Abstract Detail



The evolution of functional traits in plants: is the giant still sleeping?

Krieg, Christopher [1], McCulloh, Kate [2], Guralnick, Robert [3], Sessa, Emily [4].

Transgressive physiological traits explain broad-scale niche novelty in an allopolyploid fern complex.

Polyploidy is thought to be an important driver of plant evolution by facilitating diversification, yet the mechanisms behind the ecological success of individual polyploid species remain poorly understood. Numerous studies have examined broad patterns of species niche overlap and separation between polyploid and diploid plants and many have reported significant niche differentiation. However, few studies have used trait-based approaches to mechanistically understand broad-scale niche differentiation between polyploid and diploid progenitor species. The work presented here integrates ecophysiology and niche modelling to better understand the evolution of novel traits and their role in driving niche divergence, using species in the North American Polystichum polyploid complex as a model system. Several ecophysiological traits were measured in over 35 populations across the geographic ranges of two parental diploids and their allopolyploid offspring. Analyses show strong trait by environment relationships in all three species. For example, traits related to gas-exchange, such as mesophyll conductance and maximum carboxylation rate were positively correlated with growing season temperatures at broad geographic scales. However, multivariate analyses show significant differences in trait combinations among species where at least two species co-occur. Comparative multidimensional analyses of species trait space within shared niche space vs. novel niche space occupied only by the polyploid species revealed novel trait combinations in the polyploid species in the driest part if its distribution. Ongoing work will shed more light on how polyploidy may drive the evolution of novel ecophysiological traits that confer competitive advantages and transgressive physiological tolerances in polyploid complexes.


1 - Gainesville, FL, United States
2 - Department Of Botany, 430 Lincoln Dr, Madison, WI, 53706, United States
3 - University of Florida, Gainesville, FL, 32611, United States
4 - University Of Florida, Biology, Box 118525, Gainesville, FL, 32611, United States

Keywords:
ferns
polyploidy
niche divergence
ecophysiology.

Presentation Type: Colloquium Presentations
Number: 0013
Abstract ID:490
Candidate for Awards:Edgar T. Wherry award


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