Journal of Applied Microbiology (2001) 91, 963-971
G. Berg, A. Fritze, N. Roskot and K. Smalla (2001)
Evaluation of potential biocontrol rhizobacteria from different host plants of Verticillium dahliae Kleb
Journal of Applied Microbiology 91 (6), 963-971
Abstract: Aims: A screening approach was developed to assess the potential of rhizobacterial strains to control Verticillium wilt caused by Verticillium dahliae Kleb.
Methods and Results: Sixty randomly chosen antagonistic bacterial strains originally isolated from rhizosphere of three different host plants of V. dahliae - strawberry, potato and oilseed rape - were evaluated for biocontrol and plant growth promotion by analysing in vitro antagonism towards V. dahliae and other plant pathogenic fungi, production of fungal cell wall-degrading enzymes and plant growth-promoting effects on strawberry seedlings. To test the plant growth-promoting effect, a microplate assay with strawberry seedlings was developed. Although the rhizobacterial strains were isolated from different plants they showed effects on the growth of strawberry seedlings. According to the in vitro biocontrol and plant growth-promoting activity, the three best candidates Pseudomonas putida B E2 (strawberry rhizosphere), Ps. chlororaphis K15 (potato rhizosphere) and Serratia plymuthica R12 (oilseed rape rhizosphere) were selected for greenhouse experiments to verify the in vitro screening results. Under greenhouse conditions the isolates selected according to this strategy were as effective, or more effective than commercial biocontrol agents and may therefore possibly be valuable as antagonists of V. dahliae.
Conclusions: In this study, the screening strategy resulted in a selection of three interesting biocontrol candidates against Verticillium: Ps. putida B E2 (strawberry rhizosphere), Ps. chlororaphis K15 (potato rhizosphere) and Ser. plymuthica R12 (oilseed rape rhizosphere).
Significance and Impact of the Study: A new combination of in vitro screening methods including a microplate assay with strawberry seedlings to test the plant growth promoting effect which allow to more efficiently select potential biological control agents was developed successfully.
(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): Gabriele Berg
Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
evaluation - screening - selection
