Effects of one dark septate endophytic fungal and two Helotiales strains on the growth of Salix planifolia cuttings on iron ore waste rock

Plants maintain beneficial mutualistic relationships with the mycobiont communities found in their rhizosphere, leading to an increase in plant productivity and health. In nutrient-depleted substrates like mine tailings, mycobiont inoculation is often recommended to help restore a successful plant cover. Our 15-week greenhouse experiment aimed to assess the individual effects of a dark septate endophyte (Phialocephala fortinii #4; KX611529) and two Helotiales strains (Rhizoscyphus ericae #22; EU221877 and Meliniomyces sp #1; KT275679) on the growth of Salix planifolia cuttings on sterilized and unsterilized waste rock. Rhizoscyphus ericae increased cuttings shoot biomass on sterilized waste rock while Meliniomyces sp had a positive effect for cuttings grown on unsterilized waste rock. However, P. fortinii strain had no effect on the survival rate, shoot production, and biomass production of S. planifolia cuttings. This study demonstrates that controlled inoculation with ecologically well-adapted mycobionts could promote plant establishment and productivity on abandoned waste rock and be an efficient and integrated biotechnological approach for ecological restoration of canadian mining boreal ecosystems.

FUNGI COLONIZING CONIFEROUS SEEDLINGS IN FOREST NURSERIES OF MIDDLE SIBERIA

The study was carried out in four forest nurseries of Middle Siberia. Affected seedlings of Scots pine (Pinus sylvestris L.), Scots Siberian stone pine (Pinus sibirica Du Tour), and Siberian spruce (Picea obovata Ledeb.) were collected for molecular phytopathological examination. In total, 14 fungal taxa were identified in the needles and roots of the plants. The most dominant among them were Sydowia polyspora (Bref. & Tavel) E., Didymella glomerata (Corda) Qian Chen & L. Cai, Cladosporium herbarum (Pers.) Link, Lophodermium seditiosum Minter, Staley & Millar, Phialocephala fortinii C. J. K. Wang & H. E. Wilcox and Cadophora finlandica (C. J. K. Wang & H. E. Wilcox) T. C. Harr. & McNew. The richness of the fungal taxa was higher in the needles than in the roots of all the tree species studied. The obtained results could be used for implementing more effective phytosanitary measures in the studied nurseries.

Investigating Host Preference of Root Endophytes of Three European Tree Species, with a Focus on Members of the Phialocephala fortinii—Acephala applanata Species Complex (PAC)

Host preference of root endophytes of the three European tree species of Norway spruce (Picea abies), common ash (Fraxinus excelsior), and sycamore maple (Acer pseudoplatanus) were investigated in two forest stands near Zurich, Switzerland. The focus was placed on members of the Phialocephala fortinii s.l. (sensu lato)—Acephala applanata species complex (PAC), as well as other dark septate endopyhtes (DSE). PAC species were identified based on 13 microsatellite loci. Eleven PAC species were found, with Phialocephala helvetica, P. europaea being the most frequent. All but cryptic species 12 (CSP12) preferred Norway spruce as a host. Though very rare in general, CSP12 was most frequently isolated from maple roots. Regarding the abundant PAC species, P. helvetica and P. europaea, the preference of spruce as a host was least pronounced in P. europaea, as it was also often isolated from ash and maple. It is the first record of PAC found on common ash (Fraxinus excelsior). Cadophora orchidicola, a close relative of PAC, has frequently been isolated from ash. Various species of the Nectriaceae (Cylindrocarpon spp.) have often been isolated, particularly from maple roots. By comparison, Pezicula spp. (Cryptosporiopsis spp.) was found to be abundant on all three hosts. Phomopsis phaseoli exhibits a clear preference for spruce.

Morphological-cultural and molecular genetic features of collection strains of mycoris mushrooms Phialocephala fortinii and Pezicula sp.

A metagenomic analysis of the endophytic microflora of Vaccinium corymbosum L. and Vaccinium myrtillus L. root systems was carried out. Two dominant species of micromycetes forming ericoid mycorrhiza were identified - Phialocephala fortinii C. J. K. Wang & H. E. Wilcox and Pezicula sp. Tul. & C. Tul. Pure cultures of mycorrhizal fungi were prepared, a comprehensive morphological and genetic assay of the strains was carried out. Based on the results of genetic-taxonomic analysis, the assumption of the polyphyletic origin of species belonging to Phialocephala and Pezicula is confirmed.

Bioactive Properties of the Aqueous Extracts of Endophytic Fungi Associated with Scots Pine (Pinus sylvestris) Roots

Despite the continuing interest in various plant and natural products, only a small portion of the biologically active compounds from nature has been discovered and exploited. In this study, antioxidant and antibacterial properties of aqueous fractions of three endophytic fungi isolated from the roots of 8-year-old Scots pines (Pinus sylvestris) growing on a drained peatland were investigated. The endophytic fungi species were Acephala applanata, Phialocephala fortinii, and Humicolopsis cephalosporioides/Coniochaeta mutabilis. The bioactivities were examined using hydrogen peroxide scavenging and oxygen radical absorbance capacity tests as well as sensitive Escherichia coli-based biosensors, which produce a luminescent signal in the presence of substances with oxidative or genotoxic properties. In addition, cell models for Parkinsonʼs disease, age-related macular degeneration, and osteoarthritis were used to evaluate the potential for pharmaceutical applications. The aqueous extracts of fungi and 19 out of 42 fractions were found to be active in one or more of the tests used. However, no activity was found in the age-related macular degeneration and osteoarthritis cell model tests. Additionally, bioactivity data was connected with metabolites putatively annotated, and out of 330 metabolites, 177 were interesting in view of the bioactivities investigated. A majority of these were peptides and all three fungal species shared a highly similar metabolome. We propose that Scots pine endophytic fungi are a rich source of interesting metabolites, and synergistic effects may cause the bioactivities, as they were found to vary after the fractionation process.

Ectomycorrhizal Community on Norway Spruce Seedlings Following Bark Beetle Infestation

Ectomycorrhizal (ECM) fungi importantly influence seedling growth, nutrition, and survival and create an extensive mycelial network interconnecting tree species and enabling resource redistribution. Due to their symbiotic relationship with trees, they are impacted by forest disturbances, which are of increasing relevance due to climate change. The effect of disturbance on seedling colonization and their morphology is still largely unknown. Seedling growth parameters and the ECM fungal assemblage on the roots of Norway spruce (Picea abies (L.) H. Karst.) seedlings were assessed in mature spruce forests attacked and destroyed by bark beetle and in a mature non-attacked forest as a reference. We did not detect significant differences in number of ECM species on seedling roots among forest types, but ECM species composition changed; Tylospora fibrillosa (Burt) Donk, Meliniomyces variabilis Hambl. & Sigler, and Phialocephala fortinii C.J.K. Wang & H.E. Wilcox were characteristic species in the forest destroyed by bark beetle, whereas Lactarius, Cortinarius, and Russula were in the mature forest. Forest type further significantly influenced the height, root length, and root collar thickness of seedlings and the proportion of exploration types of mycorrhizae.