Antifungal Metabolites of Suppressive Strains of Root-Infecting Diseases of Sugar Beet Pseudomonas Biocontrol

Document Type : Original Article

Authors

1 Plant Pathol. Res. Inst., ARC, Giza

2 Plant Pathol. Dept., Fac. Agric., Cairo Univ.

Abstract

Current study dealt with five of rhizospheric fluorescent pseudomonas strains previously found to have the potential to reduce sugar beet root-infecting Fusarium oxysporum f. sp. Betae in greenhouse. They were analyzed for their mode of action of biocontrol activity. It was found that they differed in their potency to produce secondary metabolites that can influence the pathogen by direct or indirect effects. Pseudomonas putida strain PS23 was shown to be superior in the antibiosis and activity to produce chitinase and cellulase enzymes as well comparable to the other strains. Antifungal metabolites produced by this bacterial strain were characterized by GC/MS. Several chemical constituents could be detected, where phenolic compounds were abundantly characterized. Plenty of compound types such as monoterpenoides, phenylpropenes, diterpenoides known as pest control agents were detected along with other several allelochemicals existed in metabolic products of this efficient rhizobacterial biocontrolagent.

Keywords