Cochliobolus sativus - AbsoluteAstronomy.com

The fungus

Fungus

A fungus is a member of a large 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, Fungi, which is separate from plants, animals, and bacteria...

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

Cereal

Cereals are grasses cultivated for the edible components of their grain , composed of the endosperm, germ, and bran...

diseases. The pathogen can infect and cause disease on the root

Root

In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial or aerating . Furthermore, a stem normally occurring below ground is not exceptional either...

(where it is known as common root rot

Common root rot (wheat)

Common root rot is a disease of wheat caused by one or more fungi. Cochliobolus sativus , Fusarium culmorum and F. graminearum are the most common pathogens responsible for common root rot.-Symptoms:...

), leaf and stem, and head tissue. C.sativus is extremely rare in nature and thus it is the asexual

Asexual reproduction

Asexual reproduction is a mode of reproduction by which offspring arise from a single parent, and inherit the genes of that parent only, it is reproduction which does not involve meiosis, ploidy reduction, or fertilization. A more stringent definition is agamogenesis which is reproduction without...

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 develop laterally from pores beneath each conidiophore setpum. 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.

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

Ascus

An ascus is the sexual spore-bearing cell produced in ascomycete fungi. On average, asci normally contain eight ascospores, produced by a meiotic cell division followed, in most species, by a mitotic cell division. However, asci in some genera or species can number one , two, four, or multiples...

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 pratensis¹, Aneurolepidium chinense¹, Avena sativa¹

Bromus inermis¹, B. marginatus¹, B. willdenowii¹

Calluna vulgaris¹, Chloris gayana¹, Cicer arietinum¹, Clinelymus dahuricus¹, C. sibiricus¹, Cynodon dactylon¹, C. transvaalensis¹

Dactylis glomerata¹

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 multiflorum¹

Pennisetum typhoides¹

Roegneria semicostata¹

Saccharum sp. ¹, Secale cereale¹, Setaria italica¹, Sorghum sp. ¹

Taraxacum kok-saghyz¹, Trisetum aestivum¹, Triticum aestivum¹, T. secale¹, T. turgidum subsp. durum, T. vulgare¹’’

Zea mays¹

Geographical distribution

Cochliobolus sativus has a world-wide distribution.

Geographical distribution
Africa	Kenya,¹ Malawi,¹ Sudan,¹ South Africa, ¹ Tanzania, ¹ Zimbabwe¹
Australasia	Australia,¹ China, ¹ Korea, ¹ India, ¹ Indonesia, ¹ New Zealand,¹ Papua New Guinea,¹ Taiwan, ¹ Thailand¹
Central America	Cuba, ¹ Mexico, ¹ Nicaragua¹
Europe	Austria, ¹ Belgium, ¹ Czechoslovakia, ¹ Denmark, ¹ Germany, ¹ Greece, ¹ Hungary, ¹ Italy, ¹ Poland, ¹ Scotland, ¹ United Kingdom, ¹ USSR
North America	Canada (Alberta, ¹ Manitoba, ¹ Saskatchewan¹) US (Indiana, ¹ Kansas, ¹ Minnesota, ¹ Montana, ¹ New York, ¹ North Dakota, ¹ South Dakota, ¹ Utah, ¹ Virginia¹)
South America	Argentina, ¹ Brazil¹

Main diseases

Common root rot (barley)

Common root rot is a fungal disease of barley caused by Cochliobolus sativus, Fusarium culmorum and F. graminearum.- Symptoms :Initial symptoms appear as small brown spots on the crown roots, the lower sheath, and the subcrown internode...

; Common root rot (wheat)

Common root rot (wheat)

; spot blotch (barley)

Spot blotch (barley)

Spot blotch is a disease of barley caused by Cochliobolus sativus. The disease is found everywhere that barley is grown, but only causes significant yield losses in warm, humid climates.- Symptoms :...

; Spot blotch (wheat)

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:...

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 losses Rosyara et al., 2007.

For more details Spot blotch (wheat)

Spot blotch (wheat)

External links

Research articles

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