Abstract Detail

Systematics Section/ASPT

Plumb, Rachel S. [1], Ruby, Julia [1], Zeemont, Anna [1], Sanders, Jeffrey [1], Douglas, Norman [1], Ochoterena Booth, Helga [2], Flores Olvera, Hilda [2], Moore, Michael [1].

Geographic patterns of genetic diversity in gypsum endemic taxa within Asteraceae subtribe Flaveriinae.

Our research is part of a larger project focusing on plants that are only found on gypsum (CaSO4·2H2O) soils in the Chihuahuan Desert of the southwestern United States and northern Mexico. Specifically, we are studying gypsum endemism in the subtribe Flaveriinae (Asteraceae, or sunflower family), which forms a small group of three genera: Flaveria, Haploësthes, and Sartwellia. Nine species within Flaveriinae are endemic to gypsum, including at least two species of Flaveria and nearly all of the taxa within Sartwellia and Haploësthes. Collectively, the gypsum endemic taxa within Flaveriinae occur throughout the Chihuahuan Desert despite the island-like nature of gypsum deposits in this region. Our earlier work using ITS and plastid spacer regions suggests that gypsum endemism has evolved multiple times in Flaveriinae, including in the common ancestor of Sartwellia and Haploësthes. ITS data also revealed extensive genetic diversity within and among species of the latter two genera, particularly in Mexico, and suggested that this diversity might have a strong geographic correlation. However, our earlier work was limited by relatively sparse taxon sampling of Mexican species of Sartwellia and Haploësthes.To evaluate whether genetic diversity within Mexican gypsum endemic Flaveriinaeis in fact structured geographically, we sampled 22 additional populations on gypsum throughout the Mexican portion of the Chihuahuan Desert. We compare our results in Flaveriinae to those of other studies that have examined genetic diversity in Chihuahuan Desert gypsum endemics. Ultimately, our results will help us test whether gene flow among gypsum endemics in the Chihuahuan Desert is ongoing or whether populations on different deposits have been isolated for long periods of time.

Broader Impacts:

Related Links:
Phylogenetics and phylogeography of Chihuahuan Desert gypsum endemics

1 - Oberlin College, Department of Biology, 119 Woodland St., Oberlin, OH, 44074, USA
2 - Universidad Nacional Autónoma de México, Instituto de Biología, Apartado Postal 70-233, México, DF, 04510, Mexico

Keywords:
Asteraceae
Flaveriinae
Phylogenetics
gypsum endemism.

Presentation Type: Oral Paper:Papers for Sections
Session: 1
Location: Franklin A/Hyatt
Date: Monday, July 9th, 2012
Time: 11:00 AM
Number: 1008
Abstract ID:926