Document: JUL-3-34-58

Will plants be able to evolve in response to climate change? A case study from the Great Plains.

ETTERSON, J.R.*

University of Minnesota, St. Paul, MN 55108 USA ¹

Abstract:
Impending climate change will test the capacity of plants to evolve heat and drought tolerance. This is particularly true in highly fragmented ecosystems, such as the Great Plains, where large distances between habitat patches may prevent migration of plants with the band of climate to which they are adapted. Critical factors in determining evolutionary potential are the amount and nature of genetic variation, and the magnitude and direction of selection for traits associated with fitness in warmer/drier environments. I use a quantitative genetic approach to assess the potential of an annual prairie legume, Chamaecrista fasciculata, to evolve in response to increased temperature. Specifically, I will report the results of a reciprocal transplant experiment along a latitudinal gradient in the Midwest with sites in MN, KS, and OK using pedigreed lines produced from native populations at each of these sites. In all sites, I found a negative linear relationship between the heritability of fecundity and the latitude of population origin. Extremely low levels of genetic variation for fecundity among the MN genotypes suggest that this population does not contain sufficient genetic variation to respond to selection as climate changes. However, there was significant genetic variation in the MN population for four other traits associated with fitness in warmer/drier conditions including leaf area, total plant leaf area, specific leaf area, and reproductive rate. Fecundity selection analysis indicated significant selection on these traits in all three sites. However, the direction of selection is opposite in the MN and OK sites for leaf area, specific leaf area and reproductive rate. This result corroborates previous research that demonstrated strong local adaptation along this climate gradient.

Keywords: evolutionary potential, quantitative genetics, selection analysis

This abstract is being presented at: 2:00 PM in session:
Oral Session #66: Large Scale Climate Change.