Bacterial Lipopeptides Are Effective against Pear Fire Blight

Area of Science:

• Agricultural Science
• Plant Pathology
• Microbiology

Background:

• Fire blight, caused by Erwinia amylovora, severely impacts apple and pear production in Xinjiang, China.
• Effective biocontrol agents are needed to manage this devastating plant disease.

Purpose of the Study:

• To isolate and identify bacteria with antagonistic activity against Erwinia amylovora.
• To evaluate the biocontrol potential of selected bacterial strains on apple and pear trees under laboratory conditions.

Main Methods:

• Isolation and screening of 10 bacterial strains from apple and crabapple trees.
• Identification of promising strains using biochemical tests and 16S rRNA gene sequencing.
• In vitro and controlled laboratory evaluations of biocontrol efficacy on immature fruits and leaves.

Main Results:

• Priestia megaterium H1 and Bacillus subtilis I2 were identified as effective antagonists.
• Both strains significantly reduced fire blight severity on immature fruits (53.39% and 44.76% reduction) and leaves (59.55% and 55.53% reduction).
• Lipopeptides, including surfactin, iturins, bacillomycin D, and fengycins, were detected in the bacterial extracts.

Conclusions:

• Priestia megaterium H1 and Bacillus subtilis I2 demonstrate significant potential as biocontrol agents against fire blight.
• Further field trials are necessary to confirm the practical application of these bacterial strains in natural conditions.