Ceratobasidium
Encyclopedia
Ceratobasidium is a genus
of fungi in the order
Cantharellales
. Basidiocarps (fruit bodies) are effused and the genus is sometimes grouped among the corticioid fungi
, though species also retain features of the heterobasidiomycetes
. Rhizoctonia
-like anamorphs of Ceratobasidium species are placed in the genus Ceratorhiza. Species are saprotrophic, but several are also facultative
plant pathogens, causing a number of commercially important crop diseases. Some are also endomycorrhizal
associates of orchids.
that showed affinities with the heterobasidiomycetes. These affinities were the possession of large 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.
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. Molecular research, based on cladistic analysis of DNA sequences, places Ceratobasidium (excluding the type species) within the Cantharellales.
. With a move to a more natural classification of the fungi, the new genus Ceratorhiza was introduced for anamorphs of Ceratobasidium by R.T. Moore in 1987. Some ten species have been described in Ceratorhiza, several of which are not linked to any known teleomorph.
s 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. Ceratorhiza anamorphs produce hyphae (sometimes swollen) and occasionally sclerotia (small propagules composed of thick-walled hyphae).
. Distribution appears to be cosmopolitan
.
, the cause of sharp eyespot of cereals; Ceratobasidium oryzae-sativae, the cause of aggregate sheath spot of rice
; and Ceratobasidium noxium
, the cause of kole roga or black rot of coffee
.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of fungi in the order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
Cantharellales
Cantharellales
The Cantharellales are an order of fungi in the class Agaricomycetes. The order includes not only the chanterelles , but also some of the tooth fungi , clavarioid fungi , and corticioid fungi...
. Basidiocarps (fruit bodies) are effused and the genus is sometimes grouped among the corticioid fungi
Corticioid fungi
The corticioid fungi are a group of fungi in the Basidiomycota typically having effused, smooth basidiocarps that are formed on the undersides of dead attached or fallen branches. They are sometimes colloquially called crust fungi or patch fungi...
, though species also retain features of the heterobasidiomycetes
Jelly fungi
The class Heterobasidiomycetes or jelly fungi is a paraphyletic group of several fungal orders: Tremellales, Auriculariales, Dacrymycetales. These fungi are so named because their foliose to irregularly branched fruiting body is, or appears to be, the consistency of jelly. Actually, many are...
. Rhizoctonia
Rhizoctonia
Rhizoctonia is a genus of anamorphic fungi in the order Cantharellales. Species do not produce spores, but are composed of hyphae and sclerotia and are asexual states of fungi in the genus Thanatephorus. Rhizoctonia species are saprotrophic, but are also facultative plant pathogens, causing...
-like anamorphs of Ceratobasidium species are placed in the genus Ceratorhiza. Species are saprotrophic, but several are also facultative
Facultative parasite
A facultative parasite is an organism that may resort to parasitic activity, but does not absolutely rely on any host for completion of its life cycle....
plant pathogens, causing a number of commercially important crop diseases. Some are also endomycorrhizal
Orchid mycorrhiza
Orchid mycorrhizae are symbiotic relationships between the roots of plants of the family Orchidaceae and a variety of fungi. All orchids are myco-heterotrophic at some point in their life cycle. Orchid mycorrhizae are critically important during orchid germination, as orchid seed has virtually no...
associates of orchids.
Taxonomy
Ceratobasidium was introduced in 1935 by American mycologist D.P. Rogers to accommodate species of the old form genus CorticiumCorticium
Corticium is a genus of crust fungi in the family Corticiaceae. According to a 2008 estimate, the genus contains 25 widely distributed species.-Species:*Corticium appalachiense*Corticium auberianum*Corticium boreoroseum...
that showed affinities with the heterobasidiomycetes. These affinities were the possession of large sterigmata ("Cerato-basidium" means "horned basidium
Basidium
thumb|right|500px|Schematic showing a basidiomycete mushroom, gill structure, and spore-bearing basidia on the gill margins.A basidium is a microscopic, spore-producing structure found on the hymenophore of fruiting bodies of basidiomycete fungi. The presence of basidia is one of the main...
") 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.
Current status
Research on the septal pore ultrastructureUltrastructure
Ultrastructure is the detailed structure of a biological specimen, such as a cell, tissue, or organ, that can be observed by electron microscopy...
of the little-known and atypical type species, Ceratobasidium calosporum, indicates that it is a member of the Auriculariales
Auriculariales
The Auriculariales are an order of fungi in the class Agaricomycetes. Species within the order were formerly referred to the "heterobasidiomycetes" or "jelly fungi", since many have gelatinous basidiocarps that produce spores on septate basidia...
and is unrelated to other species of Ceratobasidium. This taxonomic problem has not yet been resolved. Molecular research, based on cladistic analysis of DNA sequences, places Ceratobasidium (excluding the type species) within the Cantharellales.
The genus Ceratorhiza
Many Ceratobasidium species produce anamorphic hyphal states, sometimes with sclerotia, that were originally placed in the form genus RhizoctoniaRhizoctonia
Rhizoctonia is a genus of anamorphic fungi in the order Cantharellales. Species do not produce spores, but are composed of hyphae and sclerotia and are asexual states of fungi in the genus Thanatephorus. Rhizoctonia species are saprotrophic, but are also facultative plant pathogens, causing...
. With a move to a more natural classification of the fungi, the new genus Ceratorhiza was introduced for anamorphs of Ceratobasidium by R.T. Moore in 1987. Some ten species have been described in Ceratorhiza, several of which are not linked to any known teleomorph.
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 connectionClamp connection
A clamp connection is a structure formed by growing hyphal cells of certain fungi. It is created to ensure each septum, or segment of hypha separated by crossed walls, receives a set of differing nuclei, which are obtained through mating of hyphae of differing sexual types...
s 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. Ceratorhiza 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 mycorrhizaOrchid mycorrhiza
Orchid mycorrhizae are symbiotic relationships between the roots of plants of the family Orchidaceae and a variety of fungi. All orchids are myco-heterotrophic at some point in their life cycle. Orchid mycorrhizae are critically important during orchid germination, as orchid seed has virtually no...
. Distribution appears to be cosmopolitan
Cosmopolitan distribution
In biogeography, a taxon is said to have a cosmopolitan distribution if its range extends across all or most of the world in appropriate habitats. For instance, the killer whale has a cosmopolitan distribution, extending over most of the world's oceans. Other examples include humans, the lichen...
.
Economic importance
Ceratobasidium species are opportunistic parasites of plants, causing a variety of economically important diseases. Examples include: Ceratobasidium cerealeCeratobasidium cereale
Ceratobasidium cereale is a plant pathogen.- External links :* *...
, the cause of sharp eyespot of cereals; Ceratobasidium oryzae-sativae, the cause of aggregate sheath spot of rice
Rice
Rice is the seed of the monocot plants Oryza sativa or Oryza glaberrima . As a cereal grain, it is the most important staple food for a large part of the world's human population, especially in East Asia, Southeast Asia, South Asia, the Middle East, and the West Indies...
; and Ceratobasidium noxium
Ceratobasidium noxium
Ceratobasidium noxium is a species of fungus in the order Cantharellales. Basidiocarps are thin, effused and web-like. The species is tropical to sub-tropical and is mainly known as a plant pathogen, the causative agent of "kole-roga" or black rot of coffee and various blights of citrus and other...
, the cause of kole roga or black rot of coffee
Coffee
Coffee is a brewed beverage with a dark,init brooo acidic flavor prepared from the roasted seeds of the coffee plant, colloquially called coffee beans. The beans are found in coffee cherries, which grow on trees cultivated in over 70 countries, primarily in equatorial Latin America, Southeast Asia,...
.