STUDIES OF POLYCLONAL ANTIBODIES FOR THE DETECTION OF MLOS ASSOCIATED WITH FABA BEAN (VICIA-FABA L) USING DIFFERENT ELISA METHODS AND DOT-BLOT

Polyclonal antibodies were raised in rabbits against MLO associated with faba bean (Vicia faba L.) phyllody which exists in the Sudan. Two indirect ELISA methods were able to detect the MLO antigens. In the former, the whole antigen was directly coated onto plates, while in the second, only the F(ab')2 fragments of the IgG were used to coat the ELISA plates. Higher detectable efficiency was obtained when the F(ab')2 Method was used. Moreover the obtainable antiserum was found to exhibit a high degree of specificity through which the MLO associated with faba bean phyllody in the Sudan, are serologically differentiated from other isolates of MLO existing in the Sudan as well as European MLO isolates maintained at Versailles, and Spiroplasma citri, causal agent of Citrus Stubborn Disease. The positive reactions obtained with this antiserum against MLO phyllody naturally existing in the Sudan on Crotalaria saltiana and some Catharanthus roseus demonstrate that these plants are potential reservoirs of the disease in the Sudan. The same antiserum was used in order to distinguish healthy and diseased plant preparations using the membrane ELISA method (dot-blot).