Tobacco stunt virus (TStV) 
 

Tobacco stunt virus (TStV) currently belongs to the genus Varicosavirus (figure 1). This virus is now recognised as a strain of lettuce big-vein associated virus. The aquatic fungus Olpidium brassicae, that parasitises the roots, is its natural vector.
 
 
- Symptoms
 
Many symptoms may occur, such as curling of younger leaves, vein chlorosis and necrosis, necrotic spots on mature leaves, mottling, filiformis, shorter internodes than normal and stunting of plants.
 
 
- Characteristics
 
This virus is observed mainly in Japan and in particular infects Virginia tobacco.