These authors contributed equally to this work.
Rapid evolutionary divergence and ecotypic diversification of germination behavior in weedy rice populations
Article first published online: 13 MAY 2011
© 2011 The Authors. New Phytologist © 2011 New Phytologist Trust
Volume 191, Issue 4, pages 1119–1127, September 2011
How to Cite
Xia, H.-B., Xia, H., Ellstrand, N. C., Yang, C. and Lu, B.-R. (2011), Rapid evolutionary divergence and ecotypic diversification of germination behavior in weedy rice populations. New Phytologist, 191: 1119–1127. doi: 10.1111/j.1469-8137.2011.03766.x
- Issue published online: 11 AUG 2011
- Article first published online: 13 MAY 2011
- Received: 17 January 2011, Accepted: 5 April 2011
- ecotypic differentiation;
- latitudinal variation;
- local adaptation;
- plant–environment interaction;
- temperature response;
- weed evolution
- •Feral plants have evolved from well-studied crops, providing good systems for elucidation of how weediness evolves. As yet, they have been largely neglected for this purpose. The evolution of weediness can occur by simple back mutations in domestication genes (domestication in reverse). Whether the evolutionary steps to weediness always occur in reverse remains largely unknown.
- •We examined seed germination behavior in recently evolved weedy rice (Oryza sativa f. spontanea) populations and their coexisting cultivars in eastern and north-eastern China to address whether ‘dedomestication’ is the simple reverse of domestication.
- •We found that these weedy populations did not diverge from their progenitors by reverting to the pre-domestication trait of seed dormancy. Instead, they have evolved a novel mechanism to avoid growing in inappropriate environments via changes in critical temperature cues for seed germination. Furthermore, we found evidence for subsequent ecotypic divergence of these populations such that the critical temperature for germination correlates with the local habitat temperature at latitudinal gradients.
- •The origins of problematic plant species, weeds and invasives, have already been studied in detail. These plants can thus be used as systems for studying rapid evolution. To determine whether and how that evolution is adaptive, experiments such as those described here can be performed.