The Infection Process and Symptom Expression of Zucchini Yellow Mosaic Virus Isolates From Squashes in Cucurbit Crops

Abstract

Cucurbit species are susceptible to several diseases and different viruses have been reported to the reason of cucurbit diseases. Zucchini yellow mosaic virus (ZYMV) is one of the most economically important viral diseases. It presents an important biological variability and often causes devastating epidemics in cucurbit crops. In the present study, isolates of ZYMV were obtained from summer and winter squashes in different regions of Turkey, and the symptom expression and severity of cucurbit crops inoculated with ZYMV isolates were investigated. Cucurbit seedlings were mechanically inoculated at the cotyledon stage, and scored for symptoms on cotyledons and true leaves 4 weeks after inoculation. Symptoms of infection by ZYMV isolates first appeared on plants within seven days after inoculation (DAI). The majority of cucurbit species was systemically infected with all isolates and showed the typical mosaic, severe mosaic, mottle, and deformed leaves symptoms. Disease occurrence, severity and the area under disease progress curve (AUDPC) increased in response to increasing DAI (P < 0.05).