Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/20/2004
Publication Date: 7/1/2004
Citation: Castlebury, L.A., Carris, L.M. 2004. PHYLOGENETIC PLACEMENT OF NEOVOSSIA IOWENSIS. Meeting Abstract.
Technical Abstract: The smut genus Neovossia was erected based on Neovossia moliniae, a Tilletia-like species producing teliospores with a hyaline appendage, local infection, a large number (>40) of non-conjugating primary basidiospores, and absence of sterile cells and trimethylamine odor Two other species of Neovossia, both infecting Phragmites communis, have been described: N. iowensis was described from the USA and N. danubialis T. Sÿvulescu from Europe. The pathogens responsible for Karnal bunt of wheat, T. indica, and kernel smut of rice, T. horrida, have been placed in Neovossia by some authors and in Tilletia others. Both species produce sterile cells in the sorus and T. indica has a pronounced trimethylamine odor. Absence of sterile cells and production of numerous basidiospores were two characters used to distinguish Neovossia from Tilletia. However, examination of specimens of N. moliniae, on both Molinia (WSP 34463) and Phragmites (V 573) has revealed the presence of sterile cells in the sorus. Analysis of the nLSU for approximately 40 taxa in the Tilletiales, including N. iowensis, resulted in three well-supported lineages with a few taxa not grouping with the main lineages. Taxa infecting hosts in the grass subfamily Pooideae form one well-supported lineage. This lineage comprises most of the reticulate-spored species that germinate to form a small number of rapidly conjugating basidiospores and includes the type species of Tilletia, T. tritici. Two tuberculate-spored species with a large number of nonconjugating basidiospores, T. indica and T. walkeri, and Ingoldiomyces hyalosporus are also included in this lineage. A second major lineage recognized in all analyses contains species that infect Panicoideae, Arundinoideae and Chloridoideae (PAC) lineage (100% Bayesian, 82% MP), with 11 species including N. iowensis. All species in this group have verrucose teliospores with the exception of N. iowensis, which has foveolate teliospores, and nonconjugating, uni- or multinucleate basidiospores. Several species in this group have been described or referred to as species of Neovossia in the literature. Tilletia horrida, which has been placed in Neovossia by some authors seems to form a distinct lineage of its own. The results of this study suggest that there is not a basis for recognizing Neovossia as a genus distinct from Tilletia. However, we were not able to study viable collections of N. moliniae and the status of Neovossia remains uncertain.