Meinhard Moser

Multiple origins of sequestrate fungi related to Cortinarius (Cortinariaceae).

The aim of the present study was to investigate the phylogeny and evolution of sequestrate fungi (with gastroid or partially exposed basidiomes) in relation to their gilled relatives from the Cortinariaceae (Basidiomycetes). Phylogenetic analyses of 151 ITS sequences from 77 gilled species and 37 sequestrate taxa were performed using maximum parsimony and maximum likelihood methods. Results show that sequestrate basidiome forms occur in all three major ectomycorrhizal lineages of Cortinariaceae: the clades Cortinarius, Hebeloma/Hymenogaster/Naucoria, and Descolea. However, these forms do not appear within the saprobic outgroup Gymnopilus, indicating multiple origins of sequestrate forms from ectomycorrhizal ancestors. Additionally, within the Cortinarius clade sequestrate forms have multiple origins: emergent Cortinarius spp., Thaxterogaster, Quadrispora, Protoglossum, and two Hymenogaster spp. (H. remyi, H. sublilacinus) share common ancestors with Cortinarius spp., but these sequestrate genera are not closely related to each other (with exception of Thaxterogaster and Quadrispora). Hymenogaster sensu stricto, Setchelliogaster, and Descomyces were placed in the two other major clades. Thus, sequestrate taxa evolved independently many times within brown-spored Agaricales. Furthermore, emergent, secotioid, and gastroid forms have evolved independently from each other, and so are not necessarily intermediate forms. After their establishment, these apparently morphologically stable taxa show a tendency to radiate.

First records of ectomycorrhizal Cortinarius species (Agaricales, Basidiomycetes) from tropical India and their phylogenetic position based on rDNA ITS sequences

Three new Cortinarius species, Cortinarius conopileus, C. keralensis, and C. phlegmophorus spp. nov., are described from Kerala State in southern India. This is the first record of ectomycorrhizal Cortinarius spp. in the tropical part of India. In addition to distinct morphological characters, the comparative analysis of rDNA ITS sequences of the collections from India and morphologically similar species support the recognition of these taxa as new species. Phylogenetic analyses demonstrate that the three Indian Cortinarius spp. belong to both larger subclades of the genus Cortinarius, clade/cortinarius and clade/telamonia. As supported by morphological and molecular data, C. phlegmophorus belongs to Cortinarius subgen. Myxacium sect. Defibulati. Based on classical morphological characters, both C. keralensis and C. conopileus are representatives of subgen. Telamonia. However, C. conopileus belongs to clade/obtusi, which is a well-supported subclade of clade/cortinarius. Thus, in contrast to classical taxonomy, the clade/obtusi represents an independent evolutionary origin of telamonioid taxa. This result is also reflected by the distinct morphological characters of taxa of clade/obtusi, namely the lamellar trama with ellipsoid inflated hyphae and the presence of cystidia. In contrast, C. keralensis is a typical member of clade/telamonia. Within/telamonia, only relationships of closely related taxa are resolved due to the low genetic divergence found in ITS sequences. Based on morphological and molecular criteria, C. keralensis is a distinct taxon of sect. Saturnini.

Toxic properties of the mushroom Cortinarius orellanus (Fries)

The toxins of the mushrooms Cortinarius orellanus (Fries) and Cortinarius speciosissimus (Kühn & Romagn) were isolated by extraction procedures and Sephadex chromatography. All intermediate and end products of the purification process were tested in mice for acute toxicity after oral and i.p. administration. In both species a fluorescent main toxin and a nonfluorescent compound of minor toxicity were found. The main toxin of both species was identified by mass spectrometric and nuclear magnetic resonance analyses as the 2,2′-bipyridine- 3,3′,4,4′-tetrol-1,1′-dioxide, which is identical to orellanine. The purified compound was toxic when administered either orally or i.p. When given orally the LD50 was 33 mg/kg body weight in mice. The oral LD50 of Cortinarius orellanus (2.20 g dried mushroom/kg) and of Cortinarius speciosissimus (3.12 g/kg) depended on the orellanine content (14 mg/g in Cortinarius orellanus and 9 mg/g in Cortinarius speciosissimus). The second toxic component was ineffective in mice when given orally. It caused acute toxicity when administered i.p., but toxicity was low when compared to the main toxin. Thus it appears to be of minor importance. Intraperitoneal testing of both isolated toxins and of the extract containing the whole toxic potential of the mushrooms revealed that toxicity, time dependency and expression of toxicosis is accounted for by the sum of these two toxins. No peptidic main toxin as described by other mycologists could be detected.

Phylogeny of Rozites, Cuphocybe and Rapacea inferred from ITS and LSU rDNA sequences

Phylogenetic relationships of Rozites, Cuphocybe, and Rapacea were assessed using molecular phylogenetic approaches. These three genera are placed in Cortinariaceae and have been regarded as closely related to Cortinarius. Rozites includes more than 20 species, which are characterized by having both a membranaceous partial veil in the form of a persistent annulus and a membranaceous universal veil. Cuphocye (4 species) lacks an annulus or cortina, but has pigmented veil fibrils or scales. The monotypic genus Rapacea accommodates a distinct taxon with pale, nearly smooth and thick-walled basidiospores. We analyzed 56 sequences of the internal transcribed spacer region (ITS1, ITS2, and the intervening 5.8S rRNA gene) for nine species of Rozites, three species of Cuphocybe, 28 species of Cortinarius, Rapacea mariae and Protoglossum luteum. Two species of Hebeloma were used as outgroup. Large subunit (LSU) rDNA sequences from selected taxa were also analyzed. The results clearly demonstrate that Rozites species are nested within the clade/Cortinarius, and that Rozites is polyphyletic, suggesting that membranaceous veils have evolved several times in the genus Cortinarius. Also Rapacea and Cuphocybe are nested within Cortinarius, making the latter genus paraphyletic. Based on phylogenetic studies, Rozites, Cuphocybe and Rapacea are artificial genera and do not reflect natural relationships.

Orellanine and other fluorescent compounds in the genus Cortinarius, section Orellani

Basidiocarps of Cortinarius orellanus, C. speciosissimus, C. orelianoides, C. rainierensis, and C.fluorescens were examined for orellanine and other fluorescent compounds, using thin layer chromatography. A chromatographic comparison with an authentic reference sample of orellanine demonstrated that C. speciosissimus, C. orelianoides, and C. rainierensis contain this compound, but C. fluorescens does not. All species studied have a more or less specific pattern of fluorescent compounds.

Anamika, a new mycorrhizal genus of Cortinariaceae from India and its phylogenetic position based on ITS and LSU sequences

Anamika gen. nov. is described from southern India with one species, A. indica sp. nov. The genus is characterized by spores with a strongly cavernous ornamentation due to cavernae in the epitunica (perispore), and the possession of cheilo-, pleuro-, and caulocystidia. It seems to be associated with Hopea species (Dipterocarpaceae). Molecular data suggest a close relationship to Hebeloma and Naucoria, but indicate that it represents an independent line of evolution.