Abstract
A monoclonal antibody, designated AbF21-1D3G7C8, reacts in enzyme-linked immunosorbent assay with biovar 3 strains of Agrobacterium tumefaciens, causal agent of grapevine crown gall, from North America, Europe, and Asia, regardless of tumorigenicity. AbF21-1D3G7C8 does not react with A. tumefaciens biovars 1 or 2, or with other plant pathogens, symbionts, or saprophytes. AbF21-1D3G7C8 is useful for laboratory diagnosis of A. tumefaciens biovar 3, and thus for detections and diagnosis of grapevine crown gall, indexing of propagation wood, and quarantine testing. A. tumefaciens biovar 3 was identified in grapevine cultivars and rootstocks from New York and Washington states [USA] by means of the monoclonal antibody.