Document: ALI-3-23-7

Host plant heterogeneity and the spread of a viral disease in grasses.

POWER, A.G.*

Cornell University, Ithaca, NY 14853 USA ¹

Abstract:
Agricultural history, as well as human history, attests to the fact that diseases are variable in time and space, often moving rapidly from endemic to epidemic status. While much attention has been paid to the temporal dynamics of epidemics, spatial dynamics are less well understood. In the case of plant diseases, we are just beginning to explore the consequences for disease spread of temporal and spatial heterogeneity in host plants and host communities. Research on the aphid-transmitted barley yellow dwarf virus has demonstrated the influence of host plant and host community variation on aphid population dynamics and behavior, which in turn drive virus epidemics. The barley yellow dwarf virus infects over 100 species of wild and domesticated grasses. Recent field experiments indicate that heterogeneity in host community composition can have strong effects on virus spread, driven in part by aphid preferences for particular host species. Moreover, heterogeneity in host plant genotype results in changes in aphid movement behavior that slow virus spread in genetically diverse stands. At the landscape scale, heterogeneity in the availability of agricultural hosts can significantly influence virus epidemiology in wild hosts.

Keywords:

This abstract is being presented at: 1:25 PM in session:
Symposium # 23: Why Variation is Not Just Noise: The Influence of Variability on Plant-Herbivore and Plant-Pathogen Interactions.