[Genetic diversity of 6 species in Polygonatum by SSR marker].

Polygonatum is a genus of the perennial herb family Liliaceae, with great potential in food, medicine and other field. In this study, genetic diversity and cluster structure analysis of 6 species in Polygonatum were investigated the molecular marker technique of simple sequence repeat (SSR). A total of 49 SSR makers were used to study genetic diversity and population structure within 60 germplasm resources which obtained from 38 counties and cities in 14 provinces of China. A total of 211 alleles were identified and the number of alleles ranged from 2 to 10, with an average of 4.306 1 alleles per SSR. The range of polymorphism information content (PIC) varied from 0.731 8 to 0.031 7, with the average of 0.309 6. The cluster analysis classified 60 germplasm resources into four defined groups at the genetic distance value of 0.26, among which most species with relatives were clustered into the same group. Extraordinarily, there were 6 germplasm resources clustered into other species, indicating that the classification of inter-genus and geographical distribution was crossed in Polygonatum. The genetic diversity index of the 4 geographical populations from high to low was: Western region, Central China, Southern China, Eastern China. The population structure analysis, also indicating divided the entire collection into four groups, which was similar to the assignment pattern of cluster structure analysis. These results suggested that the Polygonatum germplasm resources used in this study is rich in relatively high genetic diversity with large variation range, relatively fuzzy boundaries of species. It appeared the phenomenon that there is a difference decreases between the alternate leaf system and the rotation leaf system. The genetic diversity in the western region was higher than that in other regions, and the western region may be the origin center of the genus Polygonatum.