Abstract Detail



Reproductive Processes

Krosnick, Shawn [1], Pugh, Savana [2], Keeton, Dustin [2], Campbell, Lesley [3], Call, Geoff [4].

Pollen-stigma interactions in Physaria globosa (Brassicaceae): conservation implications.

Physaria globosa is a federally endangered species endemic to just 31 sites across Tennessee, Kentucky, and Indiana. This species typically grows on steep, rocky, wooded slopes, ledges of bluffs and talus areas, and is usually found near rivers or streams. Most populations are closely associated with calcareous soils. Both self-compatible and self-incompatible species are present in the genus Physaria. To document self-compatibility, several individual plants were obtained and then cultivated ex-situ from a population in Hartsville, TN. For each individual controlled outcrosses, self-pollinations, and autogamous-self treatments were performed during March and April of 2018-2019. Flowers were collected after 48 hours, fixed in FAA and later visualized with aniline blue staining and fluorescence microscopy for pollen tube germination. Stigma clogging trials were performed using pollen from geitnogamous anthers from neighboring flowers in the same raceme combined with anthers from compatible outcrossed donors. Clogging trials with Sedum pulchellum were included to simulate heterospecific pollen deposition at local field sites. Pollen interactions were tested between equal mixtures of self/outcrossed pollen, self/outcrossed/S. pulchellum, and outcrossed only. Stigma receptivity and pollen germination time were also assessed. The results are considered in light of potential conservation implications for P. globosa.


1 - Tennessee Tech University, Dept. Of Biology, 1100 East Dixie Avenue, Pennebaker Hall #207, Cookeville, TN, 38505, United States
2 - Tennessee Tech University, Dept. of Biology, 1100 North Dixie Avenue, PENN 207, Dept. of Biology, Cookeville, 38505, USA
3 - Ryerson University, Department of Chemistry and Biology, 350 Victoria St., Toronto, ON, M5B2K3, Canada
4 - U.S. Fish & Wildlife Service, Tennessee Ecological Services Field Office, 446 Neal Street, Cookeville, TN, 38506, USA

Keywords:
Physaria globosa
conservation
pollen
stigma.

Presentation Type: Oral Paper
Number: 0014
Abstract ID:755
Candidate for Awards:None


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