Biodiversity of viruses infecting tomato in Italy: methods for diagnosis and diversification

An account is given of strain-specific diagnostic methods currently adopted in Italy to detect alfalfa mosaic alfamovirus (AMV), cucumber mosaic cucumovirus (CMV) and tomato spotted wilt tospovirus (TSWV). These viruses are highly detrimental to tomato crops as the introduction of new virus strains has deeply changed the population structure of resident viruses. RT-PCR coupled with restriction analysis of amplicons proved suitable for differentiating CMV and AMV strains whereas single-stranded conformational polymorphism (SSCP) was used for the identification of TSWV isolates. Application of strain-specific diagnostic methods to phytosanitary inspection of plant propagules is suggested as a powerful tool for timely identification of new virus strains