STUDIES IN HETEROBASIDIOMYCETES - PART 141 - PHYLOGENETIC STUDIES ON NUCLEAR LARGE SUBUNIT RIBOSOMAL DNA-SEQUENCES OF SMUT FUNGI AND RELATED TAXA

To show phylogenetic relationships among the smut fungi and their rela tives, we sequenced a part of the nuclear LSU rDNA from 43 different s pecies of smut fungi and related taxa. Our data were combined with the existing sequences of seven further smut fungi and 17 other basidiomy cetes. Two sets of sequences were analyzed. The first set with a repre sentative number of simple septate basidiomycetes, complex septate bas idiomycetes, and smut fungi was analyzed with the neighbor-joining met hod to estimate the general topology of the basidiomycetes phylogeny a nd the positions of the smut fungi. The tripartite subclassification o f the basidiomycetes into the Urediniomycetes, Ustilaginomycetes, and Hymenomycetes was confirmed and two groups of smut fungi appeared. The smut genera Aurantiosporium, Microbotryum, Fulvisporium, and Ustilent yloma are members of the Urediniomycetes, whereas the other smut speci es tested are members of the Ustilaginomycetes with Entorrhiza as a ba sal taxon. The second set of 46 Ustilaginomycetes was analyzed using t he neighbor-joining and the maximum parsimony methods to show the inne r topology of the Ustilaginomycetes. The results indicated three major lineages among Ustilaginomycetes corresponding to the Entorrhizomycet idae, Exobasidiomycetidae, and Ustilaginomycetidae. The Entorrhizomyce tidae are represented by Entorrhiza species. The Ustilaginomycetidae c ontain at least two groups, the Urocystales and Ustilaginales. The Exo basidiomycetidae include five orders, i.e., Doassansiales, Entylomatal es, Exobasidiales, Georgefischeriales, and Tilletiales, and Graphiola phoenicis and Microstroma juglandis. Our results support a classificat ion mainly based on ultrastructure. The description of the Glomosporia ceae is emended. The Doassansiopsaceae, Melanotaeniaceae, and Urocysta ceae are proposed as new taxa.