关键词:

共培养, 粉红螺旋聚孢霉, 枯草芽胞杆菌, 拮抗作用, 促生, 杀线活性

Abstract: Clonostachys rosea is an important biocontrol fungus against many kinds of plant diseases. In this paper, the biological characters and biocontrol activities of the fermentation filtrates of C. rosea 67-1 and Bacillus subtilis B006 co-cultured in different nutritional media were investigated. The effects of the filtrates on sclerotial formation of Rhizoctonia solani and hyphal growth of Fusarium oxysporum f. sp. conglutinans and F. oxysporum f. sp. niveum were determined on agar plates. The nematicidal activities of the filtrates to the juveniles of root-knot nematode were tested by using 6-well tissue culture plates. The effects of the co-culture filtrates on germination of cucumber seeds and the growth of seedlings were determined in lab and in greenhouse. Results showed that the co-cultured fermentation filtrates of C. rosea and B. subtilis significantly reduced the sclerotia formation ofR. solani and the biomass of F. oxysporum, in which the inhibition rates of the growth of F. oxysporum f. sp. conglutinansincreased by over 40%; in the media of glucose/ammonium sulfate the rates decreased by 86.6% and 62.7% compared to the strain 67-1 and B006, respectively. The nematicidal activities of the co-cultured filtrates significantly increased.  After treated with the fermentation filtrates co-cultured in the media of corn/soybean flour and glucose/ammonium sulfate, the mortality rates of the juveniles reached more than 65%, which were 37.0% and 50.8% higher than those in 67-1 filtrates and 79.1% and 94.7% higher than B006, respectively. After soaked in the co-culture filtrates, the vigor index of cucumber seeds, seedling length and root fresh weight increased by 7.4-30.4%. The research provides new insight into the improvement of control efficiency of C. roseaand the development of new highly efficient biocontrol agents.

Key words:

co-culture; Clonostachys rosea, Bacillus subtilis, antagonism, growth-promoting, nematicidal activity