Chiang, Jyh-min , McEwan, Ryan W. , Ballard, H. E. , Wyatt, Sarah .
Simulated environments reveal ecotypic differentiation in Arabidopsis thaliana.
Arabidopsis thaliana, the "model organism" in plant biology, has a natural range which extends across a wide variety of environmental conditions. We suspected that these environmental conditions serve as ecological filters and may drive sub-species level or "ecotypic" differentiation. We examined the potential for ecotype differentiation within A. thaliana by planting species from across the range into simulated environmental conditions. In particular we used a reciprocal transplant procedure in which seeds from Finland, the United Kingdom and Cape Verde Island, were planted into controlled environments mimicking those three locales. For comparison, we also included seeds from Kazakhstan and from the "Columbia" A. thaliana (COL) typically used in molecular research. The environments differed in terms of day length (Finland > United Kingdom > Cape Verde, long to short) and temperature (Cape Verde > Finland > United Kingdom, high to low). There was dramatic temporal variation in silique production among the populations as COL first produced mature siliques 35 days after planting, while some Finland replicates produced siliques > 100 days after COL had begun production. Total silique production per replicate differed among populations (P < 0.0001), with WT (2306 ± 133) nearly twice that of Cape Verde (1169 ± 152). Environmental conditions influenced total silique production (P = 0.014); however, populations did not exhibit fidelity to their environmental origin, and COL silique production was greatest across all conditions. Our work provides strong evidence for ecotypic differentiation in A. thaliana and sets the stage for ongoing molecular investigations of the population-level speciation process.
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1 - Ohio University, Department of Environmental & Plant Biology, Porter Hall, Richland Avenue, Athens, Ohio, 45701-2979, USA
Presentation Type: Poster
Location: Salon C, D & E - Gov Ballroom/Hilton
Date: Tuesday, August 16th, 2005
Time: 12:30 PM