Isolation and selection of plant growth-promoting rhizobacteria as inducers of systemic resistance in melon
- 978 Downloads
Backgroud and aims
Powdery mildew elicited by Podosphaera fusca is an important threat to cucurbits. In order to find alternatives to the current use of chemicals, we examined the potential use of plant growth-promoting rhizobacteria (PGPR) for controlling the disease by induction of systemic resistance in the host plant.
A collection of Bacillus and Pseudomonas strains from different origins was studied, including strains isolated from roots of disease-free melon plants obtained from a greenhouse plagued by powdery mildew. The selection of best candidates was based on the evaluation of different traits commonly associated with PGPR, such as antifungal and siderophore production, swimming and swarming motilities, biofilm formation, auxin production and promotion of root development.
Three Bacillus strains, B. subtilis UMAF6614 and UMAF6639 and B. cereus UMAF8564, and two Pseudomonas fluorescens strains, UMAF6031 and UMAF6033, were selected after ranking the strains using a nonparametric statistics test. Applied to melon seedlings, the selected strains were able to promote plant growth, increasing fresh weight up to 30%. Furthermore, these strains provided protection against powdery mildew and also against angular leaf spot caused by Pseudomonas syringae pv. lachrymans, with disease reductions of up to 60%.
These results suggest that the use of ISR-promoting PGPR could be a promising strategy for the integrated control of cucurbit powdery mildew and other cucurbit diseases.
KeywordsBacillus cereus Bacillus subtilis Biological control Induced systemic resistance (ISR) Podosphaera fusca Powdery mildews Pseudomonas fluorescens
This study was supported by grants from Plan Nacional de I+D+I of the Ministerio de Ciencia e Innovación, Spain (AGL2007-65340-C02-01 and AGL2010-21848-C02-01), cofinanced by FEDER funds (European Union).
- Bélanger RR, Labbé C (2002) Control of powdery mildews without chemicals: prophylactic and biological alternatives for horticultural crops. In: Bélanger RR, Bushnell WR, Dik AJ, Carver TLW (eds) The powdery mildews. A comprehensive treatise. APS Press, USA, pp 256–267Google Scholar
- Cazorla FM, Duckett SB, Bergström T, Noreen S, Odijk R, Lugtenberg BJJ, Thomas-Oates JE, Bloemberg GV (2006) Biocontrol of Dematophora root of avocado by antagonistic Pseudomonas fluorescens PCL1606 correlates with the production of 2-hexyl 5-propyl resorcinol. Mol Plant Microbe Interact 19:418–428PubMedCrossRefGoogle Scholar
- Chambel L, Pelica F, Teodoro AM, Neves-Martins J, Palminha J (1994) Development of a new in vitro PGPR screening method. In: Proceedings of the Third International Workshop on Plant Growth-Promoting Rhizobacteria. Adelaide, Australia, p. 33Google Scholar
- Ongena M, Jacques P, Touré Y, Destain J, Jabrane A, Thonart P (2005) Involvement of fengycin-type lipopeptides in the multifaceted biocontrol potencial of Bacillus subtilis. Appl Environ Microbiol 69:29–38Google Scholar
- Romero D, de Vicente A, Rakotoaly RH, Dufour SE, Veening JW, Arrebola E, Cazorla FM, Kuipers OP, Paquot M, Pérez-García A (2007a) The iturin and fengycin families of lipopeptides are key factors in antagonism of Bacillus subtilis toward Podosphaera fusca. Mol Plant Microbe Interact 20:430–440PubMedCrossRefGoogle Scholar