Fungalpedia – Note 3319, Pucciniomycetes
Pucciniomycetes R. Bauer, Begerow, J.P. Samp., M. Weiss & Oberw., Mycol. Progr. 5(1): 48 (2006).
Citation when using this data: Wijayawardene NN et al. 2024 – Fungalpedia.
Index Fungorum, Faceoffungi, MycoBank, GenBank, Fig 1.
Classification: Pucciniomycotina, Basidiomycota, Dikarya, Fungi.
With over 8000 known species, Pucciniomycetes is the largest class of Pucciniomycotina. This class was introduced by Bauer et al. (2006), and currently comprises five orders: Helicobasidiales Pachnocybales, Platygloeales, Pucciniales, and Septobasidiales. There exists much ecological and morphological diversity, and no synapomorphic characters are known for this class (Aime et al. 2014; Begerow et al. 2018). At the ultrastructural level, Pucciniomycetes have septal pores which can be occluded by a plug, and are mostly associated with microbodies that delineate an organelle-free zone. Hyphae of Pucciniomycetes are clampless. Basidia of Pucciniomycetes are usually transversally septate. Basidiospores usually germinate by hyphae, yeast budding is known only from some Septobasidiales species (Oberwinkler 2017). The majority of the species belongs to the Pucciniales, which are the obligate phytoparasitic rust fungi (Aime et al. 2014). The order Pachnocybales is monotypic, and contains the presumably saprobic Pachnocybe ferruginea. This species is characterised by holobasidia producing sessile statismospores. Septobasidiales are entomopathogenic fungi producing dense hyphal mats covering scale insects on their plant hosts. It is generally believed that Septobasidiales species parasitize in the scale insects, but the nature of this association remains to be better understood (Aime et al. 2014). Septobasidiales produce transversally septate basidia, and the basidiospores can germinate by yeast budding. Platygloeales are all characterised by transversally septate basidia, and mainly comprise parasites of ferns and mosses (e.g. Eocronartium, Herpobasidium, Jola, Insolibasidium, Platycarpa, and Ptechelitium), but also some saprobic fungi such as Platygloea disciformis. Helicobasidiales species have a dual ecological strategy. The sexual morphs of these species are characterised by transversally septate basidia, and are known as the ‘Helicobasidium stage’, in which they are phytoparasitic. The asexual morphs are mycoparasites of rusts (Pucciniales), and were previously classified in the genus Tuberculina. During the mycoparasitic stage, these fungi interact with their host fungus via micrometer fusion-pore interaction, in which migration of nuclei and mitochondria from the mycoparasite to the host cell was observed (Bauer 2004; Bauer et al. 2004; Lutz 2004).
Notes: Much diversity in the Pucciniomycetes remains to be discovered. The best-investigated group is the phytoparasitic Pucciniales because of their economic importance (Aime et al. 2014). The known diversity in the other orders is much smaller, and few taxonomic treatments are available covering the genera in these groups. Septobasidiales mainly occur in warmer regions, and the high diversity of scale insecs may harbour a high, yet undiscovered, diversity of associated Septobasidiales. The number of currently accepted Helicobasidiales species is low compared to the number of potential host species in the order Pucciniales. Many names are available for Tuberculina, and this complex genus is in urgent need of a taxonomic revision in which the host range of the different species is assessed.
Type order: Pucciniales Caruel, Atti R. Accad. Naz. Lincei, Mem. Cl. Sci. Fis. Matem. Nat., sér. 5: 246 (1881).
Type family: Pucciniaceae Chevall. [as ‘Puccinieae’], Fl. gén. env. Paris (Paris) 1: 413 (1826).
Type genus: Puccinia Pers., Neues Mag. Bot. 1: 118 (1794).
Type species: Puccinia graminis Pers. 1794 (Designated by Laundon, Mycol. Pap. 99: 15. 1965).
Other accepted species: Species Fungorum – search Pucciniomycetes.
Figure 1 – Examples of the members of Pucciniales. a Aecidium-type aecia gathered on leaves. b Aeciospores of the family Pucciniaceae. c Teliospores of the family Pucciniaceae. d,g Telia on leaves. e,h Urediniospores of the family Phragmidiaceae. f Teliospores of the family Phragmidiaceae. i Teliospores of the Uredinineae incertae sedis. j Uredinia and telia on leaves. k Urediniospores of the family Melampsoraceae. l Urediniospores of the family Coleosporiaceae. Scale bars: a,d,g,j = 0.5 mm, b,c,e,f,h,i,k,l = 10 µm.
References
Begerow D, McTaggart A, Agerer R. 2018 – 1/3 Basidiomycota and Entorrhizomycota In: Frey, W. (Ed.) A. Engler’s Syllabus der Pflanzenfamilien. Germany: Bontraeger Science Publishers.
Oberwinkler F. 2017 – Yeasts in Pucciniomycotina. Mycol Prog 16:831–856.
Entry by
Nalin N. Wijayawardene, Center for Yunnan Plateau Biological Resources Protection and Utilization, College of Biological Resource and Food Engineering, Qujing Normal University, Qujing, Yunnan 655011, P.R. China, Tropical Microbiology Research Foundation, 96/N/10, Meemanagoda Road, 10230 Pannipitiya, Sri Lanka, Department of Bioprocess Technology, Faculty of Technology, Rajarata University, Sri Lanka
Published online 2 October 2026