Natural Occurrence of Pepino mosaic virus in Lycopersicon Species in Central and Southern Peru

Pepino mosaic virus (PepMV), a potexvirus first described in 1980 from pepino ( Solanum muricatum ) plants cultivated in Peru, was isolated from diseased tomato plants in the Netherlands in 1999, and is now the cause of an emerging tomato disease in Europe. In a survey of central and southern Peru, 65 wild and four cultivated populations of Lycopersicon , as well as six populations of other species of Solanaceae , were tested for the presence of PepMV and six other viruses. Of the Lycopersicon population sampled, 23 (35.4%) reacted positively in double antibody sandwich (DAS)-enzyme-linked immunosorbent assay (ELISA) with antisera to PepMV. DAS-ELISA tests for PepMV of other solanaceous species were negative, except for one sample of pepino ( Solanum muricatum ). Mechanical inoculation of susceptible Lycopersicon esculentum cv. NE-1 plants with crude sap extracts of 20 of these samples confirmed that 15 of them (from the Departments of Apurimac, Arequipa and Moquegua) were infected with PepMV; these inoculated plants were also DAS-ELISA positive and, in most cases, developed symptoms. Thirteen of the infective extracts were obtained from plants of wild Lycopersicon species (three L. chilense , three L. chmielewskii , two L. parviflorum and five L. peruvianum ) and one each from the cultivated species L. esculentum and S. muricatum . The wild Lycopersicon species are newly reported natural hosts of PepMV. Tests for the other six viruses were negative, except that two samples contained Tomato mosaic virus . Thus, PepMV occurs in Lycopersicon species in central and southern Peru, even in isolated wild populations. These results indicate that the virus is not new to the region and has an efficient mechanism of natural transmission.