Satellite-Mediated Protection of Tomato Against Cucumber Mosaic Virus: I. Greenhouse Experiments and Simulated Epidemic Conditions in the Field. M. S. Montasser, Research Associate, Botany Department, University of Maryland, College Park. M. E. Tousignant, and J. M. Kaper. Chemist, and Research Chemist, Microbiology and Plant Pathology Laboratory, Plant Sciences Institute, U.S. Department of Agriculture, Agricultural Research Service, Beltsville, MD 20705. Plant Dis. 75:86-92. Accepted for publication 4 July 1990. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1991. DOI: 10.1094/PD-75-0086.

Cucumber mosaic virus (CMV) strain S, with its naturally occurring satellite, can be used as a biological control agent to protect tomato (Lycopersicon esculentum ‘UC82B’) plants against disease induced by two severe CMV strains (D and 16). In greenhouse experiments, tomato plants were preinoculated or “vaccinated” with total RNA extracted from CMV-S and when challenge-inoculated after 3 wk with the severe strains, were protected against their effects. No synergistic effects were observed in mixed infections of CMV-S and a number of viruses commonly infecting tomato. Satellite-mediated protection was more protective and could be established sooner after vaccination than conventional cross-protection. In field studies, the fruit yield from protected and challenge-inoculated plants was double that of similarly challenged but not protected plants, whether the challenge was applied mechanically or by aphids.