Towards breeding thrips-resistant varieties in Capsicum

Thrips are small insects but a major pest in pepper cultivation worldwide. They are difficult to control because of their high reproductive rate, short life cycle, cryptic behaviour and their wide host range. Protective measures such as chemical and biological control are used to prevent thrips outbreaks in crops, but these are only partially effective. Therefore, host plant resistance is a desired trait for pepper growers. Previously, thrips-resistant pepper accessions were identified. The aim of this thesis is to further characterize the resistance mechanism of the resistant pepper accession CGN16975, and to study its potential as a source for breeding thrips-resistant Capsicum varieties. The gene or genes on chromosome 6 that contribute to thrips resistance were fine mapped and a multidisciplinary approach was used to select candidate genes. Furthermore the role of metabolites in this resistance mechanism was studied. Altogether, the work in this thesis contributes to protection of pepper against thrips, and shows that the resistance mechanism in CGN16975 can be used as a source for breeding thrips-resistant Capsicum varieties.