Tobacco Rattle Virus (TRV) Transmission by Sugar Beet Seeds

Abstract

ABSTRACTThe study involves tobacco rattle virus (TRV) detection in racemes of two-year beet plants, seedlings, grown from seeds of these plants and seedlings from commercially available sugar beet seeds. Parts of sugar beet roots with a history of TRV were used for growing of two-year floriferous plants. Since plants had symptoms of yellow mosaic on leaves and raceme stipules, we tested each raceme separately with antiserum to TRV and broad beans wilt virus (BBWV) by ELISA. BBWV also causes yellow mosaic on leaves and raceme stipules and is usually combined with TRV infection in beet lately. Of 13 flowering plants, 8 were diagnosed with TRV and 2—with BBWV. TRV virus concentration in racemes was more than 0.3 to more than 0.5 optical units. BBWV showed lower concentration—more than 0.25 optical units in a limited number of plants (only 2), which did not interfere with TRV detection in racemes of flowering beet plants. Artificial vegetative propagation of beet has led to TRV transmission with racemes of two-year beet plants of up to 62%. Seedlings, originating from seeds of two-year beet plant, with extinction value of 0.550 optical units for the sample of its raceme, accounts for 20% of TRV transmission. The results of testing seedlings, grown from commercially available seeds, showed 15% TRV transmission for one batch and 20% for the other. TRV infection of racemes was investigated in samples, collected from a seed-production field. We detected 5% TRV infection in racemes of this field. The progeny of such racemes may transmit TRV to commercial fields, let alone nematode transmission of the virus.