Molecular assessment of siderophore production ability in Pseudomonas fluorescent strains, as a control agent of root rots in sugar beet

Root rot is the most important disease of sugar beet caused by Rhizoctonia solani fungus which lives in soil. Many soil bacteria such as Pseudomonas spp. by production of materials such as siderophores could control soil borne pathogens. So in this study, after identifying Pseudomonas fluorescents in the Rhizosphere of Sabzevar sugar beet fields and the assessment of the bacteria to inhibit R. solani growth, detection of siderophore biosynthetic gene was performed. For this purpose, plant samples along with its Rhizosphere soil were collected. To obtain specific Pseudomonas, Pseudomonas agar F medium was used. After 2 subcultures on the same medium, three Pseudomonas fluorescent strains based on microbial tests were identified. To evaluate the growth inhibition of R. solani by Pseudomonas fluorescent, dual culture tests were done. Based on inhibition areola, it was shown that C7 and C3 isolates have severe and moderate deterrence respectively but C5 strain has no deterrent effect. PCR results also showed that only C7 isolate contained siderophore biosynthetic genes.