The survey of genetic diversity and population structure analysis of Iranian sweet pomegranate (Punica granatum L.) germplasm using ssr markers.

摘要

The pomegranate (Punica granatum L.) is a native horticultural plant of Iran which has been cultivated from ancient times for its economic, ornamental and medicinal properties globally. Although the number of Punica species is very low, a high morphological diversity has been observed. In this study, seven microsatellite markers (SSR) were tested on 194 accessions of the sweet pomegranate germplasm obtained from the Iranian National Pomegranate Base Collection and which had been collected from 23 different regions of Iran. All markers showed significant polymorphism among the studied samples. A total number of 29 alleles were observed, with the number of alleles per locus ranging between two to eight. The average polymorphism information content and heterozygosity of these markers were 0.807 and 0.847 respectively, proving the suitability of microsatellite markers for genetic diversity studies. In order to assess genetic relationships and population structure, cluster analysis was performed by UPGMA and NJ with Mega4 software, STRUCTURE analysis model-based Bayesian by Structure2.2 software and principal coordinate analysis (PCoA) with NTSYS software. Results of all mentioned methods have shown that cultivars and genotypes are generally clustered independently from their geographical origin and their proposed denomination suggesting severe admixture in studied samples. Survey of our study indicated that there is a high genetic diversity among sweet pomegranate germplasm in Iran.