Abstract Detail



Conservation Biology

Wallace, Catherine  [1], Molano-Flores, Brenda [2], Coons, Janice [3].

Using scanning electron microscopy to compare pollen grain morphology and assess hybridization between Physaria kingii subsp. kaibabensis and its congeners.

Physaria kingii subsp. kaibabensis (Kaibab bladderpod; Brassicaceae), is an Arizona narrow endemic in the Kaibab Plateau. It is globally considered critically imperiled or imperiled with questionable taxonomy and is considered vulnerable in Arizona with a natural heritage rank of S3. Plant morphology of field specimens suggest hybridization associated with this species, which could affect its conservation status. To address this issue, the pollen morphology of Physaria kingii subsp. kaibabensis and two congeners (Physaria arizonica and Physaria kingii subsp. latifolia) were compared to pollen from plants at sites that potentially contained hybrids. Plant material was collected from 12 sites (mostly within the Kaibab National Forest, AZ), with 10 plants per site used to image 10 pollen grains per plant, for a total of 1200 pollen grains. Pollen grains were described (i.e., equatorial diameter length, polar axis length, P/E ratio, shape, exine structure, and aperture number) using scanning electron microscopy (SEM). Statistical analyses (i.e., ANOVAs and Tukey post hoc tests) based on morphometric data were used to determine differences among species and hybrids. All species imaged had pollen grains with reticulate surfaces and were found to be pentacolpate.  Overall, morphometric differences were found among species and hybrids. This study is the first one to compare pollen morphology for these specific Physaria species and to use pollen morphology to assess hybridization among these species. However, pollen morphology alone is not enough to determine the level of hybridization that is occurring among these species.  Molecular studies are needed to assess hybridization and the conservation status for Physaria kingii subsp. kaibabensis.


1 - University of Illinois at Urbana-Champaign, The Imaging Technology Group-Beckman Institute for Advanced Science and Technology, , 405 North Mathews, Urbana, IL, 61801, United States
2 - University Of Illinois, Illinois Natural History Survey, 1816 South Oak Street, Champaign, IL, 61820, United States
3 - Eastern Illinois University, Biological Sciences Department, 600 Lincoln Avenue, Charleston, IL, 61920.0, United States

Keywords:
SEM
hybridization 
Physaria 
pollen morphology .

Presentation Type: Poster This poster will be presented at 5:30 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PCB003
Abstract ID:242
Candidate for Awards:None


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