The cryptic lifestyle of most fungi necessitates molecular identification of the guild in environmental studies.Over the past decades, rapid development and affordability of molecular tools have tremendously improved insights of the fungal diversity in all ecosystems and habitats. Yet, in spite of the progress of molecular methods, knowledge about functional properties of the fungal taxa is vague and interpretation of environmental studies in an ecologically meaningful manner remains challenging. In order to facilitate functional assignments and ecological interpretation of environmental studies we introduce a user friendly traits and character database FungalTraits operating at genus and species hypothesis levels. Combining the information from previous efforts such as FUNGuild and Fun Fun together with involvement of expert knowledge, we reannotated 10210 and 151 fungal and Stramenopila genera, respectively. This resulted in a stand-alone spreadsheet dataset covering 17 lifestyle related traits of fungal and Stramenopila genera, designed for rapid functional assignments of environmental studies. In order to assign the trait states to fungal species hypotheses, the scientific community of experts manually categorised and assigned available trait information to 697413 fungal ITS sequences. On the basis of those sequences we were able to summarise trait and host information into 92623 fungal species hypotheses at 1% dissimilarity threshold.

Since 1999, an unusual Phytophthora species has repeatedly been found associated with stem lesions and root and collar rot on young olive trees in Southern Italy. In all cases, this species was obtained from recently established commercial plantations or from nursery plants. Morphologically, the Phytophthora isolates were characterized by the abundant production of caducous non-papillate conidia-like sporangia (pseudoconidia) and caducous papillate sporangia with a short pedicel, resembling P. palmivora var. heterocystica. Additional isolates with similar features were obtained from nursery plants of Ziziphus spina-christi in Iran, Juniperus oxycedrus and Capparis spinosa in Italy, and mature trees in commercial farms of Durio zibethinus in Vietnam. In this study, morphology, breeding system and growth characteristics of these Phytophthora isolates with peculiar features were examined, and combined mitochondrial and nuclear multigene phylogenetic analyses were performed. The proportion between pseudoconidia and sporangia varied amongst isolates and depended on the availability of free water. Oogonia with amphigynous antheridia and aplerotic oospores were produced in dual cultures with an A2 mating type strain of P. palmivora, indicating all isolates were A1 mating type. Phylogenetically, these isolates grouped in a distinct well-supported clade sister to P. palmivora; thus, they constitute a separate taxon. The new species, described here as Phytophthora heterospora sp. nov., proved to be highly pathogenic to both olive and durian plants in stem inoculation tests.

Studies on the ecological role of fungi and, to a lesser extent, oomycetes, are receiving increasing attention, mainly due to their participation in the cycling of organic matter in aquatic ecosystems. To unravel their importance in humification processes, we isolated several strains of fungi and oomycetes from Anzali lagoon, Iran. We then performed taxonomic characterization by morphological and molecular methods, analyzed the ability to degrade several polymeric substrates, performed metabolic fingerprinting with Ecoplates, and determined the degradation of humic substances (HS) using liquid chromatography‐organic carbon detection. Our analyses highlighted the capacity of aquatic fungi to better degrade a plethora of organic molecules, including complex polymers. Specifically, we were able to demonstrate not only the utilization of these complex polymers, but also the role of fungi in the production of HS. In contrast, oomycetes, despite some morphological and physiological similarities with aquatic fungi, exhibited a propensity toward opportunism, quickly benefitting from the availability of small organic molecules, while exhibiting sensitivity toward more complex polymers. Despite their contrasting roles, our study highlights the importance of both oomycetes and fungi in aquatic organic matter transformation and cycling with potential implications for the global carbon cycle.

Studies on the diversity, distribution and ecological role of Saprolegniales (Oomycota) in freshwater ecosystems are currently receiving attention due to a greater understanding of their role in carbon cycling in various aquatic ecosystems. In this study, we characterized several Saprolegniales species isolated from Anzali lagoon, Gilan province, Iran, using morphological and molecular methods. Four species of Saprolegnia were identified, including S. anisospora and S. diclina as first reports for Iran, as well as Achlya strains, which were closely related to A. bisexualis, A. debaryana and A. intricata. Evaluation of the ligno-, cellulo-and chitinolytic activities was performed using plate assay methods. Most of the Saprolegniales isolates were obtained in autumn, and nearly 50% of the strains showed chitinolytic and cellulolytic activities. However, only a few Saprolegniales strains showed lignolytic activities. This study has important implications for better understanding the ecological niche of oomycetes, and to differentiate them from morphologically similar, but functionally different aquatic fungi in freshwater ecosystems.Aquat Ecol (2020) 54:323-336 https://doi.org/10.1007/s10452-019-09745-w( 0123456789().,-volV) (0123456789().,-volV)