Human impacts on genetic diversity and differentiation in six natural populations of Madhuca hainanensis, an endemic and endangered timber species in China

The endemic and valuable timber Madhuca hainanensis Chun& F.C. How is a top priority canopy species for conservation in Hainan due to its high risk of extinction. To investigate human impacts on genetic diversity and differentiation on Madhuca hainanensis, we studied the genetic variability and differentiation of 112 individuals from 6 natural wild populations in three regions and different protected areas on Hainan Island, with 15 selected inter-simple sequence repeat (ISSR) markers. High levels of genetic diversity within species (PPB = 96.9%, I = 0.4914, h = 0.3261), while accordingly low levels within-population diversity (PPB = 65.8%, I = 0.3333, h = 0.2206) were detected. Genetic diversity of M. hainanensis mainly exists within populations (G(ST) = 0.1975). The genetic diversity of protected group was higher than that of un-protected group. The AMOVA results revealed that there was a significant differentiation among regions and among protected and unprotected groups. The Mantel test demonstrated that there was no significant correlation between pair-wise population PhiPT matrix and geographic distance matrix. All above indicated that the genetic differentiation among regions might be due to the serious human activity, but not geographic isolation. We recommend that strict in-situ conservation efforts should be implemented quickly for future management to prevent further deforestation. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.