Systematics Section / ASPT
Bailey, C. Donovan , Koch, Marcus , Mayer, Michael , Klaus, Mummenhoff , OKane, Steve L. , Warwick, Suzanne I. , Windham, Michael D. , Al-Shehbaz, Ihsan .
A Global nrDNA ITS Phylogeny for the Brassicaceae.
THE taxonomy of the 338 genera and 3700 species that comprise the Brassicaceae has been plagued by convergent evolution in nearly every morphological feature used to define tribes and genera. Phylogenetic analysis of 746 nrDNA ITS Brassicaceae sequences (representing 24 of the 25 currently recognized tribes, 146 genera, and 461 species), produced the most comprehensive single-locus-based phylogenetic analysis of the family published to date. This extensive sampling offered a test of monophyly for many tribes and genera. Results from parsimony ratchet and Bayesian analyses recovered support for a large number of clades, many of which correspond to currently recognized tribes. In the most comprehensive analysis, tribes Alysseae, Anchonieae plus Hesperideae, Boechereae, Cardamineae, Eutremeae, Halimolobeae, Iberideae, Noccaeeae, Physarieae, Schizopetaleae, Smelowskieae, and Thlaspideae were all monophyletic. Several broadly defined genera (e.g., Draba and Smelowskia) were supported as monophyletic, whereas others (e.g., Sisymbrium and Alyssum) were clearly polyphyletic. Despite these successes, little support for the backbone of the phylogeny was recovered, suggesting that several lineages within the Brassicaceae may have undergone rapid radiations that may be difficult to resolve. We discuss ongoing research projects aimed at achieving complete generic sampling and generating more fully resolved and supported phylogenies of the Brassicaceae.
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1 - New Mexico State University, Department of Biology, Po Box 30001, Department 3Af, Las Cruces, New Mexico, 88003-8001, USA
2 - Heidelberg Institute of Plant Sciences, Biodiversity and Plant Systematics, Heidelberg, , Germany
3 - University of San Diego, Department of Biology, 5998 Alcala Park, San Diego, California, 92110-2492, USA
4 - Universität Osnabrück, Fachbereich Biologie, Spezielle Botanik, Osnabrück, , Germany
5 - University of Northern Iowa, Department of Biology, Cedar Falls, Iowa, , USA
6 - Agriculture and Agri-Food Canada, Eastern Cereal and Oilseed Research Centre, Ottawa, Ontario, , Canada
7 - University of Utah, Utah Museum of Natural History, 1390 E. President's Circle, Salt Lake City, Utah, 84112, USA
8 - Missouri Botanical Garden, Po Box 299, St Louis, Missouri, 63166-0299, USA
Presentation Type: Oral Paper:Papers for Sections
Location: 134/Performing Arts Center
Date: Tuesday, August 1st, 2006
Time: 12:00 PM