VIEW ARTICLE

Resistance

Phytoalexin Production in Five Cultivars of Peas Differentially Resistant to Three Races of Pseudomonas syringae pv. pisi. Lee A. Hadwiger, Professor, Department of Plant Pathology, Washington State University, Pullman 99164-6430; David M. Webster, research plant scientist, Asgrow Seed Company, Twin Falls, ID 83303. Phytopathology 74:1312-1314. Accepted for publication 31 May 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/Phyto-74-1312.

Five cultivars of peas are differentially susceptible to three races of Pseudomonas syringae pv. pisi. Within a given cultivar, the host-pathogen combination in which resistance was expressed in seedling assays resulted in high levels of pisatin and yellow-green pigmentation in epidermal cells in endocarp tissue. These responses were either absent or lower in susceptible interactions. Pisatin at 68 μg/ml was inhibitory to in vitro growth of all three races of P. syringae pv. pisi.