Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/26/2001
Publication Date: N/A
Technical Abstract: Taxonomic concepts in smut fungi range from extreme splitting based primarily on hosts, resulting in a proliferation of names, to extreme lumping based on similar teliospore morphology. Synonymies resulting from the latter view may mask the number of genetically diverse taxa, but attempts to demonstrate host ranges by experimental means may underestimate natural host specificity. Similarly, high levels of inoculum that develop on cultivated crops may produce "accidental" hosts and result in wide host ranges such as reported for the dwarf bunt pathogen Tilletia controversa. Our application of RAPD and DNA sequence analyses to the characterization of Tilletia species infecting wild grass hosts has in general supported narrow species boundaries corresponding to specialization at the host species level. The focus on agriculturally important smut fungi, which represent a small proportion of known taxa, may provide a misleading view of host specialization and, hence, the genetic diversity present in this group of obligate plant parasites.