Detection of Strawberry mottle virus by molecular hybridization

Strawberry mottle virus (SMoV) is one of the viral pathogens affecting strawberries (Fragaria spp.) production severely worldwide. Currently, reverse transcription-polymerase chain reaction (RT-PCR) is frequently used to detect SMoV, which is sometimes not successful because of unsatisfied nucleic acid quality and the contamination of secondary metabolites resulting in poor PCR amplification. In the study, we developed a digoxigenin-labelled cDNA probe for SMoV detection by dot-blot hybridization. Total nucleic acid was extracted with modified CTAB method from strawberry plants infected by SMoV, the SMoV specific fragment was amplified with RT-PCR, which was cloned and sequenced. The cloned fragment was then labeled with digoxigenin by PCR, which is used as probe in dot-blot hybridization to test the samples infected by SMoV. The result showed that dot-blot hybridization had the same result of RT-PCR in testing SMoV. Our research provided an important alternative to RT-PCR technique for detecting SMoV. To our knowledge, this is the first report for detection of SMoV by cDNA probe. In addition, it is a potential method to test other strawberry viruses.