THE COSTS AND BENEFITS OF TOLERANCE TO COMPETITION IN IPOMOEA PURPUREA, THE COMMON MORNING GLORY
Article first published online: 28 MAR 2014
© 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.
Volume 68, Issue 6, pages 1698–1709, June 2014
How to Cite
Chaney, L. and Baucom, R. S. (2014), THE COSTS AND BENEFITS OF TOLERANCE TO COMPETITION IN IPOMOEA PURPUREA, THE COMMON MORNING GLORY. Evolution, 68: 1698–1709. doi: 10.1111/evo.12383
- Issue published online: 3 JUN 2014
- Article first published online: 28 MAR 2014
- Accepted manuscript online: 24 FEB 2014 12:45PM EST
- Manuscript Accepted: 11 FEB 2014
- Manuscript Received: 19 SEP 2013
- genetic variation;
Tolerance to competition has been hypothesized to reduce the negative impact of plant–plant competition on fitness. Although competitive interactions are a strong selective force, an analysis of net selection on tolerance to competition is absent in the literature. Using 55 full/half-sibling families from 18 maternal lines in the crop weed Ipomoea purpurea, we measured fitness and putative tolerance traits when grown with and without competition in an agricultural field. We tested for the presence of genetic variation for tolerance to competition and determined if there were costs and benefits of this trait. We also assessed correlations between tolerance and potential tolerance traits. We uncovered a fitness benefit of tolerance in the presence of competition and a cost in its absence. We failed to detect evidence of additive genetic variation underlying tolerance, but did uncover the presence of a significant maternal-line effect for tolerance, which suggests its evolutionary trajectory is not easily predicted. The cost of tolerance is likely due to later initiation of flowering of tolerant individuals in the absence of competition, whereas relative growth rate was found to positively covary with tolerance in the presence of competition, and can thus be considered a tolerance trait.