Species delimitation is fundamental to the basic understanding of biodiversity because of the central role that the concept of species plays in most branches of biology. However, few studies have been designed to test conflicting delineations of plant species under an integrated species
concept using DNA barcodes in combination with other lines of evidence. Such an approach may deliver more objective, testable and uniform species units as subjects for a range of studies. Here we aim to examine competing hypotheses of species delimitation in Orychophragmus, a member
of the mustard family, based on these methods and principles. Two to seven species have previously been recognized in this genus by different taxonomists. We sequenced five commonly used DNA barcodes (nuclear ribosomal ITS and chloroplast matK, rbcL, trnH-psbA, and trnL-F)
for 160 individuals collected across the major distribution ranges of all taxa currently recognized in the genus. Based on the monophyletic clusters produced by analysis of the combined nrITS and cpDNA sequence variations, we recovered nine independent evolutionary lineages that were further
supported by diagnosable morphological traits, distinct inter-cluster genetic gaps, reproductive isolation, and geographical distribution. These lineages may be treated as nine species. We also found substantial differences in the capacity of nrITS and cpDNA barcodes to discriminate between
closely related species in two clades of the genus. Our empirical study of Orychophragmus highlights the importance of applying both chloroplast DNA and nrITS barcodes for species delimitation in plants.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Article Media
Document Type: Research Article
MOE Key Laboratory for Bio-Resources and Eco-Environment, College of Life Science, Sichuan University, Chengdu 610065, P. R. China
Missouri Botanical Garden, P.O. Box 299, St. Louis, Missouri 63166-0299, U.S.A.
MOE Key Laboratory for Bio-Resources and Eco-Environment, College of Life Science, Sichuan University, Chengdu 610065, P. R. China;, Email: [email protected]
Publication date: 28 August 2015
More about this publication?