Host plant resistance against aphids in Capsicum

Pepper (Capsicum annuum) is an economically-important crop which is mainly grown as a vegetable in the Netherlands. The aphid species Myzus persicae and Aulacorthum solani are two major pest insects of agricultural crops, including pepper. They cause direct damage by feeding such as defoliation, wilting or fruit deformation, but also indirect damage by transmitting viruses through their saliva. The damage caused by these aphids greatly affects fruit yield. Both aphids can be controlled by conventional synthetic insecticides, but some aphid populations are developing resistance to some compounds. Moreover, because insecticides pose a problem to our health and the environment, more and more compounds are being banned. An alternative to rely less on insecticides to control aphids is integrated pest management using biological control combined with host plant resistance. However, resistance to A. solani in pepper is currently lacking, and the introgression of a previously identified resistance to M. persicae from a C. baccatum accession into a C. annuum background did not result in a resistant phenotype. This project aims to identify a source of resistance to A. solani and to characterize its genetics and mechanism. It also aims to identify and map an additional factor needed for the resistance to M. persicae to be functional in C. annuum. From a scientific point of view, this project will contribute to improving our understanding of insect resistance genetics and mechanisms, which are not well characterized. From a societal point of view, this project will also provide knowledge and plant material for plant breeders to create new aphid-resistant pepper varieties, and for pepper growers to rely less on insecticides.