title: Phylogenetic placement of plant pathogenic Sclerotium species among teleomorph genera.
abstract: Phylogenetic analyses and morphological characteristics were used to assess the taxonomic placement of eight plant-pathogenic Sclerotium species. Members of this genus produce only sclerotia and no fruiting bodies or spores, so Sclerotium species have been difficult to place taxonomically. Sequences of rDNA large subunit (LSU) and internal transcribed spacer (ITS) regions were determined for isolates of Sclerotium cepivorum, S. coffeicola, S. denigrans, S. hydrophilum, Ceratorhiza oryzae-sativae, S. perniciosum, S. rhizodes, S. rolfsii and S. rolfsii var. delphinii. Parsimony analysis grouped two species previously thought to be in the Basidiomycota, S. denigrans and S. perniciosum, within the Ascomycota; these species were found to have affinities with the teleomorph genera Sclerotinia and Stromatinia and the asexual Sclerotium cepivorum, which was known earlier to be related to Sclerotinia species. The other Sclerotium species were placed in one of two basidiomycetous groups, genera Athelia or Ceratobasidium. Based on rDNA analysis and morphology the basidiomycetous Sclerotium hydrophilum and S. rhizodes were transferred to genus Ceratorhiza, the anamorph of Ceratobasidium species. Sclerotium coffeicola was found to be close to S. rolfsii var. delphinii and S. rolfsii var. rolfsii, which was shown earlier to have an Athelia teleomorph.
authors.affiliation: Department of Plant Pathology, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Zhihan
authors.initials: Z
authors.lastname: Xu
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Harrington
authors.forename: Mark L
authors.initials: ML
authors.lastname: Gleason
authors.forename: Jean C
authors.initials: JC
authors.lastname: Batzer
mesh_terms: D001203:Ascomycota / Q000145:classification / Q000235:genetics* / Q000648:ultrastructure; D001483:Base Sequence; D001487:Basidiomycota / Q000145:classification / Q000235:genetics* / Q000648:ultrastructure; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000145:classification / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012339:RNA, Ribosomal, 28S / Q000737:chemistry / Q000235:genetics; D016415:Sequence Alignment
chemical_list: D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer; D012339:RNA, Ribosomal, 28S