Fungal Associates of the Moss Leucobryum candidum (Brid. ex P. Beauv.) Wilson in Southeast Queensland, Australia

The suite of fungi that associate with mosses, bryophilous fungi, can be explored further to provide insights into the symbiotic functionality of mosses as well as the ecosystems in which they reside. So far, in-depth studies on the taxonomic diversity, ecology, and physiological functions of bryophilous fungi associated with the Australasian moss species Leucobryum candidum are lacking. To generate information on the physiology, biology, and ecology of these organisms and their interactions with the moss host, the combined use of selective isolation and molecular characterisation of the fungal associates was carried out. Once the pure cultures of the fungal associates were obtained, a bioactivity assay was used to investigate the effect of fungal metabolites on moss growth in vitro. Overall, L. candidum species collected from six different locations within Southeast Queensland exposed to different environmental parameters were found to have a highly diverse community of fungal species from 10 orders and 17 families. A total of 25 of the 33 isolates that were identified using molecular sequencing techniques were unique species, confirming high beta diversity of the fungal associates of L. candidum collected from coastal, forest, and urban environments in Southeast Queensland. The highest numbers of culturable isolates came from coastal and forest sites. Urban sites accounted for the lowest numbers of culturable isolates. The taxonomic matches for these associates were known to have diverse endophytic, saprophytic, and parasitic roles within vascular plants. Selected moss samples were inoculated with fermentation extracts of fungal isolates (USC-F426 and USC-F427) and their effects on the moss samples were observed for any change in heights, weights, diameters, and morphological characteristics. A significant (p ≤ 0.05) difference in the heights of the in vitro-assessed L. candidum between treatments was observed. No significant differences, however, were seen between the weights and diameters and no discernible host symptoms were detected, other than a few morphological change observations.