DETECTION OF GEMINIVIRUSES FROM TROPICAL COUNTRIES BY A DOUBLE MONOCLONAL-ANTIBODY ELISA USING ANTIBODIES TO AFRICAN CASSAVA MOSAIC-VIRUS

Using double antibody sandwich enzyme-linked immunosorbent assay (DAS- ELISA) tests, monoclonal antibodies (mAbs), which were prepared agains t particles of a Nigerian isolate of African cassava mosaic virus (ACM V), differentiated African geminiviruses (tomato yellow leaf curl viru s, TYLCV; ACMV from West and East Africa; and okra leaf curl virus) fr om those originating in other countries of the world (euphorbia mosaic virus; Indian cassava mosaic virus; and TYLCV (Indian isolate)). All these viruses belong to the whitefly-transmitted geminivirus subgroup III. One mAb reacted with all 7 tested viruses and isolates. For detec ting TYLCV from Senegal, it proved necessary to use a reducing agent i n extraction buffer. A diagnostic DAS-ELISA was developed. This relies only on the use of mAbs and is useful for large-scale field screening .