DNA barcoding for identification of Melicope pteleifolia and its close species based on ITS2 sequences

摘要

Melicope pteleifolia (Evodia lepta), named San-cha-ku in traditional Chinese medicine, is commonly used for the treatment of cold and gastropathy. Due to its wide regional distribution and a broad range of closely-related species, M. pteleifolia and its close species have been used in different regions of China. However, it is challenging to identify M. pteleifolia from other close species by only using traditional methods. Here, we report a molecular identification method based on ITS2 sequences of DNA barcoding to differentiate M. pteleifolia from its adulterants or related species. Our results showed that the ITS2 sequence length of M. pteleifolia was 221 bp. The K2P model that assesses the relative variation of the ITS2 regions was used to evaluate the genetic distance of M. pteleifolia from its closely related species. The inter-specifi distance was 0.1187, which is larger than the intra-specifi distance of 0.0116. The identification efficiency of ITS2 was 100% when evaluated with Blastn. The identification of NJ trees showed that M. pteleifolia formed into one clade, which can be distinguished successfully from its adulterants or related species. Our results suggested that M. pteleifolia can be identified stably and accurately through evaluating the ITS2 regions.