Genetic diversity of Afzelia xylocarpa (Kurz) Craib in Vietnam based on analyses of chloroplast markers and random amplified polymorphic DNA (RAPD)

Abstract

Afzelia xylocarpa (Kurz) Craib is not only an endangered species in Vietnam, but also around the world. The wood of this tree species is very valuable as it is used to construct houses and high quality furniture. Habitat loss and exploitation of A. xylocarpa by man have threatened the population to such an extent that the number of mature trees of this species has dwindled to quite a low quantity. Declining numbers of A. xylocarpa in turn causes a constriction of the gene pool. Thus, it is very important to evaluate the genetic diversity of A. xylocarpa (Kurz) Craib in order to conserve and sustain the surviving population of these trees. 50 samples of A. xylocarpa (Kurz) Craib were collected from seven locations in four provinces (Gia Lai, Dac Lac, Dong Nai and Ninh Thuan) and used to evaluate the genetic diversity of these trees based on the analysis of chloroplast 16S rRNA, non-coding regions between trnH-trnK, trnD-trnT and psbC-trnS chloroplast genes using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and random amplified polymorphic DNA (RAPD) markers. The data obtained reveals that the 50 samples of A. xylocarpa (Kurz) Craib have low level of genetic diversity, as supported by the fact that the genetic similarity coefficients of the trees ranged from 49 to 100%. At the similarity level of 49%, the 50 samples were grouped into two main groups. There was no clear local specificities of the samples as the samples from same locality were not found in same group. Due to low level of genetic diversity, low numbers of trees and scattered occurrence, setting up suitable conservation strategies are urgently needed.

Key words: Afzelia xylocarpa (Kurz) Craib, genetic diversity, non-coding sequences, random amplified polymorphic DNA (RAPD) markers.