Application of tree-based,distance-based and character-based DNA barcoding methods for the identification of Crambidae species (Insecta: Lepidoptera) in Baihuashan,China

DNA barcoding has recently been proposed as a promising tool for rapid and accurate species identification in a wide range of animal taxa. Three broad methods( tree-based,distance-based and character-based) are commonly used. The first method requires the recovery of species as discrete clades( monophyly) on a phylogenetic tree. The second method is based on the degree of DNA sequence variation within and between species. The last method characterizes species through a series of diagnostic characters. To explore the feasibility of DNA barcoding based on different methods in the identification of Crambid moths,the COⅠ genes of 88 samples belonging to 14 species of the Crambidae from Baihuashan were analyzed. The results show that samples belonging to the same species cluster in one monophyly and all species were successfully distinguished by the NJ phylogenetic tree. The intraspecific and interspecific genetic distances were calculated using the Kimura-2-parameter model. An obvious barcoding gap between intraspecific and interspecific divergences for COⅠ genes was found,while the groups automatically defined by ABGD perfectly match the groups defined by morphological characters. Diagnostic nucleotide positions were found in each species and the character-based barcode method successfully identified every species. This study indicates that the species within the Crambidae can be readilly distinguished using these three barcoding approaches based on the COⅠ gene.