This issue of Mycological Research News features: An online database of names and descriptions as an alternative to registration; Enzyme dispensability in Saccharomyces cerevisiae; Concern over the state of Spanish mycology; Do fungal biocontrol agents pose a threat?; Convergence of invasive growth in fungi and straminipiles; and Adhesins: cell-surface proteins of adaptive value in medically important fungi.

Eleven research papers appear in this part. The Neighbour-Sensing model of hyphal growth is used to simulate colonial growth, and β-tubulin gene sequences provide an additional perspective on basidiomycete evolution. Molecular studies address variation in Serpula lacrymans in Europe, the Mycosphaerella punctiformis complex, genetic variability in Typhula incarnata; and the placement of ‘Cephalosporium caerulens’ in Sarocladium. A third part of the series on the Hygrophoraceae in the Greater Antilles is presented, and a new species of Laboulbenia with a range of morphologies is described from Brazil.

Interconidial anastomoses between Colletotrichum species from different hosts are reported and enable comparisons to be made. Studies of fungi associated with Betula pendula shoots of diseased trees are reported, as are the effects of water-stress and washing on Metarhizium anisopliae conidia.

The following new scientific names are introduced: Hygrocybe albomarginata, H. ovinoides, H. pseudoadonis, H. viridiphylla, H. zonata, Laboulbenia richardiana, and Ramularia endophylla spp. nov.; H. mycenoides (syn. Hygrophorus mycenoides), H. papillata (syn. Hygrophorus papillatus), and H. subovina (syn. Hygrophorus subovinus) combs. nov.

The Neighbour-Sensing model brings together the basic essentials of hyphal growth kinetics into a vector-based mathematical model in which the growth vector of each virtual hyphal tip is calculated by reference to the surrounding virtual mycelium. The model predicts the growth pattern of many hyphae into three spatial dimensions and has been used to simulate complex fungal fruit body shapes. In this paper we show how the Neighbour-Sensing model can simulate growth in semi-solid substrata like agar or soil, enabling realistic simulation of mycelial colonies of filamentous fungi grown in ‘Petri-dish style’ experimental conditions. Newly implemented capabilities in the model include: a measurement and logging system within the program that maintains basic statistics about the mycelium it is simulating, this facilitates kinetic experimentation; inclusion of ‘substrates’ in the data space causing positive or negative tropisms for the growing mycelium; a horizontal plane tropism that provides a way of simulating colonies growing in or on a substratum like agar or soil by imposing a horizontal constraint on the data space the cyberhyphal tips can explore; three categories of hypha – standard hyphae are those that start the simulation, leading hyphae can emerge from the colony peripheral growth zone to take on a leading role, and secondary hyphae are branches that can arise late, far behind the peripheral growth zone, when mature hyphal segments resume branching to in-fill the older parts of the colony. We show how the model can be used to investigate hyphal growth kinetics in silico in experimental scenarios that would be difficult or impracticable in vivo. We also show that the Neighbour-Sensing model can generate sufficiently realistic cord-like structures to encourage the belief that this model is now sufficiently advanced for parameters to be defined that simulate specific in silico cyberfungi. The potential utility of these cyberspecies is that they provide a means to model the morphogenetic effects of a variety of factors, from environmental and nutritional features to mutations, in experimentally realistic situations, offering a valuable addition to the experimental toolkit of all those interested in fungal growth and morphology.

36 fungal β-tubulin sequences were analysed to study the evolution of this gene and the phylogeny of basidiomycetes. The analysis comprises a representative selection of all major lineages of basidiomycetous fungi and some selected ascomycetes for comparison. Intron positions vary between the different lineages, but seem to be conserved in the Hymenomycetes and Ustilaginomycetes. The most conserved regions seem to be highly susceptible for introns. Splicing and branching sites of the introns are more variable in basidiomycetes than reported from other fungal groups so far.

Basidiomycete monophyly was confirmed with our data in respect to the ascomycetes studied. By analysing amino acid sequences, the Hymenomycetes and the Ustilaginomycetes were resolved as monophyletic groups. The phylogeny within these two groups is similar to that obtained with other genes. Based on β-tubulin data Naohidea sebacea, Chionosphaera apobasidialis, Jaculispora submersa, Platygloea pustulata, Platygloea disciformis and Melampsora lini, representing the Urediniomycetes, are not resolved in most analyses. The early radiation of major basidiomycetous lineages seems to be reflected in the highly conserved β-tubulin gene.

The devastating dry rot fungus, Serpula lacrymans, has a worldwide occurrence in buildings. We investigated the genetic variation in European isolates belonging to five vegetative compatibility groups (VCGs) by AFLP analysis. Our results indicate that S. lacrymans in Europe is genetically extremely homogenous; only five out of 308 scored AFLP fragments (1.6%) were polymorphic. In contrast, S. himantioides, the closest relative of S. lacrymans, possessed 31.3% polymorphic fragments (84 out of 268). AFLP polymorphisms observed in S. lacrymans were distributed independently of the VCG boundaries, indicating that the VCGs do not represent clones but that different genets of S. lacrymans frequently share similar vic alleles due to low genetic variation. Thus, although the European S. lacrymans is genetically extremely homogeneous, and our results suggest that the species reproduces and spreads mainly sexually and not by clones.

Mycosphaerella punctiformis, the type species of the genus Mycosphaerella, is epitypified by material collected on Quercus robur in The Netherlands. The teleomorph is described in planta, and the Ramularia anamorph, for which the new name R. endophylla is proposed, and the Asteromella spermatial state are characterized in vitro. Sequence data of the nuclear ribosomal DNA are presented and analyzed together with other Mycosphaerella spp. with Ramularia and several other anamorphs. Several strains originating from Quercus, Acer and Tilia showed diverging ITS sequences, indicating that the M. punctiformis complex may comprise more than a single phylogenetic species, but this could not be confirmed by the analysis of our dataset. An endophytic phase is established for the first time in the life-cycle of M. punctiformis, as the species was repeatedly isolated from surface sterilized green healthy leaves of Quercus robur in summer at the epitype locality.

Randomly amplified polymorphic DNA (RAPD) markers were used to assess the genetic diversity of isolates of grey snow mould (‘gray snow mold’), Typhula incarnata, taken from infected turfgrasses from 40 different locations in the northern USA. Data from 115 markers using 37 RAPD primers showed 48% polymorphism. The distance coefficients between isolates indicate the wide genetic diversity of T. incarnata across the sample area. Dendrograms generated using neighbour-joining (NJ) bootstrap analyses showed three clades and suggest possible recent colonization from common founder groups. Partitioning of the genetic variance using analysis of molecular variance (AMOVA) of four groups based on geographic locations (Michigan, lower and upper peninsula; Minnesota; Wisconsin) showed that genetic variation attributable among groups and within groups was 12.67 and 87.33%, respectively. No correlation was found between geographic distance and pairwise genetic distance of the groups. High outcrossing and sexual recombination of T. incarnata may well be key factors explaining the genetic variability as shown with the low Fixation index (FST) and high average of genetic diversity per locus within groups.

Fermentation processes for the biochemical reagents cerulenin and helvolic acid employ ‘Cephalosporium caerulens,’ an invalidly published designation that has been used for more than 40 years. However, its identity has never been critically examined because strains were unavailable from major culture collections. An authentic strain of ‘C. caerulens’, derived from the original strain KF-140, was recently found and compared to Sarocladium oryzae, another Acremonium-like fungus which also produces cerulenin and helvolic acid. Morphological comparisons, rDNA sequence data, and chromatography of secondary metabolites established that ‘C. caerulens’ and S. oryzae are conspecific. Sequence data from ribosomal DNA genes indicated S. oryzae belongs to the Hypocreales and is allied with members of the Ceratostomataceae, Scopinella species, Emericellopsis species and certain Acremonium-like anamorphs of uncertain familial relationships. At least two of the isolates of S. oryzae produced titres of cerulenin and helvolic acid similar to those of KF-140. This finding demonstrates that manufacture of cerulenin need not be limited to the original strain.

A key to 17 species in the genus Hygrocybe, subgenus Pseudohygrocybe, sections Coccineae and Neohygrocybe sensu Boertmann is provided for the Greater Antilles. Five new species and five taxa that are new reports for the region are described. The new species in section Coccineae are H. pseudoadonis, H. viridiphylla, and H. zonata. The new species in section Neohygrocybe are H. albomarginata and H. ovinoides. The new reports are H. caespitosa, H. coccinea, H. cf. miniata, H. papillata, and H. subovina. Three new combinations are proposed: Hygrocybe mycenoides, H. papillata and H. subovina.

Morphologically different thalli of Laboulbenia richardiana sp. nov. (Laboulbeniales, Ascomycota) were found on various parts of the body of the South American fly Richardia teevani. These thalli lack a separate cell IV and have similar appendages and perithecial apices. They are interpreted here as ‘growth forms’ of a single biological species. Spore characteristics and insect behavior support this view, rather than the hypothesis of several different species displaying position specificity.

Colletotrichum lindemuthianum is a pathogen of the common bean plant (Phaseolus vulgaris) causing anthracnose. Large numbers of isolates can rapidly arise with different genetic and chromosomal compositions but their origin is unknown since sexual fruit bodies have only been found in the laboratory. We have recently described the occurrence of special kinds of hyphae that create anastomoses directly between conidia. In this work we show that conidial anastomoses can occur between two different Colletotrichum species. The implications of this observation on the generation of genetic diversity in these species are discussed.

The fungi associated with diseased and healthy shoots of young, planted Betula pendula were studied at five sites in Scotland where crown die-back of birch is occurring. At each site, 30 diseased and 30 healthy shoots were sampled twice, with 1 yr-old shoots collected in May 2002, and 4–5-month-old shoots collected in September/October 2002. Overall, 34 different fungal species were recorded, with 92% and 60% of all diseased and healthy shoot pieces, respectively, colonised by at least one fungal species. The main colonisers of both diseased and healthy shoots were Melanconium bicolor, Discula betulina and Godronia urceolus, and the fungi most frequently found on diseased shoots only included Marssonina betulae and Fusarium avenaceum. The pathogenicity of these fungi was tested on seedlings of B. pendula and B. pubescens. Melanconium bicolor required a wound for lesion development on both birch species and caused larger lesions on B. pubescens than on B. pendula. Discula betulina caused lesions on stems and shoots of both birch species, including non-wounded current shoots. Marssonina betulae caused lesions and die-back of wounded and non-wounded current shoots of B. pendula seedlings. This fungus was not pathogenic on B. pubescens. Fusarium avenaceum caused restricted lesions on the main stems of both birch species. Godronia urceolus was not pathogenic on either birch species. Further work needs to focus on the role of these fungi in causing crown die-back of young, planted B. pendula in Scotland.

The entomopathogenic fungus Metarhizium anisopliae was physiologically manipulated by culturing in liquid culture under a range of water-stress conditions (0.98, 0.97 and 0.96 water activity, aw) imposed by either PEG 200, KCl or NaCl at 25 °C to optimise blastospore production and quality in terms of accumulation of endogenous compatible solutes and germinability. Optimum spore yield occurred at 0.98aw, when PEG 200 was the solute. Blastospores produced under different water-stress levels were subjected to hypo-osmotic and iso-osmotic washing treatments before quantification of endogenous sugar alcohols (polyols) and germinability studies. Endogenous amounts of the low molecular weight polyol erythritol were greatly affected by culture age, water-stress and hypotonic or isotonic washing treatment. Endogenous erythritol in blastospores produced under 0.98 and 0.97aw increased with culture age. Osmoprotection (washing with isotonic PEG 200 solution) of blastospores produced under all water-stress conditions resulted in retention of higher amounts of erythritol. Increased endogenous retention of the high molecular weight polyol mannitol was also observed with an isotonic washing treatment but only in blastospores produced under intermediate water-stress (0.98 and 0.97aw). Germination of all treatments was >90% on a medium with freely available water. Under water-stress conditions (0.96aw) only 10% of unmodified blastospores washed with water germinated. However, those grown under modified water availability conditions (0.98aw) and washed with isotonic solutions had significantly improved germination (38–90%). Blastospores produced at [les ]0.97aw washed with isotonic solutions had decreased germination. These results could have significant implications for conserving ecophysiological quality of fungal biocontrol propagules during harvesting and have an impact on storage and formulation.