Disease: Karnal BuntPathogen: Tilletia indicaHost: Wheat, Triticum aestivum
Karnal bunt of wheat was discovered in 1996 in the United States, 66 years after its first discovery in Karnal, India. In the US, the disease is now limited by quarantine to areas in Arizona, New Mexico, California and Texas. The symptoms of the disease appear only on the seeds and they include the dark misshapen seeds of wheat (Figure, left). Infected seeds contain the black teliospores of the bunt fungus (Figure, right). The black powdery spores are typical of smut diseases, which includes bunt. It is the teliospores that provide the mechanism for long- and short-distance dispersal of this fungus.