五节芒表型性状和SSR标记遗传多样性分析

本研究利用25个表型性状和33对SSR标记,对53份五节芒种质资源的遗传多样性进行了评价。表型性状分析结果表明,25个表型性状在不同五节芒种质间表现出较大差异,变异系数的变化范围为6.53%～69.82%,其中整株干重、三级花序数、二级花序数等性状变异较大,是造成表型差异的主要因素。表型聚类将53份供试材料划分为3个类群,大部分材料聚在第Ⅲ类群内,但仍有部分材料独立成群。SSR标记分析结果表明, 26对SSR引物在53份五节芒中表现出多态性,这些多态性引物共产生81条DNA带,其中多态性条带为74条,占91.36%。多态性信息含量(PIC)为0.086～0.374,平均为0.245。53份五节芒遗传相似性系数在0.693 2～0.965 9,平均遗传多样性指数(H)为0.258 7,Shannon信息指数(I)为0.400 4。基于SSR分子标记的聚类分析表明,种质资源与其地理分布并不存在明显的相关性。表型性状和SSR分子标记结果均表明五节芒种质具有丰富的遗传多样性。

Genetic diversity of Miscanthus floridulus revealed by morphological characters and SSR markers

In this study, a total of 25 morphological characters and 33 SSR markers were used to reveal the genetic diversity in 53 accessions of Miscanthus floridulus germplasms from China. All of 25 morphological characters displayed significant difference in these M. floridulus germplasms, with a coefficient of variation ranging from 6.53% to 69.82%, in which the dry weight per plant, the third-class branch number of panicle and the second-class branch number of panicle were with the highest CV values and were the major factors responsible for morphological variation. Clustering analysis based on morphological data showed that 53 M. floridulus germplasms were divided into three groups, and most of which were clustered into the third group. SSR analysis showed that 26 of 33 primer pairs were polymorphic which generated a total of 81 DNA fragments, with 74 of which being polymorphic. The polymorphic information content (PIC) for each SSR primer ranged from 0.086 to 0.374 with an average of 0.245, the genetic similarity coefficients from 0.693 2 to 0.965 9, the gene diversity of Nei’s (H) 0.258 7, and the average information index of Shannon (I) 0.400 4. SSR marker clustering analysis based on SSR data indicated that there was no direct correlation between the genetic distance and the geographic distance for M. floridulus germplasms. Both SSR and morphological analyses suggested a higher genetic diversity existing in the M. floridulus germplasms.