Potato virus Y , one of the most important plant viruses affecting potato production. PVY infection of potato plants results in a variety of symptoms depending on the viral strain. The mildest symptoms is causing production loss, the most serious is called 'potato tuber necrotic ringspot disease' (PTNRD) which is transmitted by aphid vectors.
Potato leafroll virus
Potato leafroll virus infects potato and is a particular problem in the USA. During the summer, the virus is spread by insects and by the green peach aphid, Myzus persicae. During the winter months the viruses lie dormant in the plants and are the primary source of new infections of other plants in the next year. The symptoms of this disease include a slight curling of new leaves and the leaves become discolored, ranging from a light green through yellow to red and the underside of the leaves turns purple. The disease will reduced the yields and quality of the potato crops but not killing plant.
Potato mop top virus
The Potato mop top virus (PMTV) is a pomovirus vectored by the fungus Spongospora subterrenea, which causes powdery scab of potato. The virus can be found in scab spore-balls and can remain viable in the field up to 18 years without the host. Symptoms of PMTV vary depending on environmental conditions. The symptoms may include yellow rings, V shape markings, and blotches, especially on the lower leaves. Stems may also be stunted, giving a “mop top” effect.
Tobacco rattle virus
Tobacco rattle virus (TRV) is a Tobravirus which causes corky ringspot or spraing disease. Often found in sandy soils. Symptoms often do not appear on the foliage, but the tuber contains corky layers of tissue interspersed with rings of healthy tissue and brown flecks distributed throughout the tuber. This virus is transmitted by 'stubby-root' nematodes .
