Potato virus M – PVM

Kind of organism : Virus

Detection method : ELISA

All diseases & pests

Causal agent(s) 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).


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.

Symptoms on foliage

Depending on the virus strain and the potato cultivar, PVM symptoms range from very mild to severe: mottle, mosaic pattern, crinkling and rolling leaves and possibly associated with stunted shoots.

Typical symptoms of PVM have been called paracrinkle or potato leaf rolling mosaic as they have the appearance of rolling in the top of the plants (photo 1) with mild mosaic and ”spoon-shaped” rolled leaflets. Leaf rolling due to PVM is soft when touched whereas Potato leaf roll virus induces a «cracking» leaf rolling. It occurs in developed plants, usually on the top leaflets.

With some cultivars, the following symptoms may also be observed (photos 2 et 3):

Symptoms are more visible with cloudy and temperate weather.

Risk factors

The development of PVM infection results from a combination of:


As PVM virus has generally a very limited effect on yield, PVM is controlled in most of the seed potato-producing countries by testing the selection material and the basic seed potatoes to ensure healthy seed potatoes.

General measures used for the production of certified seed potatoes limit the infection by viral diseases such as PVM. They include:

Additional control measures in seed potato production include: