Anderson, Rebecca R. , Byers, Diane .
Selection and adaptation in heterogeneous soil nutrient environments.
ARABIDOPSIS thaliana is a species native to western Eurasia but is now fairly widespread throughout North America, Europe, and Asia. Given this distribution, phenotypic plasticity is likely to facilitate its success in the colonization of different environments. Phenotypic plasticity is the ability of a single genotype to demonstrate variable phenotypes when exposed to different environments and can be an important adaptive mechanism. We are using Arabidopsis thaliana from natural populations as a model species to better understand the role of phenotypic plasticity in response to selection in variable soil nutrient environments. We have compared the response of 18 traits from 180 maternal lines in 18 Michigan populations of wild A. thaliana in low and high soil phosphorus conditions comparable to the sites where these populations were sampled. Timing of reproduction and other life cycle shifts are significantly delayed under low phosphorus conditions. Allocation of resources is also affected by changing nutrient conditions. For example, plants produce significantly more fruits under high phosphorus conditions, though the average fruit length increases with low phosphorus. Several traits had significant treatment by population interactions including above ground biomass and height at flowering day. Because there is a fitness cost in the form of lower fruit production in response to this natural range of nutrient variation, selection for phenotypic plasticity as this species colonizes different habitats is likely. This research compared these plant responses with the natural soil nutrient variation of the wild populations (their selection history), a step not previously taken in most A. thaliana ecological research. This allows us to evaluate the potential role phenotypic plasticity plays in colonization of its current range of environments and adaptation to changing environments. -DU
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1 - Illinois State University, Department of Biological Sciences, Campus Box 4120, Normal, Illinois, 61790-4120, USA
2 - Illinois State University, Department of Biological Sciences, Campus Box 4120, Normal, Illinois, 61790-4120, USA
Presentation Type: Oral Paper:Papers for Sections
Date: Tuesday, August 1st, 2006
Time: 8:00 AM