Abstract:One antagonistic bacterial strain was isolated form soli and identified as Bacillus amyloliquefaciens X-42 based on its morphology and 16S rDNA sequences.This strain produced a series of metabolites that exhibited a strong inhibitory activity to Fusarium graminearum.From its secreted metabolites during fermentation,some lipopeptides were precipitated with ammonia sulfate and used for antifungal assays.These lipopeptides were able to directly damage mycelia and conidiospores of F.graminearum,resulting in severely deformed,partly enlarged structures.Field assays showed a significant reduction of Fusarium head blight (FHB) diseases on wheat when X-42 suspension was sprayed on wheat spikes either before or after inoculation with F.graminearum.Relative protective efficacies ranged from 79% to 88%,comparable to that treated with chemical fungicide carbendazim.This study may serve as foundation for the development of new and environmental friendly biological agents to control FHB.
