Preliminary report on the genetic structure of Glyphoglossus molossus (Anura: Microhylidae) from the Khorat Plateau, north-eastern Thailand

Glyphoglossus molossus, is one of the most economically important amphibians in the Khorat Plateau, north-eastern Thailand. It is categorised as a near-threatened species by IUCN due to over-exploitation. Here, we examined the genetic structure of G. molossus using partial mitochondrial cytochrome-b gene sequences from specimens collected at 11 localities. The sequence analysis revealed the presence of 15 haplotypes, 5 of which are shared by 2 or more populations, and 10 haplotypes that are confined to a single population. The relatively low haplotype (h) and nucleotide (pi) diversities suggest that the Phu Phan Mountain Range is not high enough to act as an effective dispersal barrier between the Sakon Nakhon and Khorat Basins. However, AMOVA and phylogenetic analyses based on Maximum likelihood (ML) and Bayesian inference (BI) strongly supported the presence of two genetically divergent clades, Sakon Nakhon Basin and the northern part of the Khorat Basin (clade A) and the southern part of the Khorat Basin (clade B). These two lineages are separated by substantial geographical distance, which has putatively resulted in a reduction of gene flow. Further studies, with more extensive genetic sampling, especially from throughout the species range will aid in better interpreting our results.