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Genetic Constraints and Selection Acting on Tolerance to Herbivory in the Common Morning Glory Ipomoea purpurea.

Publication ,  Journal Article
Tiffin, P; Rausher, MD
Published in: The American naturalist
December 1999

Tolerance to herbivory minimizes the effects of herbivory on plant fitness. In the presence of herbivores, maximal levels of tolerance may be expected to evolve. In many plant species, however, tolerance is found at an intermediate level. Tolerance may be prevented from evolving to a maximal level by genetic constraints or stabilizing selection. We report on a field study of Ipomoea purpurea, the common morning glory, in which we measured three types of costs that may be associated with tolerance and the pattern of selection acting on tolerance to two types of herbivore damage: apical meristem damage and folivory. We used genetic correlations to test for the presence of three types of costs: a trade-off between tolerance and fitness in the absence of herbivore damage, a trade-off between tolerance and resistance, and genetic covariances among tolerance to different types of damage. We found no evidence that tolerance to apical meristem damage or tolerance to folivory was correlated with resistance, although these two types of tolerance were positively correlated with one another. Tolerance to both types of damage involved costs of lower fitness in the absence of herbivory. Selection acting on tolerance to either type of herbivory was not detected at natural levels of herbivory. Selection is expected to act against tolerance at reduced levels of herbivory and favor tolerance at elevated levels of herbivory. In addition, significant correlational selection gradients indicate that the pattern of selection acting on tolerance depends on values of resistance. Although we found no evidence for stabilizing selection, fluctuating selection resulting from fluctuating herbivore loads may be responsible for maintaining tolerance at an intermediate level.

Duke Scholars

Published In

The American naturalist

DOI

EISSN

1537-5323

ISSN

0003-0147

Publication Date

December 1999

Volume

154

Issue

6

Start / End Page

700 / 716

Related Subject Headings

  • Ecology
  • 31 Biological sciences
  • 06 Biological Sciences
 

Citation

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Tiffin, P., & Rausher, M. D. (1999). Genetic Constraints and Selection Acting on Tolerance to Herbivory in the Common Morning Glory Ipomoea purpurea. The American Naturalist, 154(6), 700–716. https://doi.org/10.1086/303271
Tiffin, Peter, and Mark D. Rausher. “Genetic Constraints and Selection Acting on Tolerance to Herbivory in the Common Morning Glory Ipomoea purpurea.The American Naturalist 154, no. 6 (December 1999): 700–716. https://doi.org/10.1086/303271.
Tiffin, Peter, and Mark D. Rausher. “Genetic Constraints and Selection Acting on Tolerance to Herbivory in the Common Morning Glory Ipomoea purpurea.The American Naturalist, vol. 154, no. 6, Dec. 1999, pp. 700–16. Epmc, doi:10.1086/303271.
Journal cover image

Published In

The American naturalist

DOI

EISSN

1537-5323

ISSN

0003-0147

Publication Date

December 1999

Volume

154

Issue

6

Start / End Page

700 / 716

Related Subject Headings

  • Ecology
  • 31 Biological sciences
  • 06 Biological Sciences