Effects of seasonal dynamics of phenolics in oak forest on truffles (Tuber macrosporum Vitt.)

Abstract

We studies the seasonal dynamics of phenolics in leaves, litter and soil of the dominant host tree oak (Quercus robur L.) growing with ectomycorrhizal fungi truffles (T. macrosporum) in oak forest (Fraxino angustifoliae-Quercetum roboris Joy. et Tomic 1979) near River Danube, near Belgrade. In litter, the highest content of free phenolics was in April (primordial growth period of truffles) and bound phenolics in August (truffles ripening- start of harvest). Due to intensive decomposition of forest litter during the vegetative growth period, free phenolic acids increased and the bound phenolic acids decreased. There was reduction in ratio of bound cinnamic to benzoic acids, it indicated the microbial degradation of lignin and the transformation of cinnamic derivatives into benzoic acid derivatives. In the top soil layer, where the majority of truffle fruit bodies were found (28.31 kg/ha/year). the free phenolics (direct influence on truffle growth and development) contents were up to 58.36 mu g/g. As the mycelia and fruit bodies of truffle grow in phenolic-rich forest soil, hence, we assumed that the truffle is well-adapted to high phenolics content.