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.