Genetic structure and diversity of Glehnia littoralis, an endangered medicinal plant in China

• Genetic structure and gene flow of wild Glehnia littoralis populations were assessed.
• The main reason for the endangered status of G. littoralis in China is human activity.
• A conservation plan of in situ protection combined with core collection is proposed.

The medicinal plant Glehnia littoralis has become increasingly endangered in China. To assist in the formulation of conservation strategies for this species, we assessed the genetic diversity of G. littoralis with a total of 172 samples from 10 populations using SRAP markers. The results showed that Nei's gene diversity (H) per locus ranged from 0.04 to 0.2504, with an average of 0.245, and that Shannon's information index (I) ranged from 0.233 to 0.6253, averaging 0.5516 at the population level. The total genetic diversity (Ht) was 0.2471, and 66.5% (Hs = 0.1643) of the total genetic variation was attributed to within-population diversity (P < 0.05), with the rest (33.5%) due to differences between populations (Gst = 0.3353), indicating that gene flow was restricted among populations (Nm = 0.9911). AMOVA also suggested that the main source of variation was within populations (77.8%), whereas 22.2% of differentiation was found among populations. Estimates of genetic distance were not correlated with geographic distance according to a Mantel test (r = 0.0792, P = 0.329). These results show that high levels of genetic variation are present within and among populations. The endangered status of this species is likely due to the destruction of the habitats of the wild populations, rather than a loss of genetic diversity.