''Tomato mosaic virus'' (ToMV) is a plant

pathogenic virus A viral disease (or viral infection) occurs when an organism's body is invaded by pathogenic viruses, and infection, infectious virus particles (virions) attach to and enter susceptible cells. Structural Characteristics Basic structural charact ...

. It is found worldwide and affects

tomato The tomato is the edible berry of the plant ''Solanum lycopersicum'', commonly known as the tomato plant. The species originated in western South America, Mexico, and Central America. The Mexican Nahuatl word gave rise to the Spanish word ...

es and many other plants.

Symptoms

The foliage of affected tomato plants shows mottling, with alternating yellowish and darker green areas, the latter often appearing thicker and raised giving a blister-like appearance. The leaves tend to be

fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except t ...

-like in appearance with pointed tips and younger leaves may be twisted. The fruit may be distorted, yellow blotches and necrotic spots may occur on both ripe and green fruit and there may be internal browning of the fruit wall. In young plants, the infection reduces the set of fruit and may cause distortions and blemishes. The entire plant may be dwarfed and the flowers discoloured. Environmental conditions influence the symptoms. These include temperature, day length and light intensity as well as the variety, the age of the plant at infection and the virulence of the strain of ToMV.

Host plants

Besides

Solanaceous The Solanaceae , or nightshades, are a family of flowering plants that ranges from annual and perennial herbs to vines, lianas, epiphytes, shrubs, and trees, and includes a number of agricultural crops, medicinal plants, spices, weeds, and orna ...

plants, such as

pepper Pepper or peppers may refer to: Food and spice * Piperaceae or the pepper family, a large family of flowering plant ** Black pepper * ''Capsicum'' or pepper, a genus of flowering plants in the nightshade family Solanaceae ** Bell pepper ** Chili ...

and

petunia ''Petunia'' is genus of 20 species of flowering plants of South American origin. The popular flower of the same name derived its epithet from the French, which took the word ''petun'', meaning "tobacco," from a Tupi–Guarani language. A tende ...

, ToMV affects a wide range of other crop and ornamental plants. These include

snapdragon ''Antirrhinum'' is a genus of plants commonly known as dragon flowers, snapdragons and dog flower because of the flowers' fancied resemblance to the face of a dragon that opens and closes its mouth when laterally squeezed. They are native to r ...

delphinium ''Delphinium'' is a genus of about 300 species of annual and perennial flowering plants in the family (biology), family Ranunculaceae, native plant, native throughout the Northern Hemisphere and also on the high mountains of tropical Africa. Th ...

and marigold and a great many other plants to a lesser extent. The infection is generally restricted to plants that are grown in seedbeds and transplanted as it is in the handling processes that the virus is likely to gain entry. Symptoms on other plant hosts include blistering,

chlorosis In botany, chlorosis is a condition in which leaves produce insufficient chlorophyll. As chlorophyll is responsible for the green color of leaves, chlorotic leaves are pale, yellow, or yellow-white. The affected plant has little or no ability to ...

, curling, distortion, dwarfing and mottling of the leaves.

Means of infection

The virus may be introduced on infected seed. Only a small number of seedlings need to be infected for the virus to spread rapidly. It can also be spread on contaminated tools and the clothing and hands of workers during routine activities.

References

External links

ICTVdB - The Universal Virus Database: Tomato mosaic virus
{{DEFAULTSORT:Tomato Mosaic Virus Tobamovirus Viral plant pathogens and diseases