RESPONSE OF GREENHOUSE-GROWN CUCUMBER CULTIVARS TO AN ISOLATE OF ZUCCHINI YELLOW MOSAIC-VIRUS (ZYMV)

Mechanical inoculation of 12 greenhouse-grown cucumber (Cucumis sativu s) cultivars at the three- to four-leaf stage with an isolate of zucch ini yellow mosaic virus (ZYMV) from Saudi Arabia resulted in various s ymptoms in 11 cultivars. Significant differences in plant height, frui t numbers, and fruit weight were observed between the inoculated and t he control plants of the 11 affected cultivars. The cultivar Dina was asymptomatic, and no significant differences were observed between the inoculated and control plants for any of the parameters tested. Virus recovery test from cultivar Dina performed on the susceptible cultiva r, Farol, together with lack of virus detection by enzyme-linked immun osorbent assay (ELISA) indicated that this ZYMV isolate did not infect Dina. However, inoculation of Dina at the cotyledon stage revealed mi nor symptoms that were confined to a few of the lower leaves, suggesti ng that Dina is resistant but not immune to this ZYMV isolate. Virus t iter in Dina was low and the virus was restricted to the older leaves; whereas in Farol virus titer was considerably higher and the virus sp read to all leaves.