P-467 - First Report of Southern Blight (Agroathelia rolfsii) infecting Blue Star Creeper (Isotoma fluviatilis) in Tennessee

Blue star creeper (Isotoma fluviatilis) is a perennial ground cover commonly used in landscapes.  In October 2024, landscape plants in Tennessee, United States exhibited symptoms depicting water-soaked lesions at the base of the stem, wilting, leaf yellowing, and eventual plant death leading to large patches of dead vegetation. Pathogen identification based on the morphological characteristics from axenic culture revealed typical features of Agroathelia rolfsii, characterized by dense, white, cottony mycelia and spherical sclerotia ranging from 0.8-2.1 mm in diameter (n=25). Molecular analysis targeting three different loci further confirmed A. rolfsii. Ongoing pathogenicity tests with 10 inoculated plants and 10 control plants under greenhouse conditions aim to confirm Koch’s postulates. This report is the first documented case of southern blight in I.fluviatilis, expanding the current host range of A. rolfsii in landscape plants. These findings underscore the importance of sustainable disease management in mitigating potential disease outbreaks and economic losses in ornamental production and the landscape industry.