Nunez , Oscar Toro , Mort, Mark .
Phylogenetic relationships of Mathewsia and Schizopetalon (Brassicaceae) based on two nrDNA and cpDNA regions.
Schizopetalon (10spp) and Mathewsia (9 spp) are two small genera of Brassicaceae endemic from southern Peru to northern Chile. These genera are characterized by their contrasting habits; Schizopetalon comprising annuals, whereas Mathewsia is entirely perennial. Most of their species occur along the southern Atacama Desert with species disjunct between the coast and the Andes. These characteristics make them suitable for evolutionary studies of adaptation and diversification in extremely arid environments. Broad studies of Brassicaceae support the monophyly of both genera and place them as sister taxa; however, there has been no focused phylogenetic study of either genus. We performed phylogenetic analyses of separate and combined nuclear (i.e. nrDNA ITS and ETS) and cpDNA (i.e. psbA-trnH and rps16 introns) data sets, from a total of 22 individuals representing 13 species (~70% of total taxa), to assess the monophyly and elucidate the phylogenetic relationships within each genus. Our results suggest that Schizopetalon is monophyletic but relationships among species are only weakly supported. In contrast, Mathewsia is not resolved as monophyletic because a species from the high Andes, M. nivea, is sister to a Mathewsia + Schizopetalon clade. In both genera, species were placed in groups representing the northern (southern Peru and Atacama) and southern (central Chile) areas of distribution. Also, analyses showed S. bipinnatifidum and M. biennis as polyphyletic.
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1 - University of Kansas, Department of Ecology and Evolutionary Biology, Natural History Museum and Biodiversity Research Center, 1200 Sunnyside Avenue, Lawrence, Kansas, 66045, USA
2 - University of Kansas, Department of Ecology and Evolutionary Biology, NAtural History Museum and Biodiversity Research Center, 1200 Sunnyside Avenue, Lawrence, Kansas, 66046, USA
Presentation Type: Poster:Posters for Sections
Location: Khorassan Ballroom/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 5:30 PM