VIEW ARTICLE

Ecology and Epidemiology

Spread of Plant Pathogenic Bacteria with Fungal Hyphae. Curt Leben, Professor, Department of Plant Pathology, Ohio Agricultural Research and Development Center, Ohio State University, Wooster 44691; Phytopathology 74:983-986. Accepted for publication 23 March 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/Phyto-74-983.

Plant pathogenic bacteria spread along hyphae on agar, the extent depending on the bacterium-fungus combination and nutrients in the medium. Spread near Pythium ultimum was better than near Rhizopus stolonifer and Trichoderma koningii. Cells of Pseudomonas syringae pv. lachrymans were in static masses adjacent to old hyphae of P. ultimum, motile in narrow water bands adjacent to middle-aged hyphae, and not detected near young hyphae. P. ultimum was not inhibited by any of five bacterial pathogens. Growth of R. stolonifer and T. koningii was inhibited by some bacteria, and young hyphae of R. stolonifer “avoided” bacteria on agar surfaces by growing under them. Bacteria spread via hyphae 2- 3 mm across an air gap and 7.5 mm on a glass surface. Results are discussed in relation to the ecology of plant pathogenic bacteria and to fungus culture contamination by bacteria.