Supported by NSERC Canada and the Canadian Foundation for Innovation.
Longitudinal trends in climate drive flowering time clines in North American Arabidopsis thaliana
Article first published online: 3 MAY 2012
© 2011 The Authors. MicrobiologyOpen published by Blackwell Publishing Ltd.
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
Ecology and Evolution
Volume 2, Issue 6, pages 1162–1180, June 2012
How to Cite
Samis, K. E., Murren, C. J., Bossdorf, O., Donohue, K., Fenster, C. B., Malmberg, R. L., Purugganan, M. D. and Stinchcombe, J. R. (2012), Longitudinal trends in climate drive flowering time clines in North American Arabidopsis thaliana. Ecology and Evolution, 2: 1162–1180. doi: 10.1002/ece3.262
- Issue published online: 12 JUN 2012
- Article first published online: 3 MAY 2012
- Received: 10 February 2012; Revised: 21 March 2012; Accepted: 26 March 2012
- ecological genomics;
- invasive species;
- parallel adaptation;
Introduced species frequently show geographic differentiation, and when differentiation mirrors the ancestral range, it is often taken as evidence of adaptive evolution. The mouse-ear cress (Arabidopsis thaliana) was introduced to North America from Eurasia 150–200 years ago, providing an opportunity to study parallel adaptation in a genetic model organism. Here, we test for clinal variation in flowering time using 199 North American (NA) accessions of A. thaliana, and evaluate the contributions of major flowering time genes FRI, FLC, and PHYC as well as potential ecological mechanisms underlying differentiation. We find evidence for substantial within population genetic variation in quantitative traits and flowering time, and putatively adaptive longitudinal differentiation, despite low levels of variation at FRI, FLC, and PHYC and genome-wide reductions in population structure relative to Eurasian (EA) samples. The observed longitudinal cline in flowering time in North America is parallel to an EA cline, robust to the effects of population structure, and associated with geographic variation in winter precipitation and temperature. We detected major effects of FRI on quantitative traits associated with reproductive fitness, although the haplotype associated with higher fitness remains rare in North America. Collectively, our results suggest the evolution of parallel flowering time clines through novel genetic mechanisms.