First Report of Natural Occurrence of Zucchini Lethal Chlorosis Tospovirus on Cucumber and Chrysanthemum Stem Necrosis Tospovirus on Tomato in Brazil.

During a field survey in 1994, five cucumber (Cucumis sativus) cv. Hokushin plants showing symptom of yellowing, mottling, and vein banding on the leaves were collected from a commercial field of the Federal District. By electron microscopy, quasi-spherical particles with double membrane, typical tospovirus-like particles were found in the infected leaf material. All samples strongly reacted with antibody of zucchini lethal chlorosis tospovirus (ZLCV), but not with antibodies of other to-spoviruses reported in Brazil (1): tomato spotted wilt virus (TSWV), tomato chlorotic spot virus (TCSV), groundnut ringspot virus (GRSV), chrysanthemum stem necrosis virus (CSNV), or iris yellow spot virusonion isolate (IYSV). The virus was identified as ZLCV, which was first isolated in 1994 from zucchini (Cucurbita pepo) in São Paulo State, Brazil. Tomato (Lycopersicon esculentum) plants showing stem necrosis and necrotic spots and rings on the leaves were collected in Viçosa, Minas Gerais State. By electron microscopy, molecular studies, and enzyme-linked immunosorbent assay with antibodies of the six tospoviruses occurring in Brazil, the virus was identified as CSNV. This virus was first reported in 1995 on a Chrysanthemum sp. in São Paulo State and recently reported in the Netherlands from Dendranthema indicum. This is the first report of the natural occurrence of ZLCV and CSNV on cucumber and tomato, respectively. Reference: (1) A. C. de Ávila et al. 1998. Pages 32-34 in: Int. Symp. on Tospoviruses and Thrips in Floral and Vegetable Crops, 4th.