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POSTERS: New and emerging diseases

Outbreak of Xanthomonas in Ohio – a real Paeonia in the neck
John Long - Department of Plant Pathology, The Ohio State University. Taylor Klass- The Ohio State University, Jonathan Jacobs- Department of Plant Pathology, The Ohio State University, Francesca Peduto Hand- The Ohio State University

The bacterial genus Xanthomonas, comprises roughly 30 species that infect hundreds of different plants. This host range includes ornamental plants in the floriculture industry, valued at $223 million in Ohio and $4.37 billion in the United States. The spread of these pathogenic bacteria and damage from severe outbreaks or misidentification is a cause of concern for many producers. In 2013, potted peony plants at an Ohio nursery showed dark purple, necrotic lesions on the leaves. Diagnostic procedures at The Ohio State University identified Xanthomonas hortorum as the causal agent based on colony morphology, partial genome sequencing and fulfillment of Koch’s postulates. Sequence data is nearly identical to a recent Xanthomonas outbreak in Virginia, suggesting that the pathogen is crossing state lines. Currently, there are no damage estimates or rapid screens available. In this study, we generated genome-enabled diagnostic primers specific to X. hortorum. This set of primers is designed to identify X. hortorum from other closely related Xanthomonas species to enable rapid identification and monitoring during future occurrences.