First Report of Pepino mosaic virus on Tomato in Spain

At the beginning of 2000, a damaging disease developed on protected tomato (Lycopersicon esculentum) crops grown in polyethylene greenhouses in different regions of Spain. Production losses were estimated at 15 to 80%. The tomato plants showed a variety of symptoms. The most common symptoms were leaf distortion, chlorosis, and mosaic. Some plants showed a dark green mosaic and bubbling of the leaf surface. Green striations were also observed on the stem and sepals. Most of the diseased plants had discolored fruits. Symptoms decreased as environmental temperature increased. The involvement of Pepino mosaic virus (PepMV) was suspected. To identify the etiological agent, ≈500 symptomatic tomato plants were collected from several locations in Alicante, Murcia, Almeria and the Canary Islands. Flexuous viral particles 510 nm long were observed by transmission electron microscopy, suggesting the presence of a potexvirus in the tissue extracts analyzed. All samples were tested by ELISA (enzyme-linked immunosorbent assay), using polyclonal antibodies to Narcissus mosaic virus (Adgen, Auchincriuve, Scotland), a virus serologically related to PepMV, and two antisera specific to PepMV (Adgen, Scotland and DMSZ, Braunschweig, Germany). PepMV was detected in 35% of the samples. Like PepMV, the virus infected (as confirmed by ELISA) greenhouse-grown Datura stramonium, Nicandra physalodes, Nicotiana benthamiana, N. clevelandii, Solanum tuberosum, and Vigna sinensis and did not infect Capsicum anuum, Cucumis sativus, Chenopodium amaranticolor, C. quinoa, Petunia × hybrida, Phaseolus vulgaris, Physalis floridana, N. glutinosa, N. rustica, or N. tabacum. The virus did infect Gomphrena globosa, which normally is not infected by PepMV. The first report of PepMV was on pepino (Solanum muricatum) in Peru in 1974 (1), but this virus has been recently reported in the Netherlands, England, Germany, and France on protected tomato crops (2). To our knowledge, this is the first report of PepMV in Spain, including the Canary Islands. References: (1) R. A. C. Jones et al. Ann. Appl. Biol. 94:61, 1980. (2) European and Mediterranean Plant Protection Organisation (EPPO). Alert List Viruses. On-line publication/2000/003.