Influence of graft-inoculation methods on the spread of two forms of reversion virus in black currant (Ribes nigrum L.) plants.

Plants of two black currant cultivars (Ben Lomond and Titania) graft-inoculated with two form (R and E) of reversion virus (BRAV) were investigated. Three, hand grafting methods were used for inoculation of healthy plants. The preliminary results collected in two seasons (1996 and 1997) showed that all types of grafting were efficient in inoculating of black currant plants with reversion disease, but levels of infection were different. In the second year after inoculation (1996), plants of both cultivars showed the characteristic symptoms of reversion on flower bud, flowers and later in the season, on leaves. The severity of symptoms increased with time resulting in a destruction of the whole plants. It would be suggested that the cultivar Ben Lomond was more susceptible to the reversion virus than cultivar Titania. Reversion had a significant influence on yield reduction of fruit harvested from infected plants. For both investigated genotypes, the yield decreased dramatically and a drop of 45 to 50% was recorded from shrubs showing severe symptoms of reversion.