Potato virus Y (PVY) the type member of the potyvirus group, is a common virus among solanaceous crops, infecting potato, tomato and pepper. PVY has been characterized into many strains but generally falls into three main groups, PVY-O (ordinary), PVY-N (necrotic) and PVY-C (stipple streak). Strains are characterized on the basis of the plant symptoms produced in a set of selected potato and tobacco cultivars.

Disease severity depends on PVY strain, host tolerance, time of infection and environmental factors. In potato, PVY is transmitted to the new crop via seed tubers and in a non-persistent manner by the green peach aphid (Myzus persicae) and other aphid vectors. Infection occurs when aphids acquire the virus from an infected plant and carry the virus to another, introducing it into the host as they feed. Primary symptoms caused by PVY may be mild or hardly detectable, which causes problems particularly in seed potato production. The symptom most useful for diagnosing PVY infection is a mosaic pattern that develops along the veins.