Presumptive Procedure (Dome Test) for Detection of Seedborne Bacterial Pathogens in Dry Beans. J. R. Venette, Associate Professor, Department of Plant Pathology, North Dakota State University, Fargo 58105. R. S. Lamppa, D. A. Albaugh, and J. B. Nayes. Technician, Graduate Assistant, and Former Graduate Research Assistant, Department of Plant Pathology, North Dakota State University, Fargo 58105. Plant Dis. 71:984-990. Accepted for publication 22 June 1987. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1987. DOI: 10.1094/PD-71-0984.

An assay of bean seed lots for pathogenic bacteria, referred to as the dome test, is described. Seeds are soaked in water, the soaked bean infusion is vacuum-infiltrated into pregerminated seeds from the same lot, and symptoms are observed on the seedlings grown in high humidity. In tests of 233 lots of bean seeds, all of the lots produced at least some seedlings with water-soaked spots on primary leaves. Intensity of water-soaking varied among seed lots. Plant pathogens were isolated from lesions on plants from 118 of 139 lots and were characterized by biochemical, physiological, morphological, and pathogenicity tests as Pseudomonas syringae pv. syringae or pv. phaseolicola or Xanthomonas campestris pv. phaseoli.