ABSTRACT
This chapter provides a brief account of the development of studies on structure, composition, properties, cytopathology, and taxonomy of Potyviruses. Most Potyviruses have fairly restricted host ranges and are transmitted non-persistently by aphids and in some cases through seeds. It is generally agreed that to qualify for inclusion in the Potyvirus group, a virus isolate must have particles with the characteristic morphology and be able to induce typical cylindrical inclusions in the cytoplasm of infected cells. The antigenic properties of Potyviruses have been used extensively for their differentiation but there are a number of contradictory reports regarding some relationships. Although much work on the antigenic properties of Potyviruses has been done with intact virus particles as antigen, some has also been done with dissociated viral proteins. Different Potyviruses induce a variety of cytopathic effects whose differences have been used for taxonomic purposes. Infection of plant cells by Potyviruses induces characteristic changes in the cytoplasm and sometimes also in the nuclei.
