Identification of Soybean mosaic virus Strains by RT-PCR/RFLP Analysis of Cylindrical Inclusion Coding Region

A reverse-transcriptase polymerase chain reaction/restriction fragment length polymorphism (RT-PCR/RFLP) was employed successfully for detection and identification of Soybean mosaic virus (SMV) strains. A primer pair amplifying a 1,385-bp fragment of the cylindrical inclusion (CI) coding region was used for RT-PCR and the RFLP profiles of the RT-PCR products were compared after restriction digestion with RsaI, EcoRI, or AccI restriction endonucleases. These enzymes were chosen based on the nucleotide sequences of SMV strains G2, G5, G5H, G7, and G7H in the CI coding region. These five strains, as well as seedborne SMV isolates from local soybean cultivars, could be differentiated by RT-PCR/RFLP analysis. The results correlated well with strain identification by symptom phenotypes produced on differential cultivars inoculated with strains and isolates. The sensitivity of RT-PCR enabled detection of SMV from plants with necrotic symptoms in which the number of virus particles was too low to be detected by enzyme-linked immunosorbent assay.