Data from: Population genetic structure of the endemic rosewoods Dalbergia cochinchinensis and D. oliveri at a regional scale reflects the Indochinese landscape and life-history traits

Indochina is a biodiversity hot spot and harbors a high number of endemic
species, most of which are poorly studied. This study explores the genetic
structure and reproductive system of the threatened endemic timber species
Dalbergia cochinchinensis and Dalbergia oliveri using microsatellite data
from populations across Indochina and relates it to landscape
characteristics and life-history traits. We found that the major water
bodies in the region, Mekong and Tonle Sap, represented barriers to gene
flow and that higher levels of genetic diversity were found in populations
in the center of the distribution area, particularly in Cambodia. We
suggest that this pattern is ancient, reflecting the demographic history
of the species and possible location of refugia during earlier time
periods with limited forest cover, which was supported by signs of old
genetic bottlenecks. The D. oliveri populations had generally high levels
of genetic diversity (mean He = 0.73), but also strong genetic
differentiation among populations (global GST = 0.13), while D.
cochinchinensis had a moderate level of genetic diversity (mean He =
0.55), and an even stronger level of differentiation (global GST = 0.25).
These differences in genetic structure can be accounted for by a higher
level of gene flow in D. oliveri due to a higher dispersal capacity, but
also by the broader distribution area for D. oliveri, and the pioneer
characteristics of D. cochinchinensis. This study represents the first
detailed analysis of landscape genetics for tree species in Indochina, and
the found patterns might be common for other species with similar ecology.