Application of DNA barcoding tool for authentication of traditionally important medicinal Dendrobium (Orchidaceae) species from Sikkim Himalaya

Abstract

Dendrobium, the second largest genus of the Orchidaceae family, is equally important for ornamental value and traditional medicine. Sikkim Himalaya region is rich in traditional knowledge of medicinal plants and their diversity. However, these regions were least explored through modern molecular tools. Reference databases association with DNA Barcoding technique is a new tool for species authentication. Here, we tested the efficiency of DNA barcoding loci (ITS, matK, rbcL, trnH-psbA) based on similarity search, characters based and phylogenetic methods to authenticate the medicinally important Dendrobium species. DNA from young leaves of studied species were isolated, and ITS (∼700 bp), rbcL(∼650 bp), matK (∼ 800 bp), trnH-psbA (∼ 450 bp) were amplified and sequenced for species-level identification. ITS, rbcL and trnH-psbA regions showed easy amplification and sequencing. Among the 54 sequences, 9 sequences were first time submitted to GenBank. In case of similarity search, ITS showed most efficient to identify all Dendrobium species except two species Dendrobium thyrsiflorum and Dendrobium densiflorum. However, the characters-based method easily differentiated between Dendrobium thyrsiflorum and Dendrobium densiflorum. The similarity-based methods and ITS sequence information together may help correct species identification for medicinal plants of Dendrobium.