First Report of Tobacco Streak Virus on Lisianthus in Brazil. Juliana C. de Freitas, Departamento de Fitopatologia, ESALQ/USP, Piracicaba, SP, 13418-900; Brazil . E. W. Kitajima, Nucleo de Apoio a Pesquisa em Micro-scopia Eletronica, ESALQ/USP, Piracicaba, SP, 13418-900, J. A. M. Rezende, Departamento de Fitopatologia, ESALQ/USP, Piracicaba, SP, 13418-900; Brazil. Plant Dis. 80:1080. Accepted for publication 8 July 1996. Copyright 1996 The American Phytopathological Society. DOI: 10.1094/PD-80-1080B.
The cultivation of lisianthus, Eustoma grandiflorum (Raf.) Shinn. (Gentianaceae), for pot and cut flower production has increased recently in the State of Sao Paulo, Brazil. About 10 viruses have been reported infecting lisianthus throughout the world. A high incidence of plants showing viruslike symptoms is resulting in economic losses to commercial crops grown in the field in Ibiuna and Paranapanema counties. The main symptoms were irregularly shaped and necrotic ringspot lesions on the leaves. Flowers were slightly smaller and died earlier. Stems were apparently unaffected. Ultrathin sections of symptomatic leaves, examined in the electron microscope, showed numerous isometric particles, 25 to 30 nm in diameter, some of them associated with the plasmodesma. Extracts from diseased plants reacted strongly in plate trapped antigen— enzyme linked immunosorbent assay (PTA-ELISA) with two antisera against tobacco streak ilarvirus (TSV), from the Universidade de Brasilia, DF, Brazil, and from R. W. Fulton, the University of Wisconsin, Madison. Sap from infected lisianthus was mechanically inoculated to Carborundum-dusted leaves of several species of plants belonging to the Amaranthaceae, Chenopodiaceae, Cucurbitaceae, Gentianaceae, Legumi-nosae, and Solanaceae. Symptoms shown by inoculated lisianthus were similar to those observed on naturally infected plants. Nicotiana tabacum L. cvs. Samsun, Turkish NN, Xanthi, and White Burley, and Datura stramonium L. developed characteristic symptoms of TSV strains (I). Extracts from these plants also reacted with TSV antisera. Chenopodium quinoa Willd., C. murale L., Gomphrena globosa L., N. benthamiana L., N. glutinosa L., Phaseolus vulgaris L.cvs. Manteiga and Black Turtle 2, Physalis floridana Rydb, and Vigna unguiculata (L.) Walp. were also infected with the lisianthus isolate of TSV. Based on the particle morphology, strong serological reaction with antisera against TSV, and characteristic symptoms induced on N. tabacum and D. stramonium, we concluded that lisianthus plants were infected by TSV. Infection of lisianthus with an ilarvirus, named lisianthus line pattern virus, was reported in Italy, but serological tests showed that it was distantly related to TSV (2).References: (1) A. S. Costa and A. M. B. Carvalho. Phytopathol. Z. 42:113 1961. (2) V. Lisa et al. Acta Hortic. 377:81, 1994.