Constructing a DNA barcode reference library for southern herbs in China: A resource for authentication of southern Chinese medicine

PLoS One. 2018 Jul 25;13(7):e0201240. doi: 10.1371/journal.pone.0201240. eCollection 2018.

Abstract

Southern Chinese Medicine (SCM) is an important sect of Traditional Chinese Medicine (TCM) with its own special cultural style. Species identification is essential for TCM quality control because authentic herbs are possibly substituted with adulterants that would threaten the health of the public or even cause death. Here, we provided the first local reference DNA barcode library based on the second internal transcribed spacer (ITS2) for the molecular identification of SCM. A total of 1512 specimens of southern herbs representing 359 species were collected under the instructions and identification of taxonomic experts. Genomic DNA was extracted, and the PCR reaction proceeded according to standard procedures. After Sanger sequencing, sequence assembling and annotation, a reliable ITS2 barcode library with 1276 sequences from 309 species of Southern herbs was constructed. The PCR efficiency of the whole samples was 84.39%. Characteristics of the ITS2 barcode were analyzed, including sequence lengths and GC contents in different taxa. Neighbor-joining trees based on Kimura 2-Parameter (K2P) genetic distances showed a 67.56% successful rate of species identification with ITS2 barcode. In addition, 96.57% of species could be successfully identified at the genus level by the BLAST method. Eleven plant species were discovered to be cryptic. In addition, we found that there is an incorrect sequence existing in the public database, making a reliable local DNA barcode reference more meaningful. ITS2 barcodes exhibit advantages in TCM identification. This DNA barcode reference library could be used in Southern Chinese Medicine quality control, thus contributing to protecting public health.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • China
  • DNA Barcoding, Taxonomic / methods*
  • DNA, Plant / genetics*
  • Drugs, Chinese Herbal / metabolism
  • Gene Library*
  • Genetic Variation
  • Medicine, Chinese Traditional
  • Plants, Medicinal / genetics*
  • Quality Control

Substances

  • DNA, Plant
  • Drugs, Chinese Herbal

Grants and funding

This work was supported by Guangdong Provincial Hospital of Chinese Medicine Special Fund (2015KT1817, http://www.gdhtcm.com/) and the China Academy of Chinese Medical Sciences Special Fund for Health Service Development of Chinese Medicine (ZZ0908067), ZH Huang received the funding. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.