Zanella et al. 2015 (Conference Paper) Vriesea

Patterns of genetic diversity and phylogeography, insights into speciation history with Atlantic Rainforest species

Author(s):—C. Zanella, C. Palma-Silva, M. Goetze & F. Bered in Benko-Iseppon, A.M.; Alves, M. & Louzada, R. (2015) An overview and abstracts of the First World Congress on Bromeliaceae Evolution. Rodriguésia 66(2): A1-A66.

Publication:— (2015).

Abstract:—The Bromeliaceae family is one of the morphologically and ecologically most diverse flowering plant families native to the New World and is well known for its recent adaptive radiation, evolving to live in numerous niches and occupying the most diverse types of environments. Due to its recent evolutionary history, generic boundaries often suffer changes, with incipient species not completely defined. Brazilian Atlantic Forest (BAF) is one of the diversity centers of bromeliads, being also one of the diversity centers of the genus Vriesea. Vriesea carinata and V. incurvata may be interesting models for studying BAF historical patterns, species cohesion processes and reproductive barrier mechanisms. These species are endemic to BAF, with wide distribution throughout this ecoregion, being found in sympatry, where they might share pollinators. We studied the phylogeographic patterns of V. carinata and V. incurvata, aiming to provide insights into the historical processes that underlined diversification in BAF. We evaluated the hypothesis that V. carinata and V. incurvata would present the same phylogeographic pattern, since they could be subjected to the same climatic changes in the past because they present similar geographic distribution. We sampled 16 populations of V. carinata and 11 of V. incurvata, aiming to describe the patterns of genetic variation in two plastid sequences (cpDNA) and 14 nuclear microsatellites. V. carinata and V. incurvata showed moderate levels of nuclear and plastid genetic diversity. Both species showed isolation by distance and present expansion towardssouthern margins. Vriesea carinata and V. incurvata showed similar phylogeographic patterns, with strong genetic discontinuity among north/south populations and without haplotypic sharing among these regions. The presence of two genetically distinct groups would seem to support the hypothesis that V. carinata and V. incurvata survived in more than one fragmented refugia during Pleistocene climatic oscillations. The results are consistent with records encountered in the literature for the BAF. However, more studies are required to understand the complex history of the BAF, since this pattern was probably shaped throughout the Pleistocene,but earlier events, such as uplift of the Brazilian East Coast during the Tertiary may be also have influenced the distribution and diversification of taxa.

Keywords:—Vriesea; Population Genetics; Phylogeography.