Development and validation of SSR markers in Eleutherococcus senticosus

Eleutherococcus senticosus (Siberian ginseng) is an important medicinal tree found in Russian taiga, and northern regions of Korea, Japan, and China. In this study, we analyzed the genome-wide distribution of microsatellites in E. senticosus using developed SSR markers. A total of 711 clones from an SSR-enriched genomic DNA library were sequenced, of which 47 clones (6.6%) were redundant. Of the 664 independent clones, only 12 polymorphic SSR markers were obtained, which also revealed successful amplicons in E. senticosus accessions. Using the developed SSR markers, we estimated genetic diversity and population structure among 131 E. senticosus accessions in Korea and China. The number of alleles ranged from 2 to 11, with an average of 7.4 alleles. The mean values of observed heterozygosity ($H_O$) and expected heterozygosity ($H_E$) were 0.59 and 0.56, respectively. The average polymorphism information content (PIC) was 0.51 in all 131 E. senticosus accessions. E. senticosus accessions in Korea and China showed a close genetic similarity. Significantly low pairwise genetic divergence was observed between the two regions, suggesting a relatively narrow level of genetic basis among E. senticosus accessions. Our results not only provide molecular tools for genetic studies in E. senticosus but are also helpful for conservation and E. senticosus breeding programs.