TY - JOUR

T1 - Population genetic structure of the endemic rosewoods Dalbergia cochinchinensis and D. oliveri at a regional scale reflects the Indochinese landscape and life-history traits

AU - Hartvig, Ida

AU - So, Thea

AU - Changtragoon, Suchitra

AU - Tran, Hoa Thi

AU - Bouamanivong, Somsanith

AU - Theilade, Ida

AU - Kjær, Erik Dahl

AU - Nielsen, Lene Rostgaard

PY - 2018

Y1 - 2018

N2 - 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.

AB - 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.

KW - Forest cover change

KW - Indochina

KW - Landscape genetics

KW - Mekong River

KW - Plant mating systems

KW - Tropical trees

U2 - 10.1002/ece3.3626

DO - 10.1002/ece3.3626

M3 - Journal article

C2 - 29321891

AN - SCOPUS:85036577897

VL - 8

SP - 530

EP - 545

JO - Ecology and Evolution

JF - Ecology and Evolution

SN - 2045-7758

IS - 1

ER -