A new description and illustration of Polydesmus elegans, the type species of Polydesmus, is given. It was formerly considered as congeneric with Sporidesmium. Two new genera, Imimyces to accommodate I. aquaticus, I. bambusae, I. carrii, I. densus, I. heterocateniformis and I. hollowayensis, and Linkosia to accommodate the single species L. coccothrinacis, are proposed. A key to species of Imimyces is provided, and a new species and six new combinations are proposed.

Vesicular–arbuscular (VA) mycorrhizas are described from anatomically preserved roots of the Middle Eocene taxodiaceous conifer Metasequoia milleri, and compared to those of the living species M. glyptostroboides. Virtually identical VA mycorrhizal structures occur in the root cortex of both species, where they conform to the Paris-type. Coiled hyphae are most common within cells of the inner cortical region, and these produce numerous, highly branched arbuscules. Close similarity of fungal position and structure within roots of the living and fossil Metasequoia species demonstrates that modern Paris-type VA mycorrhizal associations characterized taxodiaceous conifers by the early Tertiary.

DNA was extracted from dried specimens of nine taxa of the Cantharellaceae. Approximately 325 bases near the 5′ end of the nuclear 28S ribosomal gene were sequenced, and the sequences were compared. Sequence analyses demonstrated that Cantharellus and Craterellus should be treated as distinct genera. The phylogeny generated using parsimony suggests that Cantharellus tubaeformis and Pseudocraterellus sinuosus should be considered species of Craterellus. As a result of this study, we recognize the first placement of these two species in Craterellus by Fries and Quélet. A reassessment of the morphological characters used to separate Cantharellus and Craterellus is indicated.

The potential as biocontrol agents of the apple scab pathogen, Venturia inaequalis and the effect of environmental factors on growth, pycnidial production and spore germination of four isolates of Microsphaeropsis were examined on culture media and leaf discs. V. inaequalis ascospore production was reduced by 52, 77, 89 and 95% on leaf discs treated with the isolates IMI 294735, P176A, DAOM 198536 and P130A, respectively. For all isolates, optimum temperature for mycelial growth was 25 °C. More pycnidia were produced on culture media than on leaf discs. On culture media, optimum temperature was from 15 to 25 °, while on leaf discs it varied among isolates. Pycnidial production was inhibited by darkness and a minimum of 8 h light d−1 was required. Spores of isolates P130A and DAOM 198536 germinated at temperatures above 15 ° and at pH 4–5, as compared to 10 ° and pH 4–8 for isolates P176A and IMI 294735. The best candidates were P130A and DAOM 198536 and optimum conditions for growth, pycnidial production and spore germination were temperatures between 20 and 25 °, pH approx. 4 and light.

Genetic variation within 34 Pythium irregulare isolates was analyzed using restriction fragment length polymorphisms (RFLPs) as genetic markers. Most isolates had two alleles at several codominant RFLP loci and were scored as heterozygous. Heterozygotes were detected in F1 progeny from an in vitro cross and segregation ratios of the F2 progeny were not significantly different from those expected for allelic variation in a diploid. This confirmed that outcrossing occurs and contributes to genetic variation within the species. Phenetic analysis showed that isolates formed genetically related groups due to their host species and not due to similarities in their geographical origins. All isolates originating from medic formed a discrete group and were highly differentiated from the cereal and sub-clover isolates. The allelic distributions between isolates from these host-groups were significantly different. Most isolates also showed significant differences in their pathogenicity between hosts, indicating that they varied in pathogenic fitness and were better adapted to parasitising some hosts relative to others. These isolates were however, not necessarily more pathogenic on their host of origin. This research provided estimates of the extent of genetic and pathogenic diversity within P. irregulare and qualitative evidence for the occurrence of host-mediated selection and sexual outcrossing in the field.

The morphology of the extracellular mucilaginous material (ECM) produced by Coniophora puteana and Coriolus versicolor during colonization of Scots pine and beech was studied using SEM. Wood specimens were examined in the frozen hydrated (FH) condition using low-temperature SEM, and in the freeze-dried (FD) and critical point dried (CPD) state, using conventional SEM. All techniques produced artifacts but the ECM was best preserved when examined in the FH state. Very little difference was observed between FH and FD preparations, but critical point drying damaged the ECM extensively. Copious amounts of ECM were produced by both fungi. It was found to line much of the lumen surface, establishing contact between the mycelium and the wood substratum. Most aerial hyphae were coated with ECM, appearing glued together in a bundle-like fashion. The ECM thickness varied within the same wood cell and from one cell to another. A peculiar granular pattern, in which the ECM was definitely involved, was seen on occasion to encircle the infecting hyphae where they contacted the wood surface. Other morphological patterns of ECM distribution were also observed. Calcium oxalate crystals of varying shapes and sizes were often seen associated with the mycelia and mucilage of the two fungi in beech but not in Scots pine. The probable roles played by the ECM in wood decay mechanisms are discussed.

The phylogeny of the Agyriales was investigated using nucleotide sequences of ITS1, 5.8S, and ITS2 rDNA. Sequences of these regions from 15 new sequences of 13 agyrialean fungi were aligned to those of four representatives of Ostropales used as outgroup. Six different alignments were analysed cladistically using maximum parsimony. The Agyriales were supported as a monophyletic group in the strict consensus tree and the synonymy of the Rimulariaceae and Saccomorphaceae was confirmed. The Schaereriaceae is also shown to belong to the Agyriaceae. The distribution of selected characters in the Agyriales is investigated and it is shown that the ascus type is variable within the group, while the ascoma ontogeny is invariant within the Agyriaceae. Trapelia as usually circumscribed is polyphyletic. The T. geochroa group is not closely related to Trapelia s. str. and the new genus Ainoa is described to accommodate T. geochroa and T. mooreana.

The ergocalciferol (vitamin D2) content of individual fruit bodies of the edible mushroom Cantharellus cibarius (chanterelle) was measured with HPLC 2–6 years after drying. The concentrations of ergocalciferol in different fruit bodies varied between 0·12 and 6·30 μg g DW−1, with a mean of 1·43 μg g DW−1. This result indicates that dried and stored chanterelles contain significant amounts of ergocalciferol. The huge range in concentration challenges the validity of food tables based on means from pooled samples. The range may reflect differences in exposure to sun light, as fruit bodies within the same cluster showed little variation. Our study indicates that mycelial cultivation for ergocalciferol production is an interesting prospect if strains and incubation conditions are selected carefully. No significant difference in ergocalciferol concentration between pigmented and albino forms was found.

The effect of increasing culture age on cell surface hydrophobicity (CSH) and cell surface electrostatic charge (measured as zeta potential) of conidia from five isolates of Coniothyrium minitans representing three different morphological types was examined. Conidial CSH of three isolates (A2 960/1, CH1 and CH2) decreased with culture age, whereas CSH of two others (B 1300/2 and IMI 134523) remained high for the whole 42 day experimental period. In contrast, cell surface electrostatic charge decreased uniformly in conidia of all five isolates for the first 34 d and then rose slightly at 42 d. The variation in cell surface electrostatic charge (spectrum width) of the sampled conidia decreased with age for all five isolates. In all five isolates cell surface electrostatic charge of conidia became increasingly negative as the pH of the buffer used to suspend conidia was increased from pH 3·0 to 9·0. No relationship between colony morphology of C. minitans and conidial CSH and cell surface electrostatic charge was found.

A novel source of α-amylase has been identified in Pycnoporus sanguineus. Spores incubated in the submerged system using wheat bran as a carbon source showed α-amylase activity. Induction of α-amylase was also observed from mycelium incubated in submerged fermentation (LM4) using starch or wheat bran as the carbon source. The effect of the inhibitors on the production of enzyme by mycelium incubated in the presence of glucose, suggested the existence of catabolic repression. A comparative study showed that in a solid state fermentation system (SSM), even in the presence of high levels of glucose, the production of α-amylase was 4-fold greater than that in a submerged system. High levels of β-glucosidase and xylanase activities were also found in SSM after 72 h incubation. P. sanguineus produces at least three important hydrolytic enzymes using economical procedures.

Oxalate decarboxylase activity was present in liquid culture medium and mycelium of Agaricus bisporus. Enzyme activity in the mycelium peaked at two-weekly intervals after primary growth phase and into secondary metabolism, with activity peaks in the medium occurring 7 d later than in the mycelium. The enzyme was partially purified and had two isozymes with pIs 3.0 and 3.4. Characterization of the protein by SDS–PAGE and Western blotting against a polyclonal antibody raised to oxalate decarboxylase from Collybia velutipes showed a major protein band of 64 kDa. Oxalate decarboxylase was also detected in the fruit body up to the cup stage of development. The pH optimum for the enzyme was 3.6 and temperature optimum was 35 °C.

The root systems of Carex flacca and C. pilulifera, growing in the Burren (western Ireland), were shown to be colonized by Cortinarius (Dermocybe) cinnamomeus. This basidiomycete formed ectomycorrhiza-like structures, which possessed a distinct fungal mantle (85–100 μm thick), hyphal infection in epidermal cells, rhizomorphs and extramatrical hyphae, but lacked a Hartig net. These ectomycorrhiza-like structures were formed on first-order lateral roots but were distinct, morphologically and anatomically, from dauciform roots. Structures typical of arbuscular mycorrhizas were never observed. The colonization of root systems of C. flacca by C. cinnamomeus was confirmed by PCR/RFLPs and DNA sequencing of the ITS region of rDNA.

An extracellular protease designated BBP (Beauveria bassiana protease) was purified from a B. bassiana isolate and subsequently characterized. It was produced in the late stages of growth in a gelatin medium, and was purified using a combination of ion-exchange chromatography and preparative gel electrophoresis. Inhibition by phenylmethylsulphonyl fluoride and chymostatin indicates that BBP is a serine type with chymotrypsin activity. Substrate specificity indicates that the protease has elastase activity as well. The protease was stable at 25 °C and had an alkaline pH optimum (7.5–9.5). Another protease was purified from the same isolate that produced BBP, and was identified as Pr1 based on its isoelectric point, amino terminal sequence, substrate specificity and cuticle degrading ability. A comparison between the two showed that BBP had a lower isoelectric point (pI 7.5) than Pr1 (pI [ges ] 10) and was 0.5 kDa smaller. The proteases also exhibited differences in substrate specificity with Pr1 being most active against Suc-Ala-Ala-Pro-Phe-pNA, and BBP being most active against MeOSuc-Ala-Ala-Pro-Met-pNA. The two proteases had equal cuticle-degrading activity and both were expressed in cuticle media, although the timing of their expression differed.

All 39 marine species described so far from Spartina spp. are listed. Anthostomella torosa sp. nov. is described from culms of Juncus roemerianus in North Carolina, and A. spissitecta sp. nov. is described from leaf sheaths of saltmarsh Spartina alterniflora in the USA (Connecticut, Florida, North Carolina, Rhode Island) and from S. densiflora in Argentina (Buenos Aires). Both species occur close to the rhizome and are classified as obligate marine fungi. The new species are compared with similar taxa, and a table comprises characteristics of the nine known aquatic Anthostomella species.

The adhesion of conidia of Drechmeria coniospora to the nematode Panagrellus redivivus was reduced after treatment of the conidia with Pronase E, or the detergents sodium dodecyl sulphate (SDS) and dodecyltrimethylammonium bromide (DTAB) suggesting involvement of proteinaceous compounds in the adhesion process. In the TEM the thick extracellular pad covering the adhesive bud of the conidia was completely removed after treatment with Pronase E. After treatment with SDS or DTAB the proteinaceous compounds appeared to be dissolved leaving mainly carbohydrates in the pad as observed on OsO4 without and OsO4 with Ruthenium red-stained material, respectively. The detergent extracts after SDS and DTAB treatments contained nine and seven peptides, respectively, with molecular masses in the range from 6 to 80 kDa on SDS-PAGE gels, and five biotinylated peptides were found in each extract, after blotting to nitrocellulose membranes, indicating that these were surface proteins. None of the detergent extracts was able to reduce adhesion of the conidia after treatment of the nematodes. The detergent extracts contained protease- and phosphatase activity. The protease inhibitor, chymostatin, inhibited infection of nematodes and growth of the conidia, suggesting the involvement of chymotrypsin-like proteases in the infection process. On gelatin-containing substrate gel electrophoresis two proteases were clearly chymostatin sensitive.

The majority of microbes living on forest trees are still unnamed and our knowledge of their species richness is vague. This paper describes the fungal diversity of the above ground parts of a 61 year old Norway spruce tree lacking visible signs of damage or disease. The problem involved with identification of the fungi to named species was circumvented by classifying them into operational chemotaxonomic units (OCTUs) by using their combined fatty acid and sterol profiles (FAST-profiles). The variation of these units was chosen to correspond to a within-species-variation determined for several morphologically defined taxonomic species occurring on Norway spruce. Ninety-nine OCTUs were identified from 666 fungal isolates obtained. Bacteria were found only occasionally from the inner bark samples (three isolates) and from needles (five isolates). Models describing the accumulation of OCTUs against the number of samples taken were used for extrapolation of the total number of fungal OCTUs in the above ground parts of the tree. Our results suggest that an undamaged, apparently healthy Norway spruce, harbours in its above ground parts nearly two hundred fungal species. The majority were estimated to be needle epiphytes. At the large forest area scale, the species richness may be one order of magnitude higher.

Eighty-four isolates of Penicillium chrysogenum and related species were examined by isozyme analysis. Four main groups could be defined by cluster analysis; P. chrysogenum var. chrysogenum, P. flavigenum sp. nov., P. chrysogenum var. dipodomyis and P. nalgiovense. P. flavigenum is described as new species, and P. chrysogenum var. dipodomyis raised to species level as P. dipodomyis. The genetic distance between these groups was calculated by employing a formula that accounts for the differences in alleles and loci obtained by isozyme analysis of these fungi. The genetic distances and cluster analysis suggest that the groups should be considered as four separate species. The practical implication of the separation and the ecological characteristics of the four species are discussed.

Basidiomes of Amanita muscaria were collected from sites in three 30–36-yr-old Pinus radiata plantations in New South Wales, Australia. Following DNA extraction from basidiome stipes, inter-simple sequence repeat PCR using the degenerate primers 5′DHB(CGA)5 and 5′DDB(CCA)5, was used to identify the mycelial genotypes from which basidiomes arose. Each site was found to contain 8–10 A. muscaria genotypes, with six genotypes common to all three sites and one common to two sites. The presence of common genotypes at the three sites is taken to indicate that they were introduced as vegetative inocula when seedlings were planted and have persisted for < 36 yr.

A field study was carried out in a remote broadleaved Fagus longipetiolata forest in Shaanxi province, China to study the natural local distribution of Lentinula edodes. Following spatial mapping, 24 fruit bodies were collected for tissue isolation into axenic culture. 24 genets distributed on fallen tree trunks within a distance of 120 m were identified and clustered into 7 groups using the unweighted pair-group method algorithm using data based on colony morphologies, abilities to degrade aromatic poly-R478 dye, somatic incompatibility reaction patterns and DNA fingerprints. Among the parameters used, the somatic incompatibility reaction, a polygenic phenotype, was the most differentiating, identifying 22 incompatible classes. Two sets of fruit bodies of different genets were so close together that they would otherwise have been described as aggregate fruits of presumed identical origin. Eighteen genets found on the same 5.6 m long tree trunk divided roughly into two clusters, matching their spatial distribution, and a nearby branch bore another distinct cluster. More heterogeneity was encountered between isolates the greater the distance separating them on the original site. Genets on the same tree trunk showed more compatible somatic reactions among themselves, and their DNA fingerprints showed higher similarity. Nevertheless, considering the totality of phenotypic characters, each fruit body is a genet in L. edodes. Such features are concluded to result from a reproductive strategy which depends on basidiospore dispersal. Within each cluster of isolates from the collection site genets seemed to have arisen from multiple sib-mating events. Thus, a cluster may represent a lineage of L. edodes. Individualism in L. edodes is based on a strong somatic incompatibility system. Strong competition from contaminating individuals arriving as air-borne basidiospores could explain decreased and fluctuating crop yields which are now frequently observed in later flushes from the outdoor wood log cultivation system. Further, it would also explain why multispore spawn is not favoured in artificial cultivation of this economically important edible mushroom.

The effect of Trichoderma atroviride, T. harzianum, T. longibrachiatum, Clonostachys rosea and Bacillus subtilis isolates applied to wheat seeds against Rhizoctonia cerealis disease of seedlings was investigated under controlled greenhouse conditions. Most Trichoderma isolates significantly reduced the incidence of disease compared with the infected control. Bacillus subtilis was also effective against sharp eyespot, although less active than Trichoderma spp. Interactions between the antagonistic microorganisms and the cereal pathogenic fungus in dual culture experiments on agar growth medium were also studied. Almost all tested antagonists showed competitive activity against R. cerealis: inhibition of its mycelial growth and hyphal interaction. The production of extracellular β-N-acetylhexosaminidase, chitin 1,4-β-chitobiosidase, glucan 1,3-β-glucosidase and protease activity by the tested microorganisms in the presence of cell walls of R. cerealis was then determined. All isolates showed glucosaminidase and chitobiosidase activity. They also produced glucosidase activity, except B. subtilis, whereas only C. rosea, B. subtilis and one isolate of T. harzianum showed detectable levels of protease activity.