Virus - Vector Relationships of Yellow Mosaic Virus and Whitefly (Bemisia tabaci) in Ridge Gourd

Yellow mosaic virus disease of Ridge gourd caused by begomovirus is a major constraint in cucurbits cultivation. Ridge gourd yellow mosaic virus (YMV) was transmitted to healthy ridge gourd plants only by the whitefly, Bemisia tabaci and not through sap inoculation. Even a single viruliferous whitefly was able to cause 20.00 per cent infection but 100 per cent infection was obtained when 10 whiteflies were used per plant. YMV disease was successfully transmitted through B. tabaci whitefly which were given 12 h of Threshold Acquisition access period (AAP) and inoculation period. The percentage of transmission increased with increase in both acquiisition and inoculation feeding periods. Ten adult B. tabaci whiteflies were sufficient to cause 100 % transmission and the whitefly retained the infectivity up to be 6-9 days. Keywords: YMV, ridge gourd, whitefly, virus-vector relationships.