Tobacco Mosaic Virus
This particular mosaic virus attacks tomatoes, eggplant, peppers, causing the leaves to be mottled light and dark green (they often look like they are variegated). They may also be thickened, puckered, brittle and distorted as well. Depending upon the age, variety of plant and strain of virus, they may not have a significant effect on the plant (maybe just slowing growth slightly) or they may cause stunting and severely reduce the harvest. They don’t usually kill the plants. Mosaic is sometimes introduced into the garden on vegetable seedlings, so it’s best to grow your own, using disease-free seeds. If you must buy plants it’s a good idea to check them for signs of mottling, dwarfing, or stunting before buying them. These viruses are often spread by cucumber beetles or aphids (and other sucking insects), so if the disease is prevalent in your area you might want to use row covers to keep them off of your plants. If any plants start to exhibit symptoms, remove them immediately to reduce source of infection. Viruses are frequently spread by gardeners, so don’t touch wet plants and wash your hands frequently with soap and water (especially after touching infected plants). The virus can often be found in cigarette tobacco and smokers can transmit the virus on their hands. Some resistant cultivars are available. You can minimize the effect of viruses by keeping the plants in good health. Give them a fertile soil and adequate water (not too much or too little).
Image: R.J. Reynolds Tobacco Company Slide Set, R.J. Reynolds Tobacco Company, Bugwood.org