Tobacco mosaic virus
(TMV) 

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- classification : Potyviridae, Tobamovirus


Tobacco mosaic virus (TMV) is shown in figure 1. Two groups of strains that differ in biological and serological properties have been reported: tobacco strains (TMV) and tomato mosaic virus (ToMV) strains. ToMV is today considered a different virus altogether. It also seems to infect tobacco in some eastern European countries.
 

Figure 1

TMV is spread worldwide. It occurs in all tobacco production areas, where susceptible varieties are grown and it causes serious loss. TMV is feared in many Asian countries (China, Thailand, Vietnam ...) and Oceania (Indonesia, Australia ...). Many countries in the Americas are highly infected (Argentina, Brazil, some U.S. states). The virus is also observed in Africa and the Middle East, where its incidence appears generally lower than in other production areas. It occurs in European countries, and it is particularly severe in Spain and Italy.
 
Certainly monoculture of tobacco varieties resistant to TMV has almost eradicated this virus responsible for the common tobacco mosaic or "blight" in France. It is occasionally found on susceptible varieties of Burley or Virginia tobacco type. Its persistence in France should be taken in consideration when establishing breeding programs.