The

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 fr ...

''Cochliobolus sativus'' is the teleomorph (sexual stage) of ''Bipolaris sorokiniana'' (anamorph) which is the causal agent of a wide variety of

cereal A cereal is any grass cultivated for the edible components of its grain (botanically, a type of fruit called a caryopsis), composed of the endosperm, germ, and bran. Cereal grain crops are grown in greater quantities and provide more food ...

diseases. The

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 g ...

can infect and cause disease on roots (where it is known as common root rot), leaf and stem, and head tissue. ''C. sativus'' is extremely rare in nature and thus it is the asexual or anamorphic stage which causes infections. The two most common diseases caused by ''B. sorokiniana'' are spot blotch and common root rot, mainly on wheat and barley crops.

Identification

The mycelium of ''B. sorokiniana'' is usually deep olive-brown. New cultures produce abundant simple conidiophores, which may be single or clustered and measure 6–10 x 110–220 μm with septations.

Conidia A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non- motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to t ...

develop laterally from pores beneath each conidiophore septum. Conidia are olive-brown and ovate to oblong, with rounded ends and a prominent basal scar. They measure 15–28 x 40–120 μm and are 3- to 10-septate. Some may be slightly curved. Their walls are smooth and noticeably thickened at the septa. Ascus The sexual state (''C. sativus''), when formed in culture, is in the form of black, globose pseudothecia 300–400 μm in diameter, with erect beaks 50–200 μm long.

Asci ASCI or Asci may refer to: * Advertising Standards Council of India * Asci, the plural of ascus, in fungal anatomy * Accelerated Strategic Computing Initiative * American Society for Clinical Investigation * Argus Sour Crude Index * Association of ...

are clavate and measure 20–35 x 150–250 μm.

Ascospores An ascus (; ) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera or ...

are hyaline, uniformly filamentous, and spirally flexed within asci. They measure 5–10 x 200–250 μm and are 4- to 10-septate.

Host species

Agropyron cristatum ''Agropyron cristatum'', the crested wheat grass, crested wheatgrass, fairway crested wheat grass, is a species in the family Poaceae. This plant is often used as forage and erosion control. It is well known as a widespread introduced species ...

¹, Allium sp. ¹,

Alopecurus pratensis ''Alopecurus pratensis'', known as the meadow foxtail or the field meadow foxtail, is a perennial grass belonging to the grass family (Poaceae). It is native to Europe and Asia. This common plant is found on grasslands, especially on neutral s ...

¹, Aneurolepidium chinense¹,

Avena sativa The oat (''Avena sativa''), sometimes called the common oat, is a species of cereal grain grown for its seed, which is known by the same name (usually in the plural, unlike other cereals and pseudocereals). While oats are suitable for human co ...

¹'' ''

Bromus inermis ''Bromus inermis'' is a species of the true grass family (Poaceae). This rhizomatous grass is native to Europe and North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisph ...

¹, B. marginatus¹, B. willdenowii¹'' ''

Calluna vulgaris ''Calluna vulgaris'', common heather, ling, or simply heather, is the sole species in the genus ''Calluna'' in the flowering plant family Ericaceae. It is a low-growing evergreen shrub growing to tall, or rarely to and taller, and is found wid ...

¹,

Chloris gayana ''Chloris gayana'' is a species of grass known by the common name Rhodes grass. It is native to Africa but it can be found throughout the tropical and subtropical world as a naturalized species. It can grow in many types of habitat. It is also c ...

¹,

Cicer arietinum The chickpea or chick pea (''Cicer arietinum'') is an annual legume of the family Fabaceae, subfamily Faboideae. Its different types are variously known as gram" or Bengal gram, garbanzo or garbanzo bean, or Egyptian pea. Chickpea seeds are high ...

¹,

Clinelymus dahuricus ''Elymus'' is a genus of perennial plants with approximately 150 species in the grass family, related to rye, wheat, and other widely grown cereal grains. ''Elymus'' is a cosmopolitan genus, represented by species across all continents of the w ...

¹, C. sibiricus¹,

Cynodon dactylon ''Cynodon dactylon'', commonly known as Bermuda grass, is a grass found worldwide. It is native to Europe, Africa, Australia and much of Asia. It has been introduced to the Americas. Although it is not native to Bermuda, it is an abundant invasiv ...

¹, C. transvaalensis¹'' ''

Dactylis glomerata ''Dactylis Glomerata'' is the sixth studio album by Swedish doom metal band Candlemass, released in 1998. This was their first album released since their split in 1994. The album was originally destined to be the second release by Candlemass m ...

¹'' '' Echinochloa crus-galli¹,

Elymus junceus ''Psathyrostachys juncea'' is a species of grass known by the common name Russian wildrye. It was formerly classified as ''Elymus junceus''. It is native to Russia and China, and has been introduced to other parts of the world, such as Canada an ...

¹'' ''Festuca sp. ¹'' ''Guzmania sp. ¹'' ''

Hordeum brevisubulatum ''Hordeum brevisubulatum'' is a widespread species of wild barley ''Hordeum spontaneum'', commonly known as wild barley or spontaneous barley, is the wild form of the grass in the family Poaceae that gave rise to the cereal barley (''Hordeum ...

¹, H. distichon¹, H. sativum var. hexastichon¹, H. vulgare¹, H. vulgare var. hexastichon¹'' '' Lablab purpureus¹, Linum usitatissimum¹,

Lolium multiflorum ''Lolium multiflorum'' (Italian rye-grass, annual ryegrass) is a ryegrass native to temperate Europe, though its precise native range is unknown. It is a herbaceous annual, biennial, or perennial grass that is grown for silage, and as a cover ...

¹'' '' Pennisetum typhoides¹'' '' Roegneria semicostata¹'' ''Saccharum sp. ¹,

Secale cereale Rye (''Secale cereale'') is a grass grown extensively as a grain, a cover crop and a forage crop. It is a member of the wheat tribe (Triticeae) and is closely related to both wheat (''Triticum'') and barley (genus ''Hordeum''). Rye grain i ...

¹, Setaria italica¹, Sorghum sp. ¹'' ''

Taraxacum kok-saghyz ''Taraxacum kok-saghyz'', often abbreviated as ''TKS'' and commonly referred to as the Kazakh dandelion, rubber root, or Russian dandelion, is a species of dandelion native to Kazakhstan, Kyrgyzstan and Uzbekistan, that is notable for its prod ...

¹, Trisetum aestivum¹, Triticum aestivum¹, T. secale¹, T. turgidum subsp. durum, T. vulgare¹’’ ''

Zea mays Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. The ...

¹''

Notes

1
USDA ARS Fungal Database

Geographical distribution

''Cochliobolus sativus'' has a world-wide distribution.

Notes

1
USDA ARS Fungal Database

Main diseases

Common root rot (barley); Common root rot (wheat); spot blotch (barley);

Spot blotch (wheat) Spot blotch is a leaf disease of wheat caused by '' Cochliobolus sativus''. ''Cochliobolus sativus'' also infects other plant parts and in conjunction with other pathogens causes common root rot and black point. Introduction Foliar blight, He ...

Spot blotch of wheat

This is most important disease in non-tradition wheat growing areas. The ''B. sorokiniana'' comes with ''

Pyrenophora tritici-repentis ''Pyrenophora tritici-repentis'' (teleomorph) and ''Drechslera tritici-repentis'' (anamorph) is a necrotrophic plant pathogen of fungal origin, phylum Ascomycota. The pathogen causes a disease originally named yellow spot but now commonly call ...

'' and causes millions of tons of wheat loss each year. The symptoms are blotch as well as induced senescence due to premature chlorophyll losse
Rosyara et al., 2007

References

External links

Index Fungorum

USDA ARS Fungal Database

Diagnosis of Common Root Rot of Wheat and Barley
{{Taxonbar, from=Q5139370 Fungal plant pathogens and diseases Cereal diseases Barley diseases Wheat diseases Cochliobolus Fungi described in 1890