Abstract:

The antagonistic bacteria with antibacterial activity were screened out, and their disease control effect was determined, so as to provide a basis for the biological control of Korla fragrant pear canker. Bacteria were isolated from various raw materials, including fruit and vegetable enzyme solution and Korla fragrant pear branches. The antibacterial activity of the isolated strains against Korla fragrant pear canker was determined by plate confrontation culture and bacterial fermentation broth, from which the antagonistic strains with significant bacteriostatic effect were selected. The disease control effect was tested by in vitro branch method. Twelve bacterial strains with bacteriostatic activity against V. ceratosperma were screened, and the bacteriostatic rate was 54.72%-86.43%. The results of in vitro branch method showed that the protective control effect of antagonistic bacteria XG-FX22 and G-FX12 isolated from enzyme solution was 77.71% and 65.29%, respectively, and the therapeutic control effect was 66.71% and 66.14%, respectively. Strains G-FX12 and XG-FX22 were identified as Bacillus velezensis by morphology and 16S rDNA sequence analysis. The results provide a scientific basis for the exploration of biocontrol resources and the effective disease control of Korla fragrant pear canker.

Key words: Korla fragrant pear, Valsa ceratosperma, enzyme, endophutic antagonistic, screening, control efficacy