PARENT SESSION
Contributed Oral Session 86: Herbivory: Genetic Variability in Insect - Plant Interactions
Wednesday, August 10, 8:00 AM - 11:30 AM, Meeting Room 521 A, Level 5, Palais des congrès de Montréal
Flowering phenology mediates fitness responses of Arabidopsis thaliana to natural insect herbivory.
Bidart-Bouzat, M. Gabriela1, 1 Michigan State University, Hickory Corners, MI
ABSTRACT- Limited experimental evidence exists regarding the role of flowering phenology as a potential escape strategy of plants from herbivory, and whether insect herbivores are likely candidates to impose selection on flowering time. In a common garden experiment, I demonstrated that differences in the flowering phenology of Arabidopsis thaliana (i.e., early vs. late flowering genotypes) influenced plant fitness responses to natural insect herbivory. Overall, early flowering genotypes were more succesful in escaping insect herbivores (which numbers peaked later in the season) and thus, had lower damage and higher fitness than late flowering ones. However, path analysis indicated flowering earlier appeared to be constrained by a positive association between size and age at first reproduction, and fitness. Additionally, insect damage and flowering time were genotype-dependent and associated with fitness suggesting that insect herbivory represents an important factor selecting for early flowering in those environments where insect abundance peaks later in the plant reproductive season.
Key words: Arabidopsis thaliana, Insect herbivory, Flowering phenology, Genotypic variation