Effect of Plant Growth Promoting Rhizobacteria in Inhibiting the Growth of Botrytis cinerea in vitro

Abstract

This study aimed to evaluate the effect of three species of plant growth-promoting rhizobacteria (PGPRs): Frateuria aurantia, Rhizobium leguminosarum and Bacillus megaterium on the growth of the fungus Botrytis cinerea in vitro. The antagonism effect between the bacterial isolates used and the volatile substances secreted in preventing the growth of the gray mold fungus, Botrytis cinerea was assessed on PDA medium. The results obtained showed that all bacterial species used were able to inhibit the growth of colonies of the fungus Botrytis cinerea by producing compounds in the medium or secreting volatile substances. The bacteria Bacillus megaterium achieved superiority in inhibiting significantly the growth of the fungus over the other bacterial species using the two approaches (antagonism with bacterial secretions directly in the medium, and with volatile products), where the diameter of the colony of the pathogenic fungus reached 1.3. and 2.6 cm, respectively, compared with 8.4 cm for the control, and the inhibition rate reached 84.5 and 69.0%, respectively. The results obtained confirmed the ability of the PGPR bacteria used in inhibiting the growth of the pathogenic fungus Botrytis cinerea and its potential to be used as a biological control component in the management of this fungus.

Keywords:

PGPR, Botrytis cinerea, PDA, Antagonism, volatile compounds.