| Many of Thai insect-pathogenic fungi strains that are kept in BIOTEC Culture Collection (BCC), Thailand are still labeled only up to genus level. The majority of insect-pathogenic fungi have been long recognized to belong in the Clavicipitaceae. A major phylogenetic reclassification of the Clavicipitaceae has split this family into three families, Clavicipitaceae Cordycipitaceae, and Ophiocordycipitaceae. In this study, large ribosomal subunit (LSU) gene was used to assess the taxonomic position of family level from 80 samples of insect-pathogenic fungi from BCC. Furthermore, morphological identification often failed to give an accurate identification. Recently, DNA barcoding has been promoted as a potentially powerful method for the efficient and accurate identification of unknown species. The concept of DNA barcoding proposes effective and broad spectrum identification based on sequence diversity using short and standardized gene regions. This study assessed the feasibility of using internal transcribed spacer (ITS) as a barcode marker for identifying species in four insect-pathogenic fungi genera, Cordyceps, Paecilomyces sensu lato, Verticillium, and Akanthomyces. The LSU gene and ITS region were amplified and sequenced. Phylogenetic analyses were performed by Neighbour-Joining method. Pairwise nucleotide divergences were used to obtain intrageneric and intergeneric variation. The result showed that based on LSU gene, most of samples in this study were in three different families, Cordycipitaceae, Ophiocordycipitaceae, and Clavicipitaceae. Our preliminary results indicated that ITS could not distinguish species within and between four genera of insect-pathogenic fungi. Further work should be carried out regarding to the limitations in this study. |