Ascospore germlings of Monosporascus cannonballus attached to melon roots were examined with the scanning electron microscope. Results showed that ascospores germinated with one to three germ tubes. Sixty percent of the ascospores germinated with two germ tubes. No germ pores were observed. Instead, germ tubes emerged from a single linear fissure on each ascospore. The largest fissure measured 25 μm in length and 6 μm at its greatest width. Germ tubes of ascospore germlings were firmly anchored to melon roots. However, no structures resembling appressoria were observed. Rather, the tips of germ tubes, upon contact with the epidermis, appeared to have penetrated the epidermis directly. When the germ tube at the point of attachment was dislodged, no infection peg was present at the germ tube tip.

A key to 13 species in the genus Hygrocybe subgenus Pseudohygrocybe section Firmae is provided for the Greater Antilles. Seven new species and one species that is a new report for the Greater Antilles are described. The new species are H. brunneosquamosa, H. cinereofirma, H. flavocampanulata, H. laboyi, H. miniatofirma, H. neofirma and H. olivaceofirma. The new report is H. trinitensis.

Endophytic fungi were isolated from 7500 samples of wild Musa acuminata collected from five sites at Doi Suthep Pui National Park, Thailand during December 1998 to July 1999. Overall colonization rates from surface sterilized tissues were 56·5, 48·9, 48, 47·9 and 41·7% for the Medicinal Plant Garden, Ban Suthep, Queen Sirikit Botanic Garden, San Gu, and Montatarn waterfall sites respectively. Sixty-one different fungal taxa were isolated. Fewer isolates were recovered from younger than older samples. Xylariaceous taxa and Guignardia cocoicola were the most frequently isolated endophytes from leaves and were either absent or rare in midrib, petiole and pseudostem. Colletotrichum gloeosporioides, C. musae, Guignardia cocoicola, various sterile mycelia and xylariaceous spp. were common at all sites. The endophyte fungal communities at the five sites were found to differ. Deightoniella torulosa was the most frequent isolate at the Ban Suthep site and was either absent or rare at other sites. Colletotrichum species were most common in the midribs and petioles at all sites, while Pyriculariopsis parasitica and Dactylaria sp. were most common in the pseudostems. The endophyte communities isolated from M. acuminata in this study are compared with those from previous studies on tropical hosts. Several of the endophytes isolated are established pathogens of banana and provide support for the hypothesis that some endophytes are latent pathogens. The diversity of fungi on banana is discussed in relation to global estimates of numbers of fungus species.

Seven dominant mangrove species of an estuarine mangrove forest in south India were studied for the presence of foliar endophytes. Mitosporic fungi, ascomycetes and sterile mycelia were isolated from the leaves of the mangrove hosts studied. Although many endophytes were common to more than one host, the endophyte assemblage of each mangrove species was dominated by different endophyte species.

The influence of Cd(II), Cu(II) and Zn(II) on growth and thiol production in an aquatic hyphomycete (Articulospora tetracladia) and a zygomycete (Mucor racemosus) were studied. Growth of a strain of M. racemosus, isolated from effluents contaminated by heavy metals, was not inhibited by Cd concentrations of up to 100 μM. M. racemosus was more sensitive to Cu and Zn. The production of SH-containing compounds by M. racemosus was positively correlated with Cd concentration in the nutrient medium. By contrast, glutathione concentration in the mycelium was negatively correlated with Cd concentration. Addition of Zn or Cu to the medium had no significant effect on mycelial levels of thiol compounds or glutathione. One strain of A. tetracladia, isolated from a clean stream (At-BB), significantly increased the production of thiol compounds and of glutathione in the presence of Cd; the other strain from a Cu enriched stream (At-CS) showed no significant response. Addition of Zn or Cu did not significantly change levels of thiols or glutathione, with one exception: glutathione levels in At-CS were negatively correlated with external Cu levels. Declining glutathione levels in M. racemosus exposed to Cd was coupled with the appearance of several phytochelatins. No such compounds were found in A. tetracladia.

The ability of commercially-available citric, oxalic and gluconic acids to bind Co2+ and Zn2+ was investigated and compared with culture filtrates from Aspergillus niger, a fungus capable of citric, gluconic and oxalic acid production, grown in the presence and absence of cobalt or zinc phosphate. This work demonstrated that citric and oxalic acid and the A. niger culture filtrates can bind Co2+ and Zn2+ and in some cases, the culture filtrates were more efficient than commercial organic acids. Gluconic acid did not bind Co2+ or Zn2+ under the conditions used in this study. The presence of insoluble metal phosphates in the growth medium was found to markedly influence the production of organic acids and, while large concentrations of gluconic acid were produced in the presence of Co3(PO4)2, the culture filtrate was unable to bind Zn2+. The production of oxalic acid by A. niger when grown in the presence of Zn3(PO4)2 led to the precipitation of insoluble zinc oxalate, a phenomenon with implications for metal tolerance and toxicity. The significance of these findings in relation to the environmental mobility of metals and phosphate, and the role of fungi in such transformations are discussed.

Polygalacturonases (PGs) are important pectolytic enzymes produced by phytopathogenic fungi during the process of infection and colonisation of the host plants. In this work, PGs produced by isolates of seven Fusarium species associated to Pinus pinea have been analysed for: activity, isoform pattern observed by isoelectric focusing, endo- or exo-mode of action and their production in cultures growing on pectin and galacturonic acid. Of the seven isolates, those of F. oxysporum and F. moniliforme exhibited high PG activity and the most complex isoform patterns including acidic ones. These isolates were also more efficient in degrading the PG substrate, during which both endo and exo type polygalacturonase activities were detected. It is suggested that these features could be useful to the fungus during infection and colonisation of its host, specially during seed germination and early development.

A xylanase gene, XYL2, was identified and characterised in Cochliobolus sativus (anamorph Bipolaris sorokiniana), a necrotrophic cereal pathogen that attacks both shoots and roots. The fungus was grown on a xylanase inducing medium containing mineral salts, oat spelt xylan, cellulose, and peptone, RNA was isolated, and a complementary DNA (cDNA) library constructed. The library was screened with a xylanase (XYL1) cDNA clone from the maize pathogen Cochliobolus carbonum. Xylanase cDNA clones, all representing a single gene, were identified. Corresponding genomic DNA was amplified by PCR. Sequencing of the cDNA and the PCR products gave a nucleotide sequence of 2211 bp containing two introns in an open reading frame of 693 bp that codes for a xylanase from glycosyl hydrolase family 11. The most similar sequences to this gene in nucleotide sequence databases are the XYL2 gene of C. carbonum and a xylanase (XYL1) cDNA from a saprophytic fungus, Humicola insolens. Northern blot analysis and reverse transcription PCR (RT-PCR) showed expression of the gene when the fungus was grown on xylan or cellulose, but not when peptone or sucrose was the only carbon source. Expression of XYL2 in inoculated barley seedlings was detected by RT-PCR.

Leptographium species are common inhabitants of fresh conifer logs and lumber that are known for their ability to cause blue-stain and, in some cases, their association with disease. L. procerum has been associated with a root disease although controversy surrounds its role in tree death. During the course of the past two decades, a relatively large number of isolates tentatively identified as L. procerum have been collected in various parts of the world. Some of these display morphological characters unlike those of L. procerum s. str. and this has prompted us to re-examine them. Four groups of morphologically distinct isolates were identified, of which L. procerum s. str. represented one. The remaining isolates of Leptographium are newly described as L. alethinum, L. pityophilum and L. euphyes spp. nov.

Brunneosporella aquatica gen. et sp. nov., Aqualignicola hyalina gen. et sp. nov., Jobellisia viridifusca sp. nov. and Porosphaerellopsis bipolaris sp. nov. are described and illustrated from wood submerged in freshwater collected in Hong Kong. Both Brunneosporella and Aqualignicola have characteristic features of the Annulatascaceae and their placement within this family is discussed. Jobellisia viridifusca sp. nov. differs from all described species in having an ascomatal wall with a bright orange middle wall layer and fusiform, greenish-brown ascospores. Porosphaerellopsis bipolaris sp. nov. is unique in producing multiseptate ascospores with bipolar mucilagilous pads.

Cultures of Penzigia cranioides and Poronia pileiformis obtained from material collected in Taiwan produced anamorphs in Xylocoremium and Lindquistia, respectively. The former is reminiscent of those produced by undoubted Xylaria species. Penzigia cranioides, the type species of the genus, is therefore accepted as X. cranioides. Penzigia thus becomes a taxonomic synonym of Xylaria. The position of P. pileiformis in Poronia is considered justified primarily on its anamorph; an epitype is designated.

Uptake of 14C-labelled glutamine by seven Australian Pisolithus isolates (representing two species) was investigated over the concentration range 0.5 mmol m−3–20 mol m−3. Total uptake did not conform to simple Michaelis-Menten kinetics over this concentration range. At concentrations above 0.5 mol m−3 much of the glutamine uptake appeared to be diffusion-like. At concentrations below 0.5 mol m−3, subtraction of uptake in the presence of 2,4-dinitrophenol from total uptake revealed an active component that followed Michaelis-Menten kinetics. Estimated Km and Vmax values for active glutamine uptake by all isolates were in the ranges 4.0−210 mmol m−3 and 80−637 nmol g−1 d wt. min−1 respectively. pH optima for glutamine uptake were in the ranges 4.5–6.0, 3.7–5.0 or 3.0–4.5, depending on the isolate. While intraspecific variation was observed, there were no apparent relationships between the two Pisolithus species and either kinetic parameters for glutamine uptake or the pH optimum for the process.

The abilities of 12 ericoid mycorrhizal endophytes isolated from Woollsia pungens (Epacridaceae) and three Hymenoscyphus spp. isolates to grow on a range of amino acids as sole nitrogen sources were investigated in axenic liquid culture. The majority of endophytes grew to some extent on all amino acids tested, with most isolates from W. pungens showing a significant preference for histidine and/or alanine. Poorest growth of the endophytes from W. pungens was observed on lysine. In contrast, the Hymenoscyphus spp. isolates showed either no preference or a preference for lysine over histidine. Although some isolates produced some growth on the sulphur-containing amino acid cysteine, biomass production on this substrate by all isolates was significantly enhanced in the absence of inorganic sulphur.

Immunoblotting combined with computer imaging and a simple, non-linear mathematical model were used to demonstrate the potential of a technique for non-destructive visualisation and analysis of fungal growth of Rhizoctonia solani over the surface of non-sterile sand. Immunoblotting detected actively growing regions of mycelium enabling visualisation of individual hyphae at the colony edge. A zone of active growth was detected expanding radially over time. Active growth did not continue in the centre of the fungal colony leading to the development of a ring of mycelium surrounding the inoculum. Change in the density of actively growing mycelium with distance from the inoculum unit was summarised for each colony at each time by a Gaussian function, describing a wave of actively growing mycelium, symmetrical in density about its centre but differing amongst replicate colonies. The effectiveness of the immunoblotting technique to detect differences in colony growth was tested by comparing the growth of replicate colonies for two contrasting isolates of R. solani. When both isolates of R. solani were grown at 23 °C the amplitude of the wave increased to a maximum and then decayed over time, the location of the centre of the wave moved outwards at a constant rate, whilst the width of the wave increased. Increasing the temperature to 28 °, accelerated this intrinsic growth process for one isolate, but retarded growth of the other.

The new genus Lichenopyrenis is described for L. galligena, a cecidiogenous species parasitic on the lichen Leptochidium albociliatum. This genus is characterized by perithecioid ascomata with a cellular wall, formed by relatively large, somewhat compressed cells, fissitunicate, I- asci, wide hamathecium filaments, and 1-septate, pale orange brown ascospores with distoseptate thickenings which at maturity are seemingly bulging out of the exospore wall at the septum and apices. The conidia have a rhexolytic type of secession, and are attached to the conidiogenous cells by a separating cell. Lichenopyrenis is referred tentatively to the family Pleomassariaceae.

A fossilised fungal colony is described and illustrated from Dominican amber dating back 15–45 Myr. Many hyphae in the coenocytic mycelium had produced terminal or intercalary protuberances resembling the sporangia of some extant zygomycetes and oomycetes. Other hyphae had produced cylindrical arthroconidia similar to those of Geotrichum and related extant yeasts. Many fossilised diaspores had germinated prior to preservation. The fungus seems to have been a rapidly growing saprophyte, utilising fluid substrates, possibly plant exudate. The palaeoenvironment proposed for the mycelium, namely that of a moist epiphytic or epixylic microhabitat, supports earlier conclusions that the original Dominican amber forest possessed a tropical moist forest biome.

Pycnodallia dupla gen. sp. nov. and Hymenopsis chlorothrix sp. nov. are described from saltmarsh Juncus roemerianus in North Carolina. Conidiomata of P. dupla develop on senescent inflorescences and involucral leaves, between 40 and 60 cm above the rhizome, therefore, the species can be considered as facultative marine. Conidiomata of H. chlorothrix are found on dead culms, 16–43 cm above the rhizome. This species is classified as obligately marine. Dwayaangam junci, the anamorph of Orbilia junci, has been found for the first time in nature. Conidia develop on the medulla of leaves, in lesions caused by grasshoppers.

To investigate the spatial and temporal diversity in the fungal community of the Dead Sea, we collected Dead Sea water samples at eight near-shore localities and at different stations offshore over a 1-year period (1999–2000). In addition, depth profiles were sampled at a deep station (304 m) in the centre of the sea. In the course of the study we obtained 476 isolates, comprising 38 species from 19 genera of Oomycota (1), Zygomycota (2), Ascomycota (13), and mitosporic fungi (3). This brings the total number of species recovered from the Dead Sea to 55. Approximately 43% of the isolates belonged to the genera Aspergillus and Eurotium. Most of the species found appeared only in winter. Fungal diversity increased near the outlets of less saline springs near the shore. The species Aspergillus terreus, A. sydowii, A. versicolor, Eurotium herbariorum, Penicillium westlingii, Cladosporium cladosporoides and C. sphaerospermum were isolated consistently and probably form a stable core of the community. The results suggest that a remarkably diverse fungal diversity may be found in the hypersaline Dead Sea waters. To what extent the fungal diversity recovered was present as dormant spores or as vegetative mycelia remains to be determined.

Inocybe barrasae and I. ortegae spp. nov. from Spain are illustrated and described. Type collections of I. cryptocystis, I. cicatricata, I. dolichospora, I. mystica and I. rennyi were compared with the two, and different interpretations of I. confusa in the literature are discussed.

Yelsemia arthropodii, causing smut galls of Arthropodium in Australia, is described as a new genus and species of Tilletiales. It has been found twice in the field as a capsule smut, in dry inland areas of Western Australia and New South Wales. Seed inoculated with ustilospores produced infected plants with systemic mycelium and galls in capsules, pedicels, peduncles and leaf axils. Dark brown, unicellular ustilospores have two prominent opposite hyaline polar caps through which they geminate to produce holobasidia bearing 2–5 apical septate fusiform sporidia. Sporidial cells germinate by hyphae which often anastomose with one another or with cells of other sporidia. Yelsemia is compared with Ustilago speculariae, a capsule smut of Triodanis in the USA with similar ustilospores, whose germination is unknown.