Study on the characteristics of genetic diversity of different populations of Guizhou endemic plant Rhododendron pudingense based on SSR molecular markers

Abstract

Abstract Background Rhododendron pudingense, firstly discovered in Puding county of Guizhou province in 2020, have adapted to living in rocky fissure habitat, which has important ornamental, and economic values. However, the genetic diversity and population structure of this species have been rarely described, which seriously affects the collection and protection of wild germplasm resources. Results In the present study, 13 pairs of primers for polymorphic simple sequence repeats (SSRs) were used to investigate the genetic diversity of 65 R. pudingense accessions from four different geographic populations. A total of 254 alleles (Na) were obtained with an average of 139.6 effective alleles (Ne) per locus. The average values of polymorphic information content (PIC), observed heterozygosity (Ho), and expected heterozygosity (He) were 0.8826, 0.4501, and 0.8993, respectivelysuggesting high genetic diversity. The average genetic differentiation coefficient (Fst) was 0.1182, suggested that moderate divergence occurred in R. pudingense population. The average values of genetic differentiation coefficient and gene flow among populations were 0.1279 and 1.8984, respectively. The analysis of molecular variance (AMOVA) indicated that most of the population differences (89%) were attributed to within-population variation. The UPGMA clustering analysis showed consistent results with the genetic distance and genetic identity analysis, indicating that the genetic background between the populations of Wanmo (WM) and Puding (PD) were similar, while the populations of Zhenning (ZN) and Qinglong (QL) showed significant genetic difference. Conclusions This is the first comprehensive analysis of genetic diversity and population structure of R. pudingense in Guizhou province. The research results revealed the high genetic diversity and moderate population diferentiation in this horticulture plant. This study provide a theoretical basis for the conservation of wild resources of the R. pudingense and lay the foundation for the breeding or cultivation of this new species.