LWV21024 Aphid and whitelfly resistance in pumpkin and squash (BO-68-001-050)

Host plant resistance against the insects that transmit viruses does not only result in reduced transmission of several viruses, including newly emerging ones, it also lowers feeding-related damage of insects. Breeding of insect resistant varieties is therefore a durable strategy for both insect and virus control in Cucurbita. In this project, the first steps towards this goal are taken. We will first develop an insect assay to evaluate survival and reproduction of both aphids and whiteflies on pumpkin and squash. Next, we will undertake a comprehensive evaluation of the Cucurbita germplasm, including the widely cultivated C. pepo, C. moschata and C. maxima, and (crossable) wild relatives. The most promising resistant sources will be genetically characterized using bi-parental mapping, resulting in molecular markers tagging the resistance gene(s), which will be used to generate early-generation breeding lines. The mechanism of resistance will be characterized using a range of approaches including a detailed characterization of insect biology and behavior on, and transcriptomics and metabolomics of, resistant and susceptible plants. When the project is successful it will provide companies with all tools needed for the development of novel varieties that can be grown with less or no pesticide inputs.