Biocontrol of fungal pathogens by the use of Plant Growth Promoting Rhizobacteria and nitrogen fixing microorganisms

摘要

Plant Growth Promoting Rhizobacteria (PGPR) isolated from chickpea and wheat rhizospheres, were screened for siderophore production. The fluorescent pseudomonads varied in siderophore production. The PGPR strains and nodule bacteria were tested for their antagonistic potential against phytopathogenic fungi in vitro. Cell free filtrates of PGPR strains showed activity against phytopathogenic fungi with most distinct antagonism being produced in Potato Dextrose broth, Malt Extract broth and Czapex Doxbroth. Six Rhizobium (chickpea) and Bradyrhizobium (Vigna) strains were also evaluated in vitro against the mycelial growth of six pathogenic fungi on solid and liquid media. All the tested strains of rhizobia suppressed the growth of the pathogenic fungi either in the absence or presence of iron. This indicates that the siderophores played a minor role in biocontrol potential of Rhizobium and Bradyrhizobium strains against pathogenic fungi.