Abstract Detail



Pteridology

Triester, Natalie [1], Krieg, Christopher [2], McCulloh, Kate [1], Sessa, Emily [3].

Functional impact of cell size in a polyploid fern complex: implications for co-existence mechanisms.

Polyploidization, or whole genome duplication (WGD), is an important driver of diversification in plants and is among the fastest mechanisms of sympatric speciation. Although WGD is often associated with larger cell sizes as a result of the excess genomic material after genome duplication, few studies have examined the functional impact of increased cell size for naturally occurring polyploids. Niche theory predicts that trait differentiation between co-occurring species is critical for stable coexistence of species in plant communities. Polystichum scopulinum is an allotetraploid fern that often co-occurs with one of its two parents P. imbricans and P. lemmonii. We examined the impact of cell size on key traits such as stomata size and density, stomatal conductance, mean hydraulic conductance of the xylem, and vein density in two co-occurring species of ferns: the allotetraploid and either one of the diploid parents. Our samples were collected from sites across the western US including Washington, Oregon and California. Light microscopy of xylem cross-sections, and leaf anatomy reveal a general pattern of larger cell sizes in the polyploid species, but the extent to which the polyploid differed from the co-occurring parent was both species and site dependent. The polyploid species also showed greater variation among sites than the diploid, indicating that increased phenotypic plasticity may be advantageous to co-existing alongside parental species.


1 - University of Wisconsin, Department of Botany, Madison, WI, 53706, USA
2 - University of Florida, Department of Biology, Gainesville, FL, 32611, USA
3 - University Of Florida, Gainesville, FL, 32611, United States

Keywords:
ferns
ecophysiology
Polyploidy
Adaptation
functional traits.

Presentation Type: Poster
Number: PPT006
Abstract ID:646
Candidate for Awards:None


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