INFLUENCE OF VIRAL INFECTION ON LATE BLIGHT DEVELOPMENT

Abstract

Multiplex of diseases is common in potato under field conditions and development of one pathogen is
affected by the presence of other pathogens. In the present study, the effect of viruses infection (PVX, PVYo, PVM, PVS),
individually and in mixed infection, was studied on development of late blight. Results revealed that development of late
blight is affected by virus infection and virus-infected plants had less development of Phytophthora infestans (except PVS)
than were healthy ones. Plants infected with PVS enhanced late blight susceptibility (36.30%) while other viruses decreased
it. Highest reduction in disease severity (71.48%) was recorded in PVX followed by PVM/PVYo (65.93%) infected leaves.
Amount of sporulation was also significantly higher on PVS infected leaves while it was significantly smaller on leaves
infected with other viruses.