Simultaneous Detection of Three Tobamoviruses in Cucurbits by Rapid Immunofilter Paper Assay

A multi-rapid immunofilter paper assay (multi-RIPA) system was prepared for simultaneous diagnosis of three Tobamoviruses, Cucumber green mottle mosaic virus (CGMMV), Kyuri green mottle mosaic virus (KGMMV), and Zucchini green mottle mosaic virus (ZGMMV) in cucurbitaceous crops. Each of these viruses was specifically detected by the multi-RIPA from cucumber, watermelon, zucchini, and bottle gourd inoculated with the three Tobamoviruses singly or in combination. The three viruses could infect cucumber, watermelon, and bottle gourd ; however, CGMMV could not infect zucchini as the latex-coated CGMMV antibody showed a negative reaction in the multi-RIPA of the virus-infected plant extract. When the minimum detection level of multi-RIPA was compared with that of double antibody sandwich-enzyme-linked immunosorbent assay (DAS-ELISA) using CGMMV, the latter was 10 times more sensitive than the former. The detection limit of the multi-RIPA for the purified CGMMV was 50 ng/ml. In a survey of the threeviruses in cucurbits growing in commercial fields in 1999 and 2000, CGMMV was detected in watermelon and cucumber, and ZGMMV was detected only in zucchini growing in plastic houses at the suburbs of Chonju, Korea. However, KGMMV was not found in the commercially growing cucurbit crops in our study, The results suggest that the multi-RIPA can be a simple, rapid, specific and convenient tool to detect simultaneously the Tobamoviruses.