THE ORGANISM CAUSING DWARF BUNT OF WHEAT

Abstract

When Fischer described Tilletia brevifaciens as the organism causing dwarf bunt of winter wheat, he showed that it was specifically distinct from T. caries (Fr.) Tul. However, he failed to indicate how his new species was separated from other species of Tilletia already described. Some of these species were restudied. It has been found that Tilletia brevifaciens is not specifically distinct from T. contraversa Kühn originally described on Agropyron repens, but also known on other species of Agropyron. Wheat probably first contracted dwarf bunt in the mountainous areas of Europe, where native species of Agropyron are found naturally infected by T. contraversa. The pathogen has been introduced into North America.