Glomeromycota in mosses: arbuscular mycorrhizal structures in Leptodontium capituligerum (Pottiaceae) from the Argentine Chaco Serrano

Arbuscular mycorrhizal fungi (AMF) associations in mosses remain poorly documented compared with those reported for liverworts and hornworts. In this contribution, we report fungal structures compatible with Glomeromycota in living gametophytes of Leptodontium capituligerum (Pottiaceae) from the Chaco Serrano of Tucumán, Argentina. Gametophytes were clarified with KOH, stained with trypan blue, and examined using light and scanning electron microscopy. Intercellular aseptate hyphae, intracellular hyphal coils, arbuscules, vesicles, and spores morphologically compatible with AMF were observed in leaves and stems. Both Arumand Paris-type morphologies were detected. In addition, dark septate endophytes and other septate fungi were associated with leaves and rhizoids. These observations provide additional evidence supporting fungal symbioses in mosses and reinforce the hypothesis that associations between Bryophyta and Glomeromycota may be more frequent than previously assumed.