Genetic Diversity and Population Structure of Actinidia eriantha by ITS Sequences

Abstract

Background: Actinidia eriantha Benth is a widely used natural product from Traditional Chinese Medicine in the Actinidiaceae family. However, its wild resources have been declining due to over-exploitation. It has become urgent to investigate the genetic diversity for the conservation of A. eriantha, to evaluate the current species and discover strategies for preservation. Methods: The internal transcribed spacer (ITS) was used to evaluate the genetic diversity among and within populations of this species. Dnasp, PERMUT and Arlequin 3.0 software were used to calculate the genetic diversity index, and MEGA 5.0 software was used to construct the neighbor-joining (NJ) tree. Results: A total of 27 haplotypes were obtained by ITS sequence analysis of 12 populations, and the most frequently haplotype observed was H1. AMOVA analysis revealed that the genetic variation rates were 10.91% (FST = 0.22290) and 77.71% (FSC = 0.12306) among and within populations, respectively, with high genetic diversity at the species level (Hd = 0.692). The genetic distance among populations ranged from 0 to 0.004. The results of Permut analysis showed that there was no significant correlation between genetic distance and geographic distance (NST > GST). The NJ tree was divided into two Clades (Clade A and Clade B), Clade B has obvious geographical specificity, and haplotypes of this clade are all specific to the GX-ZY population. Four types were found according to ITS sequences of A. eriantha, haplotypes H1 and H5 were ancient haplotypes. Conclusion: Our findings indicated that genetic diversity within populations was higher than observed among populations. This study is significant for further research endeavors focused on the efficient collection and preservation of wild resources of A. eriantha.