Properties of a tobacco necrosis virus from New Zealand

Abstract A virus isolated from roots of Solanum nigrum produced local lesions on leaves of, Nicotiana tabacum, Datura tatula, N. clevelandii, N. glutinosa, Chenopodium amaranticolor, C. quinoa, C. album, Phaseolus vulgaris, and Glycine max. Nicotiana clevelandii was also systemically infected. The virus was purified by differential and density-gradient centrifugation and sedimented as a single zone in sucrose density-gradient columns. An antiserum, prepared by injecting a rabbit with virus from gradients, produced a single precipitation band when tested against infective sap by the geldiffusion method and by immuno-electrophoresis. The diameters of the isometric virus particles stained in potassium phosphotungstate and in uranyl acetate were 235 A and 220 A respectively. Particles stained in phosphotungstate showed various stages of disintegration. The virus is a strain of the tobacco necrosis virus as proposed by Babos and Kassanis.