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Etiology

Characterization of a New Potyvirus from Potato. C. E. Fribourg, Universidad Nacional Agraria, Apartado 456, Lima, Peru; J. Nakashima, International Potato Center, Apartado 5969, Lima, Peru. Phytopathology 74:1363-1369. Accepted for publication 1 June 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/Phyto-74-1363.

A virus with flexuous filamentous particles that failed to react serologically with antisera to potato virus Y (PVY) and potato virus A (PVA) was isolated in central Peru from a potato clone showing symptoms of mosaic, veinal necrosis, and leaf drop. The host range of the virus was restricted to 20 species in the family Solanaceae. Symptoms induced in potato cultivars infected by grafting were mainly mild mosaics, systemic chlorotic spots, partial vein necrosis of the leaf undersides, and premature senescence of lower leaves. The virus (code-named UF) and a similar isolate previously reported from the Netherlands (PVY^C- GI) did not induce a hypersensitive response in potato cultivars carrying gene Nc. UF was transmitted with difficulty by Myzus persicae. Sap or purified preparations contained flexuous filaments with a normal length of 760 nm. In serological comparisons made by using partially purified antigens and six different antisera, UF was found to be distantly related to PVA and to isolates belonging to the three groups of PVY strains presently recognized, but it was closely related to PVY^C-GI and another potyvirus isolated from potato in Northern Ireland (PVY^C -AB). The results show that all three should be considered as isolates of a distinct potyvirus different from PVY and PVA and we propose that the virus be named PVV (potato virus V).