Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: 3/15/2000
Publication Date: 8/15/2000
Technical Abstract: Teliospore morphology and host are the basic characters used to distinguish taxa in the genus Tilletia. There are three basic types of teliospore ornamentation within this genus: reticulate, smooth, and echinulate or tuberculate. To determine the relationships of taxa within this group, the internal transcribed spacer region of the rDNA repeat and the 5' end of nuclear large subunit rDNA genes were sequenced and analyzed for 20 taxa. Taxa in the T. fusca complex grouped with T. cerebrina, T. togwateei, and the type species T. caries, all of which have reticulate teliospores. This group of taxa formed a sister group to T. indica and T. walkeri, both of which have tuberculate spores (bootstrap support >90%). Forming a sister group to the taxa above were T. sumatii, T. opaca, T. boutelouae and taxa in the T. barclayana complex. Surprisingly, T. horrida was more closely related to T. opaca than it was to the two other representatives of the T. barclayana complex were it has traditionally been placed. Two reticulate-spored taxa, T. asperifolia and T. lycuroides, consistently were placed well outside the reticulate-spored group including T. caries. These data suggest that teliospore ornamentation type may not be a reliable character for predicting relationships within this group.