Abstract:
【Objective】This study was conducted to isolate and screen the antagonists against banana fusarium wilt from the rhizosphere soil of different crops, and then identify them and evaluate their control effects, to provide new bacteria resources forthe biological control of banana fusarium wilt.【Method】 Targeting the Foc 1402 strain of
Fusarium oxysporum f. sp.
cubense 4, Foc 4,the bacteria in rhizosphere soil of different crops were isolated by gradient dilution coating method,and the antagonistic bacteria of banana fusarium wilt were screened by the plate confrontation method and the Oxford cup assay. The isolates were identified by morphological,physiological,biochemical features and the analysis of 16S rDNA sequences. And the control effects of antagonistic bacteria on banana fusarium wilt were evaluated through pot experiments using banana seedlings of Williams B6.【Result】 A total of 345 bacterial strains were isolated from rhizosphere soil of different crops. Of these,7 strains with strong antagonistic activity against banana fusarium wilt were screened, and the highest inhibition rate was 72.65%. According to the results of morphological,physiological and biochemical characteristics and 16s rDNA sequence analysis,strains Ba02,Ba310,Ba48,Ba62 and Ba63 were identified as
Bacillus amyloliquefaciens,the strain Bc11 was identified as
Burkholderia cepacia,and the strain Pt05 was identified as
Paenibacillus terrae. Pot experiments revealed that the control effects of 7 antagonistic bacteria on banana fusarium wilt were 20.00%-68.89%,and the strain Bc11 was the most effective against banana fusarium wilt(68.89%) .【Conclusion】In this study,7 biocontrol bacteria withstrong control effects on banana fusarium wilt were screened from the rhizosphere soil of different crops. Among them,
P. terrae is a new member of the biocontrol bacteria family of banana fusarium wilt. At the same time,the different kinds of antagonistic bacteria obtained can serve as candidate strain resources for the development of biocontrol agents against banana fusarium wilt,and have good application prospects in the subsequent development of disease resistant composite bacterial agents.