Genetic diversity and population structure analysis of Sm. revealed by SSR marker.

Sm is a vulnerable medicinal plant distributed in the Himalayan countries. This plant has numerous pharmacological benefits, including anticancer, anti-inflammatory, analgesic, and antipyretic properties. The distribution, conservation status, and traditional usage of this species are fairly known in Nepal. However, its diversity and population structure at the molecular level are unexplored. This study analyzes, the genetic diversity and population structure of 32  germplasms collected from Central, Eastern and Western regions of Nepal using 15 simple sequence repeat (SSR) markers. All the SSR primers were polymorphic and amplified 60 alleles ranging from 50 bp to 900 bp. The polymorphic information content (PIC) value ranged from 0 to 0.75. The average value of the observed heterozygosity (Ho), expected heterozygosity (He), Shannon's information index (I), and total heterozygosity (Ht) were 0.63, 0.53, 0.92 and 0.32, respectively. The analysis of molecular variance (AMOVA), showed a maximum variation of 74% within the individual in a population and only 26% variation among the population. In the population STRUCTURE analysis two clusters were formed where Eastern germplasms (EN) were separated far from the Central and Western germplasms (CWN), this clustering was in complete correspondence to the unweighted pair group method based on arithmetic average (UPGMA) and principle coordinate analysis (PCoA). Furthermore, in the UPGMA and PCoA, germplasms collected from the same or relatively similar geographic origin were closer. These findings are critical for developing conservation policies, facilitating evolutionary research, sustainable utilization and commercial cultivation of this pharmacologically important and threatened species.