The utility of DNA barcodes to confirm the identification of palm collections in botanical gardens

PLoS One. 2020 Jul 31;15(7):e0235569. doi: 10.1371/journal.pone.0235569. eCollection 2020.


The palm family (Arecaceae) is of high ecological and economic value, yet identification in the family remains a challenge for both taxonomists and horticulturalists. The family consists of approximately 2600 species across 181 genera and DNA barcoding may be a useful tool for species identification within the group. However, there have been few systematic evaluations of DNA barcodes for the palm family. In the present study, five DNA barcodes (rbcL, matK, trnH-psbA, ITS, ITS2) were evaluated for species identification ability across 669 samples representing 314 species and 100 genera in the Arecaceae, employing four analytical methods. The ITS gene region was found to not be a suitable barcode for the palm family, due in part, to low recovery rates and paralogous gene copies. Among the four analyses used, species resolution for ITS2 was much higher than that achieved with the plastid barcodes alone (rbcL, matK, trnH-psbA), and the barcode combination ITS2 + matK + rbcL gave the highest resolution among all single barcodes and their combinations, followed by ITS2 + matK. Among 669 palm samples analyzed, 110 samples (16.3%) were found to be misidentified. The 2992 DNA barcode sequences generated in this study greatly enriches the existing identification toolbox available to plant taxonomists that are interested in researching genetic relationships among palm taxa as well as for horticulturalists that need to confirm palm collections for botanical garden curation and horticultural applications. Our results indicate that the use of the ITS2 DNA barcode gene region provides a useful and cost-effective tool to confirm the identity of taxa in the Palm family.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arecaceae / classification*
  • Arecaceae / genetics*
  • DNA Barcoding, Taxonomic*
  • Gardens*

Grant support

Xue-jun Ge received the financial support of the following: the Biological Resources Program of Chinese Academy of Sciences (ZSSD-009) and the International Partnership Program of Chinese Academy of Sciences ( GJHZ1620). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.