Occurrence, distribution and relative importance of viruses infecting hot pepper and tomato in the major growing areas of Ethiopia

Hot pepper and tomato fields in the main growing areas in the Rift Valley and the west of Ethiopia were surveyed for virus infections in 1994. A total of 286 samples from hot pepper and 222 samples from tomato plants and associated Datura stramonium L. and Nicandra a physalodes Gaertn. weeds with symptoms suggestive of virus infections were collected and analysed using electron microscopy, serology and test plant reactions. Potato virus Y (PVY), Ethiopian pepper mottle virus (EPMV), pepper veinal mottle virus (PVMV) and tomato mosaic virus (ToMV) were detected in hot pepper samples while tomato samples were shown to be infected with tomato mild mottle virus (TMMV), PVY and ToMV. The most widespread and predominant viruses which also occurred frequently in mixed infections were PVY and EPMV in hot pepper and PVY and TMMV in tomato. TMMV was also found in many samples of D. stramonium and N. physalodes. ToMV was identified in only few samples from both crops in the Rift Valley by its characteristic particle morphology, serological properties and symptomatology. PVMV was found in hot pepper samples only from western Ethiopia, but no natural infection of tomato with this virus was revealed. This is the first report on the natural occurrence of TMMV in tomato, D. stramonium and N. physalodes: as well as of ToMV in hot pepper and tomato in Ethiopia.