Genetic diversity and population structure of Bruguiera cylindrica along coastal areas in Thailand

Bruguiera cylindrica (L.) Blume is an important true mangrove species and is the common mangrove species in Thailand. Studies related to the genetic diversity and population structure of B. cylindrica are limited. Here, the genetic diversity and population structure of 78 B. cylindrica accessions from the mangrove forests in Thailand were explored using 2611 single nucleotide polymorphism (SNP) markers. A low level of genetic diversity was inferred from the genetic diversity parameters (Ho = 0.289, He = 0.257, and I = 0.400). The results of STRUCTURE, a principal component analysis (PCA) and a maximum-likelihood (ML) tree suggested that the genetic structure of the studied B. cylindrica populations fell into two clusters corresponding to geographical regions. The analysis of molecular variance (AMOVA) pointed to higher levels of variation within populations than between populations, and the mean pairwise genetic differentiation (FST = 0.225) indicated high genetic population differentiation. This study revealed the genetic variation of B. cylindrica along the coast of Thailand for the first time and also provides valuable genetic information for this species that will be helpful for management and conservation of the species.