ABSTRACT
The name Nepovirus was originally proposed by Cadman as an abbreviation for distinctive properties of certain viruses — nematode transmission and polyhedral particles. Characteristics of the group were described by Harrison and co-workers and Wildy. The type member of the group is tobacco ring spot virus. Properties of the nepovirus group have been reviewed by several investigators. Nepoviruses have a single coat protein of molecular weight ca. 55,000 to 60,000 Da. Particles of viruses in this group are isometric, with diameters of ca. 25 to 30 nm. The irregularly shaped vesiculated cytoplasmic inclusions induced by nepoviruses are similar to inclusions induced by alfalfa mosaic, bromo-, caria-, como-, faba-, and sobe-moviruses. Nepovirus infections can be distinguished from those induced by comoviruses and sobemoviruses, since virus particles of these groups aggregate in xylem elements and nepovirus particles do not. Carlaviruses induce the formation of cytoplasmic banded-body inclusions and nepoviruses do not.
