Fungalpedia – Note 593, Phaeosphaeria
Phaeosphaeria I. Miyake
Citation when using this data: Zhang et al. 2025 (in prep.) – Fungalpedia, Ascomycota.
Index Fungorum, Facesoffungi, MycoBank, GenBank, Fig. 1
Classification: Phaeosphaeriaceae, Pleosporales, Pleosporomycetidae, Dothideomycetes, Pezizomycotina, Ascomycota, Fungi
Miyake (1909) established the genus Phaeosphaeria within the family Mycosphaerellaceae. However, Phaeosphaeria was treated as a synonym of Leptosphaeria for a long time due to the morphological similarities (Müller 1950; Zhang et al. 2012). Holm (1957) found the existence of pseudoparaphyses in P. oryzae, the type species of Phaeosphaeria, leading to the reassignment of Phaeosphaeria to the generic level to accommodate 17 predominantly graminicolous species characterized by somewhat small ascomata. Currently, Phaeosphaeria is recognized as a separate genus (Leuchtmann 1984; Fukuhara 2002; Câmara et al. 2002), as well as the generic type within Phaeosphaeriaceae (Barr 1979), with P. oryzae as the type species (Eriksson 1967; Quaedvlieg et al. 2013). Later, Eriksson (1981) re-evaluated the generic concept of Phaeosphaeria, emphasizing the characteristics of small ascomata, dictyospores, and a host preference on monocotyledons (Eriksson 1967; Zhang et al. 2012; Phookamsak et al. 2014).
Morphologically, six subgenera, viz., Fusispora, Ovispora, Phaeosphaeria, Sicispora, Spathispora and Vagispora, were proposed based on ascospore shape and septation (Shoemaker and Babcock 1989). The sexual morph is characterized by foliicolous form, glabrous, immersed ascomata with central ostiole; septate pseudoparaphyses encased in mucous; stipitate, biseriate asci and narrowly fusiform, septate, brown conidia enclosed in a mucoid sheath or not (Leuchtmann 1984; Shoemaker and Babcock 1989; Fukuhara 2002; Tanaka and Harada 2004; Quaedvlieg et al. 2013; Pem et al. 2024). The asexual morphs have hyphomycetous and coelomycetous forms. The hyphomycetous morph is processed by hyaline, ampulliform to subcylindrical or doliiform conidiogenous cells and euseptate, subcylindrical to narrowly obclavate, pale brown conidia, while the septoria-like coelomycetous morph forms hyaline to brown, subglobose to cylindrical to subcylindrical conidia (Quaedvlieg et al. 2013; Phookamsak et al. 2014; Hyde et al. 2017; Jayawardena et al. 2019). Phylogenetically, the position of Phaeosphaeria sensu stricto is problematic and polyphyletic, with many species being transferred to other genera, such as Amarenomyces, Juncaceicola, Loratospora, Neosetophoma, Parastagonospora, Phaeopoacea, Pseudophaeosphaeria, Septoriella, or even other families in Pleosporales (Quaedvlieg et al. 2013; Phookamsak et al. 2014; Hongsanan et al. 2020a). Furthermore, the four genes of LSU, ITS, SSU, and tef1-α are used as molecular markers for Phaeosphaeria (Phookamsak et al. 2014). Recently, Hongsanan et al. (2020a) recognized 210 morphological species (171 species as Phaeosphaeria, 39 species as Phaeoseptoria), with sequence data available for 19 species. Fresh collections are warranted, alongside molecular data, to confirm the phylogenetic status of these species.
Members of Phaeosphaeria are commonly reported as pathogens on various hosts globally, especially on monocotyledonous plants, but have also record as endophytes or saprobes (Hedjaroude 1969; Shoemaker and Babcock 1989; Phookamsak et al. 2014; Hongsanan et al. 2020a). Based on our checklist of fungi on pteridophytes (Table 2), sixteen species of Phaeosphaeria were associated to pteridophytes. Of these, 41 records represented 15 species that were related to the pteridophytes host families of Equisetaceae and Lycopodiaceae, and only one species, Phaeosphaeria lycopodiicola var. major, was found on Selaginella helvetica, belonging to Selaginellaceae.
Type species: Phaeosphaeria oryzae I. Miyake.
≡ Pleospora oryzae (I. Miyake) Hara.
≡ Trematosphaerella oryzae (I. Miyake) Padwick.
≡ Leptosphaerella oryzae (I. Miyake) Hara.
≡ Leptosphaerulina oryzae (I. Miyake) Karan.
= Phaeoseptoria oryzae I. Miyake.
Other accepted species: Species Fungorum – search Phaeosphaeria.
Figure 1 – Phaeosphaeria species (a–d Type species of Phaeosphaeria oryzae, redrawn from Phookamsak et al. (2014); e–g An example of a fungus was found on a fern: Phaeosphaeria berlesei on Equisetum sp., redrawn from Holm and Holm (1981b)). a Appearance of ascomata on host substrate. b Section through ascoma. c Asci with ascospores. d Ascospores. e Appearance of ascomata of Phaeosphaeria berlesei on Equisetum sp. f Asci. g Ascospores.
References
Barr ME 1979 – A classification of Loculoascomycetes. Mycologia 71:935–957
Eriksson O 1967 – On graminicolous pyrenomycetes from Fennoscandia. 1. Dictyosporous species (339–380). II. Phragmosporous and scolecosporous species (381–440). III. Amerosporous and didymosporous species (441–466). Arkiv før Botanik 6:339– 466.
Eriksson O 1981 – The families of bitunicate ascomycetes. Nordic Journal of Botany 1:800–800
Holm L, Holm K 1981b – Nordic equiseticolous pyrenomycetes. Nordic Journal of Botany 1:109–119.
Holm L 1957 – Études taxonomiques sur les Pléosporacées. Symbolae Botanicae Upsalienses 14:1–188.
Miyake I 1909 – Studies on the parasitic fungi of rice in Japan. Bot Mag Tokyo 23:85–97.
Shoemaker RA, Babcock C 1989 – Phaeosphaeria. Canadian Journal of Botany 67:1500–1599.
Zhang Y, Crous PW, Schoch CL, Hyde KD 2012 – Pleosporales. Fungal Diversity 53:1–221.
Entry by
Jing-Yi Zhang, School of Food and Pharmaceutical Engineering, Guizhou Institute of Technology, Guiyang, 550025, People’s Republic of China, Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, 57100, Thailand, School of Science, Mae Fah Luang University, Chiang Rai, 57100, Thailand, Guizhou Key Laboratory of Agricultural Microbiology, Guizhou Academy of Agricultural Sciences, Guiyang, 550009, People’s Republic of China.
Published online 11 June 2025