Glabrocyphella stercoraria, a new cyphellaceous fungus, is described on the basis of morphological and ecological features. It is characterized by grey-brown colours, lack of special hairs on the surface of the fruitbody, spore size, absence of clamps and coprophilous habitat. The holotypes of Glabrocyphella upplandensis, G. brunneocrystallina and G. palmarum have been examined and compared with the new species. Observations about the status and the possible taxonomic relationships of Glabrocyphella with some other members of the reduced series of Tricholomataceae, Arrhenia (including Leptoglossum) and Rimbachia (including Mniopetalum), are discussed.

This listing covers the period January 1, 1997 through to February 28, 1997. Citations are arranged in groups which roughly correspond with the British Mycological Society's Special Interest Committees.

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Filosporella pinguis sp. nov., Pachycladina parva sp. nov. and Pleuropedium macrum sp. nov. from stream foam collected in the catchment of the Miramichi River, New Brunswick, are described and illustrated. Filosporella pinguis has a microconidial state. Keys to species in the above genera are provided.

A new species of Cryptosporiopsis is described. It was isolated frequently from roots of healthy-looking and declining oaks (Quercus robur and Q. petraea). The relationship to C. radicicola, a similar species also occurring on oak roots, is discussed. The new species is separated from C. radicicola by means of morphological and physiological characters, genomic analysis by the PCR-based RAPD technique as well as by the production of metabolites.

Growth and ochratoxin A accumulation by two isolates of Penicillium verrucosum, IBT5010 and IBT12803, were examined in co-cultures with the antagonistic yeast Pichia anomala or baker's yeast Saccharomyces cerevisiae. Each yeast was co-cultured with Penicillium verrucosum in malt extract agar supplemented with 1% yeast extract and incubated at 25°C for 14 d. Ochratoxin A was found to be stable at 25°, whether or not yeast was present. Pichia anomala and Saccharomyces cerevisiae reduced mould growth to about the same extent in vitro. Both yeasts significantly reduced the growth of Penicillium verrucosum isolates at 3×103 yeast c.f.u./plate. In all co-cultures in vitro accumulated ochratoxin A was reduced to below the detection limit (100 ng/plate) by yeast amounts as low as 3×103 c.f.u./plate. In wheat, the growth of Penicillium verrucosum IBT5010, measured as c.f.u., was not reduced in the presence of Pichia anomala, whereas the growth of Penicillium verrucosum IBT12803 was clearly inhibited by this yeast. A similar pattern was observed for ochratoxin A accumulation in wheat when the two mould strains were co-cultured with Pichia anomala. Mycotoxin production was more sensitive to the presence of yeasts than was mould growth. Co-cultivation with yeasts gave no detectable stimulation of ochratoxin A accumulation in agar or wheat.

Colletotrichum gloeosporioides f. sp. malvae (C. g. malvae) is effective in controlling round-leaved mallow (Malva pusilla), a common weed in the Canadian prairies. To confirm host range experiments, the latent period and penetration of C. g. malvae was determined under controlled environmental conditions on field crops (wheat, flax, lentil, mustard, rape seed, sugar beet, sunflower, safflower) and on crops in the Malvaceae (okra and cotton) as well as on round-leaved mallow, from which C. g. malvae was originally isolated. In non-target crop plants, very little germination, appressoria formation, or penetration of C. g. malvae were observed compared with the infection occurring on round-leaved mallow. Of the non-target species tested, most penetration was observed on safflower, with only 5·1% penetration form the total appressoria formed compared with 17% on round-leaved mallow. C. g. malvae was re-isolated from all crop cvs tested, but only from inoculated stems and leaves. The recovery of C. g. malvae significantly decreased with time of isolation of plant material for most cvs. Of the millions of conidia applied to non-target crops, only a few were present after 72 h, few appressoria were produced, and only minimal penetration occurred. The behaviour of C. g. malvae conidia on the surface of leaf material of non-target plants supports the visual disease ratings observed in the experiments of crop tolerance under controlled and field condition and host-range tests.

The action of high concentrations of benomyl was investigated in the wild-type strain St Lawrence of Neurospora crassa and in mutants displaying various levels of tolerance to the drug. Germ-tube formation by macroconidia, germination pattern (single versus multiple germ-tube emergence) and hyphal tip extension of these strains showed different sensitivities to the microtubule inhibitor, benomyl. The wild-type strain, whose vegetative growth was inhibited at micromolar concentrations, still germinated by multipolar outgrowth at 100 μm. At such a level, germination of the moderately resistant mutant Bml 511(r) was inhibited more than the wild type. Highly resistant mutants capable of hyphal growth at 500 μm were obtained by mutating strain Bml 511(r) using uv. One of these, strain E1-91, showed temporary sensitivity to the microtubule inhibitor and produced multiple germ-tubes. This strain was deficient in the β-tubulin polypeptide during the first hour of germination.

Gelasinospora bonaerensis sp. nov., isolated from a soil sample collected in Argentina, is described and illustrated and the sequences corresponding to the ITS1/ITS2 regions and the 5·8 S ribosomal RNA are provided. Its taxonomic relationships with other species of the genus are discussed.

Myriogenospora atramentosa produces partial to complete sterility of host grasses. Geographical and host species distributions were assessed and updated. It is reported only from the New World and appears to be limited to the highly evolved grass tribes Andropogoneae and Paniceae. Included in these tribes are the previously unreported host species Panicum scoparium, Paspalum urvillei, Erianthus brevibarbis, E. contortus, E. giganteus, and hybrids from crosses with Erianthus spp. Additionally, M. atramentosa is reported for the first time growing on Paspalum notatum (bahiagrass), and Panicum hemitomon in South Carolina, U.S.A. Sequence data (ITS regions 1 and 2 and 5·8S rDNA) from several isolates indicated that there is a significant level of DNA sequence differentiation between isolates of M. atramentosa, which suggests that there are at least two distinct sequence groups, or cryptic species, within the currently defined morphological species.

Two types of genetic markers, vegetative compatibility and RAPD, were evaluated for their ability to assess genetic variation among 38 isolates of the entomopathogenic fungus, Paecilomyces fumosoroseus. Both markers revealed significant polymorphisms. Nitrate non-utilizing mutants were generated from chlorate-containing media and used as forcing markers to observe heterokaryon formation and determine vegetative compatibility. Nineteen separate vegetative compatibility groups (VCGs) were identified, only seven having at least two members and 12 represented by single isolates. No correlation was observed between VCG and either insect host or geographic origin. Nine RAPD primers produced 365 unique fragments and could distinguish three different phenetic groups. RAPD profiles conclusively showed that strains within some VCGs were genetically unrelated, indicating that these strains were not clonal in origin. The large number of VCGs suggests that formation of heterokaryons and possible genetic exchange are uncommon. DNA fingerprinting with RAPD-PCR provides high resolution of genotype distribution and could be useful in tracking the fate of biocontrol agents released into the environment.

Investigation of Phaeocollybia in British Columbia, Washington, Oregon and California has led to a better understanding of the characters and biology of the genus as a whole. Generically significant characters – pseudorhizas, pellicular veil, tibiiform diverticula, and sarcodimitic tissues – are examined in depth with four variations of branched and unbranched pseudorhizal patterns outlined. Basidiome development is traced from subterranean initiation to fully mature emergent basidiomes. Hypotheses on the ontogeny of Phaeocollybia basidiomes and biological associations are developed based on extensive observations of primordia and numerous field excavations. Comparisons between rhizomorphs and the thread-like pseudorhizal extensions of certain species are made and the term ‘rhizomorphic pseudorhiza’ is introduced. Possible biological strategies are explored and evidence for consideration of Phaeocollybia as a mycorrhizal genus is presented.

Observations are presented showing that mature thalli of the rumen anaerobic fungal isolate Neocallimastix frontalis strain RE1 attach to cellulose. This process and subsequent development of the thalli have been studied. Thalli matured without attachment and then attached directly by means of rhizoids to the surface of the substrate. This process was quantified by the measurement of attachment of 14C-radiolabelled fungal cells pregrown on [UL-14C]-d-glucose to filter paper. Washed cell suspensions were separated into zoospores and thalli by filtration and the time-course of attachment of each fraction to filter paper strips was determined. Both thalli and zoospores made a significant contribution to the colonization process. It is suggested that the previously unrecognized ability of mature thalli to attach to cellulose could be of importance in the degradation of plant material in the rumen.

After attachment to filter paper the formation of dark brown pigmented sporangia was observed after incubation for periods in excess of 4 d. These had some similarities to resistant sporangia which have been described in aerobic and anaerobic chytrids, but they differed in some important respects. The pigmented cytoplasm retracted, leaving a clear margin within an unthickened cell wall. Histochemical tests showed that the pigment was not melanin and strain RE1 was able to grow and form the pigment in the presence of each of three inhibitors, tricyclazole, PP389 and glyphosate, which block melanin biosynthesis pathways in fungi.

Candida sake was cultured on nutrient yeast dextrose broth, which was diluted and/or modified by the addition of either glycerol, glucose to 0·96 or trehalose to 0·97 water activity (aw) to modify endogenous sugar alcohol and sugar content. Sugar alcohols (glycerol, erythritol, arabitol and mannitol) and sugars (trehalose and glucose) were extracted from the yeast cells and quantified using HPLC. Total polyol and sugar content varied significantly between treatments. The total intracellular concentrations in NYDB medium were significantly increased in NYDB+glucose media. The major intracellular polyols/sugars in cells grown on unmodified NYDB were arabitol, trehalose and glucose with small amounts of glycerol and erythritol. This was changed by reducing aw of the growth medium, particularly with glucose or glycerol. The major polyols in C. sake cells grown on glucose-modified media were arabitol and the low mol wt polyol glycerol, with smaller amounts of glucose. In glycerol-amended full strength normal and diluted media, glycerol was the major intracellular polyol with lower amounts of the other polyols and sugars. The viability of the yeast cells with modified polyols/sugars was significantly improved at lowered aw level (0·935 and 0·95) when compared to unmodified yeast cells. Improvements in water stress tolerance was better in yeast cells grown for 48 than 24 h, especially in those from NYDB modified with either glucose, glycerol or trehalose. Such modifications of endogenous reserves were also shown to preserve or improve the biocontrol potential of the yeast against Penicillium expansum rot of apples. Thus physiological manipulation of intracellular polyol and sugar content may provide a means for developing biocontrol agents with improved ecological fitness in field environments.

Endophytic fungi were isolated from nine plant species growing on gypsum and saline soils in central Spain. The plants sampled were Arundo donax, Atriplex halimus, Diplotaxis erucoides, Ephedra nebrodensis, Phragmites australis, Rosmarinus officinalis, Scirpus holoschoenus, S. maritimus and Stipa tenacissima. A total of 152 fungal species were recovered from 2880 samples of leaves, stems or twigs, taken from 45 individual plants. Ephedra and Rosmarinus showed the highest diversity of endophytes, whereas both species of Scirpus showed the lowest. The most frequently isolated fungi were Alternaria alternata, Sporormiella intermedia, Rhizoctonia sp., Epicoccum purpurascens, Pleospora herbarum, Cladosporium herbarum, Sporormiella australis and a sterile fungus. A total of 187 strains belonging to 136 species were tested for the production of antimicrobial activities, using a panel of bacteria and yeasts, some of them of clinical relevance. Production of antimicrobial compounds was detected in 45 strains, belonging to 37 species. Large differences were observed among isolates from the same species, with respect to their ability to produce metabolites with antimicrobial activity.

The green fluorescent protein (GFP) has been widely used as an extremely useful vital marker in a large number of organisms, but good expression in filamentous ascomycetes has not been reported. To facilitate the research of fungal development and fungal-plant interaction, we constructed two plasmid vectors for the expression of the synthetic SGFP-TYG gene in ascomycete species, and used these vectors for transformation of the maize pathogen Cochliobolus heterostrophus. High level expression of GFP was obtained, as detected by anti-GFP antibodies and by fluorescence microscopy. The intense fluorescence was used as a highly efficient vital marker to detect cytoplasmic and developmental changes that occur in the fungus, and to follow phytopathogenic development of the fungus on and inside maize leaves. The hyphae within the leaf form a unique parallel growth pattern, closely associated with, and apparently determined by, the anatomy of the leaf. Fluorescence intensity was quantified by digital analysis of the green fluorescence image and was highly correlated with the amount of mycelium and levels of disease. Expression of GFP was obtained in additional ascomycetes that were transformed with the new constructs, indicating that SGFP-TYG can be used as a highly effective vital marker in ascomycetes.

In experiments where groundnut plants with sporulating late leaf spot lesions were exposed to increasing ‘gusty’ and ‘steady’ wind speeds, conidia were more effectively removed by gusty winds than by steady winds of the same mean wind speed. Rain drops dislodged conidia more efficiently than wind, with large drops dispersing conidia more effectively than small ones. No conidia were caught in still air. After most of the conidia had been removed by exposure to high wind speeds, rain was found to remove additional conidia. When plants were exposed to continuous wind or rain, most of the conidia were dispersed during the first few minutes, and the concentration of conidia then declined exponentially with time. From field observations on rain-free days, airborne concentrations of conidia tended to increase as the wind speed increased during the day and with a further increase in wind speed, concentrations decreased. On rainy days, the onset of the first shower coincided with a phenomenal increase in the airborne concentrations of conidia.

A transformation system is described for the edible mushrooms Pleurotus ostreatus and Volvariella volvacea. The system developed is based on a positive selection strategy using the trp3iar gene from Coprinus cinereus, which confers resistance to the antimetabolite 5-fluoroindole. Transformation frequencies were low in both species. Southern blot analysis confirmed the integration of transforming DNA into the genome of transformants and indicated the presence of tandemly duplicated copies of the plasmid in some of these transformants. The system has potential for introducing beneficial traits such as enhanced substrate bioconversion and faster sporophore development.

A total of 479 samples of nests or feeding sites of 38 species of Australian termite were plated onto a medium selective for isolation of Metarhizium spp. Sixty-seven samples were positive for Metarhizium spp. and a total of 97 isolates of M. anisopliae were obtained. Very few isolates were obtained directly from infected termites. Most isolates were obtained from nest-mound material from eastern Australia. Termite-associated material from the two common mound-building species of termite, Nasutitermes exitiosus and Coptotermes lacteus, provided 75 of the isolates. Similar material from 26 species of termites revealed no Metarhizium. A detailed study of two sites found that some of the Metarhizium isolates found in nest-mound material, including also some M. flavoviride and M. album, were of morphological types also present in adjacent soil. The DNA of isolates from mounds and the adjacent soil were compared using RAPDs and sequence analysis of the ITS region of the nuclear rDNA and the same types were found from both sources. The possible role of the fungus in termite ecology is discussed and it is thought most likely that Metarhizium is only opportunistically a pathogen of termites. Thus, isolates obtained from termite nest material are probably there because of the incorporation of soil into termite nests.

The diversity and frequency of leaf endophytic fungi occurring in naturally regenerating and planted stands of manuka were investigated at several sites. A restricted and characteristic range of species was isolated from all sites, although marked differences were noted between natural and planted stands. In natural stands a Phyllosticta species was the single dominant endophyte. This fungus appears to be host species specific, as it was not isolated from the closely related kanuka (Kunzea ericoides) in mixed, even-aged stands of manuka and kanuka. The frequency of the Phyllosticta sp. fluctuated greatly between individual trees across single stands. No obvious environmental or other gradients were recognized which could explain this patchy distribution. The Phyllosticta sp., along with the two next most common species in natural stands, Diploceras leptospermi and an unidentified coelomycete, were absent from most of the planted stands sampled, and at very low frequencies when present. Although several of the planted stands were close to natural stands and had been established for several years, the difference between them has been maintained. The most common endophytes in planted stands were Botryosphaeria and Alternaria spp. These species, found at low levels in natural stands, are likely to be ‘opportunistic’ endophytes. They are probably also characteristic of the epiphytic mycota, invading only the living leaves of plants under stress. The difference in leaf endophyte communities between planted and natural stands of manuka may be an indication of wider differences in the microbial communities of the respective stands, and could prove significant for site restoration projects. Such projects using nursery-raised manuka plants as a pioneer species may be establishing stands lacking much of the natural diversity of manuka communities for extended periods following establishment.

A morphological and molecular analysis was performed on 25 individuals of Phaeoacremonium isolated from diseased European and Californian grapevines (Esca disease). An unexpectedly high intra-generic molecular divergence was evidenced by partial rDNA sequencing between P. chlamydosporum isolates on one hand and an aggregate including P. angustius and P. aleophilum isolates and some undescribed ones on the other. These two groups show 26% nucleotide differences within the 26S rDNA fragment sequenced and were unalignable within the ITS2, suggesting distant phylogenetic relationships. Moreover, P. chlamydosporum appeared more closely related to Phialophora verrucosa (supposed to be an anamorph of the Herpotrichiellacae), than to the type species of the genus, P. parasiticum (more related to Magnaporthaceae).