Bacillus methylotrophicus has potential applications against Monilinia fructicola

Abstract

Biocontrol is a cost-effective and environmentally friendly technique used in agricultural production. We isolated and screened a bacterial strain from the soils of a peach orchard with high yield. Using biochemical and physiological analysis as well as phylogenetic sequencing data, we identified a strain of Bacillus methylotrophicus, strain XJ-C. The results of our screening trials showed that XJ-C was able to suppress M. fructicola at an inhibition rate of 81.57%. Following the application of a 1×109 CFU/mL XJ-C strain suspension to the fruits, leaves, and shoots of peach trees infected with M. fructicola, the inhibition rate reached 64.31%, 97.34%, and 64.28%, respectively. Using OM and SEM, we observed that, under the inhibition of strain XJ-C, M. fructicola mycelium and spores were abnormally shaped. Under TEM, cell walls were transparent, organelles had disappeared, and the intracellular vacuole was deformed. Thus, XJ-C has the potential to be used in biocontrol.