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Etiology

Passion Fruit Yellow Mosaic Virus, a New Tymovirus Found in Brazil. O. A. Crestani, Departamento de Biologia Celular, Universidade de Brasilia, 70910 Brasilia, DF, Brazil, Present address: Estação Experimental de Videira, EMPASC, C. Postal 3, 89560 Videira, SC, Brazil; E. W. Kitajima(2), M. T. Lin(3), and V. L. A. Marinho(4). (2)(3)(4)Departamento de Biologia Celular, Universidade de Brasilia, 70910 Brasilia, DF, Brazil. Phytopathology 76:951-955. Accepted for publication 19 March 1986. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/Phyto-76-951.

Golden passion fruit (Passiflora edulis f. flavicarpa) plants with symptoms of yellow net, yellow mosaic, and leaf crinkle were found in low incidence at Papucaia, Cachoeiras de Macacu County, State of Rio de Janeiro. These symptoms could be reproduced in about 2 wk by graft or mechanical transmission to healthy golden passion fruit seedlings. Leaf-dip preparations from diseased plants contained large numbers of isometric particles about 30 nm in diameter. Similar particles were seen mostly in the vacuoles of infected cells. Chloroplasts in these cells had characteristic peripheral, double-membraned vesicles. Particles were readily purified, were infective, and are considered to be the causal agent of this passion fruit disease. Comparative serological studies revealed that the virus belongs to the tymovirus group and is related to the cluster that includes Kennedya yellow mosaic, okra mosaic, cocoa yellow mosaic, Clitoria yellow vein, Desmodium yellow mottle, and turnip yellow mosaic viruses. Its host range is restricted to species of the genus Passiflora, and it was transmitted experimentally by the chrysomelid beetle, Diabrotica speciosa. The persistence of infectivity in expressed sap was as follows: Thermal inactivation point, 50-55 C; dilution end point, 10^-3-10^-4; and longevity in vitro, 8 days at room temperature. After centrifugation in a sucrose density gradient, two components, top (62 S) and bottom (126 S), were resolved with infectivity associated with the latter. The top component was made up essentially of empty particles. RNA of about 2 x 10 ⁶ was present in the particles of the bottom component. The capsid was composed of a single polypeptide about 20.5 kDa. The virus was named passion fruit yellow mosaic virus.