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【Objective】Pod rot caused by Fusarium spp. is a major soil-borne peanut disease in Guangdong, which affects the yield and quality of peanut seriously. In order to provide a theoretical basis for green prevention and control of pod rot, a biocontrol bacterium was screened and its identification, physiological biochemistry characteristics and control efficiency in fields were evaluated.【Method】Strains with wide amitbacterial spectrum activity the pathogens of peanut pod rot were screened from biocontrol Bacillus strains preserved in laboratory by plate antagoinsm method, and identified by sequence amplification and phylogenetic analysis of 16S rDNA, gyrA, and gyrB sequences. Then, their physiological and biochemical characteristics, carbon source utilization capacity of Biolog-GN plate, biofilm formation in MSgg, BGM1, and BGDM media were determined. Meanwhile, the control effects of these strains on peanut pod rot were conducted by field plot tests.【Result】A Bacillus strain ZKY01 with wide antibacterial spectrum activity was selected, and its plate inhibition rates on Fusarium sp. G15, F. oxysporum R5 and F. solani R4.2 were 72.23 (±3.36)%, 54.14 (±10.33)% and 69.37 (±2.17)%, respectively. According to the phylogenetic analysis, the strain ZKY01 was identified as Bacillus velezensis. ZKY01 could grow normally in 3% to 10% NaCl solution, and temperature suitable for its growth ranged from 10 ℃ to 50 ℃. It could use 50 kinds of carbon sources and form robust pellicles on MSgg, BGM1 and BGDM liquid media. Field control test results showed that ZKY01 wettable powder drenching at seedling stage had a control effect of 95.14% against Fusarium-caused peanut pod rot.【Conclusion】Bacillus velezensis ZKY01 has great application potential in the biological control of peanut pod rot caused by Fusarium spp. |
