Abstract Detail



Molecular Ecology

Sharpe , Samantha Lipson [1], Johnson, Loretta [1], Galliart, Matt [1], Parrish, Olivia [1].

Rapid evolution in response to heavy metals: Evolutionary adaptation of  Andropogon virginicus in abandoned mines.

Anthropogenic activities have severely altered the earth’s ecosystems, driving many species to undergo rapid evolution in response to extreme and changing environmental conditions. This research investigates genotypic and phenotypic components of adaptive variation in heavy metal exposed populations of Andropogon virginicus, a common perennial grass that often grows in contaminated mine soil. The study area is the Tar Creek EPA Superfund Site, an abandoned Lead and Zinc mine active for 100 years that spans Kansas, Oklahoma, and Missouri. Using a greenhouse soil reciprocal transplant, we compared populations of A. virginicus collected from Tar Creek with those collected from nearby non-mine sites to determine if ecotypic adaptation to contaminated soils has occurred in mine populations. To assess phenotypic adaptation, we measured vegetative morphology (leaf area), fitness (seed production), and physiology (SPAD) over the course of the growing season. Plants from 20 populations were genotyped with GBS to analyze differentiation on the genetic level.  We identified ~6,000 single nucleotide polymorphisms (SNPs), including 47 outliers under divergent selection between mine and non-mine populations, two of which are related to Zinc binding. For both of these SNPs, a single allele is fixed in the mine populations while both alleles are present in non-mine populations, indicating potentially greater selection for one allele variant in the mine site. Preliminary evidence supports phenotypic differences between mine and non-mine populations, including a potential trade off in mine populations between reproduction and vegetative growth. In a greenhouse reciprocal soil transplant, plants from mine populations produced more biomass than plants from old field populations early in the growing season, but mine plants were half as likely to flower as old field plants. These results indicate genotypic and phenotypic divergence between mine and non-mine populations linked to metal tolerance.


1 - Kansas State University, Biology, Ackert Hall Rm 232, Manhattan , KS, 66506-4901, United States

Keywords:
local adaptation
divergence
phenotypic plasticity 
heavy metal tolerance
Genetic diversity.

Presentation Type: Oral Paper
Number:
Abstract ID:757
Candidate for Awards:None


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