The question of how many species of
there are has occasioned much speculation, with figures mostly posited from around half a million to 10 million, and in one extreme case even a sizable portion of ...the spectacular number of 1 trillion. Here we examine new evidence from various sources to derive an updated estimate of global fungal diversity. The rates and patterns in the description of new species from the 1750s show no sign of approaching an asymptote and even accelerated in the 2010s after the advent of molecular approaches to species delimitation. Species recognition studies of (semi-)cryptic species hidden in morpho-species complexes suggest a weighted average ratio of about an order of magnitude for the number of species recognized after and before such studies. New evidence also comes from extrapolations of plant:fungus ratios, with information now being generated from environmental sequence studies, including comparisons of molecular and fieldwork data from the same sites. We further draw attention to undescribed species awaiting discovery in biodiversity hot spots in the tropics, little-explored habitats (such as lichen-inhabiting fungi), and material in collections awaiting study. We conclude that the commonly cited estimate of 1.5 million species is conservative and that the actual range is properly estimated at 2.2 to 3.8 million. With 120,000 currently accepted species, it appears that at best just 8%, and in the worst case scenario just 3%, are named so far. Improved estimates hinge particularly on reliable statistical and phylogenetic approaches to analyze the rapidly increasing amount of environmental sequence data.
Scientific names are crucial in communicating knowledge about fungi. In plant pathology, they link information regarding the biology, host range, distribution, and potential risk. Our understanding ...of fungal biodiversity and fungal systematics has undergone an exponential leap, incorporating genomics, web-based systems, and DNA data for rapid identification to link species to metadata. The impact of our ability to recognize hitherto unknown organisms on plant pathology and trade is enormous and continues to grow. Major challenges for phytomycology are intertwined with the Genera of Fungi project, which adds DNA barcodes to known biodiversity and corrects the application of old, established names via epi- or neotypification. Implementing the one fungus-one name system and linking names to validated type specimens, cultures, and reference sequences will provide the foundation on which the future of plant pathology and the communication of names of plant pathogens will rest.
Lichens are symbiotic associations resulting from interactions among fungi (primary and secondary mycobionts), algae and/or cyanobacteria (primary and secondary photobionts), and specific elements of ...the bacterial microbiome associated with the lichen thallus. The question of what is a species, both concerning the lichen as a whole and its main fungal component, the primary mycobiont, has faced many challenges throughout history and has reached new dimensions with the advent of molecular phylogenetics and phylogenomics. In this paper, we briefly revise the definition of lichens and the scientific and vernacular naming conventions, concluding that the scientific, Latinized name usually associated with lichens invariably refers to the primary mycobiont, whereas the vernacular name encompasses the entire lichen. Although the same lichen mycobiont may produce different phenotypes when associating with different photobionts or growing in axenic culture, this discrete variation does not warrant the application of different scientific names, but must follow the principle "one fungus = one name". Instead, broadly agreed informal designations should be used for such discrete morphologies, such as chloromorph and cyanomorph for lichens formed by the same mycobiont but with either green algae or cyanobacteria. The taxonomic recognition of species in lichen-forming fungi is not different from other fungi and conceptual and nomenclatural approaches follow the same principles. We identify a number of current challenges and provide recommendations to address these. Species delimitation in lichen-forming fungi should not be tailored to particular species concepts but instead be derived from empirical evidence, applying one or several of the following principles in what we call the LPR approach: lineage (L) coherence vs. divergence (phylogenetic component), phenotype (P) coherence vs. divergence (morphological component), and/or reproductive (R) compatibility vs. isolation (biological component). Species hypotheses can be established based on either L or P, then using either P or L (plus R) to corroborate them. The reliability of species hypotheses depends not only on the nature and number of characters but also on the context: the closer the relationship and/or similarity between species, the higher the number of characters and/or specimens that should be analyzed to provide reliable delimitations. Alpha taxonomy should follow scientific evidence and an evolutionary framework but should also offer alternative practical solutions, as long as these are scientifically defendable. Taxa that are delimited phylogenetically but not readily identifiable in the field, or are genuinely cryptic, should not be rejected due to the inaccessibility of proper tools. Instead, they can be provisionally treated as undifferentiated complexes for purposes that do not require precise determinations. The application of infraspecific (gamma) taxonomy should be restricted to cases where there is a biological rationale, i.e
.
, lineages of a species complex that show limited phylogenetic divergence but no evidence of reproductive isolation. Gamma taxonomy should not be used to denote discrete phenotypical variation or ecotypes not warranting the distinction at species level. We revise the species pair concept in lichen-forming fungi, which recognizes sexually and asexually reproducing morphs with the same underlying phenotype as different species. We conclude that in most cases this concept does not hold, but the actual situation is complex and not necessarily correlated with reproductive strategy. In cases where no molecular data are available or where single or multi-marker approaches do not provide resolution, we recommend maintaining species pairs until molecular or phylogenomic data are available. This recommendation is based on the example of the species pair
Usnea aurantiacoatra
vs.
U. antarctica
, which can only be resolved with phylogenomic approaches, such as microsatellites or RADseq. Overall, we consider that species delimitation in lichen-forming fungi has advanced dramatically over the past three decades, resulting in a solid framework, but that empirical evidence is still missing for many taxa. Therefore, while phylogenomic approaches focusing on particular examples will be increasingly employed to resolve difficult species complexes, broad screening using single barcoding markers will aid in placing as many taxa as possible into a molecular matrix. We provide a practical protocol how to assess and formally treat taxonomic novelties. While this paper focuses on lichen fungi, many of the aspects discussed herein apply generally to fungal taxonomy. The new combination
Arthonia minor
(Lücking) Lücking comb. et stat. nov. (Bas.:
Arthonia cyanea
f.
minor
Lücking) is proposed.
This fifth annual edition of MycoNews starts with an editorial on the critical importance of International Mycological Congresses (IMCs) to the health of mycology. Items on Counting down to IMC12, ...the State of the World's Plants and Fungi 2023, and progress towards Improving nomenclatural stability in medically important fungi follow. Reports are provided of several mycological meetings in 2023: the Asian Mycological Congress, XIX Congress of European Mycologists, a meeting of European Mycological Groups and Societies, the XI Latin American Mycological Congress, Westerdijk Spring Symposium on Fungal Evolution, the Brazilian Society of Mycology, the Annual Meeting of the Mycological Society of China, and the Fifth Iranian Mycological Congress. Information is provided on how to make nominations for the various IMA Awards due to be presented at IMC12 in August, the new Future is Fungi Award launched in 2023, and the Adel-Azeem and Stamets Award for work on Psilocybe in Africa. The Westerdijk Fungal Biodiversity Institute Awards for 2023 were made to Andrey Yurkov and Cathie Aime and the citations to those awards are provided. We include tributes to the passing of two eminent mycologists, Lorelei Norvell and Takashi Matsushima, and also send birthday greetings to Bryce Kendrick who turned 90, and Maria Ławrynowicz, Yu Li, and Anthony Whalley who all became octogenarians. Reviews of seven mycological books published in 2022-2023 are included in the Book News section.
True fungi (Fungi) and fungus-like organisms (e.g. Mycetozoa, Oomycota) constitute the second largest group of organisms based on global richness estimates, with around 3 million predicted species. ...Compared to plants and animals, fungi have simple body plans with often morphologically and ecologically obscure structures. This poses challenges for accurate and precise identifications. Here we provide a conceptual framework for the identification of fungi, encouraging the approach of integrative (polyphasic) taxonomy for species delimitation, i.e. the combination of genealogy (phylogeny), phenotype (including autecology), and reproductive biology (when feasible). This allows objective evaluation of diagnostic characters, either phenotypic or molecular or both. Verification of identifications is crucial but often neglected. Because of clade-specific evolutionary histories, there is currently no single tool for the identification of fungi, although DNA barcoding using the internal transcribed spacer (ITS) remains a first diagnosis, particularly in metabarcoding studies. Secondary DNA barcodes are increasingly implemented for groups where ITS does not provide sufficient precision. Issues of pairwise sequence similarity-based identifications and OTU clustering are discussed, and multiple sequence alignment-based phylogenetic approaches with subsequent verification are recommended as more accurate alternatives. In metabarcoding approaches, the trade-off between speed and accuracy and precision of molecular identifications must be carefully considered. Intragenomic variation of the ITS and other barcoding markers should be properly documented, as phylotype diversity is not necessarily a proxy of species richness. Important strategies to improve molecular identification of fungi are: (1) broadly document intraspecific and intragenomic variation of barcoding markers; (2) substantially expand sequence repositories, focusing on undersampled clades and missing taxa; (3) improve curation of sequence labels in primary repositories and substantially increase the number of sequences based on verified material; (4) link sequence data to digital information of voucher specimens including imagery. In parallel, technological improvements to genome sequencing offer promising alternatives to DNA barcoding in the future. Despite the prevalence of DNA-based fungal taxonomy, phenotype-based approaches remain an important strategy to catalog the global diversity of fungi and establish initial species hypotheses.
A personal synopsis of the decisions made at the Nomenclature Section meeting of the International Botanical Congress in Melbourne in July 2011 is provided, with an emphasis on those which will ...affect the working practices of, or will otherwise be of interest to, mycologists. The topics covered include the re-naming of the Code, the acceptance of English as an alternative to Latin for validating diagnoses, conditions for permitting electronic publication of names, mandatory deposit of key nomenclatural information in a recognized repository for the valid publication of fungal names, the discontinuance of dual nomenclature for pleomorphic fungi, clarification of the typification of sanctioned names, and acceptability of names originally published under the zoological code. Collectively, these changes are the most fundamental to have been enacted at a single Congress since the 1950s, and herald the dawn of a new era in the practice of fungal nomenclature.
This fourth annual edition of MycoNews starts with an editorial asking if mycology is approaching a tipping point, and note of the journal's 2021 Impact Factor almost doubling from 2020. Updated ...information and new speakers for IMC12 in 2024 is presented. Reports are provided for the Rise of the Fungi symposium in Amsterdam and of MycoRiseUP! in Warsaw in 2022. Information on activities of the International Commission on the Taxonomy of Fungi (ICTF) in the last two years are presented, including the formation of new Working Groups. Procedures for the nomination of IMA awards and for nomenclature proposals to be presented at IMC12 are provided. The Westerdijk Institute awards to Feng-Yan Bai and Marc Stadler are recorded, and Michael Wingfield and Geoffrey Kibby are congratulated on special awards they have received. Tributes are paid to the passing of two distinguished mycologists during the year, John Parmelee and John Pitt. Reviews of six mycological books published in 2021-22 are also provided.
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