J Syst Evol ›› 2011, Vol. 49 ›› Issue (3): 203-212.DOI: 10.1111/j.1759-6831.2011.00130.x

• Research Articles • Previous Articles     Next Articles

Application of DNA barcodes in Hedyotis L. (Spermacoceae, Rubiaceae)

1,2Xing GUO 3Mark P. SIMMONS 4Paul Pui-Hay BUT 4Pang-Chui SHAW 1Rui-Jiang WANG*   

  1. 1(Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, PR China)
    2(Graduate University of the Chinese Academy of Sciences, Beijing 100049, PR China)
    3(Department of Biology, Colorado State University, Fort Collins, Colorado 80523-1878, USA)
    4(School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, PR China)
  • Received:2010-11-17 Published:2011-06-01

Abstract: The potential application of DNA barcodes of plastid (matK, trnH–psbA, petD, and rbcL) and nuclear (internal transcribed spacer (ITS) of rDNA) DNA regions was investigated for 25 Hedyotis taxa. The ITS showed the best species discrimination by resolving 23 of the species as exclusive lineages with no shared alleles between any of the 24 distinct species (H. assimilis and H. mellii are not supported as distinct species based on our molecular and morphological data). Conversely, rbcL performed the worst and only resolved 10 of the species as exclusive lineages, and 10 species with shared alleles. Using ITS has the advantage of high PCR amplification success and it provides good intra- and interspecific variation distribution patterns. The most powerful plastid markers were petD and trnH–psbA, but we could amplify and sequence trnH–psbA for only 83% of the accessions sampled. Combination of ITS and petD performed extremely well, with all 24 of the distinct species resolved as exclusive lineages and no shared alleles between any of the distinct species. We therefore recommend ITS, or a combination of ITS and petD, as the standard DNA barcode in Hedyotis, but acknowledge that there are no shared alleles between distinct species for matK and rbcL combined.

Key words: DNA barcode, Hedyotis, molecular identification, Rubiaceae, taxonomy.