Biocontrol Science and Technology (2015) 25, 928-949

N.N. Kamou, H. Karasali, G. Menexes, K.M. Kasiotis, M.C. Bon, E.N. Papadakis, G.D. Tzelepis, L. Lotos and A.L. Lagopodi (2015)
Isolation screening and characterisation of local beneficial rhizobacteria based upon their ability to suppress the growth of Fusarium oxysporum f. sp. radicis-lycopersici and tomato foot and root rot
Biocontrol Science and Technology 25 (8), 928-949
Abstract: Local beneficial rhizobacteria were selected based upon their ability to control the fungus Fusarium oxysporum f. sp. radicis-lycopersici which causes crown and root rot of tomato. Seven out of 384 strains prevailed in multiple and dual cultures and were identified as Pseudomonas chlororaphis (one strain), Bacillus cereus (one strain), Serratia marcescens (three strains) and Serratia rubidaea (two strains), by sequencing the 16S rRNA or the 16S and 23S rRNA inter-spacer region. The seven selected rhizobacteria were tested for their biocontrol and growth-promoting effects in planta, and their antifungal properties in vitro. All strains significantly reduced disease severity under controlled conditions, in a gnotobiotic system and in pots. Moreover, one P. chlororaphis and one S. marcescens strain significantly decreased disease severity to the level of the healthy control under natural conditions in pots experiments. The inhibitory activity of bacterial liquid cultures' metabolites on the fungus was demonstrated for all strains in vitro, using filter paper, thin layer chromatography and microtiter bioassays. Genes encoding phenazines were tentatively detected by PCR in the P. chlororaphis strain and chitinase-encoding genes were detected in one S. rubidaea and all three S. marcescens strains. Production of phenazine-1-carboxamide and hydrogen cyanide was evidenced for the P. chlororaphis strain while protease activity and production of siderophore-like compounds was confirmed in all bacterial strains. Possible use of these strains as biological control agents and their impact on natural biocontrol of pathogens in soils is discussed.
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Link to article at publishers website
Database assignments for author(s): Marie-Claude Bon

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution
evaluation - screening - selection

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Fusarium crown and root rot	Tomato (Solanum lycopersicum)
Serratia marcescens (antagonist)	Fusarium crown and root rot	Tomato (Solanum lycopersicum)
Pseudomonas chlororaphis (antagonist)	Fusarium crown and root rot	Tomato (Solanum lycopersicum)