Potato virus M

(PVM)

• Causal agent and transmission

PVM belongs to the Carlavirus group like the Potato virus S (PVS). 

It has a limited range of natural hosts. Most susceptible species belong to the Solanaceae, of which the potato is the most important. But experimentally, PVM has been transmitted to some Chenopodiaceae and Fabaceae.

It is transmitted in a non-persistent manner by the aphid Myzus persicae, less efficiently by Aphis frangulae, A. nasturtii, and Macrosiphum euphorbiae. Some isolates may be transmitted mechanically (e.g. by machinery).

•  Significance

PVM is common throughout the world, especially in Eastern Europe and Russia where some cultivars can be 100% infected.

Yield losses are usually low (10-20%) although some virulent strains may cause more severe leaf deformation and lead to higher (up to 50%) yield loss.