Developing DNA Barcodes for Species Identification of Berberis and Dysosma Genera in Vietnam

摘要

Berberidaceae is the well-known traditional herbal medicine family, including 14 genera and about 700 species, and is considered as a very complex family in term of classification. Nowaday, DNA barcoding can be used to overcome the existed limitation in morphological-based species identification of this family. Therefore, the objective of this study was to find the most efficient DNA barcode regions for identifying species of Berberis and Dysosma genera. Leaf specimens of Berberis wallichianae, Berberis julianae, Mahonia bealei, and Dysosma difformis were collected and dried in silica gel. Total DNA extraction and purification, PCR amplification and DNA sequencing were performed with standard chemicals and kits. Six candidate DNA barcode regions including ITS, matK, 18S, psbA-trnH, rbcL, and trnL were amplified, and sequenced. Data were analysed using Seqscape 2.6, DNASTAR Lasergene 7.1, Bioedit 7.0.9.0, and MEGA 7 softwares. Analysis of six obtained DNA barcode sequences of collected samples revealed that ITS and psbA-trnH regions provided the lowest similarity in sequence and the highest species discriminating power for Berberis genus, while ITS and 18S regions were suitable for species identification of Dysosma genus. Accordingly, phylogenetic trees based on ITS, psbA-trnH, and 18S sequences were constructed. In this study, ITS and psbA-trnH regions were the most efficient markers for molecular identification of species belong to Berberis genus. ITS and 18S regions were considered as DNA barcodes for species discrimination of Dysosma genus. Our results support the identification of valuable medicinal plant species within Berberis and Dysosma genera.