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Morphology of Rhytisma filamentosum. a Leaf bearing immature ascostroma (bar = 20 mm). b Opened ascostroma on the leaf surface (bar = 2 mm). c Ascus with ascospores (bar = 50 μm). d Ascospore (bar = 50 μm). e Illustration of general view of ascostroma in a vertical leaf section (bar = 2 mm). f Illustration of ascomata in a vertical section (bar = 500 μm). g Illustration of ascus with ascospores, paraphyses, and ascospores (bar = 100 μm)
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We describe a new fungal species, Rhytisma filamentosum, which causes tar spot disease on Salix integra in Nagano Prefecture, Japan. Its most distinctive morphological features are asci and ascospores that are distinctly longer than those of other Rhytisma species on Salix. rDNA ITS and LSU sequence analyses also indicate that this fungus is suffic...
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... filamentosum S. Masumoto, M. Tojo, M. Uchida & S. Imura, sp. nov. (Fig. 1) MycoBank No: MB811952 Etymology: referring to longer ascospores than the closely related species such as R. salicinum, R. umbonatum, and R. polare. Abbreviations of morphology: I irregular, R roughly circular, OI orbicular or slightly irregular, IS irregular split, CS circular split, LS longitudinal split, AM amphigenous, AD adaxial ...
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... These eight paratypes had similar morphology to the holotypes. The morphologies of representative strains are shown in Table 1. Ascostromata (Fig. 1a, b, e) developing amphigenously on living leaves were black, not shiny, roughly circular, 2.9-6.7 mm in diameter, 1.0-1.5 mm thick, unilocular. Young stromata collected on October 8, 2012 (Fig. 1a) on living leaves appeared as black epiphyllous spots surrounded by yellow halos and rising significantly above the leaf surfaces. We found ...
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... These eight paratypes had similar morphology to the holotypes. The morphologies of representative strains are shown in Table 1. Ascostromata (Fig. 1a, b, e) developing amphigenously on living leaves were black, not shiny, roughly circular, 2.9-6.7 mm in diameter, 1.0-1.5 mm thick, unilocular. Young stromata collected on October 8, 2012 (Fig. 1a) on living leaves appeared as black epiphyllous spots surrounded by yellow halos and rising significantly above the leaf surfaces. We found also hypophyllous stromata on the underside of the epiphyllous stromata and about half the width of the latter. In the median vertical section, stromata were composed of an outer black layer, white ...
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... (Fig. 1b, e, f) were found on the adaxial surfaces of living leaves, and were ring-shaped, 600-1500 μm in width, rising from the stromatal surface when mature, opening by a circular split, and exposing a yellow hymenium to surface view. In median vertical section, ascomata were 50-170 μm wide, the upper layer developing asci and paraphyses, and the ...
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... (Fig. 1g) were filiform, unbranched or sometimes branched, 150-250 × 1.5-3.0 μm, septate, and slightly swollen at apices. Asci (Fig. 1c, g) were 8- spored, narrowly clavate or mostly cylindrical and short stalked, 140-230×10-17 μm, thin-walled, with slightly beaked apices. Ascospores (Fig. 1d, g) were 100-160× 2.0-4.0 μm, filiform, with ...
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... (Fig. 1g) were filiform, unbranched or sometimes branched, 150-250 × 1.5-3.0 μm, septate, and slightly swollen at apices. Asci (Fig. 1c, g) were 8- spored, narrowly clavate or mostly cylindrical and short stalked, 140-230×10-17 μm, thin-walled, with slightly beaked apices. Ascospores (Fig. 1d, g) were 100-160× 2.0-4.0 μm, filiform, with gelatinous appendages at api- ces, hyaline, thin-walled, and surrounded by a thin gelat- inous sheath 0.5-2.0 μm wide. Conidiomata were ...
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... (Fig. 1g) were filiform, unbranched or sometimes branched, 150-250 × 1.5-3.0 μm, septate, and slightly swollen at apices. Asci (Fig. 1c, g) were 8- spored, narrowly clavate or mostly cylindrical and short stalked, 140-230×10-17 μm, thin-walled, with slightly beaked apices. Ascospores (Fig. 1d, g) were 100-160× 2.0-4.0 μm, filiform, with gelatinous appendages at api- ces, hyaline, thin-walled, and surrounded by a thin gelat- inous sheath 0.5-2.0 μm wide. Conidiomata were not ...
Citations
... org/, accessed 24 January 2022). However, only 18 species were accepted according to Kirk et al. (2008), with six additional species described subsequently (Wang et al. 2009;Suto 2009;Hou et al. 2010;Masumoto et al. 2015). There are two reasons for this reduced number of accepted species. ...
... Although shapes of stromata, ascomata and ascospores are diverse, this clade is treated as a separate genus based on host relationships and phylogenetic analyses. (Masumoto et al. 2015). ...
... Material examined: the type (see above). Notes This species was described in detail by Masumoto et al. (2015). It appears to be restricted to Salix integra and has only been reported from two localities in Nagano Prefecture, Japan. ...
Rhytisma Fr. is the type genus of Rhytismataceae (Rhytismatales, Leotiomycetes, Ascomycota). Rhytisma-like species include members of Cryptomyces, Rhytisma and Vladracula. They are parasites on leaves of broadleaf trees and cause tar spot diseases. In this study, a phylogeny based on the large subunit of the ribosomal rRNA gene (nrLSU) and the mitochondrial small subunit (mtSSU) is presented, including sequences of 39 newly collected specimens from East Asia, Europe, and temperate as well as tropical America. Based on analyses of morphology, phylogeny as well as host-specificity and diversification time estimates, the family Rhytismataceae sensu stricto is proposed, and eight genera are accepted in this narrow family, including four novel genera (Densorhytisma, Fanglania, Johnstoniella and Shiqia), the type genus Rhytisma, and the reinstated genera Lophodermina, Placuntium and Xyloma. Lophodermina clusters within the main Rhytisma clade in our analyses, but is divergent in morphological terms, not having large compound stromata. Thirty species are recognized, including seven novel species (Fanglania hubeiensis, F. parasitica, Johnstoniella yunnanensis, Rhytisma japonicum, Rh. taiwanense, Xyloma globosum, and X. shennongjiaense), fifteen new combinations (Densorhytisma anhuiense, D. huangshanense, F. concova, F. himalensis, F. ilicis-integrae, F. ilicis-latifoliae, F. ilicis-pedunculosae, J. lonicerae, Rh. annuliforme, Shiqia menziesii, S. yuexiensis, X. filamentosum, X. maximum, X. muelleri, and X. polare), one new name (J. xylostei), seven known species (Lophodermina melaleuca, Placuntium andromedae, Rhytisma acerinum, Rh. americanum, Rh. punctatum, X. salicinum, and X. umbonatum). In addition, seven immature specimens were studied but not assigned to existing species, herein referred to as Fanglania sp. 1, Johnstoniella sp. 1, Johnstoniella sp. 2, Placuntium sp. 1, Placuntium sp. 2, Rhytisma sp. 1, and Xyloma sp. 1. The systematic positions of Cryptomyces maximus, Cr. muelleri and Vladracula annuliformis are re-assigned based on phylogenetic analysis. One Rhytisma-like species from tropical America was segregated from Rhytismataceae s.str., thus a novel genus Neorhytisma was established to accommodate this species, with the one new combinations Neorhytisma panamense. The results of the molecular phylogenetic analysis indicate that Rhytisma-like species are host-specific at genus level. Apparently, Rhytisma-like species coevolved with their hosts, and Rhytisma-like species on Ericaceae seem to be in the process of host jumping. Morphological characteristics of ascomata are important for the delimitation of species and genera of Rhytisma-like species. This study provides a key to genera and species of recognized Rhytisma-like species worldwide.
... These fungi are usually parasites that live on the leaves of deciduous trees, where they cause tar spot symptoms. Willow-genus Salix-is the host plant with the highest number of Rhytisma species, with four Rhytisma spp. on 64 Salix spp. reported so far (Jung et al., 2020;Masumoto et al., 2014Masumoto et al., , 2015Minter, 1997aMinter, , 1997b. Willow species are diverse, with over 400 species and a widespread distribution globally (POWO, 2022). ...
A novel fungal pathogen, Rhytisma arcticum , is described, causing tar spot disease on Salix arctica in Ellesmere Island, Canada. Stromata, asci and ascospores—distinctly smaller than other Rhytisma species found on Salix —are its distinctive morphological features. rDNA internal transcribed spacer (ITS) and large‐subunit (LSU) sequence analyses revealed a close relation of this species to R. polare previously reported on Spitsbergen Island. This study describes a novel plant pathogen species in one of the northernmost locations of the world.
... accessed on 6 April 2022); over 50 species of Melampsora causing rust disease [5][6][7][8][9] (https://nt.ars-grin.gov/fungaldatabases, accessed on 6 April 2022); Colletotrichum salicis causing anthracnose disease [10]; and Rhytisma filamentosum causing tar-spot disease [11,12]. Among various diseases that affect willow trees, canker and dieback disease caused by Cytospora are the main branch and stem diseases in China, especially in the north ( Figure 1) [4,[13][14][15][16]. ...
Species of Cytospora are considered important plant pathogens of a wide range of plant hosts, especially Salicaceae plants. Salix (Salicaceae, Malpighiales) has been widely cultivated in China because of its strong ecological adaptability, fast growth, and easy reproduction. In this study, a total of eight species of Cytospora were discovered on Salix in China, including C. ailanthicola, C. alba, C. chrysosperma, C. gigaspora, C. nivea, C. paracinnamomea, C. rostrata, and C. sophoriopsis. Among them, C. alba and C. paracinnamomea were identified as novel species based on morphology and phylogenetic analyses of ITS, act, rpb2, tef1-α, and tub2 gene sequences and were confirmed as pathogens of willow canker disease by pathogenicity tests. The mycelial growth rates of strains from these two novel species (C. alba and C. paracinnamomea) had optimum temperatures of 21 to 22 °C and an optimum pH value of 5 to 6. The effectiveness of six carbon sources on the mycelial growth showed that fructose and maltose had the highest influence. Cytospora species richness was significantly positively correlated with dry and wet areas. This study represents a significant evaluation of Cytospora associated with willow canker disease in China and provides a theoretical basis for predicting the potential risk of willow canker disease.
... Salas-Lizana & Oono (2018) recently described L. fissuratum, a species occurring sympatrically with the morphologically similar L. nitens, from Pinus lambertiana and P. monticola in the Pacific Northwest. Furthermore, the ongoing descriptions of novel Rhytismataceae species, cryptic and otherwise, from Asia also indicate a greater global species diversity than previously recognized (e.g.: Kaneko 2003, Fan et al. 2012, Masumoto et al. 2015, Zhang et al. 2015, Li et al. 2016. Rhytismataceae host preferences should be further investigated, especially for putative host-jumping in introduced trees. ...
Tryblidiopsis pinastri (Leotiomycetes, Rhytismatales) was described from Picea abies in Europe and was also thought to occur on North American Picea. However, previously published sequences of Picea foliar endophytes from Eastern Canada suggested the presence of at least two cryptic Tryblidiopsis species, distinct from T. pinastri and other known species. Our subsequent sampling of Tryblidiopsis ascomata from dead attached Picea glauca branches resulted in the collection of a putatively undescribed species previously isolated as a P. glauca endophyte. Morphological evidence combined with phylogenetic analyses based on nuclear ribosomal internal transcribed spacer (ITS) and large subunit ribosomal (LSU) DNA sequences support the distinctiveness of this species, described here as T. magnesii.
... The detection of a novel Lophodermium species on an endemic North American host with a poorly characterized microbiota is expected given the recent descriptions of novel Lophodermium and other Rhytismataceae species worldwide (e.g., Wang et al. 2014;Koukol et al. 2015;Masumoto et al. 2015;Zhang et al. 2015). Furthering our understanding of the biodiversity and taxonomy of Rhytismatales species will provide insight into the coevolution of these fungi and their hosts, provide reference sequences facilitating the identification of sequences from endophyte and other ecological surveys, and potentially lead to the identification of novel bioactive secondary metabolites. ...
A morphologically distinct Lophodermium species was collected from fallen secondary needles of Pinus resinosa Aiton over two consecutive years in Eastern Ontario; subsequent herbarium studies confirmed its presence in Nova Scotia, Quebec, and Maine. Symptomatic needles frequently exhibited red bands and completely subepidermal ascomata and conidiomata. Ascospore isolates from specimens were used to reconstruct phylogenies inferred from internal transcribed spacer rDNA and partial actin gene sequences. Both phylogenetic analyses delineated the specimens from other sequenced Lophodermium species. Phylogenetic evidence combined with morphological characters of ascomata and conidiomata supported the distinctiveness of this species, described here as Lophodermium resinosum sp. nov.
Rhytismatales M.E. Barr ex Minter (Leotiomycetes, Ascomycota) is an order mostly consists of plant-associated ascomycetes with a global distribution. Among host plant taxa in diverse relationships, Rhododendron L. is one of the most preferred host genera of Rhytismatales. Rhododendron is the largest genus of Ericaceae Juss. and presents a high species diversity in southwestern China. In this study, the species diversity of Rhytismatales on twigs of Rhododendron spp. is investigated based on over 100 specimens recently collected in China. These were examined morphologically and by multi-gene phylogenetic analyses based on molecular sequence data from the internal transcribed spacer (ITS) region, the large subunit of the ribosomal RNA gene (nrLSU) and the mitochondrial small subunit (mtSSU rDNA). Eight monophyletic groups with strong support and distinct morphological characteristics are proposed as new genera, namely Lophodermiopsis, Neotryblidiopsis, Occultimyces, Rhodohypoderma, Septofusella, Septomyces, Shuqunia, and Yingrenia. Thirty-three new species are recognized, and three new combinations are proposed. Apparently, twigs of Rhododendron spp. have been repeatedly colonized during evolution by members of Rhytismatales and most of these species specifically develop their ascomata on this substrate. Radiation on this substrate occurred relatively recently leading to species diversity within genera. Information on all 54 species of Rhytismatales on twigs of Rhododendron spp. are combined in a complete revision of this group of fungi based on morphological characteristics and phylogenetic analyses. Keys to genera and species of Rhytismatales on twigs of Rhododendron spp. worldwide are provided. The results of the molecular phylogenetic analysis indicate that a natural classification of Rhytismatales on genus level cannot be defined based on few morphological characteristics, but a combination of many morphological characteristics together with information derived from molecular sequence data, the host relationship, as well as the organ infected are necessary. Keywords-36 new taxa-Host organ specificity-Phylogeny-Taxonomy INTRODUCTION The order Rhytismatales M.E. Barr ex Minter belongs to Leotiomycetes (Ascomycota) and
Coelomycete is a general term used for asexual fungi which produce conidia in fruiting bodies: pycnidial, acervular, cupulate, pycnothyria or stromatic conidiomata. The group contains numerous plant pathogenic, saprobic and endophytic species associated with a wide range of hosts. Traditionally, morphological characters and host associations have been used as criteria to identify and classify coelomycetes, and this has resulted in a poor understanding of their generic and species boundaries. DNA based taxonomic studies have provided a better outlook of the phylogenetic and evolutionary trends in coelomycetes. However, the present outcomes represent only a preliminary step towards the understanding of coelomycetes. Many genera have not been revisited since they were first described. The present study revises the classification of the hyaline-spored coelomycetes and provides a modern taxonomic framework based on both morphology and phylogeny. In total, 248 genera were investigated, of which less than 100 are known to have sequence data. Multi-locus sequence data analyses of 28S nrDNA, 18S nrDNA, ITS, RNA polymerase II second largest subunit (rpb2), and part of the translation elongation factor 1-alpha gene (tef1) and β-tubulin (tub2) gene regions were analysed. As a result, three new genera and 23 new species are introduced. In addition, three new links between sexual and asexual genera are provided. There are 138 genera that lack sequence data, and these are treated as Ascomycota, genera incertae sedis. Line drawings and descriptions are provided based on the examination of types and fresh collections and on the literature.
The occurrence of previously unknown tar‐spot disease on Salix koriyanagi was observed during surveys for forest disease outbreaks in Korea. The fungus associated with tar‐spot disease was identified as Rhytisma filamentosum based on morphological characteristics of the fungus and molecular sequencing of the ITS and 28S rDNA regions of two samples. To our knowledge, this is the first report of R. filamentosum on S. koriyanagi from Korea, following its first discovery on Salix integra in Japan.
Knowledge of the relationships and thus the classification of fungi, has developed rapidly with increasingly widespread use of molecular techniques, over the past 10–15 years, and continues to accelerate. Several genera have been found to be polyphyletic, and their generic concepts have subsequently been emended. New names have thus been introduced for species which are phylogenetically distinct from the type species of particular genera. The ending of the separate naming of morphs of the same species in 2011, has also caused changes in fungal generic names. In order to facilitate access to all important changes, it was desirable to compile these in a single document. The present article provides a list of generic names of Ascomycota (approximately 6500 accepted names published to the end of 2016), including those which are lichen-forming. Notes and summaries of the changes since the last edition of ‘Ainsworth & Bisby’s Dictionary of the Fungi’ in 2008 are provided. The notes include the number of accepted species, classification, type species (with location of the type material), culture availability, life-styles, distribution, and selected publications that have appeared since 2008. This work is intended to provide the foundation for updating the ascomycete component of the “Without prejudice list of generic names of Fungi” published in 2013, which will be developed into a list of protected generic names. This will be subjected to the XIXth International Botanical Congress in Shenzhen in July 2017 agreeing to a modification in the rules relating to protected lists, and scrutiny by procedures determined by the Nomenclature Committee for Fungi (NCF). The previously invalidly published generic names Barriopsis, Collophora (as Collophorina), Cryomyces, Dematiopleospora, Heterospora (as Heterosporicola), Lithophila, Palmomyces (as Palmaria) and Saxomyces are validated, as are two previously invalid family names, Bartaliniaceae and Wiesneriomycetaceae. Four species of Lalaria, which were invalidly published are transferred to Taphrina and validated as new combinations. Catenomycopsis Tibell & Constant. is reduced under Chaenothecopsis Vain., while Dichomera Cooke is reduced under Botryosphaeria Ces. & De Not. (Art. 59).
