VIEW ARTICLE

Host Specialization in the Complex Species, Tilletia fusca. J. A. Hoffmann, Pathologist, Crops Research Division, ARS, USDA, Pullman, Washington 99163; J. P. Meiners, Pathologist, Crops Research Division, ARS, USDA, Pullman, Washington 99163, Present address: Plant Industry Station, Beltsville, Maryland 20705. Phytopathology 61:225-227. Accepted for publication 28 September 1970. DOI: 10.1094/Phyto-61-225.

Certain Tilletia spp. recently combined with T. fusca proved through cross inoculation to be highly host specific. Tilletia bromi-tectorum is parasitic on Bromus spp., primarily in the sections Eubromus, Neobromus, and Ceratochloa; T. guyotiana is parasitic on Bromus spp., in the sections Bromium and Bromopsis. Only two Bromus spp. were hosts of both T. bromi-tectorum and T. guyotiana. Tilletia fusca is parasitic only on species of Festuca. None of the spore collections tested was parasitic on wheat. Taxonomic implications and relationships of these bunts are discussed and three varieties are designated: T. fusca fusca, T. fusca guyotiana, and T. fusca bromi-tectorum. New host species for the T. fusca complex are reported.