Biocontrol of tomato foot and root rot by Pseudomonas bacteria in stonewool

The research described in this thesis shows that the enrichment technique based on competitive root tip colonization allows the isolation of bacteria which can protect plants from TFRR through the mechanism competition for nutrients (and niches). The efficacy of biocontrol of one of these strains, P. putida PCL1760, was estimated under industrial conditions using both conventional and molecular techniques. Quantitative PCR was used also to distinguish between different forms of Fusarum oxysporum (Fox), which cannot be distinguished using otherwise so far. It was shown that nonpathogenic Fox strains in plant material cannot reach a concentration higher than 50 fg of fungal DNA per ng of total DNA. The obtained results are an illustration of an efficient strategy, which can be exploited for the isolation of biocontrol agents for greenhouses and of the application of fast molecular methods for the estimation of their efficacy in plant protection. Moreover, this molecular method a quantitative PCR can be used to monitor pathogenic strains in tomato.