P-276 - Optimizing a root-dipping protocol to screen eggplant (Solanum melongena L.) for Verticillium dahliae resistance

Verticillium wilt, caused by the fungal pathogen Verticillium dahliae, is a major constraint to global eggplant (Solanum melongena L.) production. Disease management is challenging due to its microsclerotia that may persist in soil for up to 14 years in the absence of a host. In addition, there are currently no commercial cultivars available with verified resistance to this disease. Existing studies vary in inoculation methods, differing in spore concentration, dipping duration, and whether roots are cut before inoculation. This study aims to optimize the parameters for inoculation of Verticillium dahliae in eggplant. Root-dipping inoculation experiments were conducted to assess the effects of spore concentration, immersion time in the spore suspension, and the inclusion of root cutting on disease development. Root-drenching was also compared with root-dipping as a potentially more efficient inoculation method. Preliminary experiments showed that the root-dipping method significantly increased disease severity compared to root drenching. On the other hand, variations in spore concentration, immersion duration, and root cutting did not significantly impact disease development. The optimized protocol is currently being used in an experiment to evaluate 56 accessions from the USDA eggplant germplasm for resistance to Verticillium wilt. The established protocol provides a reliable method for screening eggplant germplasm for resistance to Verticillium wilt, contributing to the development of resistant cultivars.