Posidoniomyces Vohnik & Reblova

Vohnik, Martin, Borovec, Ondrej, Kolarikova, Zuzana, Sudova, Radka & Reblova, Martina, 2019, Extensive sampling and high-throughput sequencing reveal Posidoniomycesatricolor gen. et sp. nov. (Aigialaceae, Pleosporales) as the dominant root mycobiont of the dominant Mediterranean seagrass Posidoniaoceanica, MycoKeys 55, pp. 59-86 : 59

Posidoniomyces Vohnik & Reblova gen. nov.

Diagnosis.

In vivo, colonisation pattern of host roots resembles colonisation by the so-called dark septate endophytes (DSE) ubiquitous in the roots of most terrestrial plants. However, the dark septate hyphae and microsclerotia of Posidoniomyces never colonise vascular tissues of the host roots and are mostly confined to the hypodermis.

Type species.

Posidoniomyces atricolor Vohník & Réblová

Etymology.

Named after the host seagrass Posidonia oceanica and myces (Greek), meaning fungus.

Description.

Root mycobiont of the dominant and endemic Mediterranean seagrass Posidonia oceanica . In vivo, hyphae brown, septate, forming intracellular microsclerotia in the hypodermis of the terminal fine roots and finger-like pseudoparenchymatous net on the surface of these roots, i.e. a colonisation pattern resembling the DSE association ubiquitous in the roots of terrestrial plants. In vitro, two distinct colonial morphotypes named compact and mycelial (often with aerial hyphae) are consistently formed. Colonies brown, mycelium composed of septate, hyaline, subhyaline to pigmented hyphae with intercalary, terminal, rarely lateral, one-celled globose, subglobose to ellipsoidal swellings that are prominent especially on the surface of the compact colonies. Sexual state unknown.