Stange, Carolyn , Charboneau, Joseph , Levin, Jonathan , Moore, Michael .
The phylogenetics and phylogeography of gypsophily in Gaillardia (Asteraceae).
Gaillardia (Asteraceae) is a widespread, dry-adapted genus that contains 18 North American species, two South American species, and one cultivar. Gaillardia includes six allopatric species that are endemic to gypsum (“gypsophilic”) in the Chihuahuan Desert: G. candelaria, G. gypsophila, G. henricksonii, G. multiceps, G. powellii and G. turneri. Despite the scattered, disjunct distribution of gypsum deposits in the Chihuahuan Desert, many gypsophilic taxa, including G. multiceps, are found throughout the region. An earlier phylogeny of Gaillardia suggested that gypsophily has evolved multiple times within the genus, but did not address infraspecific variation within any gypsophilic species. In an effort to extend this research and as part of a larger comparative study of Chihuahuan Desert gypsophiles, we generated sequence data for ITS and several chloroplast spacer regions to address the following questions: (1) Is there a strong correlation between geography and genetic variation among and within species within gypsophilic clades of Gaillardia, as might be expected given the geographic isolation of gypsum deposits?; and (2) Are phylogeographic patterns within and among the gypsophilic species congruent with those of other regionally dominant gypsophiles, suggesting a common history for the Chihuahuan Desert gypsophilic flora? We sampled all species of Gaillardia, including multiple populations for nearly all species, including across the entire geographic range of the relatively widespread gypsophile G. multiceps. Preliminary analyses of chloroplast data are congruent with previous analyses, and resolve the position of the South American G. megapotamica as part of clade including G. pinnatifida. Chloroplast data also support the newly described G. candelaria as distinct from G. multiceps.
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Phylogeography of Chihuahuan Desert gypsophiles
1 - Oberlin College, Biology Department, 119 Woodland Street, Science Center K123, Oberlin, OH, 44074, USA
2 - Oberlin College, Biology Department, Science Center K123, 119 Woodland Street, Oberlin, OH, 44074, U.S.A
3 - Oberlin College, Biology Department, 119 Woodland St., Science Center K123, Oberlin, OH, 44074, USA
4 - Oberlin College, Department of Biology, 119 Woodland Street, Oberlin, OH, 44074, USA
Presentation Type: Poster:Posters for Sections
Location: Hall A/Convention Center
Date: Monday, August 2nd, 2010
Time: 5:30 PM