title: Evaluation of candidate barcoding markers in Orinus (Poaceae).
abstract: Orinus is an alpine endemic genus of Poaceae. Because of the imperfect specimens, high level of intraspecific morphological variability, and homoplasies of morphological characters, it is relatively difficult to delimitate species of Orinus by using morphology alone. To this end, the DNA barcoding has shown great potential in identifying species. The present study is the first attempt to test the feasibility of four proposed DNA barcoding markers (matK, rbcL, trnH-psbA, and ITS) in identifying four currently revised species of Orinus from the Qinghai-Tibetan Plateau (QTP). Among all the single-barcode candidates, the differentiation power was the highest for the nuclear internal transcribed spacer (ITS), while the chloroplast barcodes matK (M), rbcL (R), and trnH-psbA (H) could not identify the species. Meanwhile, the differentiation efficiency of the nuclear ITS (I) was also higher than any two- or three-locus combination of chloroplast barcodes, or even a combination of ITS and any chloroplast barcode except H + I and R + I. All the combinations of chloroplast barcodes plus the nuclear ITS, H + I, and R + I differentiated the highest portion of species. The highest differentiation rate for the barcodes or barcode combinations examined here was 100% (H + I and R + I). In summary, this case study showed that the nuclear ITS region represents a more promising barcode than any maternally inherited chloroplast region or combination of chloroplast regions in differentiating Orinus species from the QTP. Moreover, combining the ITS region with chloroplast regions may improve the barcoding success rate.
authors.affiliation: Key Laboratory of Physical Geography and Environmental Process, Qinghai Province, Key Laboratory of Medicinal Animal and Plant Resource, Qinghai-Tibetan Plateau of Qinghai Province, Key Laboratory of Education Ministry of Environments and Resources in The Qinghai-Tibetan Plateau, School of Geography and Life Science, Qinghai Normal University, Xining, Qinghai, China.|State Key Laboratory Breeding Base-Key Laboratory of Qinghai Province for Plateau Crop Germplasm Innovation and Utilization, Qinghai University, Xining, Qinghai, China.
authors.forename: X
authors.initials: X
authors.lastname: Su
authors.affiliation: Key Laboratory of Physical Geography and Environmental Process, Qinghai Province, Key Laboratory of Medicinal Animal and Plant Resource, Qinghai-Tibetan Plateau of Qinghai Province, Key Laboratory of Education Ministry of Environments and Resources in The Qinghai-Tibetan Plateau, School of Geography and Life Science, Qinghai Normal University, Xining, Qinghai, China.
authors.forename: Y P
authors.initials: YP
authors.lastname: Liu
authors.affiliation: Key Laboratory of Physical Geography and Environmental Process, Qinghai Province, Key Laboratory of Medicinal Animal and Plant Resource, Qinghai-Tibetan Plateau of Qinghai Province, Key Laboratory of Education Ministry of Environments and Resources in The Qinghai-Tibetan Plateau, School of Geography and Life Science, Qinghai Normal University, Xining, Qinghai, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Key Laboratory of Physical Geography and Environmental Process, Qinghai Province, Key Laboratory of Medicinal Animal and Plant Resource, Qinghai-Tibetan Plateau of Qinghai Province, Key Laboratory of Education Ministry of Environments and Resources in The Qinghai-Tibetan Plateau, School of Geography and Life Science, Qinghai Normal University, Xining, Qinghai, China.
authors.forename: K L
authors.initials: KL
authors.lastname: Chen
mesh_terms: D058893:DNA Barcoding, Taxonomic / Q000379:methods / Q000592:standards*; D061125:Genes, Chloroplast; D005819:Genetic Markers; D055029:Inverted Repeat Sequences; D018895:Microsatellite Repeats; D006109:Poaceae / Q000145:classification / Q000235:genetics*
chemical_list: D005819:Genetic Markers