Biogeographical history and diversification of Petunia and Calibrachoa (Solanaceae) in the Neotropical Pampas grassland

Authors

  • Jeferson N. Fregonezi,

    1. Molecular Evolution Laboratory, Genetics Department, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
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    • These authors contributed equally to the preparation of the manuscript.
  • Caroline Turchetto,

    1. Molecular Evolution Laboratory, Genetics Department, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
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    • These authors contributed equally to the preparation of the manuscript.
  • Sandro L. Bonatto,

    1. Genomic and Molecular Biology Laboratory, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
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  • Loreta B. Freitas

    Corresponding author
    • Molecular Evolution Laboratory, Genetics Department, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
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Corresponding author. E-mail: loreta.freitas@ufrgs.br

Abstract

The Pampas in the southern Neotropics is a vast region with vegetation composed mainly of grasses, and it may be the least-studied ecosystem in southern South America. Contrary to what was thought until recently, this region is heterogeneous and harbours rich biodiversity and many endemic species; however, little is known about the current geographical distribution and evolution of its plants. Here, we present results from phylogeographical studies on two genera typical of open environments (Petunia and Calibrachoa) that occur in both the Pampas and the high-altitude grasslands of southern Brazil. The rapid radiations of Petunia and Calibrachoa are examples of how strong selective pressures for different pollinators, coupled with adaptation to edaphic and climatic differences, may drive the diversification of plants in the Pampas. We also discuss factors that could have affected and driven the diversification and speciation of plants in this environment. Further studies, including some focusing on other taxa, are required to characterize the diversification of plant species in this region more accurately. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, ••, ••–••.

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