Suppression of Fusarium moniliforme in Rice by Rice-Associated Antagonistic Bacteria

Area of Science:

• Agricultural Microbiology
• Plant Pathology
• Biocontrol Agents

Background:

• Bakanae disease, caused by Fusarium moniliforme, is a significant threat to rice production worldwide.
• Effective and sustainable disease management strategies are crucial for maintaining rice yields.

Purpose of the Study:

• To assess the potential of antagonistic bacteria from various rice-associated environments for controlling bakanae disease.
• To evaluate the in vitro antibiosis and effects of bacterial isolates on rice seed germination and seedling vigor.

Main Methods:

• Isolation and screening of 441 bacterial strains from paddy water, rhizosphere soils, sclerotia, and rice plants.
• In vitro assessment of antibiosis against Fusarium moniliforme mycelial growth.
• Evaluation of bacterial effects on seed germination and seedling vigor.
• Bacterization trials in seedboxes, seedbeds, and field experiments over three years.

Main Results:

• 113 out of 441 isolates exhibited inhibitory effects against the pathogen's mycelial growth.
• Bacterial strains were categorized based on their impact on seed germination: promoting, neutral, or inhibitory.
• Bacterization significantly reduced bakanae incidence, with disease control ranging from 71.7% to 96.3% in seedbed experiments.
• Ten strains consistently reduced bakanae in field trials over three years, with five showing stable efficacy.

Conclusions:

• Antagonistic bacteria hold significant potential as biocontrol agents against bakanae disease in rice.
• Specific bacterial strains demonstrate consistent efficacy in reducing disease incidence and improving crop health.
• The study highlights the specificity of bacterial suppression against different F. moniliforme isolates.