Genetic diversity of Meconopsis integrifolia (Maxim.) Franch. In the East Himalaya–Hengduan Mountains inferred from fluorescent amplified fragment length polymorphism analysis

Abstract

Meconopsis integrifolia (Maxim.) Franch. is a representative species of the genus found in the East Himalaya-Hengduan Mountain. As a species of medical and horticultural significance, M. integrifolia is threatened by over-exploitation and habitat fragmentation. In this study, the genetic diversity and structure of M. integrifolia, represented by 183 individuals from 10 populations, were studied using 6 pairs of fluorescent Amplified Fragment Length Polymorphisms primers. Our results showed a relatively high genetic variation at the species level (PPB = 82.0%, HE = 0.2356 and I = 0.3695). In contrast, population diversity was extremely low, as measured by Nei's genetic diversity index and Shannon's diversity index (HE = 0.0317, I = 0.0480). Analyses of molecular variance (AMOVA) showed that among and within populations, the genetic variation accounted for 88.9% and 11.1% of the total genetic variation, respectively. In addition, Nei's coefficient of differentiation (GST) was found to be high (0.8636), confirming the significant high level of genetic differentiation as well as low gene flow among populations of this species. The results of Neighbor-joining cluster, PCoA, and Bayesian assignment revealed similar genetic differentiation patterns, suggesting three main genetic groups that are concordant with their geographical distribution. Three main barriers—the Mekong River, the Yalong River, and a branch of the Yalong River—were detected using BARRIER software. The possible mechanisms and implications of these findings for conservation are discussed.