The formation of aegagropiles from the Mediterranean seagrass Posidonia oceanica (L.) Delile (1813): plant tissue sources and colonisation by melanised fungal mycelium

Aegagropiles are conglomerations of fibre debris from Posidonia oceanica meadows that frequently found along Mediterranean beaches, but the plant organ which these fibres arise remains unknown. In this study, a histological comparison P. organs 3 shoots with structure aegagropile showed most them leaf sheaths and rhizomes, suggesting they degradation products “matte” rather than litter, is mainly composed detached blades. Moreover, fungal hyphae, micro-sclerotia typical traces were in peripheral tissues living organs, as well degrading aegagropiles. We assume, by comparing Vohník’s observations made endophytic fungi might be attributed to dark septate endophyte (DSE) Aigialaceae (Pleosporales), Posidoniomyces atricolor, was recently described an endosymbiont roots. It constitutes one important microorganisms abundance degrade within matte give rise different types This study shows proliferation causes Posidonia, starting early plants, continuing and, probably, litter. The DSE plays much more role simple endosymbiont; its omnipresence (and middle lamella cell death during proliferation) causing various also contributes enrichment ‘matte’ compartment ecosystem, notably favouring nitrogen retention chitinous walls.