P-412 - Genetic and Pathogenic Characterization of Fusarium spp. associated with Sugarcane in South Florida

Florida accounts for 53% of U.S. sugar cane production, primarily in the Everglades Agricultural Area (EAA). However, increasing poor stand establishment due to seed non-germination concerns growers, impacting yield. Our previous survey on soil borne pathogens on the EAA identified Fusarium spp. as a potential contributor, highlighting the need for species identification and characterization to support management strategies. Forty Fusarium spp. isolates, from non-germinated sugarcane billets, were molecularly characterized based on the  TEF1 and IGS sequences, the most prevalent species identified were Fusarium sacchari (52.5%) and F. andiyazi (32.5%), while the remaining 15% were identified as F. proliferatum, F. oxysporum, F. thapsinum, and F. pernambucanum. For the greenhouse, pathogenicity assay isolates of F. sacchari (n=3) and F. andiyazi (n=3) from different locations were inoculated on CP96-1252 and CP07-2320. All isolates in both varieties delayed seedling growth without preventing germination, highlighting their negative impact on plant development and suggesting that Fusarium spp. contribute to growth suppression, though they may not be the sole cause of non-germination under field conditions. Furthermore, genetic and phenotypic variability were observed in the Fusarium spp. population across this region. These findings suggest that Fusarium spp. contribute to sugarcane growth suppression, reinforcing the need for management. This knowledge is essential for disease control strategies, particularly in this main U.S. sugarcane-producing region.