Fungal communities in organically grown winter wheat affected by plant organ and development stage

The fungal community on the roots, stem bases, stems and grains of organically grown winter wheat was analysed using terminal restriction fragment length polymorphism (T-RFLP) combined with cloning and sequencing of the ITS region. The changes in the composition of fungi in different plant parts and over time as well as interactions between fungi were also investigated. Among 58 fungal taxa found the most common were Davidiella macrospora, Cladosporium spp., Tetracladium maxilliforme, Didymella exitialis, Microdochium nivale and an unidentified species within Ascomycetes. Several potential wheat pathogens were found: Fusarium spp. including F. poae and G. avenacea (F. avenaceum), Microdochium nivale, Oculimacula yallundae, Parastagonospora nodorum and Zymoseptoria tritici and most of them were present on all plant parts. Plant part affected the most the fungal colonization of wheat as was shown both by multivariate analysis of the whole fungal community as well as the analysis based on the identified species. The composition of fungal communities in different parts changed during the growing season but no pattern common for the whole crop could be observed. The most dynamic and significant changes were found among yeasts. Both positive and negative significant interactions between pairwise combinations of pathogens were observed. Positive significant associations were also found between pathogens and other fungi.