| 摘要 |
PROBLEM TO BE SOLVED: To obtain a strain belonging to the genus Pseudomonas aureofaciens, showing antifungal activity against Thielaviopsis basicola, exerting no bad influence on plants, effectively suppressing black root rot. SOLUTION: This strain is a bacterium having antifungal activity against Thielaviopsis basicola as a fungus to cause black root rot, such as Pseudomonas aureofaciens TB57 (FERM BP-5061). The bacterium is obtained by putting the root of tobacco collected from a field slightly causing black root rot in sterile water, stirring the root part by a mixer, streaking the prepared suspension on a king B medium, culturing it at 20-25 deg.C for 3 days and further selecting the bacterium from the prepared single colony. The culture product of the bacterium is preferably introduced into the root part or soil to control black root rot of tobacco. When the culture product of the bacterium is used as a controller, viable bacteria in the concentration of 10<5> to 10<10> bacteria/ml are preferably used. In the case of a culture filtrate, a stock solution to a diluted solution by 10 times is preferable. |
