DISSERTATION RESEARCH: Virus Roles in Wild Cucurbita pepo and the Risks of Genetically Engineered Virus Resistance

Cornell University, Ithaca NY

Investigators

Abstract

Although plant pathogens can significantly affect wild plants populations, the ecology of viruses in wild plant populations is rarely studied. Two ecological risks of genetically engineered (GE), virus-resistant crops (into which genes for virus-resistance have been inserted) prompt a need to understand the interactions of viruses within plants and the impact of viruses on wild plant populations. (1) If GE, virus-resistant crops interbreed with nearby, closely related wild plant populations, then GE virus resistance genes could enter wild populations of plants. If the targeted virus typically suppresses wild plant reproduction or survival, then virus- resistance may increase wild plant fitness and potentially increase the wild plant's invasiveness in natural and agricultural habitats. (2) If several viruses compete with each other to successfully infect a plant (crop or wild), then the plant's resistance to one virus could result in increased infection by formerly less competitive viruses. This project will examine a GE, virus-resistant squash (Cucurbita pepo) and a wild squash to examine the affect of viral infection in wild plant populations and to assess the associated risks of GE virus-resistance. In research to date, the PIs have confirmed with controlled experiments that GE virus-resistance increases wild squash fitness when virus infection is prevalent. In 2004, the PIs will determine the prevalence of virus infection in wild squash populations to predict the affect of GE virus-resistance on non-experimental, wild squash fitness. Prior research has detected competition between squash viruses. In 2004 and 2005, the PIs will conduct a series of greenhouse experiments to study this interaction more rigorously. This research will provide valuable information about virus ecology and assess potential ecological impacts of GE virus-resistance in crops.