Tomato (Solanum lycopersicum) is a commercially important vegetable crop grown worldwide. In October 2018, diseased tomato plants were observed in a field in Nashik, Maharashtra state in India. The plants showed symptoms including leaf yellowing, mosaic and mottling.
Leaf samples from four symptomatic plants (NSK-Tom-01-04) were tested with antisera raised against Cucumber mosaic virus, Groundnut bud necrosis virus and Tobacco mosaic virus (TMV), and a broad-spectrum antiserum against Cowpea mild mottle virus (CPMMV; antiserum gifted by George Thottapalli) in direct antigen coating (DAC)-ELISA.
Three samples reacted positively with the CPMMV antiserum (NSK-Tom-01, NSK-Tom-02 and NSK-Tom-03) and the fourth sample (NSK-Tom-03) reacted positively only with the TMV antiserum. Mechanical sap transmission of the CPMMV-positive leaf samples produced similar symptoms on tomato plants 8-10 days post-inoculation. To confirm infection, the inoculated plants were tested using the CPMMV antiserum in DAC-ELISA and they reacted positively.