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Etiology

Properties of a Tobacco Necrosis Virus Isolate from Pogostemum patchuli in Brazil. M. I. C. S. Gama, Graduate student, Department of Plant Biology, University of Brasilia, 70910 Brasilia, DF, Brasil, Present address of senior author: CENARGEN / EMBRAPA, Cx. P. 10 2372, 70770 Brasilia, DF, Brasil; E. W. Kitajima(2), and M. T. Lin(3). (2)(3)Professor, and associate professor, respectively, Department of Plant Biology, University of Brasilia, 70910 Brasilia, DF, Brasil. Phytopathology 72:529-532. Accepted for publication 11 August 1981. Copyright 1982 The American Phytopathological Society. DOI: 10.1094/Phyto-72-529.

An isometric virus isolated from leaves of patchouli (Pogostemum patchuli) was identified as tobacco necrosis virus (TNV). Infection in patchouli was systemic, but symptomless. Identification of TNV was based on host range, symptomatology, in vitro properties, morphology, and serology. Celosia thompsonii, Leonotis nepetaefolia, Hibiscus esculentus, and Physalis floridana were previously unreported hosts of TNV. The virus was purified and a specific antiserum was produced. Concentration of this virus in tobacco leaves was critical in serodiagnosis, since the antiserum did not react in agar gel with sap prepared from leaves with less than five lesions per square centimeter.