Evaluation of four commonly used DNA barcoding Loci for chinese medicinal plants of the family schisandraceae

PLoS One. 2015 May 4;10(5):e0125574. doi: 10.1371/journal.pone.0125574. eCollection 2015.

Abstract

Many species of Schisandraceae are used in traditional Chinese medicine and are faced with contamination and substitution risks due to inaccurate identification. Here, we investigated the discriminatory power of four commonly used DNA barcoding loci (ITS, trnH-psbA, matK, and rbcL) and corresponding multi-locus combinations for 135 individuals from 33 species of Schisandraceae, using distance-, tree-, similarity-, and character-based methods, at both the family level and the genus level. Our results showed that the two spacer regions (ITS and trnH-psbA) possess higher species-resolving power than the two coding regions (matK and rbcL). The degree of species resolution increased with most of the multi-locus combinations. Furthermore, our results implied that the best DNA barcode for the species discrimination at the family level might not always be the most suitable one at the genus level. Here we propose the combination of ITS+trnH-psbA+matK+rbcL as the most ideal DNA barcode for discriminating the medicinal plants of Schisandra and Kadsura, and the combination of ITS+trnH-psbA as the most suitable barcode for Illicium species. In addition, the closely related species Schisandra rubriflora Rehder & E. H. Wilson and Schisandra grandiflora Hook.f. & Thomson, were paraphyletic with each other on phylogenetic trees, suggesting that they should not be distinct species. Furthermore, the samples of these two species from the southern Hengduan Mountains region formed a distinct cluster that was separated from the samples of other regions, implying the presence of cryptic diversity. The feasibility of DNA barcodes for identification of geographical authenticity was also verified here. The database and paradigm that we provide in this study could be used as reference for the authentication of traditional Chinese medicinal plants utilizing DNA barcoding.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA Barcoding, Taxonomic / methods*
  • DNA, Plant / genetics
  • Genetic Loci*
  • Phylogeny
  • Plants, Medicinal / genetics*
  • Schisandraceae / genetics*
  • Sequence Analysis, DNA
  • Species Specificity

Substances

  • DNA, Plant

Grants and funding

This research was supported by National Natural Science Foundation of China grant No. 31100171 and 31270268, Major Innovation Program of Chinese Academy of Sciences (KSCX2-EW-Z-2), and National Basic Research Program of China grant No. 2014CB954101. Field work was partially supported by CAS International Research & Education Development Program (grant No. SAJC201315) and CAS External Cooperation Program of BIC (grant No. GJ II Z201321). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.