Using two attenuated isolates of cucumber mosaic virus and watermelon mosaic virus to control cucumber mosaic disease

Abstract

To establish biological control for cucumber mosaic disease, we evaluated control effect of attenuated isolates of cucumber mosaic virus (CMV) and watermelon mosaic virus (WMV). In 2015 and 2017, cucumber seedlings were inoculated with the attenuated CMV-CM14 and WMV-WM14 isolates, and grown in greenhouses. When mosaic disease severity in the control plots increased to as much as 93.3–100%, the protective inoculation with the two attenuated isolates significantly suppressed cucumber mosaic disease. In 2023, the control of mosaic disease was evaluated in production fields using the CMV-CM14- and WMV-WM14-inoculated cucumber seedlings. The results showed that protective inoculation with the two attenuated isolates was effective to control the disease even under medium occurrence conditions. Our results suggest that protective inoculation with the two attenuated isolates can be effective to suppress the infections of CMV and WMV strains occurring in Kyoto Prefecture.