Studies On Bean Yellow Mosaic Virus Infecting Some Leguminous Crops In Egypt

Bean yellow mosaic virus (BYMV) was isolated from naturally infected bean ( phaseolus valgaris , L. cv. Karnk) and faba bean ( Vicia faba , L cv. Balady) plants were collected from different districts in menoufia governorate, Egypt; showing vein chlorosis followed by green and/or yellow mosaic symptoms that may be due to virus infection. Diseased samples were subjected to identification of isolated virus based on symptomatology host range, serological tests (DAS- ELISA, Tissue blot immunoassay TBIA and electron microscopy). Histological studies of bean infected leaves by BYMV cleared that chloroplasts contained starch grain turned to spherical in shape and with lost of their envelopes totally or partially. Chlorophyll a, b and carotenoids as well as oxidative enzymes (peroxidase and polyphenol oxidase) were determined in viral infected leaves. Molecular detection of BYMV using specific primers was detected using RT-PCR; its products showed a single amplified fragment of ~ 900 bp in electrophoresis analysis.