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Molecular and morphological approaches to the recognition of ectomycorrhizal fungi are compared. The core group of Peziza is re-assessed molecularly and morphologically, leading to some revision in species concepts and names, and the species of Amanita in the Iberian Peninsula are compared by restriction analysis. A high-density genetic linkage map for Lentinula edodes has been developed, and length polymorphisms discovered in races of Puccinia striiformis f. sp. tritici. Fatty acid composition is demonstrated as having potential in the intrageneric classification of Pleurotus.

Soil-binding mucilage production is documented in a soil basidiomycete.

Ultrastructural studies concern the development of Pseudocercospora mori on mulberry leaves, and the lichenicolous lichen Rimularia insularis on Lecanora rupicola.

A revision of Ravenelia in Argentina is presented, and two new thermotolerant Thielavia species have been discovered and compared molecularly with others in the genus. A fossil Anzia from the European Tertiary is also described.

The following new scientific names are introduced: Anzia electra, Ravenelia argentinica, Thielavia arxii, and T. intermedia spp. nov.

Two methods are currently being used to describe ECM fungal communities associated with root tips: molecular techniques and morphological classification. Previous studies have found that these two approaches give conflicting results, with several fungal genotypes being identified from different ectomycorrhizas within the same morphotype. This has led researchers to question the usefulness of the morphological approach. The objective of this study was to compare the two approaches on ectomycorrhizas collected from three plant species growing in two different environments. Specifically, mycorrhizas were classified using a detailed morphological approach and then were subjected to PCR-RFLP analysis of the ITS region of the rRNA gene repeat. Ectomycorrhizas of Douglas-fir (Pseudotsuga menziesii) and paper birch (Betula papyrifera) were sampled from three widely dispersed sites with different soil types in the southern interior of British Columbia. Ectomycorrhizas of Douglas-fir and arbutoid mycorrhizas from Arctostaphylos uva-ursi were sampled from a fourth site in a different biogeoclimatic zone. For eight of eleven dominant morphotypes, one main RFLP banding pattern was observed. Ninety-three % of the mycorrhizas analyzed in these eight morphotypes would have been classified in the same way by either method. Five of the eight morphotypes were positively identified as Russula nigricans, Lactarius sp., Leccinum scabrum, Rhizopogon sect. Villosuli, and Thelephora terrestris by matching the RFLPs to those of fungal fruit bodies in our database or by sequencing the ITS region. The other morphotypes producing one dominant RFLP pattern were designated as Cenococcum, E-strain and Mycelium radicis atrovirens (MRA) based on their morphology. Morphotyping did not distinguish amongst major RFLP types for mycorrhizas classified as Amphinema-like, Piloderma-like and Rhizopogon-like A. We conclude that detailed morphological classification can be very useful as the primary method of ectomycorrhizal classification, when used in conjunction with molecular techniques. This approach will allow for an efficient use of research funds.

Species delimitation within the core group of Peziza is highly controversial. The group, typified by P. vesiculosa, is morphologically coherent and in previous analyses of LSU rDNA sequences it formed a highly supported clade. Phylogenetic diversity and species limits were investigated within the group using sequences from the complete ITS region (ITS1-5.8S-ITS2). Eighty-three specimens were selected for molecular study from a larger sample of material studied morphologically to explore the intra- and interspecific variation of each putative species. The sister group taxon, P. ampelina was used as the outgroup and two specimens of P. subcitrina were additionally included. Seven independent lineages of rDNA were identified (I–VII), each representing one to several species. These lineages form two larger clades, A (II, and I or III) and B (IV–VII), supported by macromorphology: small (generally <2 cm), shallowly cup- to disc-shaped apothecia (A) and large (up to 15 cm), deeply cup-shaped to expanded apothecia (B). The overall exciple structure (a stratified or non-stratified medullary layer) and to some degree spore surface relief, likewise support the groupings. Clade A contains taxa with smooth or nearly smooth spores (except for P. lohjaënsis), while clade B contains taxa with a range of spore ornamentations, from smooth, finely warty to distinctly warty, and spiny. The position of groups I (P. vesiculosa and P. ammophila) and III (P. lohjaënsis) are uncertain, and these taxa also deviate morphologically from the other clade A members. The following species are recognized based on morphology and ITS rDNA analyses: P. ammophila and P. vesiculosa (I); P. alcis, P. ampliata, P. domiciliana, P. fimeti, P. nivalis, and a number of putative species or intraspecific entities (II); P. lohjaënsis (III); P. sp. c (IV); P. arvernensis (V); P. echinispora and P. sp. d (VI); and P. varia (VII). The nomenclature of these species is analyzed and taxa are typified as necessary. Based on ITS and morphology, we found no justification for recognizing more than one species in the ‘P. varia complex’, including 27 specimens that have been referred to under the names P. cerea, P. micropus and P. repanda, from an array of substrates and different geographical areas. Morphological characters previously used to delimit species within this complex, such as colour variation of the apothecia, presence or absence of a stipe, stratified or non-stratified medullary exciple (or thickness of the excipular layers), cell types in the outermost exciple and moniliform vs filiform paraphyses were not correlated with the subgroups supported by ITS analyses and appeared to be plastic. Therefore, P. cerea and P. micropus are placed in synonymy with P. varia. The name P. repanda is rejected. Levels of sequence divergence were low within group II, comprising 33 small apothecial specimens. Twelve fine-scale lineages were identified, but the analyses did not resolve relationships among these. P. granulosa sensu Boudier is considered a synonym of P. fimeti. These have previously been distinguished mainly by occurrence on various soil types, including burnt soil and soil mixed with sawdust or woodchips vs on dung. The substrate and habitat have been much emphasized in the taxonomy of Peziza, but the results obtained here indicate that populations on a diverse array of substrates may be closely related, or indeed, conspecific.

The genetic relatedness among 29 collections belonging to 20 of the most common species of genus Amanita in the Iberian Peninsula have been studied by means of restriction analysis of the amplified ITS1-5.8S-ITS2 region of rDNA. Sixty restriction fragments were considered for the analysis. The main conclusion is that this technique could be useful to identify and characterize isolates from Amanita species. Although ARDRA did not show an appropriate level of discrimination to unambiguously infer phylogenetic relationships at or below the section level, some general trends could be outlined when the different haplotypes generated were compared by means of neighbour joining analysis. Thus, members from the same sections were frequently grouped together.

A medium-dense genetic linkage map of Lentinula edodes (shiitake) was constructed based on 203 amplified fragment length polymorphism (AFLP) markers and two mating type factors. The segregation of these markers was generated from 95 progeny of a single cross of two distantly related strains. The map consists of 11 linkage groups comprised of eight large (over 100 centimorgans (cM)) and three small (less than 100 cM) groups, and the total genetic distance of the map was 1956.7 cM. The average rate of physical size to genetic distance could be roughly estimated to be less than 18.4 kb cM−1, which is low compared to the values obtained for other filamentous fungi. Seventeen of the AFLP markers showed highly distorted segregation ratios (χ2 values >6.63; P<0.01), and many of these were mapped in LG II (6 markers) and IV (6 markers).

Sequences of the intergenic spacer between the 28S and the 5S rDNA genes (IGS 1) were compared for three European isolates belonging to three Puccinia striiformis f. sp. tritici races, of different geographic origins and virulence spectra. Two PCR products (IGS 1-1 and IGS 1-2, of 1.3 and 1.1 kb, respectively) were recovered from all spore multiplications. The analysis of IGS 1-1 or IGS 1-2 showed that a low mutational polymorphism existed between the three isolates (from 0.7 to 1.1%) and that each IGS 1 type was characterised by a succession of repetitions. The comparison of IGS 1-1 and IGS 1-2 to each other showed that the polymorphism between the two types of IGS was due to a length polymorphism consisting of a 216 bp insertion/deletion located in the repeated region. Two hypotheses can be proposed to explain the coexistence of two different IGS 1 types within one isolate: either each nucleus of this dikaryotic fungus contains one type of IGS 1 or there are two discrete ribosomal units resulting from recombination in the same nucleus.

The mycelial fatty acid profiles of several Pleurotus strains and their application in intrageneric differentiation were investigated. In the lipids produced by strains of Pleurotus abalonus, P. calyptratus, P. columbinus, P. cornucopiae, P. cystidiosus, P. ostreatus, P. pulmonarius, P. sajor-caju and P. sapidus, the predominant fatty acid was linoleic (33–68% total lipids), while in P. eryngii strains the major fatty acid was oleic (43–46%). In all strains studied, oleic and palmitic acids were present in significant concentrations (>12%), whereas stearic acid was found in lower ones. By using the ratios C18[ratio ]1/C18[ratio ]0, C18[ratio ]2/C18[ratio ]1 and ΣC18/C16[ratio ]0 as variables, Pleurotus strains were clustered into six groups. Group I (P. ostreatus); group II, divided in three sub-groups (IIa: P. columbinus, IIb: P. eryngii, IIc: P. cornucopiae), group III, divided in two sub-groups (IIIa: P. sajor-caju, IIIb: P. pulmonarius), group IV (P. sapidus), group V (P. abalonus) and group VI divided in two sub-groups (VIa: P. cystidiosus and VIb: P. calyptratus). It is concluded that the mycelial fatty acid composition of Pleurotus can be used in the intrageneric taxonomy of the genus.

A saprophytic, lignin-decomposing basidiomycete fungal isolate (BB1), identified as a member of the russuloid lineage closest to the genus Peniophora, plays a role in soil aggregation and stabilization. In liquid media this fungus secretes large amounts of extracellular materials or mucilage that act as soil binding agents. We investigated the nature of these materials using periodate treatment and lectin cytochemistry, and studied whether or not these materials are involved in soil aggregation. Water stability of artificial fungal amended soil aggregates was destroyed by periodate treatment suggesting that polysaccharides produced by the basidiomycete were involved in soil aggregation. Binding patterns of fluorescently labeled lectins were also investigated to determine specific carbohydrate moieties present in the fungal mucilage. Fluorescently conjugated lectins (Ulex europaeus Agglutinin I and Lotus tetragonolobus lectin) bound to extracellular mucilage indicating that this basidiomycete mucilage contains fucosyl sugar residues. We also demonstrated that water stability of artificial soil aggregates prepared with fungal mycelia pretreated with L(−)fucose lectins were significantly reduced. This study indicates that fungal-derived material containing fucosyl residues plays a role in soil adhesion.

Pseudocercospora mori produced three kinds of hyphae – primary infection hyphae, internal hyphae and secondary infection hyphae. The primary infection hyphae were developed from conidia and they penetrated the leaf through stomata directly or by lateral penetration branches – the stomatopodia. Inside the stomatal chambers the stomatopodia swelled to become vesicle-like structures. The internal hyphae produced compact stromata in the sub-stomatal chambers. Each stromata carried 1–5 conidia at a time on short unbranched conidiophores. The secondary infection hyphae were developed from internal hyphae directly or from stromata. The secondary infection hyphae emerged through stomata, branched profusely on the leaf surface and produced conidia singly on short conidiophores. The secondary infection hyphae re-entered the leaf directly or by stomatopodia. Conidia were developed also from stomatopodia and from their substomatal vesicles. The conidia developed from substomatal stromata, and those produced from the secondary infection hyphae on leaf surface were similar in their morphology and size of conidiophores. The conidia were obclavate to cylindrical, 3–17 celled and measured 4–35×1.5–2 μm. Germ tubes were often found to emerge from the conidial cell nearer to stomata. The primary infection hyphae and secondary infection hyphae produced stomatopodia above stomata.

Rimularia insularis forms an photosynthetic thallus on lichens of the Lecanora rupicola group. In the thalli of R. insularis, some hyphae of the host are detectable, and they are situated mainly in the basal part of the Rimularia's medulla. No Lecanora hyphae were present in the Rimularia's algal layer and they were indistinct in the upper parts of its medulla, from where we obtained clean ITS-sequences of Rimularia. Direct PCR from various sections of the algal layer detected only one photobiont genotype, although the algal cells could be assigned to two morphologically different types. Calcium deposits were found in the upper parts of the medulla, while abundant rock substrate fragments with different mineral compositions were present in the lower parts. Cavities and fissures in the rock below the infected thalli were filled by fungal cells, PCR analyses of such parts indicated that the Rimularia hyphae extend below the host, and into the rock.

A comprehensive account of the 18 species of Ravenelia from Argentina is presented. Each species is described and illustrated. A key to the species of Ravenelia from Argentina is provided based on micromorphology. Ravenelia echinata var. ectypa and R. macrocarpa are recorded for the first time from Argentina. The name Ravenelia argentinensis was determined to belong to an anamorph, therefore the teleomorph is described as a new species, R. argentinica sp. nov. Several new anamorph/teleomorph connections were made. Names and synonyms for teleomorphs and anamorphs are listed for all species.

Two new thermotolerant species of Thielavia were isolated from Easter Island and India, after treating soil samples with 65% (v/v) ethyl alcohol: T. intermedia sp. nov. characterized by large, obovate, dark brown ascospores with a terminal germ pore; and T. arxii sp. nov. distinguished by the large, ellipsoidal to fusiform, brown ascospores with a prominent, lateral to medial germ pore. A phylogenetic study of the ITS-5.8S rDNA sequences of 18 species of Thielavia and Melanocarpus thermophilus was performed. This analysis revealed that T. intermedia could be the ancestor of the remaining species and that all the species tested were genetically closely related.

Anzia electra sp. nov. is described and illustrated from Baltic amber dating back approx. 40 Myr. The diagnostic features of the fossilised species include the small, narrow lobed foliose thallus, two-layered medulla, lack of chondroidal axis, moniliform spongiostratum, and rhizines born singly at the margins of spongiostratum cushions. The fossil species demonstrates that all distinguishing features in the thallus morphology of Anzia sect. Anzia have remained stable for tens of millions of years. Hence the divergence of anzioid lichens must have occurred in the distant past, most probably before the Tertiary. The fossil also provides the first hard evidence that the disjunct-Laurasian distributions of some modern lichens represent relicts of a formerly wider range. The close similarity of the fossil to extant species in East Asia and eastern North America suggests that the present range of Anzia sect. Anzia is highly relict.