Molecular detection and variability of Strawberry Vein Banding Virus

Novel detection methods were developed recently for the detection of Strawberry vein banding virus (SVBV) in Fragaria spp. One is based on standard PCR method; the other on nucleic acid sequence based amplification (NASBA) and real-time detection using molecular beacons (real-time NASBA). Both assays were compared with biological indexing, the only currently accepted method for strawberry certification for absence of SVBV. To investigate the variability of SVBV and to assure that the sequence differences between virus strains of different geographical origins will not hamper the efficiency of nucleic acid-based detection methods, partial genomic sequences of three new SVBV isolates were determined. Sequence information of almost the entire capsid protein gene of three new American SVBV isolates was determined and a comparison to the previously sequenced isolates of was made. Only minor sequence variability was observed in the capsid protein gene and no variability at all was found in the annealing regions of primers and probes used for detection purposes. In conclusion, the real-time NASBA and PCR methods offer the potential for a fast, sensitive and reliable routine diagnosis of SVBV in strawberry stock plants.