Application of bacteria symbiotic with Butia archeri (Arecaceae) to the biocontrol of the phytopathogenic fungi that deteriorate seeds of Glycine max

Abstract

Rhizospheric and endophytic microorganisms compete with phytopathogens for ecological niches, which led us to hypothesise that bacteria symbiotic with the palm Butia archeri may influence the germination of the seeds of Glycine max and provide effective biocontrol against phytopathogens. We evaluated seed biopriming with rhizospheric strains of the bacteria Enterobacter asburiae and Bacillus cereus, and endophytic strains of Enterobacter cloacae, Enterobacter sp., Bacillus sp. and Pantoea agglomerans. Seeds treated with E. cloacae and Enterobacter sp. presented higher germination potential, germination velocity index and accumulation of fresh biomass in the radicle than seeds that were untreated or treated with other bacteria. Seeds that were not treated were also most affected by fungi, in particular Fusarium and Penicillium, during storage. When treated with B. cereus and E. asburiae, fungal infestation of the stored seeds was reduced to levels similar to those found in seeds treated with chemical fungicide. Our combined analysis of the influence of these strains on radicular growth and the control of phytopathogens, indicates that the rhizospheric strains of B. cereus and E. asburiae may have the best potential for biocontrol. The present study also demonstrated that the microbiota associated with plants native to the Brazilian Cerrado may be a promising source of species or biomolecules with potential for the biocontrol of plant pathogens.