Genetic and Molecular Disease Management of Powdery Mildew, Bacterial Canker, and X-Disease in US Pacific Northwest Sweet Cherry: Current Obstacles and Future Opportunities

Abstract

The Pacific Northwest produces most sweet cherry fruit for the United States, which is second to Turkey in global sweet cherry production; however, yield is impeded by infection-incurred losses. Endemic pathogens significantly limiting production include Podosphaera cerasicausing powdery mildew, Pseudomonas syringaepv. syringaeand Pseudomonas syringaepv. morsprunorumraces 1 and 2 causing bacterial canker, and ‘ Candidatus Phytoplasmapruni’ causing X-disease. While significant resources are annually spent to manage these pathogens, use of disease resistant cultivars as well as an understanding of the underlying genetic and molecular mechanisms involved in plant defense responses might facilitate better infection management solutions. In particular, identification of genes responsible for conferring resistance to these pathogens and then combining resistance alleles into new sweet cherry cultivars offers a sustainable solution for disease management.