Fungalpedia – Note 592, Ramularia
Ramularia Unger.
Citation when using this data: Zhang et al. 2025 (in prep.) – Fungalpedia. Ascomycota.
Classification: Mycosphaerellaceae, Mycosphaerellales, Dothideomycetidae, Dothideomycetes, Pezizomycotina, Ascomycota, Fungi
Index Fungorum, Facesoffungi, MycoBank, GenBank, Fig. 1
Mycosphaerella was introduced by Johanson (1884) and typified by M. punctiformis. With over a thousand species, Mycosphaerella displays a remarkable diversity, making it one of the largest genera of ascomycetes and encompassing more than 30 genera of anamorphs (Crous and Wingfield 1996; Aptroot and Crous 2006; Crous et al. 2007a; Crous et al. 2011c). Based on the polythetic and problematic phylogenetic placement, combined with morphological characteristics, many new genera were proposed from Mycosphaerella sensu lato, such as Dissoconium, Phaeophleospora, Pseudocercospora, Ramularia, Stenella, etc. (Crous and Braun 2003; Aptroot and Crous 2006; Crous et al. 2006b, 2007b). Due to the generic name of Mycosphaerella being considered a “convenient name” rather than an indication of a taxonomic unit, Mycosphaerella was synonymized under Ramularia following the “One Fungus One Name” (1F1N) principle, with the latter being older (Crous et al. 2009; Videira et al. 2015b; Videira et al. 2016). A recent study provided by Hongsanan et al. (2020a) followed this treatment. However, many species of Mycosphaerella listed in IF and SF have not undergone a systematic study to be placed into Ramularia or a specific genus. Our list retains this treatment of generic names until more comprehensive research are conducted.
Ramularia (Mycosphaerellales, Dothideomycetes, Ascomycota) was established by Unger (1833) and includes over 1,000 species being phytopathogenic, saprobic, endophytic and even hyperparasitic (Videira et al. 2015b). A monograph was provided by Braun (1998). Based on molecular markers of ITS, LSU, SSU, Actin, Tub2, Calmodulin, Chs, GAPDH, Histone, rpb2 and tef1-α, phylogenetic relationship was used to further clarify their taxonomic placements of Ramularia and allied genera (Videira et al. 2015a, b, 2016; Bakhshi et al. 2021). Ramularia is characterized by its mycosphaerella-like sexual morphs, and asexual morphs processing solitary to fasciculate, hyaline conidiophores, distinct, thickened, darkened and refractive conidiogenous loci, and aseptate to transversely septate hyaline conidia with thickened, darkened, refractive scars, and absent appressoria (Crous and Wingfield 1996; Braun 1998, 1988; Aptroot and Crous 2006; Crous et al. 2009; Videira et al. 2015b, 2016). Hongsanan et al. (2020a) accept 1,662 morphological species, with 1,252 species as Mycosphaerella and 410 species as Ramularia. Among them, 154 species (71 species as Mycosphaerella and 83 species as Ramularia) have molecular data available.
Based on our checklist of fungi on pteridophytes, there are 44 species including 37 species as Mycosphaerella and seven species as Ramularia. These members are important pathogens associated with various plants, especially Corymbia and Eucalyptus (Crous et al. 2004, 2006b; Hunter et al. 2006; Andjic et al. 2007; Carnegie et al. 2007), casing leaf spots, necrosis, or chlorophyll reduction that can lead to early defoliation under high air humidity and low temperatures (Braun 1988; Verkley et al. 2004; Crous et al. 2009; Videira et al. 2015b). Ferns and their allies also serve as suitable substrates for these species (Holm and Holm 1981b; Braun 2000), with the fungi parasitising pteridophytes from 18 families.
Type species: Ramularia endophylla Verkley and U. Braun.
= Sphaeria punctiformis Pers.
= Mycosphaerella punctiformis (Pers.) Starbäck
Other accepted species: Species Fungorum – search Ramularia.
Figure 1 – Ramularia endophylla (a, c, d Sexual morph; b Asexual morph). a Colony on the host. b Conidiogenous cells and conidia. c Asci. d Ascospores. Scale bars: = 10 µm. Redrawn from Verkley et al. (2004).
References
Aptroot A, Crous PW 2006 – Mycosphaerella and its anamorphs, vol 2. CBS Biodivers Ser 5:1–231.
Braun U 1988 – Studies on Ramularia and allied genera (II). Nova Hedwigia 47:335–349.
Braun U 2000 – Miscellaneous notes on some micromycetes. Schlechtendalia 5:31–56.
Crous P, Braun U, Groenewald J 2007a – Mycosphaerella is polyphyletic. Studies in Mycology 58:1–32.
Holm L, Holm K 1981b – Nordic equiseticolous pyrenomycetes. Nordic Journal of Botany 1:109–119.
Johanson CJ 1884 – Svampar fran Island. Kongl. Vetenskaps-Akademiens 41:157–174.
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