Analysis of genetic diversity and population structure in Polygonatum cyrtonema Hua from China using SSR markers

Abstract Polygonatum cyrtonema Hua is a perennial herb of the Liliaceae family, which is a traditional medicinal and dietary herb in China. The large-scale introduction of cultivation, asexual reproduction and geographical differences have caused confusion in germplasm resources and variation in plant morphology. Therefore, based on the phenotypic trait identification analysis, 96 Polygonatum cyrtonema Hua germplasm were used as materials to analyze the genetic diversity and genetic structure of germplasm resources from seven different regions using SSR molecular marker technology. Ten polymorphic primer pairs were screened from 50 pairs of SSR primers, and a total of 70 alleles were detected, with an average of 7 alleles per locus. The polymorphic information content (PIC) generated ranged from 0.40–0.86 with a mean value of 0.72. Genetic structure and clustering analyses divided Polygonatum cyrtonema Hua into three populations (JZ population, QY population, and JD population). The genetic diversity analysis showed that the population mean allele number, observed heterozygosity (Ho), expected heterozygosity (He), and Shannon's index (I) were 6.90, 0.46, 0.57, and 1.08, respectively. The three populations were genetically differentiated from each other. The plants of the three populations have been changed from morphology to genetics. In this study, the rich genetic diversity of Polygonatum cyrtonema Hua was detected with fewer polymorphic primers, indicating the unique advantage of SSR marker technology in the analysis of genetic diversity of closely related species, and providing a reference for scientific management of Polygonatum cyrtonema Hua germplasm resources and molecular marker-assisted breeding.