Abstract
In Okayama Prefecture, natural spread of grapevine leafroll disease was suspected in a field where a woody indicator, grapevine cv. Cabernet Franc (CF) was used to index for this disease. After leafroll- and Grapevine leafroll-associated virus 3 (GLRaV-3)-free nursery vines of grape cvs. CF and Cabernet Sauvignon had been transplanted to the field in July 1999, the incidence of leafroll disease reached 82% and 20%, respectively, in autumn 2001. GLRaV-3 was detected from all symptomatic vines by ELISA. These results suggest that leafroll disease and GLRaV-3 naturally spread in the field.
