The

fungus 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 ...

''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 a grass cultivated for its edible grain. Cereals are the world's largest crops, and are therefore staple foods. They include rice, wheat, rye, oats, barley, millet, and maize ( Corn). Edible grains from other plant families, ...

diseases. The

pathogen In biology, a pathogen (, "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 Germ theory of d ...

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

conidiophore A conidium ( ; : conidia), sometimes termed an asexual chlamydospore or chlamydoconidium (: chlamydoconidia), is an Asexual reproduction, asexual, non-motility, motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word f ...

s, which may be single or clustered and measure 6–10 x 110–220 μm with septations.

Conidia A conidium ( ; : conidia), sometimes termed an asexual chlamydospore or chlamydoconidium (: chlamydoconidia), is an asexual, non- motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also ...

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 are clavate and measure 20–35 x 150–250 μm. Ascospores 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 cristatum¹, Allium sp. ¹,

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

¹, Aneurolepidium chinense¹, Avena sativa¹'' '' Bromus inermis¹, 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 wide ...

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 ...

¹,

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

¹, Clinelymus dahuricus¹, C. sibiricus¹,

Cynodon dactylon ''Cynodon dactylon'', commonly known as Bermuda grass, also known as couch grass in Australia and New Zealand, is a grass found worldwide. It is native to Europe, Africa, Australia and much of Asia. It has been introduced to the Americas. Contra ...

¹, C. transvaalensis¹'' ''

Dactylis glomerata ''Dactylis glomerata'' is a species of flowering plant in the grass family Poaceae, known as cock's-foot,Interactive Flora of NW Europ''Dactylis glomerata'' (Cock's-foot)/ref> also colloquially as orchard grass, or cat grass (due to its populari ...

¹'' '' Echinochloa crus-galli¹, Elymus junceus¹'' ''Festuca sp. ¹'' ''Guzmania sp. ¹'' '' Hordeum brevisubulatum¹, 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 cereale¹, 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, notable for its production of h ...

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

Zea mays Maize (; ''Zea mays''), also known as corn in North American English, is a tall stout Poaceae, grass that produces cereal grain. It was domesticated by indigenous peoples of Mexico, indigenous peoples in southern Mexico about 9,000 years ago ...

¹''

Notes

1
USDA ARS Fungal Database

Geographical distribution

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

Notes

1
USDA ARS Fungal Database
2

Main diseases

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

Spot blotch of wheat

This is most important disease in non-tradition wheat growing areas. The ''B. sorokiniana'' comes with '' Pyrenophora tritici-repentis'' 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 Fungus species