Analysis of genetic diversity of Japanese plum cultivars based on RAPD, ISSR and SSR markers.

摘要

Japanese plum (Prunus salicina Lindl.) originated in China, where it has been cultivated for thousands of years, but is now one of the important fruit trees in many countries of the world. Knowledge of the genetic diversity of existing germplasm can informatively guide parental selection in breeding improvement programs. Presently, many Japanese plum cultivars are described in China, but little research has been done on genetic diversity. Due to different properties of various molecular markers, it would be advantageous to use multiple molecular markers, such as RAPD (random amplified polymorphic DNA), ISSR (inter-simple sequence repeats) and SSR (simple sequence repeats) to assess multiple locus variation in a given species. In this research, we analyzed 56 genotypes (54 Japanese and 2 European plum cultivars) for their molecular variations using 24 RAPD, 10 ISSR primers, and 21 SSR primer pairs from other Prunus species. We have generated 201 (RAPD) and 86 (ISSR) bands and 102 alleles (SSR). Based on all RAPD, ISSR and SSR markers, we constructed a dendrogram of these cultivars according to the Jaccard's Coefficient of similarity. The dendrogram clearly showed a separation between European and Japanese plum. Among Japanese plum cultivars, pairwise similarity coefficients between the cultivars were within the range from 0.286 to 0.730. At the similarity coefficient of 0.455, 54 Japanese plum cultivars were classified into six groups. Cultivars from the USA and Japan were grouped into one cluster, and the majority of the native Chinese cultivars were clustered as a group of southern cultivars (GSC) and a group of northern cultivars (GNC). The combined analysis of three molecular markers was a valuable tool for assessing the genetic diversity in plum.