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POSTERS: Pathogen detection, quantification and diagnosis

Prevalence and early detection of bermudagrass root-infecting pathogens accessed by novel real-time PCR assays.
Aline Badial - Mississippi State University. Jonas King- Mississippi State University, Matthew Tucker- Mississippi State University, Maria Tomaso-Peterson- Mississippi State University

Bermudagrass Decline (BD) is a destructive disease of ultradwarf bermudagrass (UDB) putting greens in the southeastern United States. Previous studies reported a single ectotrophic root-infecting (ERI) fungus associated BD. Recently, three novel ERI fungi have been associated with BD of UDB. Current diagnostic methods for identification of ERI fungi can be inconclusive and inaccurate for distinguishing ERI fungal species. Here we present the development and application of novel real-time PCR assays designed to detect four ERI fungi associated with BD. The distribution of those fungi in UDB samples collected from putting greens across the southeastern United States was also accessed. Assay validation was carried out using DNA and plasmids and the Limit of Detection (LOD) was calculated for each assay. Results revealed novel real-time PCR assays effectively distinguished all four fungi associated with infected UDB root samples. The LOD was established at 1pg/µL of DNA proving the sensitivity of the method to detect very low amounts of fungal DNA. Fungal presence was detected in twenty-nine of thirty UDB root samples, with one fungus presenting a wider distribution and two fungi having higher DNA quantities when compared to UDB root material. The novel assays provide a reliable method for accurate detection of the four ERI fungi investigated. Due to the assay’s high sensitivity, this method can be used as a tool for early detection of BD in roots of UDB putting greens.