Phylogenetic diversity of 18S rDNA sequences of dictyostelids from Amnat Charoen Province, Thailand

Dictyostelids, a group of social amoebae, are one of the major eukaryotic microbes in soil. They play an important role in the turnover of nutrients and minerals and also in bacterial population control in nature. Species diversity of these microbes has been surveyed globally, but surveys in Thailand are rare. We collected 73 isolates of dictyostelids from soils in two districts of Amnat Charoen Province, Thailand. The majority of dictyostelids recovered from Amnat Charoen Province belong to the genus Dictyostelium, with 48.0%. The 5'-end of the 18S rDNA gene was amplified and sequenced using the Sanger sequencing approach. Phylogenetic trees were reconstructed using three different methods. These were neighbour-joining (NJ), maximum likelihood (ML) and Bayesian inference (BI). The resulting phylogeny suggests that five genera of dictyostelids (Cavenderia, Heterostelium, Raperostelium, Dictyostelium and Polysphondylium) were found in Amnat Charoen Province, with Dictyostelium as the dominant group. These data are the first on the phylogenetic diversity of dictyostelids in north-eastern Thailand and will be useful in the management of natural and microbial resources.