Archivio Journal of Plant Pathology

Abstract:

To assess the diversity of Rhizobium (Agrobacterium) species and strains, associated with crown gall disease of grapevine (Vitis vinifera) in the major grapevine growing areas of northern Iran, 105 strains of the suspected bacterium were isolated from tumors of the crown and vines collected from vineyards in the East and West Azarbayjan and Ardabil provinces. Bacterial strains were characterized by their phenotypic features, presence of virD2 and polygalacturonase genes and opine markers. Seventy seven strains were identified as Rhizobium vitis and the remaining 28 strains as R. radiobacter. Among the 99 strains of Rhizobium-carried vir gene sequences, 49, 35 and 8 strains appeared to have opine synthase genes of octopine, vitopine and nopaline types, respectively. The opine-type of the Ti plasmids of the remaining seven strains could not unequivocally be determined. Based on these findings the predominant species inducing tumor on grapevines in northern Iran is R. vitis and vitopine producers are the prevalent opine-type in R. vitis populations.