# Profiling Genetic Variation: Divergence Patterns and Population Structure of Thailand’s Endangered Celastrus paniculatus Willd

## TL;DR

This study analyzes the genetic diversity of the endangered Celastrus paniculatus in Thailand to guide conservation efforts, finding significant variation among populations.

## Contribution

The study identifies population-specific haplotypes and genetic divergence patterns to inform targeted conservation strategies.

## Key findings

- CMI showed the highest genetic diversity (Hd = 0.944), while LEI and LPN were genetically homogeneous.
- PLK displayed distinct genetic divergence through unique haplotypes separated by multiple mutation steps.
- Conservation should prioritize both genetically diverse (CMI, MKM) and distinct (PLK) populations.

## Abstract

Celastrus paniculatus, also known as the “intellect tree,” is an important medicinal plant in Thailand valued for its neuroprotective and anti-inflammatory properties. Because this species is endangered, a study was conducted to analyze its genetic diversity to create a conservation plan. The research revealed significant genetic differences among plant populations in northern and northeastern Thailand; some had high diversity, while others were genetically very unique. The study concludes that conservation efforts must focus on protecting both the genetically diverse and the genetically distinct populations to ensure the long-term survival of this valuable plant.

This study examined genetic diversity in the endangered medicinal plant Celastrus paniculatus using 62 individual samples from seven natural populations in northern and northeastern Thailand to inform conservation strategies. The analysis of the nuclear internal transcribed spacer (ITS) and ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit (rbcL) markers revealed 17 haplotypes (CpI1–CpI17) across these populations, with 15 being population-specific. The genetic diversity varied significantly among populations: CMI showed the highest diversity (Hd = 0.944 ± 0.070), while LEI and LPN displayed complete homogeneity. The haplotype network identified a central shared haplotype (CpI4), suggesting a common ancestry, with the PLK population showing a distinct genetic divergence through unique haplotypes separated by multiple mutation steps. Genetic distance calculations revealed close relationships between LEI and NPM populations (distance = 0.0004), with greater differentiation between PLK and other populations (distances > 0.005). Phylogenetic analyses confirmed the species integrity while highlighting population clusters, especially PLK in ITS analyses and LPN in rbcL analyses. This genetic structure information provides a foundation for targeted conservation planning. Results suggest that conservation efforts should prioritize both genetically diverse populations (like CMI and MKM) and genetically distinct ones (like PLK) to preserve the maximum evolutionary potential. This study delivers crucial molecular data for developing evidence-based conservation strategies to protect this valuable medicinal species from further decline.