title: Phylogenetic Analysis and Molecular Characterization of Xanthium sibiricum Using DNA Barcoding, PCR-RFLP, and Specific Primers.
abstract: The fruits ofXanthium sibiricumhave been widely used in traditional Chinese medicine for the treatment of nasal sinusitis and headaches. The genusXanthium(cocklebur) is a taxonomically complex genus. Different taxonomic concepts have been proposed, some including several species, others lumping the different taxa in a few extremely polymorphic species. Due to the morphological similarities between species, the correct authentication ofX. sibiricumis very difficult. Therefore, we established a polymerase chain reaction-restriction fragment length polymorphism method anddiagnostic PCRbased on nuclear internal transcribed spacer and chloroplasttrnQ-rps16barcodes to differentiateX. sibiriumfrom related species.Results from the phylogenetic analyses based on sequence information from four marker regions (plastidalpsbA-trnHandtrnQ-rps16and nuclear ITS andD35) support those taxonomic concepts accepting a reduced number of species, as four to five major clades are revealed in the phylogenetic reconstructions.X. sibiricum, together with some accessions from closely related taxa, is always supported as monophyletic, constituting a well-defined genetic entity. Allele-specific primer pairs for ITS andtrnQ-rps16were designed to amplify diagnostic products from the genomic DNA ofX. sibiricum. Specific PCR in combination with digestion using the restriction enzymeMseI allowed for the identification ofX. sibiricumby producing specific restriction patterns. The results demonstrate that the applied techniques provide effective and accurate authentication ofX. sibiricum.
authors.affiliation: Systematic Botany and Mycology, Department Biology I, Ludwig-Maximilians-University Munich (LMU) and GeoBio-Center (LMU), Munich, Germany.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Tomasello
authors.affiliation: Systematic Botany and Mycology, Department Biology I, Ludwig-Maximilians-University Munich (LMU) and GeoBio-Center (LMU), Munich, Germany.
authors.forename: Günther
authors.initials: G
authors.lastname: Heubl
mesh_terms: D058893:DNA Barcoding, Taxonomic; D017931:DNA Primers; D005819:Genetic Markers; D058889:Molecular Typing / Q000379:methods*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D031210:Xanthium / Q000145:classification* / Q000235:genetics
chemical_list: D017931:DNA Primers; D005819:Genetic Markers