In vitro suppression of the crown gall (Agrobacterium tumefaciens) by compost extracts bacteria

• Published in: International journal of innovation and applied studies Vol. 7; no. 2; p. 617
• Main Authors: Kerkeni, Amel, Mze, Ahmed Marichali, Ouerghemmi, Saloua, Dallai, Sana, Benzarti, Saoussen, Khedher, Mohamed Ben
• Format: Journal Article
• Language: English
• Published: Rabat International Journal of Innovation and Applied Studies 01.08.2014
• Subjects: Agrobacterium rhizogenes; Agrobacterium tumefaciens; Bacteria; Composting; Double layer; Gall; In vitro testing; Pathogens; Strain
• ISSN: 2028-9324; 2028-9324

Nine kinds of compost extracts were tested primarily for their efficiency, in vitro, against the causal agent of crown gall Agrobacterium tumefaciens (strain C58). The most efficient extracts were then selected and bacteria contained in these extracts were isolated. Twenty-seven isolates bacteria were obtained and investigated in vitro with the objective of selecting efficient antagonists against crown gall disease. The bacterial activity is compared to the reference antagonist Agrobacterium rhizogenes K84 by the double layer method. In vitro, analyzing the antagonistic activity revealed that, after incubation at 27 degree C with the pathogen, antagonists tested exhibited considerable inhibitory activity in vitro and reduced the development of the strain C58 of Agrobacterium tumefaciens with variable degrees. In fact, statistical analyses revealed four groups of antagonistic isolates. The highest level of inhibition zone diameter was observed with C5B2 against 19.37 mm in the control. Reduction of pathogen growth reached 38% compared to control. Compost extracts isolates tested in this study may be considered as potential sources of novel bioactive metabolites as well as promising candidates to develop new biocontrol agents for crown gall disease management.