Genetic Diversity of the Endemic Species Phanera sirindhorniae in the Mekong Basin of Thailand Based on ISSR Markers

Abstract

Phanera sirindhorniae, an endemic species to the Mekong Basin’s upper northeastern region in Thailand, is notable for its therapeutic properties in alleviating pain and discomfort. The objective of this study was to assess the genetic diversity of P. sirindhorniae derived from four natural sources, specifically Sakon Nakhon, Nakhon Phanom, Bueng Kan and Mukdahan provinces, utilizing Inter-Simple Sequence Repeat (ISSR) markers. A total of 51 samples were analyzed, and 10 primers exhibited distinct, robust amplified fragments and polymorphism. The amplified fragment sizes ranged from 170 to 1,300 base pairs, identifying a total of 113 amplified fragments, of which 107 (94.69 %) displayed polymorphism. Polymorphic information content (PIC) values spanned between 0.112 and 0.429, while Nei’s gene diversity ranged from 0.2088 ± 0.2184 to 0.2994 ± 0.1912. Assessment of genetic diversity within and among populations revealed the total genetic diversity (Ht = 0.3443 ± 0.0225) and the genetic diversity within populations (Hs = 0.2617 ± 0.0161). The variability among populations (Gst = 0.2401) indicated a significant degree of gene flow (Nm = 1.580). The Analysis of Molecular Variance (AMOVA) results supported this, with 74 % of genetic differentiation occurring within populations and 26 % among populations. Using the Neighbor-Joining (NJ) generated from Nei’s genetic distance-based clustering analysis, Dendrogram construction successfully classified 2 distinct groups. The analysis revealed that P. sirindhorniae from Nakhon Phanom, and Bueng Kan constituted 1 group, whereas P. sirindhorniae from Mukdahan, and Sakon Nakhon formed another. These findings provide essential data for developing genetic conservation initiatives for this valuable genetic resource. HIGHLIGHTS This study presents the inaugural analysis of genetic diversity in wild Phanera sirindhorniae populations, a species designated as endangered, utilizing Inter-Simple Sequence Repeat (ISSR) markers. A group of 10 Inter Simple Sequence Repeat (ISSR) primers showed values for Polymorphism Information Content (PIC), with (AG)8YC (PIC= 0.445) standing out. These results highlight their potential for use in the investigation of genetic diversity. The examination of P. sirindhorniae resulted in the identification of 2 distinct genetic groups, which have the potential to inform and facilitate the development of genetic conservation strategies for this crucial genetic resource. GRAPHICAL ABSTRACT