Tobacco necrosis virus (TNV)
 

Tobacco necrosis virus (TNV) is of Necrovirus genus (figure 1). The virus is transmitted by the aquatic fungus Olpidium brassicae.
 
- Symptoms
 
Brown necrotic spots appear near the veins, they may be coalescing. Occasionally young seedlings die. On mature plants, the symptoms are mainly located on the lower leaves.
 
- Characteristics 

This virus is spread worldwide, particularly in Europe, although not extensively in tobacco. It infects many hosts including vegetables and ornamentals (bean, melon, cucumber, tulip... in figure 2).