ABSTRACT
The potyvirus group has its origins in Brandes and WetterV groups 9, 10, and 11 of the elongated plant viruses. Particles of viruses in these groups ranged from 700 to 750 nm in length, and many of them were serologically related. Taxonomy of the potyviruses seems to be considered ill developed and unsatisfactory by some workers. Potyviruses form the largest of the plant virus groups, and some members and many possible members have received only limited characterizations. Potyviruses have been separated into four subdivisions according to the type of cylindrical inclusions they induce. This separation reduces the number of comparisons and aids in making appropriate comparisons necessary for virus identification at the specific or strain level. Many potyviruses have been assigned to subdivisions as possible members because their inclusion type is based on only a single cytological study. Many potyviruses also induce proteinaceous nuclear inclusions of different shapes.
