基于苹果EST-SSR的梨种质资源遗传多样性分析

Analysis of Genetic Diversity in Pear Germplasm Using Apple EST-SSRs

利用来自苹果的8对EST-SSR标记对48份梨(Pyrus)种质资源进行遗传多样性研究,以分析其在梨属植物上的通用性。结果表明,8对EST-SSR引物在供试材料上均能扩增出与苹果大小相似的产物,所有引物共检测到140个基因位点,其中多态性位点129个,多态性比例为92.14%,并且可成功区分不同品种。根据EST-SSR标记所揭示的多态性和UP-GMA法聚类分析,48份梨种质资源在相似系数0.62处可分为东方梨和西方梨两个种群,而中国的白梨(Pyrus bretschneideriRehd.)、砂梨(P.pyrifoliaBurm.f.Nakai)和秋子梨(P.ussuriensisMax-im.)相互交错在一起,没有独自成组。可见,苹果的EST-SSR标记在梨上具有高度的可转移性,可应用于梨属植物的资源评价及遗传关系研究。

Eight simple sequence repeat markers derived from expressed sequence tags（EST-SSR markers） of apple（Malus pumila） were selected for analysis their application on genetic diversity among 48 cultivars in pear（Pyrus）.The results showed that eight EST-SSR primer pairs gave an amplification product when tested on all pear cultivars,and the size of amplification bands were similar to those of apple.In this study,140 gene locus were screened by all EST-SSR,of which 129（92.14%） were polymorphic,and different cultivars could be distinguished successfully.Therefore,EST-SSR markers developed from apple showed high transferability in pear,and it would be suitable for application in germplasm evaluation and genetic relationship analysis of pear.Based on polymorphism revealed by EST-SSR markers,UPGMA cluster analysis was performed by software NTY-SIS-pc2.01,the clades formed two populations,oriental and occidental population,at the dice coefficient of 0.62.Pyrus bretschneideri Rehd.,P.ussuriensis Maxim.and P.pyrifolia Burm.f.Nakai originated in China intervened each other and could not form group independently.