1- Department of Plant Protection, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran.
2- Department of Plant Protection, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran. , s.baghaee@um.ac.ir
3- Department of Plant Protection, Faculty of Agriculture, University of Tehran, Tehran, Iran.
Abstract: (273 Views)
Among rhizobacteria, plant-beneficial effects of Pseudomonas bacteria are known in agricultural ecosystems. Screening of fluorescent pseudomonad isolates obtained from potato rhizosphere led to selecting five bio-reagents capable of controlling soft rot disease caused by Pectobacterium carotovorum subsp. carotovorum (Pcc) (JX029052) in plate assay, on intact potato tubers and under storage challenges using preventative and curative applications. The biocontrol features related to the tested rhizospheric bacteria were also evaluated. According to phenotypic tests, the representative antagonistic strains belong to the fluorescent pseudomonads group and are placed in the P. protegens cluster based on 16S rRNA gene sequencing. Strains IrPs8 and IrPs18 are potent to produce siderophore, cyanide hydrogen, and protease, form strong biofilm and carry phl, plt and prn genes on their genomes corresponding to 2, 4-diacetylphloroglucinol, pyoluteorin and pyrrolnitrin, respectively. Treated tubers inoculated with IrPs8 and IrPs18 showed a reduction in the soft rot-inducing potency of Pcc by 63.4 and 65.5% in preventative and by 57.8 and 58.3% in curative tests, respectively, under storage conditions that confirmed the in vivo results. This study highlights the potential of rhizospheric P. protegens strains as beneficial bacteria that can be suggested as preservative coatings for potato tubers under storage conditions.
Article Type:
Original Research |
Subject:
Biocontrol of Plant Diseases Received: 2024/04/23 | Revised: 2024/12/22 | Accepted: 2024/12/16 | Published: 2024/12/22