For the first time, we used natural CO2 springs, which create hypoxic soil environments, to determine whether a long-term, directional, abiotic selection pressure could change arbuscular mycorrhizal (AM) fungal community structure. We found significant levels of AM fungal community turnover between soil types and the numerical dominance of two AM fungal phylotypes (taxa) in hypoxic soils. Our results strongly suggest that direct environmental selection acting on AM fungi is a major factor regulating AM fungal communities and their phylogeographic patterns.
COBISS.SI-ID: 6679929
Changed ratios of soil gases that lead to hypoxia are most often present in waterlogged soils, but can also appear in soils not saturated with water. In natural CO2 springs (mofettes), gases in soil air differ from those in typical soils. In this study, plant roots from the mofette area Stavešinci (Slovenia) were sampled in a spatial scale and investigated for AM fungal colonization. AM fungi were found in roots from areas with high geological CO2 concentration, however mycorrhizal intensity was relatively low and no correlation between AM fungal colonization and soil pattern of CO2/O2 concentrations (up to 37% CO2) was found. The relatively high abundance of arbuscules in root cortex indicated existence of functional symbiosis at much higher CO2 concentrations than normally found in soils. In addition, concentration of two different glomalin-related soil protein fractions – EE-GRSP and TG-GRSP – was measured. No significant correlation between any of the fractions and soil gases was found, however the concentration of both fractions was significantly higher in the upper 0–5 cm, compared to the 5–10 cm layer of the soil.
COBISS.SI-ID: 7037049
A revision of Fusariumlike species led to a reconsideration of generic concepts in the Fusarium clade of the Nectriaceae. Phylogenetic analyses confirm the existence of a clade that includes genera such as Fusarium sensu stricto (including its Gibberella teleomorphs), Albonectria, Cyanonectria, Haematonectria, the newly described genus Geejayessia, and Nectria albida. In addition, the taxonomic significance of some newly described morphological structures, which we call Samuels' pores, is discussed.
COBISS.SI-ID: 3565416
Comprehensive phylogenetic reassessment of the ascomycete genus Cosmospora (Hypocreales. Nectriaceae) is undertaken using fresh isolates and historical strains, sequences of two protein encoding genes, the second largest subunit of RNA polymerase II (rpb2), and a new phylogenetic marker, the larger subunit of ATP citrate lyase. The result is an extensive revision of taxonomic concepts, typification, and nomenclatural details of many anamorphand teleomorphtypified genera of the Nectriaceae, most notably Cosmospora and Fusarium.
COBISS.SI-ID: 3565160
Fungi are found in all aerobic ecosystems, colonizing a diversity of substrates and performing a wide diversity of functions, some of which are not well understood. Many species of fungi are cosmopolitan and generalists but others are specialists found only in restricted substrates or habitats. Unusual fungal niches are habitats where extreme conditions would be expected to prevent the development of a mycobiota. In this review we describe five unusual fungal habitats in which fungi occupy poorly understood niches. Yeasts, black yeast-like fungi, melanized filamentous species as well as representatives of Aspergillus and Penicillium seem to be dominant among the mycobiota adapted to cold and saline niches. Also plant trichomes appear to be a unique niche, harboring many previously unknown taxa. The advent of new sequencing technologies is helping to elucidate the microbial diversity in many ecosystems, but more studies are needed to document the functional role of fungi in the microbial communities thriving in these unusual environments.
COBISS.SI-ID: 2462031