Advanced centre for Plant Virology, Division of Plant Pathology, Indian Agriculture Research Institute, New Delhi-110012, India.
Three isolates (CMV-Ban, CMV-Aur and CMV-Pune) of Cucumber mosaic virus (CMV) were used in this study. CMV-Ban was isolated from tobacco sample collected from Bangalore, CMV-Aur was isolated from tomato fruit collected from Aurangabad and CMV-Pune isolated from cucumber collected Pune. Host reactions were studied by sap inoculation of bottle gourd, cucumber, Chenopodium amaranticolor, pumpkin (Cucumis moschata), tobacco (Nicotiana tabacum, N. benthamiana and N. glutinosa) and tomato plants under greenhouse conditions. All the three isolates induced similar types of symptoms in cucumber, Chenopodium amaranticolor, tobacco and tomato. None of the isolates produced any symptoms in bottle gourd and pumpkin. These isolates induced the most severe symptoms in N. glutinosa compared to the other hosts. Variations of symptom severity were observed among the isolates. The coat protein (CP) gene of these three isolates contained 670 nucleotides and shared 99.5% identity among each other. The present isolates however shared 85.8% to 93.6% sequence identity with the previously reported Indian isolates belonging to subgroup IB.The CMV isolates in this study, although originating from different host plants and different regions of India, are biologically and genetically similar among themselves.
