Establishing a protocol for the artificial inoculation of Verticillium dahliae on eggplant (Solanum melongena L.)

Abstract

Verticillium wilt is a significant soilborne disease affecting eggplant (Solanum melongena L.) production worldwide. This study aims to establish a standardized protocol for the artificial inoculation of V. dahliae on eggplant to facilitate disease resistance screening in breeding programs. The research was conducted at the Guterman Greenhouse Complex, Cornell University, and involved multiple experiments to optimize inoculation conditions. Three V. dahliae isolates were tested for pathogenicity on two eggplant cultivars, and the effects of spore concentration, immersion time in the spore suspension, root cutting, and inoculation method (dipping vs. drenching) were evaluated. The study also compared the susceptibility of 24 eggplant varieties, including 12 Solanum aethiopicum varieties. Results indicated significant differences in disease severity and progression based on isolate virulence and interaction between genotype and isolate, as well as some inoculation parameters. It was concluded that 105 conidia mL-1 is a high enough concentration to produce severe symptoms, as well as 5 minutes of immersion in the spore suspension. Cutting the tips of the roots does not influence disease severity when performing artificial inoculations, and dipping the roots causes more severe symptoms in less time than root drenching. All the varieties inoculated were found to be highly susceptible 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.