Genetic Diversity of a Natural Population of Akebia Trifoliata (Thunb.) Koidz and Extraction of a Core Collection Using Simple Sequence Repeat Markers

Background: Developing a core collection can deepen our understanding of the genetic diversity of germplasm resources and lay the foundation for their rational utilization. Akebia trifoliata (Thunb.) Koidz is an important oil crop, particularly in China, but there is no relevant research report about the core collection of A.trifoliate. Results: : In this study, 28 simple sequence repeat (SSR) markers were used to assess the genetic diversity and genetic structure of a natural population of A. trifoliata, including 955 germplasms, and to extract a core collection. The genetic diversity of the natural population was moderately polymorphic. The average number of alleles ( N a ), observed heterozygosity ( H O ), expected heterozygosity ( H E ), Shannon’s information index ( I *), and polymorphic information content (PIC) were 3.71, 0.24, 0.46, 0.81, and 0.41, respectively. Two sub-populations were identified, indicating a weak genetic structure. The core collection was composed of 164 individuals (17.2% of 955 total germplasms in the population), and diversity parameters differed significantly from those of a random core germplasm collection. Conclusions: The genetic diversity of the natural population of A.trifoliata was moderately polymorphic, and the genetic structure was weak. Moreover 164 individuals could represent the genetic diversity of the 995 individals. These results have implications for germplasm management and genomics studies in A. trifoliata as well as for the establishment of core collections of other perennial liana species.