Abstract Detail


Jantzen, Johanna [1], Oliveira, Ana Luiza Freitas [2], Soltis, Douglas [3], Soltis, Pamela [4].

Using a phylogenomic approach to resolve the systematics and taxonomy of Tibouchina s.s..

Tibouchina sensu stricto (Melastomataceae) is a clade of 30 species of herbs, shrubs and small trees that occur in open savanna habitats across South America, with a center of diversity in the cerrado and campos rupestres of Brazil. Little is known about the evolutionary origins of many plant species that make up the extremely diverse flora of the cerrado and campos rupestres. Michelangeli et al. (2013) showed that Tibouchina is paraphyletic, with Tibouchina s.s. sister to a clade of the remaining species of Tibouchina sensu lato and several other genera. However, their phylogeny was limited to only 7 of the 30 currently accepted species of Tibouchina s.s. and used only one nuclear and two plastid loci. In this study, we used 237 nuclear loci and the complete plastid genome, and nearly complete taxon sampling to reconstruct the evolutionary history of Tibouchina s.s. Multiple individuals were sampled per species to test for species monophyly and to potentially identify cryptic taxa. We used transcriptome and genome skimming data to develop probes for putatively single-copy nuclear loci. These loci and off-target plastid loci were successfully sequenced from across Melastomataceae using target enrichment and Illumina sequencing methods. This approach for selecting loci and developing probes may be applied in other groups with similarly limited genomic resources. Based on our phylogenetic analyses, most species were monophyletic, but some were paraphyletic, suggesting that taxonomic changes may be necessary. We confirmed several new species, recently collected for the first time, as evolutionarily distinct lineages using both phylogenomic and morphological data. The phylogeny also identified multiple clades of species of both the cerrado and campos rupestres, providing insight into the origin of the highly diverse flora of these regions. Our study produced one of the first well-sampled, dated, phylogenetic analyses of a floristic component of the campos rupestres and will be an important resource for further studies of the evolutionary history of this ecoregion.

1 - University Of Florida, Biology, Dickinson Hall, 1659 Museum Road, Gainesville, FL, 32611, United States
2 - UNESP Rio Claro, Institute of Biosciences, Rio Claro, SP, Brazil
3 - University of Florida, Florida Museum of Natural History, PO Box 117800, Gainesville, FL, 32611, USA
4 - University Of Florida, Florida Museum Of Natural History, Po Box 117800, Gainesville, FL, 32611, United States

target enrichment
Campos rupestres.

Presentation Type: Oral Paper
Abstract ID:569
Candidate for Awards:None

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