title: Applying DNA barcodes for identification of economically important species in Brassicaceae.
abstract: Brassicaceae is a large plant family of special interest; it includes many economically important crops, herbs, and ornamentals, as well as model organisms. The taxonomy of the Brassicaceae has long been controversial because of the poorly delimited generic boundaries and artificially circumscribed tribes. Despite great effort to delimitate species and reconstruct the phylogeny of Brassicaceae, little research has been carried out to investigate the applicability and effectiveness of different DNA regions as barcodes - a recent aid for taxonomic identification - to identify economically important species in Brassicaceae. In this study, we evaluated the feasibility of five intensively recommended regions [rbcL, matK, trnH-psbA, internal transcribed spacer (ITS), ITS2] as candidate DNA barcodes to discriminate economic species of Brassicaceae in China and try to establish a new digital identification method for economic plants of Brassicaceae. All sequences of 58 samples from 27 economic species (Brassicaceae) in China were assessed in the success rates of PCR amplifications, intra- and inter-specific divergence, DNA barcoding gaps, and efficiency of identification. Compared with other markers, ITS showed superiority in species discrimination with an accurate identification of 67.2% at the species level. Consequently, as one of the most popular phylogenetic markers, our study indicated that ITS was a powerful but not perfect barcode for Brassicaceae identification. We further discuss the discrimination power of different loci due to inheritance pattern, polyploidization and hybridization in species-specific evolution. Further screening of other nuclear genes related to species isolation as plant barcode candidates is also proposed.
authors.affiliation: Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, China.
authors.forename: X Q
authors.initials: XQ
authors.lastname: Sun
authors.affiliation: Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, China.
authors.forename: Y Q
authors.initials: YQ
authors.lastname: Qu
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China.
authors.forename: H
authors.initials: H
authors.lastname: Yao
authors.affiliation: Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, China.
authors.forename: Y M
authors.initials: YM
authors.lastname: Zhang
authors.affiliation: Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, China.
authors.forename: Q Q
authors.initials: QQ
authors.lastname: Yan
authors.affiliation: Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, China hangyueyu@cnbg.net.
authors.forename: Y Y
authors.initials: YY
authors.lastname: Hang
mesh_terms: D019607:Brassicaceae / Q000145:classification / Q000235:genetics*; D002681:China; D058893:DNA Barcoding, Taxonomic / Q000379:methods*; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D056426:Genetic Loci / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics; D014644:Genetic Variation; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D018744:DNA, Plant; D021903:DNA, Ribosomal Spacer; D005819:Genetic Markers; D010940:Plant Proteins