Cucumber mosaic virus

Cucumber mosaic virus (CMV) is a plant pathogenic virus in the family Bromoviridae.It is the type member of the plant virus genus, Cucumovirus. This virus has a worldwide distribution and a very wide host range. In fact it has the reputation of having 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).Fig.4a. Symptoms in Commelina diffusaCucumber mosaic virus inclusion bodies Cucumber mosaic virus (CMV) is a plant pathogenic virus in the family Bromoviridae.It is the type member of the plant virus genus, Cucumovirus. This virus has a worldwide distribution and a very wide host range. In fact it has the reputation of having 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). In plant tissue this virus makes characteristic viral inclusion bodies which can be diagnostic. They are hexagonal in shape (Fig.1) and stain both in a protein stain and a nucleic acid stain. The inclusions can also be rhomboidal (Fig. 2b), may appear hollow (Fig. 1) and can form larger aggregates (Fig. 3b). The inclusions are not uniformly distributed and can be found in epidermal (Figs. 1 and 2b), mesophyll (Fig. 3b), and stomatal cells (Fig. 4b). These inclusions are made up of virus particles. This virus was first found in cucumbers (Cucumis sativus) showing mosaic symptoms in 1934, hence the name Cucumber mosaic. Since it was first recognized, it has been found to infect a great variety of other plants. These include other vegetables such as squash, melons, peppers, beans, tomatoes, carrots, celery, lettuce, spinach and beets, various weeds and many ornamentals and bedding plants, such as Narcissus. Symptoms seen with this virus include leaf mosaic or mottling (Fig. 2a), yellowing (Fig. 3a), ringspots (Fig. 4a), stunting, and leaf, flower and fruit distortion. CMV shows symptoms on leaves known as the 'shoestring' effect for most host species. This effect causes young leaves to appear narrow and the entire plant to be stunted.