Genetic relationships of pear germplasms using simple sequence repeat marker

Abstract

This study analyzed the genetic diversity of 115 pear germplasms using 15 SSR markers. Three to forty-one SSR alleles were detected for each locus with an average of 16 alleles per locus. The average availability of markers was 0.966. The average observed heterozygosity (H obs) was 0.603 (range: 0.140 to 0.929). The average expected heterozygosity (H exp) was 0.718 (range: 0.463 to 0.904). The average polymorphism information content (PIC) was 0.692 (range: 0.403 to 0.897). The genetic relationships of pear germplasms were classified into two major groups by geographic origins and genetic characteristics according to genetic distance. The first group was composed of European pear belonging to Pyrus communis. The second group consisted of P. pyrifolia, P. ussuriensis, P. bretschneideri, P. betulaefolia, P. calleryana, interspecific hybrids, and unclear germplasms. The results of this study suggest that genotype analysis of pear germplasms using SSR markers can identify the genetic diversity of germplasms, and can be used to provide basic information for pear breeding.