Abstract Detail

Pteridology

Pinson, Jerald [1], Chambers, Sally [1], Sessa, Emily Butler [1].

Florida’s Sinkholes, and the Separation of Generations in Ferns.

Ferns and lycophytes are the only lineages of plants in which both stages of the life-cycle, the sporophyte (diploid) and gametophyte (haploid), are independent and free-living. In approximately 10% of ferns, the gametophytes can also be long-lived, and ~30 of these species have also been identified as having a spatial separation of the two generations, in which the gametophytes never produce sporophytes in at least part of their range. There are several such species in eastern North America that likely haven’t produced a viable sporophyte for thousands of years and yet still maintain large ranges throughout several states. It is currently unknown what inhibits the production of sporophytes in fern species that show a spatial separation of generations, but there is evidence to suggest that fine scale micro-climatic conditions may be driving this pattern in several species.
In southern Florida, Lomariopsis kunzeana is known to grow as gametophytes in the moist crevices of solution, some of which support sporophytes and some of which do not, making it an ideal system in which to study the affects of environmental conditions on sporophyte production. Additionally, due to the cryptic nature of gametophyte morphology, and the relatively high number of taxa with long-lived gametophytes in Florida, there is a strong possibility that there are other species with this pattern growing in the area, as yet undocumented. We will measure light intensity and temperature levels throughout the course of a year by placing data loggers in several solution and sinkholes throughout Florida, both those that have sporophytes and those that do not for a given species. We will quantify microclimatic conditions along vertical gradients within these holes, some of which can be tens of feet deep. We will then collect and sequence fern tissue to identify gametophytes and sporophytes to species and determine a presence/absence count with depth and microclimatic conditions, and collect tissue at locations along a vertical gradient to determine if sporophyte production varies with depth.

1 - University of Florida, Biology, 876 Newell Drive, 521 Bartram Hall, Gainesville, Florida, 32611, United States

Keywords:
fern
Independent gametophyte
Florida
Sinkholes
Solution holes
alternation of generations
separation of generations.

Presentation Type: Oral Paper
Session: 7, Pteridological Section/AFS
Location: 203/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 8:45 AM
Number: 7003
Abstract ID:548
Candidate for Awards:Edgar T. Wherry award