Cucumber mosaic virus (CMV) is a plant pathogenic virus in the family Bromoviridae. This virus has a worldwide distribution and a very wide host range, having the reputation of the widest host range of any known plant virus. It can be transmitted from plant to plant both mechanically by sap and by aphids in a stylet-borne fashion. It can also be transmitted in seeds and by the parasitic weeds, Cuscuta sp. (dodder). Hosts and symptoms This virus was first characterized in cucumbers (Cucumis sativus) showing mosaic symptoms in 1934, hence the name Cucumber mosaic. Since then, it has been found to infect a great variety of other plants. These include other vegetables such as squash, melons, peppers, eggplants,tomatoes, beans, carrots, celery, lettuce, spinach, beets, many ornamentals and bedding plants, such as Narcissus, and various weeds. Its presence has been confirmed on every continent of the world, including Antarctica. Symptoms seen with this virus include leaf mosaic or mottling (Fig. 1), yellowing, ringspots, stunting, and leaf, flower and fruit distortion. CMV also induces a type of symptom on leaves known as the "shoestring" effect on many host species. This effect causes young leaves to appear narrow and the entire plant to be stunted. Specifically, CMV can cause cucumbers to turn pale and bumpy. The leaves of these plants turn mosaic and their rugosity is often changed, making leaves wrinkled and misshapen. Growth of these plants is usually also stunted and produces few flowers. Often, cucumber fruits are oddly shaped, appear gray, and tested bitter. These appearances lead to them being referred to as "white pickles". Tomato plants are usually stunted and have poorly shaped leaves, or "fernleaf", when infected by CMV. Also certain strains of CMV can cause partial or total crop loss. CMV in peppers causes slightly different symptoms than the previously mentioned. Pepper plants often have severe foliar damage, shown as mosaic and necrotic rings. Often the peppers themselves are misshapen and contain chlorotic rings and spots. In celery, CMV causes streaking and spotting and can be often confused with symptoms of the celery mosaic virus. Symptoms of CMV in lettuce, such as chlorosis, plant stunting and often do not properly head, can be very similar to those of lettuce mosaic virus. CMV has also been identified in a lesser extent to a number of plant species. It is found to be a minor virus infecting Allium crops. The