Screening and Identification of Biocontrol Strains against Potato Black Shank Disease,Pectobacterium atrosepticum

摘要

[Objective]The paper was to screen and identify biocontrol strains against potato black shank disease in Inner Mongolia.[Method]Totally 58 strains of Bacillus spp.preserved in the laboratory were used to screen and identify biocontrol agents against potato black shank disease,and the antagonistic activities of strains were determined by plate confrontation culture method.[Result]A total of 17 strains showed antagonistic activity against Pectobacterium atrosepticum in potato,accounting for 29.31%of the tested strains.Five strains with better antagonistic effect were obtained by further screening,namely Chi8-7,Genyun4-4,Gen7-4,Jing6-7,and S-7.Genyun4-4 had the most obvious bacteriostatic effect,and the average inhibition zone diameter reached 20.7 mm,significantly higher than those of other tested strains.Results of bioactivity determination also demonstrated that the strain had better bacteriostatic effect.Through morphological observation,molecular identification and physiological and biochemical characteristics determination,the strain Chi8-7 was identified as Bacillus amyloliquefaciens;the strain Genyun4-4 was identified as B.subtilis;and strains Gen7-4,Jing6-7 and S-7 were identified as B.methylotrophicus.[Conclusion]The results will lay a theoretical basis for biological control against potato black shank disease in Inner Mongolia.