Molecular phylogenetics of tribe Eudemeae (Brassicaceae) and implications for its morphology and distribution.

SALARIATO, D.L.; F.O. ZULOAGA; CANO, A. L. ; I. AL-SHEHBAZ

MOLECULAR PHYLOGENETICS AND EVOLUTION

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2014 vol. 82 p. 43 - 59

1055-7903

Tribe Eudemeae comprises a morphologically heterogeneous group of genera distributed along the Andesof South America from Colombia southward into southern Chile and Argentina. The tribe currentlyincludes seven genera: Aschersoniodoxa, Brayopsis, Dactylocardamum, Delpinophytum, Eudema, Onuris,and Xerodraba, and exhibits a wide morphological diversification in growth habit, inflorescences, andfruits. However, little is known about the phylogenetic relationships and evolution of the tribe. We presenthere a molecular phylogeny of representative sampling of all genera, utilizing sequence data from thenuclear ribosomal ITS region and chloroplast regions trnL-F, trnH-psbA, and rps16. Additionally, climaticniches 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 Delpinophytumthat was included with genera of the lineage I of Brassicaceae. Eudemeae is divided into two main lineagesdifferentiated by their geographical distribution and climatic niche: the primarily north-centralAndean lineage included Aschersoniodoxa, Brayopsis, Dactylocardamum, and Eudema, and the Patagonianand southern Andean lineage included Onuris and Xerodraba. Finally, ancestral-state reconstructions inthe 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 stemmingfrom the results are also discussed.