A Rhabdovirus associated with Hibiscus vein clearing in southern Italy

Several commercial Hibiscus rosa-sinensis cultivars showing vein clearing symptoms were observed since 2005 in Campania and Calabria (Southern Italy) from which a virus was mechanically transmitted to herbaceous hosts. Nicotiana occidentalis and N. clevelandii reacted with yellow local lesions followed by systemic vein clearing, mottling, mosaic and stunting, whereas N. benthamiana and N. glutinosa developed only systemic symptoms and Gomphrena globosa reacted locally with reddish local lesions. No symptoms were observed in N. rustica, Chenopodium quinoa, C. amaranticolor and Citrullus vulgaris. Systemic symptoms in Nicotiana spp. appeared often about one month after inoculation. Electron microscope observation of leaf dips and ultrathin sections of chlorotic perninerval leaf areas revealed the consistent presence of rhabdovirus-like particles.