Arias, Tatiana , Edger, Patrick , Pires, J. Chris .
Understanding evolutionary relationships in the tribe Brassiceae (Brassicaceae): dataset congruency, genome evolution and biogeography.
The tribe Brassiceae, with 54 genera and approximately 240 species, has long been identified as a monophyletic group within the Brassicaceae based on morphological (conduplicate cotyledons, two-segmented fruits and simple trichomes) and molecular evidence. The tribe contains important agricultural species such as the Brassica crops, grown globally for oil, condiments, vegetables, medicine and now bio-diesel. Nonetheless, the evolutionary relationships among genera and species are yet to be resolved. Some of the genera identified through classical taxonomy have proved not to be monophyletic and several sub-tribal classifications, based on chloroplast and nuclear markers, have been suggested. In these analyses, two major groups, the rapa-oleraceae and nigra clades, are well supported with chloroplast but not nuclear data and only a few genera are monophyletic. Phylogenetic reconstructions in the group have been challenging because of the small and highly dynamic genome, the high frequency of hybridization, introgression, chromosomal rearrangements, the slight morphological variation, and both recent and ancient polyploidization events. Here we will present a preliminary molecular phylogeny using whole plastid genomes and a set of single and low-copy nuclear markers. This phylogeny will be presented as an evolutionary framework in which genome evolution and historical biogeography in the tribe will be analyzed. Ages of diversification using estimated branch lengths will be correlated with ecological ranges, geography, and origin and domestication events in the tribe.
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1 - University of Missouri, Biological Sciences, 1201 Rollins Road, 311 Life Sciences Center, Columbia, Missouri, 65211, USA
Presentation Type: Oral Paper:Papers for BSA Sections
Location: Cottonwood C/Snowbird Center
Date: Wednesday, July 29th, 2009
Time: 10:30 AM