Soil-borne Verticillium wilt update January 2015
Selection and testing of bacterial strains against soil-borne pathogens
The process for the development of the seed treatment against soil-borne Verticillium wilt against Brassica diseases is globally:
- Development of molecular techniques to complement the existing knowledge about the biological control agents Serratia plymuthica and Paenibacillus polymyxa, and to analyze their interplay
- Carry out greenhouse experiments and define the crop and cultivar-specific minimum effective dose
- Carry out field trials
- Produce the product
Study mode of action of both bacteria strains
Ten bacterial strains of the bacteria genus Serratia and Paenibacillus were pre-selected for their anti-fungal activity and are being tested on oilseed rape and cauliflower at the Technical University of Graz.
The research team is looking in the set of ten bacterial strains for the optimal plant colonizer and plant growth promoter strain. The goal is to choose one strain from each genus and to develop the strains into a biological control agent for the seed treatment.
Results on molecular techniques
Two potential biocontrol strains were selected based on previous results of their plant growth promoting effects on oilseed rape and cauliflower in sterile germination pouches, and on their ability to suppress growth of a pathogenic Verticillium strain in vitro. The selected biocontrol strains were tested for their plant growth promotion effects on oilseed rape in sterile and unsterile soil system. In order to gain a better understanding of the mode of action of these potential biocontrol agents towards pathogens and their hosts, the genomes of the selected strains were sequenced. The genomes revealed several genes that potentially contribute to its antagonistic and plant growth promotion activity.
In the greenhouse of Wageningen UR the biocontrol efficacy of the different selected antagonistic bacteria strains are being investigated in pot experiments with cauliflower and oil seed rape. First field trials are also planned for next year.
Read more about our activities on soil-borne Verticillium wilt.
Picture: Via confocal microscopy the colonizing ability of the bacterial strains is illustrated.