Heinz Clémençon

Phylogenetic analyses of the Lyophylleae (Agaricales, Basidiomycota) based on nuclear and mitochondrial rDNA sequences

Current classifications of the Lyophylleae and the importance of siderophilous granulation in the basidia for the classification of agaricoid fungi were evaluated using parsimony analyses of sequence data from the nuclear ribosomal large subunit gene (nLSU), the internal transcribed spacer region of the nuclear ribosomal array (ITS), and the mitochondrial ribosomal small subunit gene (mtSSU). These three different data partitions were phylogenetically congruent on the basis of the Mickevich-Farris statistical test, but not from the ILD and the Templeton tests. Bootstrap supports for nodes in phylogenetic trees generated from combined nLSU, ITS, and mtSSU sequence data were generally higher than those in trees generated from individual data sets. This suggests a lack of major conflict in the phylogenetic signal among the different data sets. We conclude that the Mickevich-Farris test is more appropriate for estimating congruence and combinability between different sources of molecular data than the more widely used ILD and Templeton tests, at least when the different data sets have their respective resolution power at different depths in the phylogeny. Results of the combined analyses show that the Entolomataceae are a sister group to a clade composed of the Lyophylleae, Termitomyceteae, and Tricholomateae p.p. This implies that presence of siderophilous granulation in the basidia of agaric fungi has probably a single origin, and would have been lost in the Tricholomateae. Inclusion of the Termitomyceteae within the Lyophylleae suggests homology of the macro type granulation. Because the exact placement of Tricholomateae pro parte remains uncertain, it remains unclear whether the Lyophylleae (including Termitomyceteae) are monophyletic or paraphyletic. Within the Lyophylleae, genera Lyophyllum and Calocybe are shown to be artificial, as are Lyophyllum sections Lyophyllum, Difformia, and Tephrophana. Four main natural groups of Lyophylleae have been identified that should serve as a basis for developing a more natural classification system for these fungi.

Voronoi diagrams on piecewise flat surfaces and an application to biological growth

This paper introduces the notion of Voronoi diagrams and Delaunay triangulations generated by the vertices of a piecewise flat, triangulated surface. Based on properties of such structures, a generalized flip algorithm to construct the Delaunay triangulation and Voronoi diagram is presented. An application to biological membrane growth modeling is then given. A Voronoi partition of the membrane into cells is maintained during the growth process, which is driven by the creation of new cells and by restitutive forces of the elastic membrane.

Culture analysis and external interaction models of Mycelial growth

To investigate morphogenesis and in particular circularization mechanisms in young mycelia, we observe cultures of the zygomyceteMucor spinosus and develop discrete models of two-dimensional filamental branching growth. The models are based on the hypothesis that the fungus secretes a regulatory substance that diffuses into the surrounding medium and is detected by the growing hyphae. We also present a simple Markovian growth model without such a feedback, but yielding to analytical computations.

The taxonomic position of the genus Heydenia (Pyronemataceae, Pezizales) based on molecular and morphological data

Molecular and morphological data indicate that the genus Heydenia is closely related to the cleistothecial ascomycete Orbicula (Pyronemataceae, Pezizales). Observations on the disposition and the immediate surroundings of immature spores within the spore capsule suggest that the Heydenia fruiting bodies are teleomorphs producing early evanescent asci in stipitate cleistothecia. The once advocated identity of Heydenia with Onygena is refuted on molecular grounds. Onygena arietina E. Fischer is transferred to Heydenia.

Notes on three Japanese Agaricales

Three species of Agaricales from Japan are treated here. 1) From the examination of the types and additional specimens,Lyophyllum nigrescens is conspecific withHydropus nigrita from Cuba. 2)Hydropus kansaiensis sp. nov. from Otsu appears close to“Trogia” mellea from Malaysia. 3)Alnicola lactariolens sp. nov. from Otsu is a distinctive species in this genus because of the purple color of its spore print.

Enzymic studies as an aid to the taxonomy of the Lyophyllum decastes complex

The API ZYM enzyme testing system is not appropriate for recognizing taxa in the Lyophyllum decastes complex. A numerical analysis based on the electrophoretic patterns of the activities of phosphatases, phenoloxidases, esterases and β-glucosidases allows a fairly good but incomplete separation of these five taxa, which are unequivocally distinguished when we combine isozyme data and culture data. As a result, these taxa are given the taxonomic status of morphological species.

1742) Proposal to Conserve the Name Lyophyllum with a Conserved Type (Basidiomycota)

1 National Program on Environmental Health ? Biodiversity, Agriculture and Agri-Food Canada, Central Experimental Farm, K. W. Neatby Bldg., 960 Carting Ave., Ottawa, Ontario, K1A 0C6 Canada, redheads@agr.gc.ca (author for correspondence). 2 Department of Biology, Duke University, Durham, NC 27708-0338, U.S.A. 3 Department of Ecology and Evolution, University of Lausanne, Biology Building, CH-1015 Lausanne, Switzerland. 4 Department of Natural History, Royal Ontario Museum, and Department of Botany, University of Toronto, Toronto, Ontario, M5S 2C6 Canada.

Stellate Chlamydospores and Thromboplerous Hyphae in the Mycelium of the Agaric Lepista flaccida

Development and morphology of mycelial chlamydospores and thromboplerous hyphae of the agaricoid Hymenomycete Lepista flaccida are described from laboratory cultures. The chlamydospore mother cell wall produces finger-like projections that become empty, stellate appendices of the mature spore. The fully developed wall is multi-layered. The cytoplasm contains two nuclei and one or two big oil drops. In thromboplerous hyphae, initial grains of the deuteroplasm condense into a solid, homogeneous mass.

Identification and taxonomic position of two mucoralean endoparasites of Hysterangium ( Basidiomycota ) based on molecular and morphological data

Based on morphological and SSU-ITS-LSU sequence data, two new mucoralean endoparasites, Mucor lilianae and M. rudolphii, are described from basidiomes of Hysterangium spp. originating from North America and Europe, respectively. Although no cultures could be obtained and no sporangial state is known, morphology of the zygospores as well as DNA sequences confirm their placement in the genus Mucor. Both species are indistinguishable by nuSSU-ITS-LSU rDNA sequence data, but the size and morphology of the zygospores of both species are highly distinct, justifying their status as vicariant distinct species. Ontogeny and morphology of zygospores are described and illustrated by detailed light and scanning electron microscope investigations. Zygospore wall consists of two separable layers, a dark brown, warty outer layer and a hyaline inner layer with parallel ridges showing fingerprint-like patterns. Zygospore morphology fits the genus Mucor, apart from the apposed suspensors which are exceptional for the genus. Within the genus Mucor, the two new species are remarkable and unique in their highly specialised ecological niche as endoparasites of superficially intact hypogeous basidiomes of Hysterangium spp., which is much in contrast to other mucoralean necrotrophic parasites of epigeous basidiomes which effect rapid decay of their host.

Rhizomorph anatomy of Ossicaulis lignatilis (Tricholomatales), with special attention to its haustoria-like intrahyphal hyphae

The stout, basidiomal rhizomorphs of the agaricoid Hymenomycete Ossicaulis lignatilis are tightly woven from thin, generative hyphae, broad tubular hyphae, and broad thromboplerous hyphae that contain numerous thin, haustorialike, intrahyphal hyphae in their deuteroplasm. The plectology and cytology of the rhizomorphs and a possible role of the thromboplerous hyphae are described and discussed.