Tilletia

Tilletia is a genus of true smut fungi in the family Tilletiaceae that parasitize cereal crops, most notably wheat and barley. Members of Tilletia cause bunt diseases, in which developing kernels are replaced by masses of dark, powdery teliospores within the spike. The infection is typically favored by cool, moist conditions during flowering and can lead to yield loss and reduced grain quality. Many Tilletia species are seedborne or persist in crop residues, contributing to the persistence of the disease in a field or region.

Notable species include Tilletia indica, the causal agent of Karnal bunt of wheat, which has been a subject of international quarantine due to its potential impact on grain export markets. Tilletia controversa causes dwarf bunt of wheat, while Tilletia caries and Tilletia foetida are associated with common bunt, sometimes called stinking smut, in wheat and other cereals. These species differ in host range, geographic distribution, and environmental conditions that favor infection, but all produce teliospores that replace kernels in infected ears.

Management of Tilletia diseases emphasizes prevention and reduction of inoculum. Practices include using certified, disease-free seed; deploying resistant or tolerant cultivars where available; crop rotation and field sanitation to reduce overwintering inoculum; and careful grain handling to limit spread through seed lots and equipment. In regions where Karnal bunt is a concern, strict quarantine and regulation of imports are often implemented. Diagnosis relies on microscopy of teliospores and, when needed, molecular testing.