Plants are living in a microbial world. They interact not only with microbes in the soil but also the ones living in their flowers. These microbial partners can be beneficial or harmful. One of the most devastating epidemics in ornamental apple trees – fire blight – is caused by bacterial infection initiated during bloom, and can be spread from flower to flower by visiting pollinators. Breakthrough in suppressing this pathogenic microbe is needed.

At Holden, we aim to develop plant probiotics against fire blight using beneficial flower microbes from the resistant cultivars of ornamental apples (crabapples). Holden has established an invaluable resource of crabapple cultivar collection for over 30 years. At Holden’s long-term experiment plot of crabapples, every single tree has been permanently tagged. These cultivars differ in their flowers such as color and smell and disease resistance. We will monitor their flowering and study flower microbes.