''Ceratobasidium'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

in the

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Cantharellales The Cantharellales are an order (biology), order of fungi in the class (biology), class Agaricomycetes. The order includes not only the chanterelles (Cantharellaceae), but also some of the tooth fungi (Hydnaceae), clavarioid fungi (Aphelariaceae ...

Basidiocarps In fungi, a basidiocarp, basidiome, or basidioma () is the sporocarp of a basidiomycete, the multicellular structure on which the spore-producing hymenium is borne. Basidiocarps are characteristic of the hymenomycetes; rusts and smuts do no ...

(fruit bodies) are effused and the genus is sometimes grouped among the

corticioid fungi The corticioid fungi are a group of fungi in the Basidiomycota typically having effused, smooth basidiocarps (fruit bodies) that are formed on the undersides of dead tree trunks or branches. They are sometimes colloquially called crust fungi or pa ...

, though species also retain features of the

heterobasidiomycetes Heterobasidiomycetes, including jelly fungi, smuts and rusts, are basidiomycetes with septate basidia. This contrasts them to homobasidiomycetes (alternatively called holobasidiomycetes), including most mushrooms and other Agaricomycetes, whi ...

Anamorphic Anamorphic format is a cinematography technique that captures widescreen images using recording media with narrower native Aspect ratio (image), aspect ratios. Originally developed for 35 mm movie film, 35 mm film to create widescreen pres ...

forms were formerly referred to the genus ''Ceratorhiza'', but this is now considered a synonym of ''Rhizoctonia''. ''Ceratobasidium'' species, excluding the type species, type, are also now considered synonymous with ''Rhizoctonia'' and some species have been transferred to the latter genus. Species are saprotrophic, but several are also facultative parasite, facultative plant pathology, plant pathogens, causing a number of commercially important crop diseases. Some are also orchid mycorrhiza, endomycorrhizal associates of orchids.

Taxonomy

The name ''Ceratobasidium'' was introduced in 1935 by American mycologist D.P. Rogers to accommodate species of the old form genus ''Corticium (fungus), Corticium'' that showed affinities with the heterobasidiomycetes. These affinities were the possession of large basidia, sterigmata ("cerato basidium" means "horned basidium") and the production of basidiospores that produce secondary spores. Four species were originally placed in the genus, with subsequent authors adding a further 35 species. The genus ''Ceratorhiza'' was introduced for anamorphs of ''Ceratobasidium'' by Royall T. Moore, R.T. Moore in 1987, distinguishing them from anamorphs of ''Thanatephorus'' which were retained in ''Rhizoctonia''.

Current status

Molecular phylogenetics, Molecular research, based on cladistic analysis of DNA sequences, places ''Ceratobasidium'' (excluding the type species) within the Cantharellales. Following changes to the International Code of Nomenclature for algae, fungi, and plants, the practice of giving different names to teleomorph and anamorph forms of the same fungus was discontinued, meaning that ''Ceratorhiza'' became a synonym of the earlier name ''Ceratobasidium''. DNA evidence also placed ''Ceratobasidium'' species (excluding the type species) in the genus ''Rhizoctonia''. Research on the septal pore ultrastructure of the little-known and atypical type species, ''Ceratobasidium calosporum'', indicates that it is a member of the Auriculariales and is unrelated to other species of ''Ceratobasidium''. This taxonomic problem has not yet been resolved.

Description

Fruit bodies are effused, thin and often inconspicuous, smooth, waxy to dry and web-like, whitish to pale grey. Microscopically they have comparatively wide hyphae without clamp connections and basidia that are spherical to cuboid or broadly club-shaped. Basidia bear 2 to 4 sterigmata, which are comparatively large. Basidiospores are globose to cylindrical (elongated and worm-like in the type species), smooth, and colourless. They frequently produce secondary spores and germinate by hyphal tubes. Asexual anamorphs produce hyphae (sometimes swollen) and occasionally sclerotia (small propagules composed of thick-walled hyphae).

Habitat and distribution

Species are mainly saprotrophic, occurring in the soil and producing fruit bodies on dead stems and plant detritus. Some occur on attached leaves and stems. Several species have been isolated from orchid mycorrhiza. Distribution appears to be cosmopolitan distribution, cosmopolitan.

Economic importance

''Ceratobasidium'' species are opportunistic parasites of plants, causing a variety of economically important diseases. Examples include: ''Ceratobasidium cereale'', the cause of sharp eyespot of cereals and ''Ceratobasidium oryzae-sativae'', the cause of aggregate sheath spot of rice.

References

{{Taxonbar, from=Q5063742 Cantharellales Agaricomycetes genera