Detection of Tobacco mosaic virus and Tomato mosaic virus in pepper and tomato by multiplex RT-PCR.

AIMS To develop a highly sensitive and rapid protocol for simultaneous detection and differentiation of Tobacco mosaic virus (TMV) and Tomato mosaic virus (ToMV) in pepper and tomato. In this study, we use the multiplex PCR technique to detect dual infection of these two viruses. METHODS AND RESULTS A multiplex RT-PCR method consisting of one-tube reaction with two primer pairs targeted to replicase genes was developed to simultaneously detect TMV and ToMV in seed samples of pepper and tomato. Specific primers were designed from conserved regions of each of the virus genomes, and their specificity was confirmed by sequencing PCR products. RT-PCR detected up to 10(-6) dilution of total RNA extracted from infected leaves. Multiplex RT-PCR revealed the presence of both TMV and ToMV in three of 18 seed samples of tomato and one of 18 seed samples of pepper. CONCLUSIONS The multiplex PCR assay was a cost effective, quick diagnostic technique, which was helpful in differentiating TMV and ToMV accurately. SIGNIFICANCE AND IMPACT OF THE STUDY The multiplex PCR assay described in this study is a valuable tool for plant pathology and basic research studies. This method may facilitate better recognition and distinction of TMV and ToMV in both pepper and tomato.