessing genetic diversity and identifying cultivars in E.sibiricus.