The relationship of grapevine leafroll-associated closterovirus 2 with a graft incompatibility condition of grapevines

Investigations were carried out i n France (Colmar) and Ital y (Sassari and Bari) on grapevines known to contain a graft incompatibility factor revealed by the rootstock hybri d Vitis riparia x Vitis berlandieri 'Kober 5BB'. Several grapevine accessions were examined in both countries by ELIS A using antisera specific to grapevine leafroU-associated closterovirus 1, 2 and 3, grapevine trichovirus A and B and grapevine fleck virus and by field or green-graft indexing. In other trials , the viruses stili present i n vines propagated from heat-treated cv. Chardonnay accessions were analysed by ELIS A and the results of serological tests were compared wit h those coming from field indexing. The results obtained i n Ital y and France were comparable and led to the conclusion that a remarkably dose association exists between GLRaV-2 and the 'Kober 5BB' graft-incompatibility condition.