Biocontrol Science and Technology (2007) 17, 483-497

Nadjia Zermane, Thouraya Souissi, Jürgen Kroschel and Richard Sikora (2007)
Biocontrol of broomrape (Orobanche crenata Forsk. and Orobanche foetida Poir. ) by Pseudomonas fluorescens isolate Bf7-9 from the faba bean rhizosphere
Biocontrol Science and Technology 17 (5), 483-497
Abstract: Bacteria of the faba bean (Vicia faba L.)/Orobanche spp. root environment were evaluated for their potential use as biocontrol agents for the parasitic weed. Bacteria were isolated mainly from the rhizosphere of faba bean as well as from diseased Orobanche underground structures and an Orobanche-suppressive soil from three districts of northern Tunisia. Out of 351 bacterial isolates, 337 were tested for pathogenicity in an inverted pyramidal-shape screening programme including a Lactuca sativa L. seedlings bioassay, root-chamber and pot experiments. In pre-selection screening on L. sativa seedlings, 37 isolates (11%) showed a strong growth inhibitory effect, of which 70 and 84% also had a significant suppressive activity on the pre-emergence structures of O. foetida and O. crenata, respectively, in root-chamber experiments. Among five bacterial isolates selected for pot trials, strain Bf7-9 of Pseudomonas fluorescens showed high biocontrol activity against both species of Orobanche and positively influenced faba bean growth. The bacterium reduced shoot emergence of O. crenata and O. foetida by 64 and 76% and their dry weight by 39 and 63%, respectively, compared with non-inoculated controls. Pseudomonas marginalis strain Nc1-2 exhibited also a tendency to reduce incidence of O. crenata and to improve faba bean performance. Results of the present study suggest that application of naturally occurring rhizosphere bacteria offers an additional approach for biocontrol of Orobanche spp. that can supplement current methods of control in an integrated weed management strategy.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Nadjia Zermane, Jürgen Kroschel, Richard A. Sikora, Thouraya Souissi

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

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Orobanche crenata (weed)	Broad/faba bean (Vicia faba)
	Orobanche foetida (weed)	Broad/faba bean (Vicia faba)
Pseudomonas fluorescens (weed pathogen)	Orobanche crenata (weed)
Pseudomonas fluorescens (weed pathogen)	Orobanche foetida (weed)