Measuring the intrinsic cost of herbivore resistance in plants is important both for assessing the potential for engineered genes to escape and persist in the environment, and for understanding how natural selection acts on defense resource allocation in natural plant populations. This study will apply two genetic approaches to testing the cost of resistance hypothesis. First, the impact of resistance gene on plant growth and resource allocation will be examined by comparing the performance of plants genetically transformed for herbivore resistance with that of control plants of similar genetic backgrounds. This work will be done in collaboration with the PROSAMO research group at Imperial College (Silkwood Park), headed by Dr. Michael J. Crawley. Second, the principal investigator will test for negative genetic correlations among chemical defenses, growth, and reproduction in the absence of herbivores, and examine selection effects on defense production in natural populations of a common weed (Plantago lanceolata). This work, to be done in collaboration with Dr. Deane Bowers at the University of Colorado, will be one of the first studies to apply quantitative genetic analysis to chemical assays of plants from natural populations.
