Natural Infection of Tomato and Pelargonium in Germany by a Tombusvirus Originally Described from Pepper in Morocco

Two serologically apparently identical tombusviruses were isolated from glasshousegrown tomato plants showing mottle and malformation of the upper leaves and stunting of the shoot tips and, at a low rate, from a pelargonium plant, respectively. Both plant species were received from growers in southern Germany. In agar gel double diffusion tests and immuno‐electrophoresis, the two virus isolates could not be distinguished from a tombusvirus (MPV) isolated from pepper in Morocco by F ischer and L ockhart (1977), although there were some minor differences in the reported host responses. In the tomato planting, strong symptoms were produced only temporarily. The majority of the 104 tomato plants of 15 different cultivars which had become infected by MPV following mechanical inoculation of the leaves showed only mild symptoms in contrast to a similar group of plants which developed severe stunting and foliar deformation when infected with the type strain of tomato bushy stunt virus. MPV was translocated only occasionally to the upper parts of tomato seedlings which had been grown in virus‐containing soil, although root infections were more frequent. MPV is apparently not a major threat to tomato cultivation in Germany.