Elimination of Grapevine fleck virus by in vitro Chemotherapy

Abstract

Grapevine fleck virus produces a ubiquitous disease, latent in European grapevine varieties (Vitis vinifera L.) and in most American rootstocks, being found in all viticultural countries, in simple or complex infections with other more dangerous viruses. Different techniques for sanitation showed controversial results regarding fleck elimination in grapevine. In vitro culture of ‘Tamâioasa româneasca’ 3-2-2 with fleck virus and ‘Burgund’ 63 Mn with double infection (Grapevine fleck virus and Grapevine virus A), naturally infected have been submitted to chemotherapy using a combination of ribavirin and oseltamivir in three concentration variants (V1-40 mg/L ribavirin + 40 mg/L oseltamivir; V2-20 mg/L ribavirin + 40 mg/L oseltamivir; V3-20 mg/L ribavirin + 80 mg/L oseltamivir) and three consecutive subcultures. The plants regenerated after each subculture were evaluated by ELISA from the viewpoint of virus elimination and the RT-PCR was used for confirmation of the diagnostic. Due to the phytotoxic effect of viricides, the multiplication rate decreased on experimental variants in the next subculture comparatively to the control, but no mortality of explants has been registered. Grapevine fleck virus has been 100% eliminated both from simple and mixed infections on all variants by in vitro chemotherapy, under the simultaneous action of two viricides. Unsatisfactory results have been achieved with Grapevine virus A elimination.