Ecological Factors that Influence the Emergence of New Crop Diseases

Viruses transmitted by insects are the most important emerging pathogens of crops worldwide.  Potato virus Y is one of the most serious pathogens of potato crops globally, reducing both yield and quality. New, highly damaging recombinant virus strains have emerged in recent decades, adapted rapidly to potato ecosystems, and dominated virus populations over vast geographical areas.  Our research is focused on understanding the ecological factors that drive virus epidemiology, allowing recombinant virus strains to emerge, spread rapidly, and become the dominant viruses.

Many factors influence the emergence and ecological success of new insect-transmitted viruses, including the ability and frequency of different virus strains to co-exist in the same host cells and give rise to new recombinants, the ability of the recombinants to survive or dominate in a mixed infection, the efficiency by which the recombinants are acquired and transmitted by their insect vectors, and the ability of the recombinants to dominate an infection when inoculated into a new host by the insect. Adding to the improbability of the emergence of new virus strains is that host and vector populations, and the landscapes in which they interact, differ widely in their ability to support virus infection and virus transmission.

Our research is addressing the drivers of virus emergence at multiple scales, including the landscape, the potato field, and within individual hosts.  We will present data on the influence of landscape structure, vector community composition, transmission dynamics, and within-host processes on the emergence and spread of potato virus Y.