Two important seed borne bean viruses have been described; Bean Common mosaic virus (BCMV) and Bean Common mosaic necrosis virus (BCMNV). Multiplex RT-PCR, the amplification of multiple RNA targets in single reaction described for simultaneous detection of more than one targets. Amplification of multiplex RT-PCR could greatly reduce the cost of routine detections and therefore cause great help to the seed certification program of beans. With use of internal control, the risk of false negative results reduced. In this study a multiplex RT-PCR was developed for simultaneous detection of BCMV and BCMNV. Specific primers were designed based on the some available sequences of BCMV and BCMNV from the Gene Bank and we used RT-PCR for amplification of respective viral band. Infected BCMV samples amplified 586bp and BCMNV 1081bp. In addition to, one primer pair drive from 18s ribosomal RNA was used as internal control. The fragment of internal control was constantly amplified from all healthy and infected plant cultivars. We described the primer pairs and the multiplex RT-PCR conditions for detection of BCMV and BCMNV. The specificity of three pairs of primer was proved by the size of bands and sequenced of the product bands.
