The phylogenetic analysis of Dalbergia (Fabaceae: Papilionaceae) based on different DNA barcodes

Abstract

The genus Dalbergia contains approximately 250 species with many valuable trees being destroyed by targeted and illegal logging. DNA barcoding is a reliable method for the molecular identification of different species and resources conservation. In the present study, the specimen discrimination ability of internal transcribed spacer (ITS), matK, rbcL and psbA-trnH barcoding were tested on Dalbergia sequences, downloaded from the National Center for Biotechnology Information (NCBI), and the combined barcoding ITS+matK+rbcL was used to identify unknown specimens. It was found that ITS+matK+rbcL have good discrimination rates based on the analysis methods best match (BM) and best close match (BCM). These barcodes also have the best performance concerning barcode gap distribution, and are able to discriminate unknown specimens from South-China. Furthermore, it was demonstrated that D. tamarindifolia and D. rubiginosa are also relatively close to sister-species D. pinnata and D. candenatensis within the phylogenetic Dalbergia tree. Considering the overall performance of these barcodes, we suggest that the ITS+matK+rbcL region is a suitable barcode for identifying Dalbergia species.