Recent Topics Posters
Nürk, Nicolai M. , Madriñán, Santiago , Carine, Mark , Blattner, Frank R. .
Molecular phylogeny and historical biogeography of Hypericum.
The largest genus of the Hypericaceae, Hypericum (St. John’s wort), comprises 472 species of worldwide distribution. To test monophyly of sections and to get a phylogenetic hypothesis for the genus we sequenced the ITS region (nrDNA internal transcribed spacers) of multiple accessions for 192 species (40% of the genus), representing 34 out of the 36 sections. Ten outgroup representatives were included, covering the three tribes of Hypericaceae. The obtained phylogeny indicates Hypericum to be split into two Mediterranean grades and three large clades with the New World, Asia-Africa, and the Holarctic-Mediterranean as centers of their distribution. Sister to the New World clade is the genus Triadenum, what makes Hypericum polyphyletic. The phylogenetic tree is largely congruent with the results of a cladistic analysis of morphological characters. Mediterranean taxa are separated by initial splits from the reminder of Hypericum and occur also as sister-groups to the Asia-African and Holarctic taxa, respectively. Thus, an origin and early diversification of the genus around the late Tethys Ocean seems likely instead of the formerly proposed African origin, and the colonization of the extant distribution area of Hypericum implies multiple intercontinental long-distance dispersals.
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Laboratorio de Botánica y Sistemática
National History Museum – Mark Carine
1 - Institute of Plant Genetics and Crop Research (IPK), Taxonomy & Evol. Biology, Gatersleben, D-06466, Germany
2 - Universidad de los Andes, Departamento de Ciencias Biológicas, Laboratorio de Botánica y Sistemática, Apartado Aéreo 4976, Bogotá, DC, Colombia
3 - Natural History Museum, Department of Botany, Cromwell Road, London, SW7 5BD, England
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Presentation Type: Recent Topics Poster
Location: Hall A/Convention Center
Date: Monday, August 2nd, 2010
Time: 5:30 PM