Abstract Detail

Phylogenomics

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 51 nuclear loci 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 supported as 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 provides insight into the origin of the highly diverse flora of the cerrado and campos rupestres. 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

Keywords:
phylogenomics
target enrichment
Melastomataceae
Tibouchina
Cerrado
Campos rupestres.

Presentation Type: Oral Paper
Session: PHYL1, Phylogenomics I
Location: San Ignacio/Starr Pass
Date: Monday, July 29th, 2019
Time: 10:45 AM
Number: PHYL1011
Abstract ID:569
Candidate for Awards:None