The emergence of begomovirus-induced yellow leaf curl disease of tomato (Lycopersicon esculentum mill.) in Ethiopia
A systematic survey was carried out to determine the incidence and distribution of tomato virus diseases in Ethiopia. Fifty seven tomato fields were inspected, 570 plant samples were collected and tested by DAS-ELISA against eight tomato infecting viruses. The presence of a Tomato yellow leaf curl virus (TYLCV) in selected symptomatic samples was confirmed by immunocapture-polymerase chain reaction (IC-PCR). The data showed that TYLCV and Tomato mosaic virus (ToMV) were the two widespread viruses detected in 24.6% and 47.37% of the fields, respectively; whereas Tomato mild mottle virus (TMMV) followed by Potato virus Y (PVY) were detected only in few samples or completely absent in most fields in the other parts of southern and eastern parts of the country. All tomato samples were negative for Tomato spotted wilt virus (TSWV), Tomato ring spot virus (ToRSV), Tobacco mosaic virus (TMV) and Cucumber mosaic virus (CMV). High incidence (up to 95%) and prevalence of leaf curl disease was observed in fields in the Rift Valley areas (Upper Awash, Merti, Melkasa and fields along the road Mojo to Zwai). The result indicated that tomato yellow leaf curl has emerged as a major tomato virus disease causing serious losses in the fields of Rift Valley areas.
Key words/phrases: Begomoviruses, DAS-ELISA, IC-PCR, Tomato.