Transmissão de necrovírus de oliveira por Olpidium virulentus

Abstract

Neste trabalho determinou-se a capacidade de zoósporos de Olpidium virulentus vetorizarem três vírus dos géneros Alphanecrovirus: Olive latent virus 1 (OLV-1), Olive mild mosaic virus (OMMV) e Betanecrovirus, Tobacco necrosis virus D (TNV-D). Foram realizados ensaios de controlo na ausência de zoósporos obtendo-se 10% de eficiência de transmissão quando se usaram concentrações de 0,26 μg de OLV-1 mL-1, 0,5 μg de TNV-D mL-1 e 0,5 μg de OMMV mL-1. O valor de 100% de eficiência de transmissão foi obtido quando foram usadas as concentrações de 65 μg mL-1, 150 μg mL-1 e 50 μg mL-1 de OLV-1, TNV-D e OMMV, respetivamente. Quando os vírus foram previamente incubados com zoósporos de O. virulentus, nas concentrações de OMMV de 0,26 μg mL-1 e 2 μg mL-1, as taxas de transmissão obtidas foram de 10% e 100%, respetivamente, no entanto, as taxas de transmissão do OLV-1 e TNV-D não sofreram alterações quando incubados com o fungo previamente à inoculação; Abtract: Olive necrovirus transmission by Olpidium virulentus The capability of Olpidium virulentus to vector three viruses of genera Alphanecrovitus: Olive latent virus 1 (OLV-1), Olive mild mosaic virus (OMMV) and Betanecrovirus Tobacco necrosis virus D (TNV-D) was estimated. Controls in the absence of zoospores were used. In the absence of the fungus, when concentrations of 0.26 μg of OLV-1 mL-1, 0.5 μg of TNV-D mL-1 and 0.5 μg of OMMV mL-1 were used, a 10% of transmission efficiency was obtained. A 100% transmission efficiency was obtained when it was used 65 μg mL-1, 150 μg mL-1 and 50 μg mL-1 of OLV-1, TNV-D and OMMV respectively. When viruses were incubated with O. virulentus zoospores, at OMMV concentrations of 0.26 μg mL-1 and 2 μg mL-1 transmission rates were 10% and 100%, respectively, however, transmission rates of each OLV-1 and TNV-D did not change when they were incubated with the fungus.