INTEGRATING GENETICS, GENOMICS, AND PHYSIOLOGY TO INFORM BREEDING FOR FIRE BLIGHT RESISTANCE IN APPLE

Fire blight is an economically damaging bacterial disease that impacts Washington apple production. Fire blight is currently partially controlled through unsustainable chemical applications and cultural methods. Development of apple cultivars that are resistant to fire blight through breeding is a potential, long-term solution. Understanding disease progression and factors that impact resistance/susceptibility to fire blight can complement routine breeding methods and thus, enable a more comprehensive breeding approach. The goal of this project is to leverage genetics, genomics, and physiology to develop an integrated understanding of resistance to fire blight and thus, enable more informed, efficient breeding for resistance to fire blight. This goal will be accomplished via three research objectives:Objective 1. Characterize resistance/susceptibility to fire blight quantitative trait loci in a pedigree-connected apple reference germplasm set.Objective 2. Evaluate fire blight disease progression and determine leaf/shoot cellular polymorphisms associated with resistance to fire blight.Objective 3. Evaluate the effects of plant shoot vigor, as influenced by rootstock, on fire blight severity in important breeding parents 'Cripps Pink', 'Honeycrisp', 'Enterprise.'