''Waitea circinata'' is a

species In biology, a species is the basic unit of Taxonomy (biology), 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 ...

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

in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Corticiaceae The Corticiaceae are a family of fungi in the order Corticiales. The family formerly included almost all the corticioid (patch- or crust-forming) fungi, whether they were related or not, and as such was highly artificial. In its current sense, h ...

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

corticioid 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 p ...

, thin, effused, and web-like, but the fungus is more frequently encountered in its similar but sterile

anamorph In mycology, the terms teleomorph, anamorph, and holomorph apply to portions of the Biological life cycle, life cycles of fungi in the Phylum, phyla Ascomycota and Basidiomycota: *Teleomorph: the sexual reproductive stage (morph), typically a Asc ...

ic state. ''Waitea circinata'' is best known as a

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, oomy ...

, causing commercially significant damage ( brown ring patch) to amenity

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 ...

Taxonomy

''Waitea circinata'' was originally described from Australia in 1962, where it was found growing on the undersides of clods of earth in a

wheat Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus ''Triticum'' ; the most widely grown is common wheat (''T. aestivum''). The archaeolog ...

field. The new

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

Waitea ''Waitea'' is a genus of fungi in the family Corticiaceae. Basidiocarps (fruit bodies) are corticioid, thin, effused, and web-like, but species are more frequently encountered in their similar but sterile anamorphic states. Several species are p ...

'', named after the

Waite Agricultural Research Institute The University of Adelaide (informally Adelaide University) is a public research university located in Adelaide, South Australia. Established in 1874, it is the third-oldest university in Australia. The university's main campus is located on N ...

Adelaide Adelaide ( ) is the list of Australian capital cities, capital city of South Australia, the state's largest city and the list of cities in Australia by population, fifth-most populous city in Australia. "Adelaide" may refer to either Greater A ...

, was created to accommodate the species. Because of its morphological similarity to species of ''

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 ...

'', ''Waitea circinata'' was presumed to belong within the

Ceratobasidiaceae The Ceratobasidiaceae are a family of fungi in the order Cantharellales. All species within the family have basidiocarps (fruit bodies) that are thin and effused. They have sometimes been included within the corticioid fungi or alternatively with ...

, but

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

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 usu ...

has shown that it actually belongs in the

and is close to species of ''

Laetisaria ''Laetisaria'' is a genus of fungi in the family Corticiaceae. Basidiocarps (fruit bodies) are effused, corticioid, smooth, and grow as plant pathogens on grasses or agave leaves, or as lichenicolous fungi on lichens, or on dead wood. ''Laetisari ...

'' (which are also grass pathogens). Molecular research has also shown that ''Waitea circinata'' is part of a complex of at least four genetically distinct taxa, each causing visibly different diseases. These taxa were initially treated as varieties of ''W. circinata'', but have now been described as separate species. Older references to ''W. circinata'' may refer to any or all of these species.

Description

Basidiocarps are effused, thin, web-like, smooth, white to pale ochre.

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 ...

are

multinucleate Multinucleate cells (also known as multinucleated or polynuclear cells) are eukaryotic cells that have more than one nucleus per cell, i.e., multiple nuclei share one common cytoplasm. Mitosis in multinucleate cells can occur either in a coord ...

, colourless, often irregular, 2.5-11 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), rece ...

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- ...

are often constricted about the middle, with four short

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 ...

Basidiospores A basidiospore is a reproductive spore produced by Basidiomycete fungi, a grouping that includes mushrooms, shelf fungi, rusts, and smuts. Basidiospores typically each contain one haploid nucleus that is the product of meiosis, and they are ...

are smooth, oblong to cylindrical, 8-12 by 3.5-5 μm, colourless to pale ochre.

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 pinkish orange to brown, 0.5–3 mm wide.

Habitat and distribution

The species appears to be 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 ( ...

, principally associated with grasses, possibly always as a

pathogen In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a ger ...

. Though first described from Australia, it has a cosmopolitan distribution and has been recorded from Europe, North America, Asia, and New Zealand.

Economic importance

''Waitea circinata'' is the causal agent of brown ring patch (also called Waitea patch) of amenity turf grasses.

References

External links

Index Fungorum

USDA ARS Fungal Database
{{DEFAULTSORT:Waitea circinata Fungal plant pathogens and diseases Corticiales Fungi described in 1962