Aims and scope: Several viruses so far have been reported to be the cause of mosaic and yield losses in French bean (Phaseolus vulgaris L.) in Iran. Among these, BCMV, and BCMNV are more important. During a growing season, French bean plant samples were selected with various symptoms of mosaic, vein clearing, leaf rolling, leaf and stem necrosis were collected from bean cultivation fields.

Material and methods: The samples were tested serologically against the two viruses using DAS-ELISA and Tissue blot technique with the specific polyclonal antisera obtained from commercial sources .To confirm the Elisa results, selected Elisa positive samples tested applying IC- RT-PCR using virus specific polyclonal antibody and a specific set of primers designed from virus cp-genes region.

Results: The cDNA obtained were multiplied in termocycler machine. The results of agarose gel electrophoresis of approx. 373bp and 683bp band were obtained for part of the cp genes of BCMV and BCMNV. Using IC-RT-PCT both viruses were identified from samples of Arak, Neishabour, Zanjan and Karaj provinces.

 Conclusion: BCMV and BCMNV are widespread in almost all bean growing regions of Iran and often present in mixture. IC-RT-PCR test for diagnosis and identification of these two viruses is proved to be more sensitive than Elisa test. In this technique combination of a specific antisera and a specific set of primers help in distinguishing the two viruses in mixture. Key word: BCMV, BCMNV, DAS-ELISA, Tissue-blot, IC-RT-PCR