Seasonal dynamics of fungal colonisation of Plantago altissima roots in a water-fluctuating wetland

Fungal colonisation in an amphibious plant species from an intermittent lake may differ significantly among plant specimens growing under contrasting water regimes. We examined the effect of the presence of surface water on the level of fungal colonisation in tall plantain(Plantago altissima L.). We investigated the presence and abundance of arbuscular-mycorrhizal (AM) structures, dark-septate-endophyte (DSE) fungal structures, and plant growth parameters. The observed overall frequency of fungal structures during the vegetative season was relatively high, ranging from 50% to 90%. Mycorrhizal frequency was little affected by water level fluctuations. However, it dropped significantly at the end of the season in the senescence phase. The densities of arbuscules, vesicles, and hyphal coils reached the highest levels in peak season in June and July. The density of DSE structures, namely microsclerotia, showed similar dynamics over the season as forAM structures. Mycorrhizal frequency was positively related to leaf water content.