European Journal of Plant Pathology

, Volume 104, Issue 7, pp 631–643

Biocontrol of soil-borne fungal plant diseases by 2,4-diacetylphloroglucinol-producing fluorescent pseudomonads with different restriction profiles of amplified 16S rDNA

Authors

  • Abbas Sharifi-Tehrani
    • Phytopathology group, Institute for Plant SciencesSwiss Federal Institute of Technology (ETH Zentrum)
    • Department of Plant Protection, College of AgricultureUniversity of Tehran
  • Marcello Zala
    • Phytopathology group, Institute for Plant SciencesSwiss Federal Institute of Technology (ETH Zentrum)
  • Andreas Natsch
    • Phytopathology group, Institute for Plant SciencesSwiss Federal Institute of Technology (ETH Zentrum)
  • Yvan Moënne-Loccoz
    • Phytopathology group, Institute for Plant SciencesSwiss Federal Institute of Technology (ETH Zentrum)
  • Geneviève Défago
    • Phytopathology group, Institute for Plant SciencesSwiss Federal Institute of Technology (ETH Zentrum)
Article

DOI: 10.1023/A:1008672104562

Cite this article as:
Sharifi-Tehrani, A., Zala, M., Natsch, A. et al. European Journal of Plant Pathology (1998) 104: 631. doi:10.1023/A:1008672104562

Abstract

Fluorescent pseudomonads producing the antimicrobial compound 2,4-diacetylphloroglucinol (Phl) are being studied extensively for use as biocontrol agents of soil-borne fungal diseases. Some of them can produce pyoluteorin (Plt) in addition to Phl, whereas others synthesise only Phl. Here, a collection of seven Phl+ Plt- pseudomonads, seven Phl+ Plt+ pseudomonads and seven Phl- biocontrol pseudomonads were compared for protection of plant roots against fungal pathogens. The seven Phl+ Plt+ pseudomonads were identical by restriction analysis of amplified spacer ribosomal DNA (spacer ARDRA), whereas the Phl+ Plt- pseudomonads and especially the Phl- biocontrol pseudomonads were quite diverse by spacer ARDRA. Collectively, the Phl+ Plt- pseudomonads proved superior to the Phl+ Plt+ pseudomonads and the Phl- biocontrol pseudomonads for protection of tomato against Fusarium crown and root rot (in rockwool microcosms) or cucumber against Pythium damping-off (in non-sterile soil microcosms). There was no correlation between protection in vivo and inhibition of the corresponding fungal pathogen on plates. However, there was a significant correlation between the amount of Phl produced on plates and protection of tomato against Fusarium crown and root rot, but not with protection of cucumber against Pythium damping-off. Interestingly, the minority of strains unable to produce HCN, an extracellular protease, or both, were among those unable to protect plants in both pathosystems. A seedling assay was developed to compare pseudomonads for suppression of Fusarium crown and root rot in vitro, and a significant correlation was found between disease severity in vitro and in vivo. Overall, results suggest that promising biocontrol pseudomonads may be identified based on the ability to produce Phl and/or specific ARDRA-based fingerprints.

Fusarium Pythium Pseudomonas tomato cucumber 2,4-diacetylphloroglucinol

Copyright information

© Kluwer Academic Publishers 1998