Tilletia caries . [Descriptions of Fungi and Bacteria

Abstract

Abstract A description is provided for Tilletia caries [Tilletia tritici] . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Aegilops, Agropyron, Bromus, Elymus, Hordeum, Poa, Secale, Sitanion, Triticum, Triticale . DISEASE: Causes common bunt (stinking or covered smut) of wheat. Tilletia foetida (CMI Descriptions 720) causes a virtually identical disease known by the same name. The grain tissues inside the pericarp are converted to a mass of black teliospores producing a 'bunt ball' as the head matures. Diseased plants may be slightly stunted, infected ears ripen slower and the glumes project more than in healthy ears. Losses are caused both by direct loss of grain and by spoilage of grain and flour by contamination with the bunt spores which are released when the crop is harvested. Bunt spores release trimethylamine which has an odour of decaying fish. GEOGRAPHICAL DISTRIBUTION: Widespread, occurs in most countries where wheat is arown (CMI Map 294, ed. 3, 1978). TRANSMISSION: Spores are released when the grain is harvested and are dispersed by air to contaminate healthy grain and soil. Spores germinate in moist soil to produce a basidium and acicular basidiospores (primary sporidia). These fuse to produce a dikaryotic mycelium which may directly infect host seedling coleoptiles or produce further secondary sporidia.