VIEW ARTICLE

Resistance

Induction of Reciprocal Resistance in Prunus persica by Cytospora cincta and Agrobacterium tumefaciens. A. W. Helton, Department of Plant and Soil Sciences, University of Idaho, Moscow, 83843; Phytopathology 66:212-214. Accepted for publication 12 August 1975. DOI: 10.1094/Phyto-66-212.

Branches of 4-year-old (cultivar Redhaven) and 3-year-old (cultivar Golden Jubilee) peach (Prunus persica) trees were artificially infected with Agrobacterium tumefaciens in the spring. At various intervals thereafter, secondary infections by Cytospora cincta were initiated on the same branches to determine whether infection by A. tumefaciens would influence development of the cankers caused by C. cincta, and (conversely) whether the presence of cankers incited by C. cincta would influence development of the galls caused by A. tumefaciens. Expansion rates of both galls and cankers were significantly depressed in the vicinity of the other infective agent under most test conditions of the 2-year study, demonstrating that the bacterium induces a nonspecific resistance to the fungus in P. persica and vice versa.