Pyrenophora graminea
Encyclopedia
Pyrenophora graminea is the causal agent of barley stripe. Barley stripe is disease of barley
that once caused significant crop yield
losses in many areas of the world.
. Pycnidiospores are 1.4-3.2 x 1.0-1.6 μm, spherical or ellipsoidal, hyaline
, and nonseptate.
Sexual stage: Perithecia are rare in nature, they occur in barley
straw in the autumn. The perithecia are 576-728 x 442-572 μm. They are supeficial to partly submerged and are elongate, with rigid seta
e on the surface. Acsi
are club-shaped or cylindrical, clearly bitunicate, and rounded at the apex, with a short stalk at the base. Ascospores are 43-61 x 16-28 μm, light yellow-brown, ellipsoidal, and rounded at both ends, with transverse septa and one, occasionally two, septum in the median cells but never in the terminal cells.
Conidia are borne laterally and terminally on conidiophores, which usually occur in clusters of three to five. The conidia are straight with rounded ends and measure 11-24 x 30-100 μm. They are subhyaline to yellow-brown and have up to seven transverse septa.
In culture, mycelium
is gray to olivaceous and is often sterile. Conidia may be formed when infected barley pieces as placed on water agar
and incubated under diurnal light conditions followed by a period of chilling.
Barley
Barley is a major cereal grain, a member of the grass family. It serves as a major animal fodder, as a base malt for beer and certain distilled beverages, and as a component of various health foods...
that once caused significant crop yield
Crop yield
In agriculture, crop yield is not only a measure of the yield of cereal per unit area of land under cultivation, yield is also the seed generation of the plant itself...
losses in many areas of the world.
Identification
Asexual stage: Pycnidia are rarely observed in nature. They are 70-176 μm in diameter, globose to pear-shaped, and develop superficially or partly submerged. The wall is thin and fragile and is yellow to brown, with a short ostioleOstiole
An ostiole is a small hole or opening through which algae or ascomycetal fungi release their mature spores. The term is also used in higher plants, for example to denote the opening of the involuted fig inflorescence through which fig wasps enter to pollinate and breed....
. Pycnidiospores are 1.4-3.2 x 1.0-1.6 μm, spherical or ellipsoidal, hyaline
Hyaline
The term hyaline denotes a substance with a glass-like appearance.-Histopathology:In histopathological medical usage, a hyaline substance appears glassy and pink after being stained with haematoxylin and eosin — usually it is an acellular, proteinaceous material...
, and nonseptate.
Sexual stage: Perithecia are rare in nature, they occur in barley
Barley
Barley is a major cereal grain, a member of the grass family. It serves as a major animal fodder, as a base malt for beer and certain distilled beverages, and as a component of various health foods...
straw in the autumn. The perithecia are 576-728 x 442-572 μm. They are supeficial to partly submerged and are elongate, with rigid seta
Seta
Seta is a biological term derived from the Latin word for "bristle". It refers to a number of different bristle- or hair-like structures on living organisms.-Animal setae:In zoology, most "setae" occur in invertebrates....
e on the surface. Acsi
ACSI
ACSI may also refer to:* Acta Chimica Slovenica, a peer-reviewed chemical journal published by the Slovenian Chemical Society* American Customer Satisfaction Index, an economic indicator that measures the satisfaction of consumers across the U.S...
are club-shaped or cylindrical, clearly bitunicate, and rounded at the apex, with a short stalk at the base. Ascospores are 43-61 x 16-28 μm, light yellow-brown, ellipsoidal, and rounded at both ends, with transverse septa and one, occasionally two, septum in the median cells but never in the terminal cells.
Conidia are borne laterally and terminally on conidiophores, which usually occur in clusters of three to five. The conidia are straight with rounded ends and measure 11-24 x 30-100 μm. They are subhyaline to yellow-brown and have up to seven transverse septa.
In culture, mycelium
Mycelium
thumb|right|Fungal myceliaMycelium is the vegetative part of a fungus, consisting of a mass of branching, thread-like hyphae. The mass of hyphae is sometimes called shiro, especially within the fairy ring fungi. Fungal colonies composed of mycelia are found in soil and on or within many other...
is gray to olivaceous and is often sterile. Conidia may be formed when infected barley pieces as placed on water agar
Agar
Agar or agar-agar is a gelatinous substance derived from a polysaccharide that accumulates in the cell walls of agarophyte red algae. Throughout history into modern times, agar has been chiefly used as an ingredient in desserts throughout Asia and also as a solid substrate to contain culture medium...
and incubated under diurnal light conditions followed by a period of chilling.