Suppression of pythium ultimum induced damping off of cotton seedlings by pseudomonas fluorescens and its antibiotic pyoluteorin
Suppression of pythium ultimum induced damping off of cotton seedlings by pseudomonas fluorescens and its antibiotic pyoluteorin
Howell, C.R.; Stipanovic, R.D.
Phytopathology 70(8): 712-715
1980
Strain Pf-5 of P. fluorescens was antagonistic in vitro to P. ultimum. An antibiotic, pyoluteorin (4,5-dichloro-1 H-pyrrol-2-yl-2,6-dihydroxyphenyl ketone), was isolated from cultures of the Pf-5 strain and found to be inhibitory to P. ultimum, but not to R. solani. Treatment of cottonseed with pyoluteorin or with P. fluorescens at the time of planting in P. ultimum-infested soil increased seedling survival from 33 to 65% and from 28 to 71%, respectively. Although effective as a seed treatment, pyoluteorin was adsorbed and inactivated by the soil colloids when added directly to soil.