Tobacco necrosis virus

(TNV) or ABC virus

• Causal agent and transmission

Tobacco necrosis virus (TNV) affects numerous cultivated plants (tobacco, tulip, cucumber, parsley, spinach, beans, strawberry, fruit trees, vines, etc.) and weeds (chenopods, sowthistle, etc.) all over the world.

The virus is transmitted in a non-persistent mode by the zoospores of the root infecting fungus, Olpidium brassicae, the causal agent of hernia in Cruciferae.

Transmission depends on having the suitable combination of virus strain, fungus race and host species. The virus does not survive in the resting spores of the fungus.

• Significance

TNV is not often found on the potato, on which it causes a disease often known as ABC. It has been reported in the Netherlands (on cv. Eersteling), in Southern Europe, especially in Italy (on cv. Sieglinde), in Tunisia and in the United States.