Morphology, genetics and strains of the potato Y potyvirus

Potato Y potyvirus (PVY) is a type member of the Potyvirus genus in the Pot yviridae family In this study the main characteristics of PVY and its strai ns are summarised. Morphology (size, shape), physical and chemical properties [sedimentation c oefficient, thermal inactivation point (T. I. P.), deletion end point (D. E . P.), longevity in vitro (L. I. V.)], gene organisation (genome size, weig ht and structure) and replication are studied. The importance, spread and s ymptoms of the different strains, PVYO (normal strain), PVYC (strain C), PV YAn (anomalous strain), PVYN (tobacco vein necrosis strain) and PVYNTN (pot ato tuber necrotic ringspot strain) are discussed as well. Aphid vectors and the broad spectrum of the host range of PVY play an impor tant role in the spread of the pathogen. Diagnostic methods (serology, PCR techniques), assay and propagative plants , local and systemic symptoms (mosaic, necrotic lesions, top necrosis, vein necrosis, necrotic rings) and microsymptoms (inclusion bodies) are also di scussed.