Lichen-like Symbiotic Associations of Wood-decaying Fungi and Algae. I. Biodiversity and Ecology of Photobionts

Abstract

The article presents new data on the taxonomical, morphological and ecological composition and species diversity of symbiont algae associated with xylotrophic fungi. The largest part of symbionts (86%) are eukaryotic algae belonging to the divisions Chlorophyta (68% of total number of species), Ochrophyta (9%) and Charophyta (8%). The prokaryotic algae, or Cyanoprokaryota, make up the remaining 14% of species. The eukaryotic algae are an obligatory component of mycetobiont communities, whereas Cyanoprokaryota are the optional, facultative part. Out of 46 mycetobiont algae genera, 29 (or 64%) are single-species taxa, while 15 (32%) genera include two or three species. Two genera – Chlamydomonas and Klebsormidium – are represented by 6 and 4 species, respectively. The majority of mycetobiont algae have coccoid (41%) and trichal (33%) thalli, colonial-coccoid (18%) and monadic (8%) algae are rarely observed. All algae species belong to widespread epiphytic, soil and lichenophilic groups that do not require symbiosis with fungi. Obligatory mycetobionts were not observed during the study. Communities of mycetobiont algae have host-specificity and high geographical and individual variability.