Evaluating the genetic diversity of Erythropalum scandens based on using inter-simple sequence repeat markers

Erythropalum scandens Blume, an emerging medicinal plant with great potential for drug development, also possesses high edible value. In this study, we investigated the genetic diversity of the germplasm of E. scandens obtained from different geographical locations using inter simple sequence repeat (ISSR) markers. For this purpose, 18 ISSR primer pairs with a distinct background and adequate polymorphism were selected. We established an optimal ISSR-PCR reaction system (20 mu L) with the following parameters: 1 mu L DNA template (60 ng mu L-1), 1.2 mu L primers (10 mu mol mu L-1), 10 mu L MasterMix, and 7.8 mu L H2O. A total of 183 loci were amplified using the 18 primer pairs, of which 121 (66.12%) indicated polymorphism. Moreover, 34 germplasms of E. scandens exhibited genetic similarity coefficients ranging from 0.7104 to 0.9563, genetic distances ranging from 0.0447 to 0.3420, Nei's genetic diversity index of 0.1946, and Shannon's information index of 0.2982, suggesting high intraspecific genetic diversity. UPGMA cluster and PCoA analyses distinguished the germplasm of E. scandens obtained from Guangxi from those collected from Guangdong, Hainan, Fujian, and Guizhou. However, the Mantel correlation analysis revealed that the genetic variation among the 34 germplasms of E. scandens was not significantly related to geographical distance. The analysis of the genetic background of wild and cultivated germplasms of E. scandens can help guide variety selection and breeding. Furthermore, the present study revealed the genetic background and affinities among 34 germplasms of E. scandens. Overall, our findings lay the foundation for the conservation and utilization of germplasm resources, identification and classification of varieties, and variety selection and improvement of E. scandens at the molecular level.