''Ceratobasidium cornigerum'' is a
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of
fungus
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from th ...
in the
order Cantharellales
The Cantharellales are an order of fungi in the class Agaricomycetes. The order includes not only the chanterelles (Cantharellaceae), but also some of the tooth fungi (Hydnaceae), clavarioid fungi ( Aphelariaceae and Clavulinaceae), and cor ...
.
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 not ...
(fruit bodies) are thin, spread on the
substrate out like a film (effused) and web-like. An
anamorphic
Anamorphic format is the cinematography technique of shooting a widescreen picture on standard 35 mm film or other visual recording media with a non-widescreen native aspect ratio. It also refers to the projection format in which a distorted ...
state is frequently obtained when isolates are
cultured. ''Ceratobasidium cornigerum'' is
saprotroph
Saprotrophic nutrition or lysotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed (dead or waste) organic matter. It occurs in saprotrophs, and is most often associated with fungi ( ...
ic, but is also a
facultative
{{wiktionary, facultative
Facultative means "optional" or "discretionary" (antonym '' obligate''), used mainly in biology in phrases such as:
* Facultative (FAC), facultative wetland (FACW), or facultative upland (FACU): wetland indicator statuses ...
plant pathogen
Plant pathology (also phytopathology) is the scientific study of diseases in plants caused by pathogens (infectious organisms) and environmental conditions (physiological factors). Organisms that cause infectious disease include fungi, oomyc ...
, causing a number of economically important crop diseases, and an
orchid endomycorrhizal associate. The species is genetically diverse and is sometimes treated as a
complex
Complex commonly refers to:
* Complexity, the behaviour of a system whose components interact in multiple ways so possible interactions are difficult to describe
** Complex system, a system composed of many components which may interact with each ...
of closely related
taxa
In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...
. DNA research shows the species (or species complex) actually belongs within the genus ''
Rhizoctonia
''Rhizoctonia'' is a genus of fungi in the order Cantharellales. Species form thin, effused, corticioid basidiocarps (fruit bodies), but are most frequently found in their sterile, anamorphic state. ''Rhizoctonia'' species are saprotrophic, bu ...
''.
Taxonomy
''Corticium cornigerum'' was first described in 1922 by
mycologist
Mycology is the branch of biology concerned with the study of fungus, fungi, including their genetics, genetic and biochemistry, biochemical properties, their Taxonomy (biology), taxonomy and ethnomycology, their use to humans, including as a so ...
Hubert Bourdot
Hubert Bourdot (30 October 1861 – 30 September 1937) was a French Roman Catholic priest and mycologist who was a native of Imphy, a community in the department of Nièvre.
From 1898 until his death, Bourdot was a parish priest in Saint-Priest-en ...
, who found it growing in France on dead stems of
Jerusalem artichoke
The Jerusalem artichoke (''Helianthus tuberosus''), also called sunroot, sunchoke, wild sunflower, topinambur, or earth apple, is a species of sunflower native to central North America. It is cultivated widely across the temperate zone for its ...
. It was subsequently transferred to the genus ''
Ceratobasidium'' by American mycologist
Donald P. Rogers in 1935.
[ Molecular research, based on ]cladistic
Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived char ...
analysis of DNA sequences
A nucleic acid sequence is a succession of bases signified by a series of a set of five different letters that indicate the order of nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. By convention, sequences are usua ...
, places ''Ceratobasidium cornigerum'' within the genus ''Rhizoctonia'', but this taxonomic problem has yet to be resolved.
Anastomosis groups (AGs)
''Ceratobasidium cornigerum'' is one of several species whose anamorphic states are sometimes referred to as "binucleate rhizoctonias". These binucleate rhizoctonias have been divided into genetically distinct "anastomosis groups" (AGs) based initially on hyphal anastomosis
An anastomosis (, plural anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf#Veins, leaf veins, or streams. Such a connection m ...
tests, subsequently supported by analyses of DNA sequences
A nucleic acid sequence is a succession of bases signified by a series of a set of five different letters that indicate the order of nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. By convention, sequences are usua ...
. At least six of these AGs (AG-A, AG-B(o), AG-C, AG-D, AG-P, and AG-Q) have been linked to ''Ceratobasidium cornigerum'', which may therefore be considered as a variable species (comprising at least six genetically distinct populations) or as a complex
Complex commonly refers to:
* Complexity, the behaviour of a system whose components interact in multiple ways so possible interactions are difficult to describe
** Complex system, a system composed of many components which may interact with each ...
of morphologically similar species. In the latter case, it is not clear which of these AGs (if any) should take the original name ''C. cornigerum''.
Synonyms or associated species
The following taxa belong in the ''Ceratobasidium cornigerum'' complex and have been treated as synonyms
A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...
or as closely related but independent species:
* ''Ceratobasidium ramicola
''Ceratobasidium ramicola'' is a fungal plant pathogen.
References
Fungal plant pathogens and diseases
Cantharellales
Fungi described in 1969
{{fungus-plant-disease-stub ...
'' = AG-A (also includes several invalidly published names including ''Rhizoctonia candida'', ''R. endophytica'', and ''R. fragariae''). This group contains a range of crop pathogens and orchid associates.
* ''Ceratobasidium cereale
''Ceratobasidium cereale'' is a plant pathogen.
References
Fungal plant pathogens and diseases
Cantharellales
Fungi described in 1984
{{fungus-plant-disease-stub ...
'' = AG-D (also includes the dubious name ''Ceratobasidium gramineum''). This group contains cereal and grass pathogens.
* '' Ceratobasidium ochroleucum'' (= ''Corticium stevensii''), ''Ceratobasidium lantanae-camarae'', ''Corticium pervagum'', ''Corticium invisum'', and AG-P are all tropical
The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in
the Southern Hemisphere at S. The tropics are also referred to ...
or subtropical
The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Geographical z ...
, web-blight pathogens.
Description
The 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 not ...
(fruit bodies) are effused, thin, and whitish. Microscopically they have colourless hyphae
A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium.
Structure
A hypha consists of one or ...
, 3 to 9 μm wide, without clamp connection
A clamp connection is a hook-like structure formed by growing hyphal cells of certain fungi. It is a characteristic feature of Basidiomycetes fungi. It is created to ensure that each cell, or segment of hypha separated by septa (cross walls), rec ...
s. The basidia
A basidium () is a microscopic sporangium (a spore-producing structure) found on the hymenophore of fruiting bodies of basidiomycete fungi which are also called tertiary mycelium, developed from secondary mycelium. Tertiary mycelium is highly-c ...
are ellipsoid to broadly club-shaped, 9 to 14 by 8 to 12 μm, bearing four sterigmata
In biology, a sterigma (pl. sterigmata) is a small supporting structure.
It commonly refers to an extension of the basidium (the spore-bearing cells) consisting of a basal filamentous part and a slender projection which carries a spore at the ti ...
. The basidiospores are ellipsoid and broadly fusiform (spindle-shaped), measuring 6 to 11 by 4 to 6 μm. Pale brown sclerotia
A sclerotium (; (), is a compact mass of hardened fungal mycelium containing food reserves. One role of sclerotia is to survive environmental extremes. In some higher fungi such as ergot, sclerotia become detached and remain dormant until favor ...
are sometimes produced, measuring 0.5 to 3 mm across.
Habitat and distribution
If treated as a single species, ''Ceratobasidium cornigerum'' is cosmopolitan
Cosmopolitan may refer to:
Food and drink
* Cosmopolitan (cocktail), also known as a "Cosmo"
History
* Rootless cosmopolitan, a Soviet derogatory epithet during Joseph Stalin's anti-Semitic campaign of 1949–1953
Hotels and resorts
* Cosmopoli ...
and has been reported from Asia, Australia, Europe, North & South America. It occurs as a soil saprotroph
Saprotrophic nutrition or lysotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed (dead or waste) organic matter. It occurs in saprotrophs, and is most often associated with fungi ( ...
, producing basidiocarps on dead stems and fallen litter, but is also a facultative
{{wiktionary, facultative
Facultative means "optional" or "discretionary" (antonym '' obligate''), used mainly in biology in phrases such as:
* Facultative (FAC), facultative wetland (FACW), or facultative upland (FACU): wetland indicator statuses ...
plant pathogen
Plant pathology (also phytopathology) is the scientific study of diseases in plants caused by pathogens (infectious organisms) and environmental conditions (physiological factors). Organisms that cause infectious disease include fungi, oomyc ...
causing disease of crops and turf grass. It can also grow as a "web blight" pathogen on living leaves of trees and shrubs, particularly in the tropics and subtropics. It is one of the commonest endomycorrhizal associates of terrestrial orchids
Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant.
Along with the Asteraceae, they are one of the two largest families of flowering ...
.
Hosts (specifically strawberries) and symptoms
Symptoms are most visible in the first fruiting year and are most apparent during the last couple of weeks before harvest.> Early symptoms will include reduced vigor and a decrease in the ability to survive high water conditions. Plants may experience lodging when water demand is high. Infected plants may continue to grow but will show aboveground symptoms including stunting, decreased fruit size, and numerous dead older leaves. Belowground symptoms include the deterioration of roots. Infected plants may have feeder and main roots that are smaller and covered in black lesions. Feeder roots will appear water soaked. In the early stages of infection, the core of the root will appear white while the exterior begins to show black lesions. In severely affected roots, both the core and the outer tissue of the root will be black Stained feeder roots may reveal masses of moniliform cells of ''R. fragariae''. Characteristics of ''R. fragariae'' include hyphal branching pattern, dolipore septa, and moiliform resting cells. The binucleated hyphae directly penetrate the root.
Environment
Black root rot is commonly found in field with a long history of strawberry production. Increased chances of disease are likely if there are stress factors such as herbicide injury, winter or cold injury, excessive soil moisture, soil compaction or repeated freezing of roots. Black root rot is not usually introduced into the new planting through nursery stock or contaminated equipment but is instead often due to one or more of the disease-causing fungi already present in the soil. Black root rot is a disease complex on strawberry, which means that one or more organisms can infect the host. For strawberries, the common fungi are ''Pythium spp'', ''Fusarium spp'', and ''Rhizoctonia spp'', along with several species of nematodes that function together to cause disease. Strawberries have been shown to have greater levels of rot when simultaneously exposed to both ''R. fragariae'' and ''P. penetrans'' (nematode).
Importance
Black root rot is a common disease in North Carolina, a top strawberry producing region, and much of the southeastern region of the United States, having been shown to reduce yields by 20 to 40%. This is the main reason growers fumigate their fields in this region. Pre-planting fumigation may suppress the disease during the year of planting, but typically it does not offer any lasting control and cultivars resistant to black root rot are not currently available. Black root rot has been a challenge for strawberry growers for at least a century, and probably longer. Black root rot of strawberry is recorded to have been prevalent in Massachusetts, Michigan, and New York in the years 1902 and 1908. In 1920 a ''Rhizoctonia'' species was first assigned as the causal pathogen responsible for “dying out” of strawberry beds in western Washington. By 1988, ''R. fragariae'' was isolated from more than 70% of plants from commercial strawberry fields in Connecticut in cultivation for more than one year.
Economic importance
Under various names, fungi in the ''Ceratobasidium cornigerum'' complex are known to cause a range of diseases in commercial crop
A cash crop or profit crop is an agricultural crop which is grown to sell for profit. It is typically purchased by parties separate from a farm. The term is used to differentiate marketed crops from staple crop (or "subsistence crop") in subsiste ...
s.
The AG-A group (''Ceratobasidium ramicola'') causes various diseases, including "strawberry black root rot", diseases of soya bean
The soybean, soy bean, or soya bean (''Glycine max'') is a species of legume native to East Asia, widely grown for its edible bean, which has numerous uses.
Traditional unfermented food uses of soybeans include soy milk, from which tofu and ...
, pea, and pak choy
Bok choy (American English, Canadian English, and Australian English), pak choi (British English) or pok choi (''Brassica rapa'' subsp. ''chinensis'') is a type of Chinese cabbage, used as food. ''Chinensis'' varieties do not form heads and have ...
, and "silky threadblight" of ''Pittosporum
''Pittosporum'' ( or ) is a genus of about 200 species of flowering plants in the family Pittosporaceae. The genus is probably Gondwanan in origin; its present range extends from Australasia, Oceania, eastern Asia and some parts of Africa. '' Ci ...
'' and other shrubs.
The AG-D group (''Ceratobasidium cereale'') causes "sharp eyespot" of cereals and "yellow patch" in turf grass
A lawn is an area of soil-covered land planted with grasses and other durable plants such as clover which are maintained at a short height with a lawnmower (or sometimes grazing animals) and used for aesthetic and recreational purposes. L ...
.
''Corticium invisum'' was described as the causal agent of "black rot" of tea
Tea is an aromatic beverage prepared by pouring hot or boiling water over cured or fresh leaves of ''Camellia sinensis'', an evergreen shrub native to East Asia which probably originated in the borderlands of southwestern China and north ...
in Sri Lanka, whilst ''Corticium pervagum'' causes a leaf and stem blight of cocoa. ''Ceratobasidium ochroleucum'' (''Corticium stevensii'') was described causing a blight of apple and quince
The quince (; ''Cydonia oblonga'') is the sole member of the genus ''Cydonia'' in the Malinae subtribe (which also contains apples and pears, among other fruits) of the Rosaceae family (biology), family. It is a deciduous tree that bears hard ...
trees in Brazil, but the name is of uncertain application because of confusion with '' Rhizoctonia noxia''.
''Ceratobasidium lantanae-camarae'' was described from Brazil as the causal agent of a web blight of the invasive shrub ''Lantana camara
''Lantana camara'' (common lantana) is a species of flowering plant within the verbena family ( Verbenaceae), native to the American tropics. It is a very adaptable species, which can inhabit a wide variety of ecosystems; once it has been introdu ...
'', suggesting it has potential as a biocontrol
Biological control or biocontrol is a method of controlling pests, such as insects, mites, weeds, and plant diseases, using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also invo ...
agent.
References
External links
{{Taxonbar, from=Q5063741
Fungal plant pathogens and diseases
Fungal strawberry diseases
Cantharellales
Fungi of Asia
Fungi of Australia
Fungi of Europe
Fungi of North America
Fungi of South America
category:Fungi described in 1922