phenotypic and genotypic study of pseudomonas fluorescens strains pgu0 and assessment of its biocontrol against rhizoctonia solani, the causal agent of bean damping- off
چکیده(به انگلیسی؛ چکیدهی فارسی در دسترس نیست)
fluorescent pseudomonads producing 2,4-diacetylphloroglucinol (dapg) antibiotic have been well studied for use as biocontrol agents around the world. pseudomonas fluorescens pgu0 strain was isolated from the rhizosphere of sunflower in bushehr province. dual culture test showed that the strain had antagonistic activity against rhizoctonia solani fungus on different media cultures; moreover, under growth chamber condition, the strain reduced disease severity by 52% and caused an increase in dry weight of infected bean seedlings by 80%. the polymerase chain reaction (pcr) using specific primers, demonstrated the presence of key genes (phld, hcnbc and pltb) involved in the biosynthesis of antimicrobial metabolites phl, pyoluteorin (plt) and hydrogen cyanide (hcn), respectively . antibiotic production was examined by high-performance liquid chromatography (hplc) and it was found that these bacteria are capable of producing dapg and plt antibiotics. on the other hand, production of hydrogen cyanide and siderophore by the bacterium was demonstrated under lab conditions. phylogenetic analysis of 16s rdna proved similarity of this strain with other world biocontrol strains capable of producing antimicrobial metabolites like phl and plt.