Filtry biologiczne jako metoda ochrony siewek przed patogenami w szkółkach leśnych

Slow sand filtration (SSF) is a low−cost method of water disinfestation that can be used as an alternative method of water irrigation treatment in nursery to control water−borne phytopathogens. Slow sand filtration relies on physical, chemical and biological activity in controlling plant pathogens. In a SSF, the filter bed is constructed of a medium−sand with the area which can be colonised by microorganisms – biofilm. This sand media also presents a physical barrier to fungal, bacterial and oomycetes plant pathogens. In the forest nursery Kiejsze an experimental slow sand filter was constructed to study the structure of a bacterial community suppressive to plant pathogens. The total bacterial community of an experimental SSF was analyzed by denaturing gradient gel electrophoresis (DGGE) of partial 16S rRNA gene PCR products. Sequence analysis of DGGE bands from the SSF column indicated that a range of bacteria were present, among them similar to groups such as alfa−Proteobacteria, delta−Proteobacteria, beta−Proteobacteria, Planctomycetes, Actinobacteria, Firmicutes, Bacilli and an uncharacterized environmental clone. This study describes the characterization of the microbial community of SSFs used for the treatment of irrigation water in the forest nursery. Using of natural SSF filters and manipulation of microorganisms in the biofilm may be a more reproducible control method of plant pathogens in the future.