title: Molecular phylogenetics of tribe Eudemeae (Brassicaceae) and implications for its morphology and distribution.
abstract: Tribe Eudemeae comprises a morphologically heterogeneous group of genera distributed along the Andes of South America from Colombia southward into southern Chile and Argentina. The tribe currently includes seven genera: Aschersoniodoxa, Brayopsis, Dactylocardamum, Delpinophytum, Eudema, Onuris, and Xerodraba, and exhibits a wide morphological diversification in growth habit, inflorescences, and fruits. However, little is known about the phylogenetic relationships and evolution of the tribe. We present here a molecular phylogeny of representative sampling of all genera, utilizing sequence data from the nuclear ribosomal ITS region and chloroplast regions trnL-F, trnH-psbA, and rps16. Additionally, climatic niches of the tribe and its main lineages, along with the evolution of diagnostic morphological characters, were studied. All analyses confirmed the monophyly of Eudemeae, with the exception of Delpinophytum that was included with genera of the lineage I of Brassicaceae. Eudemeae is divided into two main lineages differentiated by their geographical distribution and climatic niche: the primarily north-central Andean lineage included Aschersoniodoxa, Brayopsis, Dactylocardamum, and Eudema, and the Patagonian and southern Andean lineage included Onuris and Xerodraba. Finally, ancestral-state reconstructions in the tribe generally reveal multiple and independent gains or losses of diagnostic morphological characters, such as growth form, inflorescence reduction, and fruit type. Relevant taxonomic implications stemming from the results are also discussed.
authors.affiliation: Instituto de Botánica Darwinion (CONICET - ANCEFN), Labardén 200, Casilla de Correo 22, B1642HYD San Isidro, Buenos Aires, Argentina. Electronic address: dsalariato@darwin.edu.ar.
authors.forename: Diego L
authors.initials: DL
authors.lastname: Salariato
authors.affiliation: Instituto de Botánica Darwinion (CONICET - ANCEFN), Labardén 200, Casilla de Correo 22, B1642HYD San Isidro, Buenos Aires, Argentina.
authors.forename: Fernando O
authors.initials: FO
authors.lastname: Zuloaga
authors.affiliation: Museo de Historia Natural, Universidad Nacional Mayor de San Marcos (UNMSM), Av. Arenales 1256, Lima 11, Peru; Instituto de Investigación de Ciencias Biológicas, Facultad de Ciencias Biológicas (UNMSM), Av. Venezuela s/n, Lima 1, Peru.
authors.forename: Asunción
authors.initials: A
authors.lastname: Cano
authors.affiliation: Missouri Botanical Garden, P.O. Box 299, St. Louis, MO 63166-0299, USA.
authors.forename: Ihsan A
authors.initials: IA
authors.lastname: Al-Shehbaz
mesh_terms: D001499:Bayes Theorem; D005075:Biological Evolution; D019607:Brassicaceae / Q000145:classification* / Q000235:genetics; D018742:DNA, Chloroplast / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D016013:Likelihood Functions; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013020:South America
chemical_list: D018742:DNA, Chloroplast; D018744:DNA, Plant; D021903:DNA, Ribosomal Spacer
keywords: Andes; Brassicaceae; Eudemeae; Morphology; Phylogeny; South America