Application of internal transcribed spacer (ITS) sequences for identifying Anoectochilus setaceus Blume in Thanh Hoa, Vietnam

Abstract

Background. The term “DNA barcode” is used extensively in molecular taxonomy. Basically, this technique is based on the use of a DNA sequence (about 400–800 bp) as a standard to identify and determine the species relation of organisms quickly and accurately. Therefore, DNA barcodes not only help taxonomists in classifying and identifying species, but also improve their ability to control, understand and utilize biodiversity. In this study, the authors conducted identification of samples of Anoectochilus setaceus Blume collected in Thanh Hoa through the isolated sequence of ITS gene regions.Materials and methods. Total DNA was extracted from young leaves of A. setaceus samples using CTAB method. The ITS gene segment was amplified by PCR and sequenced. This genetic sequence was analyzed, compared and used to establish a phylogenetic tree using BioEdit, BLAST and DNASTAR programs.Results and conclusion. We isolated 4 sequences of the ITS gene region in 4 A. setaceus samples collected at Xuan Lien and Pu Luong of Thanh Hoa province; the ITS gene region was 667 nucleotide long. The findings identified the samples as the same species and showed 99% similarity to the ITS gene sequence of A. roxburghii (Wall.) Lindl. published in GenBank, GQ328774. This study also demonstrates that the method employing internal transcribed spacer (ITS) sequences is an effective tool to identify A. setaceus taxa.