Resistance to Pseudomonas syringae pv. tomato in Wild Lycopersicon Species. Vince F. Lawson, Instructor, Department of Horticulture, Iowa State University, Ames 50011. W. L. Summers, Assistant Professor, Department of Horticulture, Iowa State University, Ames 50011. Plant Dis. 68:139-141. Accepted for publication 17 August 1983. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-139.

In 1981, 540 PI accessions and named cultivars of tomato were evaluated for resistance to Pseudomonas syringae pv. tomato, causal agent of bacterial speck of tomato. Resistance was found in Lycopersicon esculentum, L. glandulosum, L. hirsutum, L. peruvianum, and L. pimpinellifolium and in several accessions classified as known or suspected species crosses. Both symptomless reactions and symptoms of an intermediate degree of resistance were observed. The hypersensitive resistance to P. tomato in accessions PI 112215 of L. pimpinellifolium, PI 129157 of L. hirsutum f. glabratum, and L. esculentum ‘Ontario 7710’ was conditioned by a single dominant gene common to each of the three lines.