干旱胁迫下老芒麦遗传多样性分析

对干旱胁迫处理的20份不同居群的老芒麦10对多态性引物进行SSR分析,研究干旱胁迫处理对老芒麦遗传多样性的影响。结果显示:10对引物总扩增带数115条,平均每个引物对扩增11.5条,多态性带数为103条,占总条带数的89.57%,每对引物扩增7~15条,平均为10.3条,多态性信息含量(PIC)为0.255~0.473,平均为0.368,SSR标记效率(MI)为3.87;通过POPGENE软件得出供试材料的Nei’s遗传多样性指数(He)为0.332 4,Shannon指数(Ho)为0.492 6。NTSYSpc 2.1软件和POPGENE 32软件聚类结果均表明,胁迫处理材料与同批材料胁迫前的聚类结果差异较大。意味着干旱胁迫处理造成非编码区的微卫星序列的遗传变异和分化,致使其重复次数发生相应改变;而胁迫前后UPGMA聚类都表明产地相同的材料大多聚为一类,但不完全一致,其中,内蒙古的材料胁迫前后差异较大。分析结果表明,供试老芒麦材料间差异明显,遗传多样性丰富,应加快其开发和合理利用。

Assessment of genetic diversity in drought-stressed Elymus sibiricus using SSR markers

In order to explore the influence of drought stress on genetic diversity of Elymus sibiricus 10 primer pairs which have higher polymorphic were selected from 20 primer pairs to analyze 20 accessions of drought-stressed Elymus sibiricus by simple sequence repeat （SSR）markers.The result indicated that a total of 1 15 SSR bands were identified,of which 103（89.565）were polymorphic,and each primer generated 7 to 15 bands,with an average of 10.3,the polymorphism information content （PIC）per primer was 0.255 to 0.473, with an average of 0.368,the marker index （MI ）of SSR was 3.87,the Nei’s index （He）was 0.332 4,the Shannon＆#39;s index （Ho）was 0.492 6.The clustering result was that 20 pieces of Elymus sibiricus L.were divided into 2 branches at genetic distance of 0.36,this branch was divided into 2 branches at genetic distance of 0.5,it was quite different from untreated material.The difference between treated and untreated materials suggested that the treatment caused genetic variation and differentiation predominantly on noncoding sequences,thereby contributing to differences in fitness.UPGMA clustering showed that the accessions from the same region tended to be divided into one branch but it had special case,and we found that the material from Inner Mongolia had a larger difference after drought stress than other materials.These results revealed there was rich genetic diver-sity among the tested resources of Elymus sibiricus L.To speed up the development and reasonable utilization of it is urgent.