Identification of Dendrobium officinale species and authentication of commercial products by DNA barcoding and high-resolution melting analysis

Abstract

Dendrobium officinale is widely used as a precious traditional medicinal plant and health food in China. However, because of its high nutritional and medicinal value, it is often targeted for adulteration or mislabeling. This work aims to exploit DNA barcoding combined with high-resolution melting analysis to differentiate Dendrobium officinale（D. officinale）species from non-D. officinale species and to further identify its botanical origin. The internal transcribed spacer 2 (ITS2) was targeted as a candidate barcode for Dendrobium species identification. High resolution melting（HRM）method allowed differentiating the six Dendrobium species in three clusters with 95 % confidence interval, which is consistent with the sequencing analysis. ITS2 sequencing results implied that 43 % of commercial Dendrobium products may be mislabeled. Thus, ITS2 DNA barcoding with HRM assay could be used as a simple, specific and cost-effective tool to identify different Dendrobium species and commercial Dendrobium products, and to authenticate the origin of D. officinale.