Get access

DNA barcoding of the recently evolved genus Holcoglossum (Orchidaceae: Aeridinae): a test of DNA barcode candidates

Authors

  • XIAO-GUO XIANG,

    1. State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    Search for more papers by this author
    • These authors contributed equally to this work.

  • HAO HU,

    1. College of Life Sciences and Technology, Gansu Agricultural University, Lanzhou 730070, China
    Search for more papers by this author
    • These authors contributed equally to this work.

  • WEI WANG,

    1. State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    Search for more papers by this author
  • XIAO-HUA JIN

    1. State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    Search for more papers by this author

Xiao-Hua Jin, Fax: 8610 62590843; E-mail: xiaohuajin@ibcas.ac.cn

Abstract

Orchidaceae is one of the largest families of flowering plants. Many species of orchid are endangered, and all species are included in Conventions on International Trade of Endangered Species of Fauna and Flora (CITES) I and II, but it is very difficult to identify orchid species, even those with fertile parts. The genus Holcoglossum (Orchidaceae: Aeridinae) has long been problematic in taxonomy. It consists of both long-evolved and radiated species and is an excellent case to use for testing DNA barcodes for Orchidaceae. We investigated the power of a subset of proposed plant barcoding loci [rbcL, matK, atpF-atpH, psbK-psbI, trnH-psbA and internal transcribed spacer (ITS)] to discriminate between species in this genus. Our results showed that all these DNA regions, except psbK-psbI and atpF-atpH, can be amplified easily from Holcoglossum and sequenced with established primers. The DNA regions matK and ITS had the highest variability. Among the six loci, matK resolved eight of the 12 Holcoglossum species and had the highest discriminatory ability. However, the combination of matK and ITS showed a greater ability to identify species than matK alone. Single or combined DNA markers discriminated between Holcoglossum species distributed in tropical areas effectively, but had less ability to identify radiated species from the temperate Hengduan Mountains of China. In the study, matK proved to be a useful DNA barcode for the genus Holcoglossum; however, complementary DNA regions are still required to accelerate the investigation and preservation of radiated species of orchid.

Get access to the full text of this article

Ancillary