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Etiology

Pseudomonas syringae:Rough Colony Type Mutants and Filamentous Cells. J. D. Otta, Assistant Professor of Plant Science, Department of Plant Science, South Dakota State University, Brookings 57006; Phytopathology 66:249-252. Accepted for publication 15 October 1975. DOI: 10.1094/Phyto-66-249.

Cultures of Pseudomonas syringae grown on King’s Medium B mutated rapidly to a rough colony type. Filamentous cells were associated with the rough colony type with individual cell lengths ranging from 0.8 to 176 µm. Cells in rough cultures produced rough colony types regardless of cell length. No cells longer than 4.0 µm were observed in any of the smooth colony type cultures. No reversions of rough to smooth occurred when rough cultures were inoculated into sorghum and reisolated after 18 weeks.