Biological control of potato diseases guided by plant microbiome approaches

Plant protection against fungal pathogens is a crucial aspect of modern agriculture and mostly relies on chemical inputs. However, phytopathogens often become resistant against conventional fungicides. Additionally, the microbial diversity in agricultural soils decreases through the application of pesticides, fertilizers and the soil tillage. The aim of the ongoing SusCrop – ERA-NET project ‘PotatoMETAbiome’ is to establish microbial consortia, which are applicable for potato cultivation to mediate the resistance against soil-borne fungal pathogens (Verticillium dahliae and Rhizoctonia solani) and support the microbial diversity in soil. For the consortium assembly, pre-selected microorganisms from the strain collection for antagonistic microorganisms SCAM (Institute of Environmental Biotechnology, Graz University of Technology) will be implemented. A total of 111 bacterial strains were already tested comprising the genera Bacillus, Erwinia, Paenibacillus, Pseudomonas, Serratia, Streptomyces, Ralstonia and several yet unidentified species. Additionally, fungi of the genus Trichoderma were assessed in terms of antagonistic effects. They will be optimized in vitro in terms of their efficiency to inhibit the target phytopathogens. The best antagonistic microorganisms will be used for consortium assemblies and their VOCs profiles will be assessed. Established consortia will then be combined with root exudates, which can act as a ‘boosters’ for the microorganisms. Furthermore, the consortia will be applied in greenhouse experiments and field trials. In a final step, meta-transcriptomic datasets will be obtained to analyze the interaction of the microorganisms in the consortium.