Kates , Heather Rose , Weinmann, Sophia , Charboneau, Joseph , Plumb, Rachel , Sanders, Jeffrey , Fuentes-Soriano , Sara , Moore, Michael .
Expanding the Study of the Phylogeny and biogeography in a Chihuahuan Desert gypsum endemic, Nerisyrenia (Brassicaceae), through the use of low copy nuclear markers and increased population sampling.
Nerisyrenia Greene (Brassicaceae) is a small genus of 11 arid-adapted species endemic to the Chihuahuan Desert of southwestern North America and Mexico. With the exception of the widespread N. camporum (A. Gray) Greene, all species within Nerisyrenia are endemic to gypsum deposits and soils that are scattered in an island-like fashion throughout the Chihuahuan Desert. While early research postulated a recent origin for modern North American arid-adapted taxa, patterns of morphology, phylogeny, and biogeography within other Chihuahuan Desert gypsum endemics suggest an age of several million years. As part of a larger effort to understand the age and origins of Chihuahuan Desert gypsum endemics, we initiated a phylogenetic and phylogeographic study of Nerisyrenia to address: (1) How many times has gypsum endemism evolved within the genus?; (2) Is gypsum endemism the ancestral character state?;and (3) Is there a strong correlation between biogeographic distribution and genetic diversity both within and between gypsum endemic species of Nerisyrenia? We constructed a 5 chloroplast spacer region gene tree and an ITS gene tree using initial sampling of all species, including numerous populations of the North American species, N.camporum and N. linearifolia (S. Wats.) Greene, from across their geographic ranges. Our phylogeny revealed high levels of diversity within Nerisyrenia and indicated that the widespread gypsum endemic N. linearifolia has a significant amount of geographically-correlated variation, while non-gypsum endemic N. camporum shares chloroplast haplotypes with several other species. To better elucidate this complex evolutionary history, we have identified and sequenced two useful low copy nuclear markers (alcohol dehydrogenase and pistllata) and increased sampling across the 9 Mexican taxa. In addition to improving resolution within our phylogeny, expanded geographic sampling of Nerisyrenia may reveal greater diversity in Mexican population than in northern populations, as has been found in several other gypsum-endemics.
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The Origins and Biogeography of Gypsophily in the Chihuahuan Desert
1 - Oberlin College, Biology, Science Center K123 , 119 Woodland St. , Oberlin, OH, 44074, USA
2 - University of Wyoming, Botany, 1000 E. University Ave., University of Wyoming, Laramie, WY, 82071, USA
3 - Missouri Botanical Garden, P.O. Box 299, St. Louis, MO, 63166, USA
4 - Oberlin College, Department of Biology, 119 Woodland St., Oberlin, OH, 44074, USA
Presentation Type: Oral Paper:Papers for Sections
Location: Lindell B/Chase Park Plaza
Date: Tuesday, July 12th, 2011
Time: 11:30 AM