Serological detection of viruses infecting tomato and pepper in Southwest Nigeria and their distribution
Tomato and pepper are important vegetable crops grown in Nigeria, accounting for 50% of the African production. Pathogen diversity is a prerequisite for breeding resistant cultivars, as a means of improving the production. A survey for virus disease incidence on field grown pepper and tomato was carried out in three state of southwestern part of Nigeria, and a total of 135 leaf samples comprising 58 tomato and 77 pepper leaf samples were collected from farmers’ fields. Infecting viruses were detected using specific polyclonal antibodies were used in enzyme-linked immunosorbent assay (ELISA). Four viruses, Potato virus Y (PVY), Tomato mosaic virus (ToMV), Cucumber mosaic virus (CMV), and Pepper veinal mottle virus (PVMV) were detected. In tomato the distribution of viruses was 5.2% (CMV), 5.2% (PVY) and 39.7% for PVMV, respectively. Leaf samples of pepper had incidence rate of 19.5%, 3.9% and 67.5% for CMV, ToMV and PVMV respectively. TSWV and TYLCV were not detected in any of the samples tested. The most prevalent virus on tomato and pepper was PVMV which was also the most prevalent virus in Osun, Ogun and Oyo States in Southwest Nigeria; similarly, CMV was detected in pepper crops in all the states surveyed and the most prevalent after PVMV in the three states. Mixed viral infections were few, PVY + PVMV occurring only in one tomato leaf sample while PVMV + CMV occurred on three pepper leaf samples. The control of aphid vectors that transmit these viruses and good sanitary practices against soil borne ToMV would minimize disease incidences and subsequent yield loss.
Keywords: Tomato, Pepper, virus distribution, PVMV, CMV, PVY