Integrating Different Lines of Evidence to Establish a Novel Ascomycete Genus and Family (Anastomitrabeculia, Anastomitrabeculiaceae) in Pleosporales

Complete genome of the Medicago anthracnose fungus, Colletotrichum destructivum, reveals a mini-chromosome-like region within a core chromosome

Colletotrichum destructivum (Cd) is a phytopathogenic fungus causing significant economic losses on forage legume crops (Medicago and Trifolium species) worldwide. To gain insights into the genetic basis of fungal virulence and host specificity, we sequenced the genome of an isolate from Medicago sativa using long-read (PacBio) technology. The resulting genome assembly has a total length of 51.7 Mb and comprises ten core chromosomes and two accessory chromosomes, all of which were sequenced from telomere to telomere. A total of 15, 631 gene models were predicted, including genes encoding potentially pathogenicity-related proteins such as candidate-secreted effectors (484), secondary metabolism key enzymes (110) and carbohydrate-active enzymes (619). Synteny analysis revealed extensive structural rearrangements in the genome of Cd relative to the closely related Brassicaceae pathogen, Colletotrichum higginsianum. In addition, a 1.2 Mb species-specific region was detected within the largest core chromosome of Cd that has all the characteristics of fungal accessory chromosomes (transposon-rich, gene-poor, distinct codon usage), providing evidence for exchange between these two genomic compartments. This region was also unique in having undergone extensive intra-chromosomal segmental duplications. Our findings provide insights into the evolution of accessory regions and possible mechanisms for generating genetic diversity in this asexual fungal pathogen.

What are the 100 most cited fungal genera?

The global diversity of fungi has been estimated between 2 to 11 million species, of which only about 155 000 have been named. Most fungi are invisible to the unaided eye, but they represent a major component of biodiversity on our planet, and play essential ecological roles, supporting life as we know it. Although approximately 20 000 fungal genera are presently recognised, the ecology of most remains undetermined. Despite all this diversity, the mycological community actively researches some fungal genera more commonly than others. This poses an interesting question: why have some fungal genera impacted mycology and related fields more than others? To address this issue, we conducted a bibliometric analysis to identify the top 100 most cited fungal genera. A thorough database search of the Web of Science, Google Scholar, and PubMed was performed to establish which genera are most cited. The most cited 10 genera are Saccharomyces, Candida, Aspergillus, Fusarium, Penicillium, Trichoderma, Botrytis, Pichia, Cryptococcus and Alternaria. Case studies are presented for the 100 most cited genera with general background, notes on their ecology and economic significance and important research advances. This paper provides a historic overview of scientific research of these genera and the prospect for further research. Citation: Bhunjun CS, Chen YJ, Phukhamsakda C, Boekhout T, Groenewald JZ, McKenzie EHC, Francisco EC, Frisvad JC, Groenewald M, Hurdeal VG, Luangsa-ard J, Perrone G, Visagie CM, Bai FY, Błaszkowski J, Braun U, de Souza FA, de Queiroz MB, Dutta AK, Gonkhom D, Goto BT, Guarnaccia V, Hagen F, Houbraken J, Lachance MA, Li JJ, Luo KY, Magurno F, Mongkolsamrit S, Robert V, Roy N, Tibpromma S, Wanasinghe DN, Wang DQ, Wei DP, Zhao CL, Aiphuk W, Ajayi-Oyetunde O, Arantes TD, Araujo JC, Begerow D, Bakhshi M, Barbosa RN, Behrens FH, Bensch K, Bezerra JDP, Bilański P, Bradley CA, Bubner B, Burgess TI, Buyck B, Čadež N, Cai L, Calaça FJS, Campbell LJ, Chaverri P, Chen YY, Chethana KWT, Coetzee B, Costa MM, Chen Q, Custódio FA, Dai YC, Damm U, de Azevedo Santiago ALCM, De Miccolis Angelini RM, Dijksterhuis J, Dissanayake AJ, Doilom M, Dong W, Alvarez-Duarte E, Fischer M, Gajanayake AJ, Gené J, Gomdola D, Gomes AAM, Hausner G, He MQ, Hou L, Iturrieta-González I, Jami F, Jankowiak R, Jayawardena RS, Kandemir H, Kiss L, Kobmoo N, Kowalski T, Landi L, Lin CG, Liu JK, Liu XB, Loizides M, Luangharn T, Maharachchikumbura SSN, Makhathini Mkhwanazi GJ, Manawasinghe IS, Marin-Felix Y, McTaggart AR, Moreau PA, Morozova OV, Mostert L, Osiewacz HD, Pem D, Phookamsak R, Pollastro S, Pordel A, Poyntner C, Phillips AJL, Phonemany M, Promputtha I, Rathnayaka AR, Rodrigues AM, Romanazzi G, Rothmann L, Salgado-Salazar C, Sandoval-Denis M, Saupe SJ, Scholler M, Scott P, Shivas RG, Silar P, Souza-Motta CM, Silva-Filho AGS, Spies CFJ, Stchigel AM, Sterflinger K, Summerbell RC, Svetasheva TY, Takamatsu S, Theelen B, Theodoro RC, Thines M, Thongklang N, Torres R, Turchetti B, van den Brule T, Wang XW, Wartchow F, Welti S, Wijesinghe SN, Wu F, Xu R, Yang ZL, Yilmaz N, Yurkov A, Zhao L, Zhao RL, Zhou N, Hyde KD, Crous PW (2024). What are the 100 most cited fungal genera? Studies in Mycology 108: 1-411. doi: 10.3114/sim.2024.108.01.

Bambusicolous Fungi in Pleosporales: Introducing Four Novel Taxa and a New Habitat Record for Anastomitrabeculia didymospora

While conducting a survey of bambusicolous fungi in northern Thailand and southwestern China, several saprobic fungi were collected from dead branches, culms and twigs of bamboos, which were preliminarily identified as species belonging to Pleosporales (Dothideomycetes) based on a morphological approach. Multigene phylogenetic analyses based on ITS, LSU, SSU, rpb2, tef1-α and tub2 demonstrated four novel taxa belonging to the families Parabambusicolaceae, Pyrenochaetopsidaceae and Tetraploasphaeriaceae. Hence, Paramultiseptospora bambusae sp. et gen. nov., Pyrenochaetopsis yunnanensis sp. nov. and Tetraploa bambusae sp. nov. are introduced. In addition, Anastomitrabeculia didymospora found on bamboo twigs in terrestrial habitats is reported for the first time. Detailed morphological descriptions and updated phylogenetic trees of each family are provided herein.

The numbers of fungi: contributions from traditional taxonomic studies and challenges of metabarcoding

The global diversity of fungi has been estimated using several different approaches. There is somewhere between 2–11 million estimated species, but the number of formally described taxa is around 150,000, a tiny fraction of the total. In this paper, we examine 12 ascomycete genera as case studies to establish trends in fungal species descriptions, and introduce new species in each genus. To highlight the importance of traditional morpho-molecular methods in publishing new species, we introduce novel taxa in 12 genera that are considered to have low species discovery. We discuss whether the species are likely to be rare or due to a lack of extensive sampling and classification. The genera are Apiospora, Bambusicola, Beltrania, Capronia, Distoseptispora, Endocalyx, Neocatenulostroma, Neodeightonia, Paraconiothyrium, Peroneutypa, Phaeoacremonium and Vanakripa. We discuss host-specificity in selected genera and compare the number of species epithets in each genus with the number of ITS (barcode) sequences deposited in GenBank and UNITE. We furthermore discuss the relationship between the divergence times of these genera with those of their hosts. We hypothesize whether there might be more species in these genera and discuss hosts and habitats that should be investigated for novel species discovery.

Synopsis of Leptosphaeriaceae and Introduction of Three New Taxa and One New Record from China

Leptosphaeriaceae, a diverse family in the order Pleosporales, is remarkable for its scleroplectenchymatous or plectenchymatous peridium cells. Four Leptosphaeriaceae species were discovered and studied during the investigation of saprobic fungi from plant substrates in China. Novel taxa were defined using multiloci phylogenetic analyses and are supported by morphology. Based on maximum likelihood (ML) and Bayesian inference (BI) analyses, these isolates represent three novel taxa and one new record within Leptosphaeriaceae. A new genus, Angularia, is introduced to accommodate Angularia xanthoceratis, with a synopsis chart for 15 genera in Leptosphaeriaceae. This study also revealed a new species, Plenodomus changchunensis, and a new record of Alternariaster centaureae-diffusae. These species add to the increasing number of fungi known from China.

Taxonomy and Phylogeny of the Wood-Inhabiting Fungal Genus Hyphoderma with Descriptions of Three New Species from East Asia

Three new wood-inhabiting fungi, Hyphoderma crystallinum, H. membranaceum, and H. microporoides spp. nov., are proposed based on a combination of morphological features and molecular evidence. Hyphoderma crystallinum is characterized by the resupinate basidiomata with smooth hymenial surface scattering scattered nubby crystals, a monomitic hyphal system with clamped generative hyphae, and numerous encrusted cystidia present. Hyphoderma membranaceum is characterized by the resupinate basidiomata with tuberculate hymenial surface, presence of the moniliform cystidia, and ellipsoid to cylindrical basidiospores. Hyphoderma microporoides is characterized by the resupinate, cottony basidiomata distributing the scattered pinholes visible using hand lens on the hymenial surface, presence of halocystidia, and cylindrical to allantoid basidiospores. Sequences of ITS+nLSU rRNA gene regions of the studied samples were generated, and phylogenetic analyses were performed with maximum likelihood, maximum parsimony, and Bayesian inference methods. These phylogenetic analyses showed that three new species clustered into Hyphoderma, in which H. crystallinum was sister to H. variolosum, H. membranaceum was retrieved as a sister species of H. sinense, and H. microporoides was closely grouped with H. nemorale. In addition to new species, map to show global distribution of Hyphoderma species treated in the phylogenetic tree and an identification key to Chinese Hyphoderma are provided.

Morpho-Phylo Taxonomy of Novel Dothideomycetous Fungi Associated With Dead Woody Twigs in Yunnan Province, China

Within the field of mycology, macrofungi have been relatively well-studied when compared to microfungi. However, the diversity and distribution of microfungi inhabiting woody material have not received the same degree of research attention, especially in relatively unexplored regions, such as Yunnan Province, China. To help address this knowledge gap, we collected and examined fungal specimens from different plants at various locations across Yunnan Province. Our investigation led to the discovery of four species that are clearly distinct from extant ones. These taxonomic novelties were recognized based on morphological comparisons coupled with phylogenetic analyses of multiple gene sequences (non-translated loci and protein-coding regions). The monotypic genus Neoheleiosa gen. nov. (type: N. lincangensis) is introduced in Monoblastiaceae (Monoblastiales) for a woody-based saprobic ascomycete that possesses globose to subglobose or obpyriform ascomata with centric or eccentric, papillate ostioles, an ascomatal wall with thin-walled cells of textura globulosa, cylindric, pedicellate asci with an ocular chamber, and 1-septate, brown, guttulate, longitudinally striated, bicellular ascospores. Neoheleiosa has a close phylogenetic affinity to Heleiosa, nevertheless, it is morphologically dissimilar by its peridium cells and ornamented ascospores. Acrocalymma hongheense and A. yuxiense are described and illustrated as new species in Acrocalymmaceae. Acrocalymma hongheense is introduced with sexual and asexual (coelomycetous) features. The sexual morph is characterized by globose to subglobose, ostiolate ascomata, a peridium with textura angularis cells, cylindric-clavate asci with a furcate to truncate pedicel and an ocular chamber, hyaline, fusiform, 1-septate ascospores which are surrounded by a thick, distinct sheath, and the asexual morph is featured by pycnidial conidiomata, subcylindrical, hyaline, smooth, annelledic, conidiogenous cells, hyaline, guttulate, subcylindrical, aseptate conidia with mucoid ooze at the apex and with a rounded hilum at the base. Acrocalymma yuxiense is phylogenetically distinct from other extant species of Acrocalymma and differs from other taxa in Acrocalymma in having conidia with three vertical eusepta. Magnibotryascoma kunmingense sp. nov. is accommodated in Teichosporaceae based on its coelomycetous asexual morph which is characterized by pycnidial, globose to subglobose, papillate conidiomata, enteroblastic, annelledic, discrete, cylindrical to oblong, hyaline conidiogenous cells arising from the inner layer of pycnidium wall, subglobose, oval, guttulate, pale brown and unicelled conidia.