Detection of three viruses to affect faba bean ( vicia faba L.) by tissue-blot immunoassy (TBIA)

Faba bean ( Vicia faba L. ) ranks third in overall production among cool-season legumes crops worldwide, following pea and chickpea ( FAO 1999 ).Yields of faba bean generally show large fluctuations, which are partly caused by a range of fungal and viral diseases. Worldwide legumes can became naturally infected with more than 45 viruses 12 of which have been reported from West Asia and North Africa (WANA) (Makkouk,1994). Sensitive detection of three legume viruses was obtained by using the tissue-blot immunoassay ( TBIA) phloem limited such as bean leaf roll luteovirus (BLRV) and viruses which generally invade systemically all plant tissues such as alfalfa mosaic alfamovirus (AMV), cucumber mosaic cucumovirus (CMV), polyclonal antibodies were used in the tests proved useful in producing visible reaction. TBIA was sensitive enough to detect the virus in all parts of the plant and all growth stages. The test proved to be practical for testing groups of seedlings (5-25) after wrapping them together as one bundle by a parafilm membrane and then cutting them with a razor blade and blotting on a nitrocellulose membrane as one sample. These results suggest that this test can be easily employed for the detection of seed-borne viruses after germinating the seeds, and is more practical than regular ELISA test. It can be completed in less than four hours without sacrificing sensitivity. It is cheaper and does not required sophisticated facilities. * Schematic diagram showing the pattern of reactants in the tissue-blot immunoassay (TBIA). Key words : Legumes, Viruses, Serological test, TBIA.