Submitted to: Mycological International Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 6/24/2002
Publication Date: 8/15/2002
Citation: Castlebury, L.A., Carris, L.M. 2002. PHYLOGENETIC RELATIONSHIPS AMONG THE BUNT FUNGI. Mycological International Conference Proceedings.
Technical Abstract: There are approximately 120 species of bunt fungi in Tilletia and related genera that parasitize members of the Poaceae. Most species are distinguished by teliospore ornamentation and host. A number of non-reticulate-spored species in Tilletia have been placed in other genera in the Tilletiales including Neovossia, Conidiosporomyces, Ingoldiomyces, and Oberwinkleria. Two economically important species, T. indica (Karnal bunt) and T. horrida (rice kernel smut) have been placed in Neovossia on the basis of tuberculate teliospore ornamentation, floret infection and the production of large number of non-conjugating basidiospores. Phylogenetic analysis of large subunit nuclear rDNA sequences shows that reticulate-spored taxa with hosts in the Pooideae, including T. tritici, T. laevis and T. controversa, form a well-supported monophyletic group (bootstrap >95%). Tilletia indica and T. walkeri, also on members of the Pooideae, form a well-supported group (100%) and group with reticulate-spored taxa and Ingoldiomyces hyalospora on hosts in the Pooideae (bootstrap >70%). A few reticulate-spored taxa and other tuberculate-spored taxa on non-Pooideae hosts, including T. horrida, fall in a separate, unsupported group although a number of well-supported lineages exist within this group. Conidiosporomyces ayresii groups strongly with T. vittata. Results suggest that host may be more phylogenetically informative than morphological characters.