Genetic variability of the endangered tropical species Hopea ferrea laness in forests revealed by microsatellite analysis

Giam Malut Hopea ferrea Laness (Dipterocarpaceae) is a woody species that has become endangered due to its habitat destruction and overexploitation. In an effort to support and provide conservation and management of this species, we utilized eight microsatellite loci to investigate the genetic diversity and structure of 234 adult trees across eight populations, encompassing its geographic distribution in Vietnam. The genetic diversity of H. ferrea was found to be low in comparison to other dipterocarps, suggesting a reduction in the number of alleles due to anthropogenic activities. Heterozygosity deficits were identified across all studied populations. Interestingly, the coastal populations exhibited higher genetic diversity compared to the Highlands and southeast populations. Bottleneck effects were detected in the majority of populations, with the exception of the two Highlands populations of Chu Mon Ray and York Don. These effects indicated a reduction in the population sizes. The results of genetic differentiation mirrored the genetic structure and revealed three major clusters corresponding to the three distribution areas of the species. A low level of genetic differentiation among populations (F_ST=0.146) was detected, consistent with the AMOVA analysis. Geographic distance and anthropogenic activities emerged as the major factors limiting gene exchange among populations. Based on these findings, we propose conservation measures for this endangered species.