PARENT SESSION
Symposium #1: Ecology and agriculture.
Sponsored by ESA Agroecology section
Organized by: D. Andow, S. Gliessman, N. Jordan, M. Liebman, B. Maxwell, D. Neher, I. Perfecto, A. Power.
Monday, August 6, 2001. 8:00 AM to 12:00 PM. Lecture Hall

Ecological consequences of plant viruses in natural and agricultural systems.

Power, Alison¹, ¹

ABSTRACT- Temporal and spatial heterogeneity in host plants and host communities have important influences on the spread of plant diseases. Some diseases, like the aphid-transmitted barley yellow dwarf virus (BYDV), infect both agricultural crops and wild host plants. In addition to its crop hosts (wheat, oats, barley, rice, corn), BYDV infects over 150 species of wild grasses. Data from recent field experiments with BYDV in mixed host plant communities indicate that host diversity can have striking effects on virus spread and the impacts of disease on hosts. In addition, highly suitable host species can serve as sources of viruses that result in negative impacts on less suitable hosts. These results suggest that agricultural crops can serve as sources of diseases that may be having subtle, but significant effects on natural plant communities. Understanding the spread and impact of plant viruses in diverse plant communities also improves our ability to predict the ecological consequences of the release of crops expressing transgenic virus resistance.

KEY WORDS: disease, pathogen, agriculture, diversity