Identification of Asian pear varieties by SSR analysis

Abstract

Sixty Asian pear accessions from 6 Pyrus species were genetically identified by 9 SSR markers with a total of 133 putative alleles. Among them, 58 varieties could be successfully differentiated except for 2 pairs of synonymous or clonal varieties. All the SSR markers produced 1 or 2 discrete amplified fragments for all the diploid accessions, whereas a triploid variety showed 3 fragments with some SSRs. The number of putative alleles ranged from 7 to 20, with an average value of 14.8. The observed heterozygosity and the power of discrimination were 0.63 and 0.91, respectively. A phenogram based on the SSR genotypes was obtained, showing 3 major groups corresponding to the Japanese, Chinese and European groups. The SSR markers were highly polymorphic and could be utilized as a reliable tool for cultivar identification in Asian pears.