False loose smut is a fungal disease of barley caused by Ustilago nigra. This fungus is very similar to U. nuda, the cause of loose smut, and was first distinguished from it in 1932.[2]
The disease is not apparent until heading, at which time, smutted heads emerge slightly earlier than healthy heads. At first, each smutted head is covered by a delicate, paperlike, grayish membrane. These membranes break shortly after the smutted heads have emerged and expose a dark brown to black, powdery mass of spores. This spores are easily dislodged, leaving only the bare rachis.[3]
Disease cycle
The disease cycle of Ustilago nigra is similar to that of U. hordei, the cause of covered smut of barley. The teliospores survive on the surface or in the soil. In some cases, the teliospores that are deposited under the hull, may germinate immediately. The mycelium then grows into the lower layers of the seed and then remains dormant until seed germination.
Infection of seedling occurs between germination and emergence. Infection can occur from seed-borne teliospores or by teliospores residing in the soil. Relatively dry soil at temperatures of 15–21 °C, are most favorable for infection. The invading mycelium becomes established within the growing point. As the plant enters the boot stage, the mycelium grows rapidly into the floral tissue which is converted to masses of black teliospores. Teliospores are disseminated by wind or during combining. The teliospores may remain viable for several spores.[2]
Management
The incidence of false loose smut can be reduced by using clean seed, treated seed and resistant cultivars.
false, loose, smut, fungal, disease, barley, caused, ustilago, nigra, this, fungus, very, similar, nuda, cause, loose, smut, first, distinguished, from, 1932, ustilago, nigrascientific, classificationkingdom, fungidivision, basidiomycotaclass, ustilaginomycete. False loose smut is a fungal disease of barley caused by Ustilago nigra This fungus is very similar to U nuda the cause of loose smut and was first distinguished from it in 1932 2 Ustilago nigraScientific classificationKingdom FungiDivision BasidiomycotaClass UstilaginomycetesOrder UstilaginalesFamily UstilaginaceaeGenus UstilagoSpecies U nigraBinomial nameUstilago nigraTapke 1 1932 Contents 1 Symptoms 2 Disease cycle 3 Management 4 References 5 External links 5 1 Extension publicationsSymptoms EditThe disease is not apparent until heading at which time smutted heads emerge slightly earlier than healthy heads At first each smutted head is covered by a delicate paperlike grayish membrane These membranes break shortly after the smutted heads have emerged and expose a dark brown to black powdery mass of spores This spores are easily dislodged leaving only the bare rachis 3 Disease cycle EditThe disease cycle of Ustilago nigra is similar to that of U hordei the cause of covered smut of barley The teliospores survive on the surface or in the soil In some cases the teliospores that are deposited under the hull may germinate immediately The mycelium then grows into the lower layers of the seed and then remains dormant until seed germination Infection of seedling occurs between germination and emergence Infection can occur from seed borne teliospores or by teliospores residing in the soil Relatively dry soil at temperatures of 15 21 C are most favorable for infection The invading mycelium becomes established within the growing point As the plant enters the boot stage the mycelium grows rapidly into the floral tissue which is converted to masses of black teliospores Teliospores are disseminated by wind or during combining The teliospores may remain viable for several spores 2 Management EditThe incidence of false loose smut can be reduced by using clean seed treated seed and resistant cultivars References Edit Index Fungorum Names Record www speciesfungorum org Retrieved 2008 03 16 a b Mathre D E 1997 Compendium of barley diseases American Phytopathological Society pp 120 pp Martens J W W L Seaman T G Atkinson 1984 Diseases of field crops in Canada Canadian Phytopathological Society pp 160 pp External links EditExtension publications Edit US Oregon permanent dead link Retrieved from https en wikipedia org w index php title False loose smut amp oldid 1013465584, wikipedia, wiki, book, books, library,
