Comparative studies of Drepanopeziza species pathogenic to poplars established that for each species, holotype and herbarium specimens of D. populorum, D. tremulae and D. punctiformis were morphologically similar. Light and electron microscope studies of apothecia revealed that in radial longitudinal section, in apothecial shape and the hypothecial and epithecial tissues of the three species were similar. In general, ectal and medullary excipular tissues of D. populorum were more strongly developed than those of D. tremulae and D. punctiformis. Asci and ascospores of D. populorum were larger than the other two species but because of overlap were of limited use for species delimitation. In consideration of the established synonymy of the anamorphs of D. tremulae and D. punctiformis namely, Marssonina tremulae and M. brunnea, respectively, and close morphological similarity of their teleomorphs, synonymy of D. tremulae and D. punctiformis is suggested, with D. tremulae having priority. Although not studied, D. populi-albae is believed to be a distinct species. Accordingly, three Drepanopeziza holomorphs are recognised on poplars: D. populi-albae, anamorph=M. castagenei; D. populorum anamorph=M. populi; and D. tremulae, anamorph=M. brunnea.

The production of chloromethane (CH3Cl) by wood rotting fungi of the Hymenochaetaceae is discussed with particular emphasis on emissions by species of Phellinus and Inonotus. Recent work on the metabolic role of CH3Cl as a methyl donor in the biosynthesis of secondary metabolites both in the Hymenochaetaceae and other families of white-rot fungi is reviewed. The parameters affecting the fungal emissions of CH3Cl in forest ecosystems are considered and where possible quantified. The annual global input to the atmosphere from this source is provisionally estimated at 160000 t of which 75% is released from tropical and subtropical forests and 86% is attributable to Phellinus. The possible impact of the contribution from fungi and other biological sources on the atmospheric CH3Cl burden and stratospheric ozone depletion is assessed.

The introduction of recombinant DNA technology in the field of mushroom research has resulted in the cloning and characterization of a large number of genes. In order to study the genetics of compost colonization of A. bisporus, genes encoding enzymes involved in utilization of this substrate have been isolated. In addition, a number of genes which are induced in fruit bodies during fruit body development have been cloned and they will provide more insight in the genetics of this economically important aspect of the life cycle. Other genes that were cloned encode proteins of basic biochemical routes. They provide knowledge on the importance and regulation of these routes in the life cycle of A. bisporus and add to knowledge on the general architecture of A. bisporus genes. Here we present an overview of the currently available biochemical and molecular data of A. bisporus and we discuss the importance of the available genes as genetic markers for breeding purposes.

The 29 spore-ball-forming smut fungus genera (of the total 58 recognized genera) are analysed, grouped, briefly characterized and illustrated. Problems within the genera, similarities, possible relationships and differences between genera are discussed. The following groups and genera are treated: genera with spores in pairs (Schizonella, Mycosyrinx, Geminago), genera with permanent spore balls composed of colourless spores and sterile cells and/or modified mycelia (Burrillia, Doassansia, Doassansiopsis, Heterodoassansia, Nannfeldtiomyces, Narasimhania, Pseudodoassansia, Tracya), genera with permanent spore balls composed of pigmented spores and sterile cells (Urocystis, Moesziomyces, Dermatosorus, Testicularia), and genera with spore balls containing only spores and lacking sterile cells between the spore balls. Within the latter group, the two sub-groups were distinguished: one with light, brownish spores (Sorosporium, Thecaphora, Glomosporium, Fulvisporium), and another one with dark, blackish spores (Tolyposporium, Tolyposporella, Clintamra, Orphanomyces). Heterotolyposporium has small, hyaline spores between the pigmented spore balls. Sporisorium and Macalpinomyces have sterile cells between the true or pseudo spore balls. Odd genera are: Ustacystis, Mundkurella and Uleiella. A key to the spore-ball-forming genera of smut fungi is given. The value of the spore balls in the taxonomy of the Ustilaginales is discussed. The arrangement of the genera in groups is based on the most important characters of the spore balls. It has a practical, didactic purpose and in many cases the groups do not reflect natural relationships.

Among the numerous items of equipment with the ‘Iceman’, who died more than 5000 years ago on an alpine glacier, were three fungal objects: two different shaped fruitbody pieces of the polypore Piptoporus betulinus, each mounted separately on a leather thong, and, found in his girdle bag, a relatively large quantity of tinder material prepared from the ‘true tinder bracket’ Fomes fomentarius. A full description of these items and a chronological report on their identification is given. The question about the possible use of the fungi is discussed on the basis of a comprehensive collection of ethnomycological and pharmacological literature data.

The nature and mechanisms of successions of fungi in soil and plant litter are discussed, and an autecological study of a basidiomycete used to illustrate some methods of approach.

Perhaps like many other mycologists, my initial encounters with fungi filled me with a desire to engage with mysteries: mysteries embedded in the diversity of form and function in fungi and how this diversity might be related to the life of the forest in which so many of these organisms appear to find their homes. In all good mysteries, the resolution of underlying causes at one level of comprehension only serves to reveal deeper levels for exploration.This can open the way into a cascade that nourishes a growing empathy with fellow beings and so assuages that most fundamental need to have a sense of belonging – to be as one; to be at peace; secure in the knowledge of idiosyncrasies embraced in the fondness of others. I dreamt that fungi would somehow eventually lead me and my fellow travellers down that cascade. I still do.

Morphogenesis is not simply a matter of playing out a predefined genetic programme. Expression of developmentally important genes is epigenetic and place- and time-dependent relying on previously-formed tissue structures. Most differentiated hyphal cells require reinforcement of their differentiation ‘instructions’. This reinforcement is part of the context (chemical, electrical and structural/mechanical environment) within which they normally develop. Key words at each stage of development in fungi are: competence, induction and change. Fungal morphogenesis is compartmentalized into a collection of ‘sub-routines’ which are distinct genetically and physiologically. Flexibility in expression of developmental sub-routines illustrates that tolerance of imprecision is an important attribute of fungal morphogenesis.

This review summarizes existing information about mushroom lectins, with an emphasis on those from the following species which have been most extensively characterized including various Agaricus species, Amanita pantherina, Boletus satanas, Coprinus cinereus, Ganoderma lucidum, Flammulina velutipes, Grifola frondosa, Hericium erinaceum, Ischnoderma resinosum, Lactarius deterrimus, Laetiporus sulphureus, Tricholoma mongolicum and Volvariella volvacea. It is noted that the mushroom lectins exhibit a diversity of chemical characteristics. Some of them are monomeric, whereas others are dimeric, trimeric or tetrameric. Their molecular weights range from 12 to 190 kDa, and the sugar contents from 0 to 18%. Carbohydrate specificities involve mainly galactose, lactose and N-acetylgalactosamine. A small number of mushroom lectins are specific for fucose, raffinose, N-glycolyneuraminic acid and N-acetyl-d-lactosamine. Studies on immunomodulatory and antitumour/cytotoxic activities have been carried out on lectins from Agaricus bisporus, Boletus satanas, Flammulina velutipes, Ganoderma lucidum, Grifola frondosa, Tricholoma mongolicum and Volvariella volvacea.

Acid phosphatase production by 12 Hebeloma strains was usually derepressed when inorganic phosphorus in the growth medium was limited, but appeared to be constitutive in some strains. At low temperatures ([les ]12°) arctic strains produced more extracellular and wall-bound acid phosphatase, yet grew more slowly than the temperate strains. We suggest that low growth rates in arctic strains may be a physiological response to cold whereby resources are diverted into carbohydrate accumulation for cryoprotection. At near freezing temperatures, increased extracellular phosphatase production may compensate for a loss of enzyme activity at low temperature and serve to hydrolyse organic phosphorus in frozen soil over winter.

Coniophora eremophila and Antrodia sinuosa cause brown heartrot in living lemon trees in southern Arizona and California. They can be distinguished in the field by differences in rot characteristics. Both have a high optimum growth temperature of approximately 35°C. Coniophora eremophila has a cultural morphology typical of other Coniophora species and did not fruit in culture. Antrodia sinuosa cultures were morphologically similar to previous reports and fruited readily under laboratory conditions. Mating tests with homokaryotic single spore isolates showed it to have a heterothallic bipolar mating system. The decay capacity of C. eremophila on lemon wood test blocks under laboratory conditions was low compared to that of A. sinuosa, five other brown rot fungi, and three white rot fungi.

Genetic characterization of 15 aggressive weed mould strains that were identified morphologically as Trichoderma harzianum (sensu Rifai) from mushroom compost in commercial units in North America (designated T. harzianum group 4) was undertaken using various molecular techniques. RFLP analysis of rDNA revealed homogeneity among these strains; a low level of polymorphism was detected in mitochondrial DNA. RAPD analysis also indicated a very high degree of homogeneity among the T. harzianum group 4 strains. Nucleotide sequence determination of the rDNA internal transcribed spacer (ITS) 1 revealed five base pair differences between T. harzianum groups 4 and 2. Comparison of molecular data on T. harzianum group 4 with that of T. harzianum group 2, which caused green mould epidemics in the mushroom industries of the British Isles, indicated that T. harzianum group 4 is not the same as group 2.

The occurrence and relative abundance of Pythium species were quantified by using a cucumber seed baiting assay and P10VP agar medium, and compared among three long-term cropping systems: continuous maize (CC), continuous soybean (SS) and maize soybean rotation (CS) at two Iowa locations. Soil types were different at the two locations. Four Pythium species were isolated, P. ultimum, P. torulosum and P. paroecandrum occurred in soils of all three cropping systems, and P. spinosum occurred in one SS and one CS field. More Pythium isolates were recovered from CS and SS composite soil samples than from CC samples. P. torulosum was isolated most frequently.

The morphology of infection structure development of Puccinia recondita f. sp. tritici on and in susceptible and resistant wheat lines inoculated with urediospores was examined by SEM. The germ-tube extends over the leaf surface and elongates perpendicularly to the long axis of the leaf. When the germ-tube encounters the stomatal lip, an appressorium forms over the stoma and the pore is entered by an infection peg produced on the surface of the appressorium in contact with the host leaf. At 6 h post-inoculation (hpi), infection pegs develop terminally substomatal vesicles (SSVs) in the substomatal chambers of all wheat lines. A septum separates each SSV from its interconnective tube. A primary infection hypha forms terminally from the elongated SSV either parallel to the long axis of the stomatal slit or perpendicular to the leaf surface. When a primary infection hypha attaches to a host cell, a septum forms cutting off the tip of the hypha, delimiting a terminal haustorium mother cell (HMC) by 12 hpi. Secondary infection hyphae arise from a position proximal to, and in the proximity of, the HMC septum. Additional HMCs are formed when a secondary hypha or a tertiary hypha adheres to a plant cell. Infection sites with HMCs were observed at 24 hpi and at subsequent sampling stages. There were no significant differences between the infection processes on the three wheat lines examined in this study.

The suitability of random amplified polymorphic DNA for identification of Pythium aphanidermatum was investigated. Three oligoprimers were selected after testing three isolates of P. aphanidermatum and one isolate of P. ultimum with a total of 40 primers. The selected 10-mer primers were used with 20 isolates of P. aphanidermatum, four isolates of P. deliense, two isolates of P. ultimum, two isolates of P. irregulare and one isolate of P. paroecandrum. Most of the P. aphanidermatum isolates (13 of 20), were obtained from samples of Cucumis sativus, or water from cucumber greenhouses. The three selected primers gave identical fingerprints for 18 of the 20 P. aphanidermatum isolates, including all the isolates from cucumbers. Two of the primers gave fingerprints that could be used to differentiate between isolates of the Pythium species studied. The banding pattern of P. aphanidermatum given by the third primer could not easily be distinguished from the fingerprint of P. deliense. However, when used in conjunction with the other two primers, the third primer can be used to verify the identity of P. aphanidermatum.

Arthrowallemia anam. gen. nov., characterized by holothallic conidiogenesis, secession randomly schizolytic, and cylindrical, septate, brown conidia emerging from conspicuous unbranched conidiophores, is described and illustrated. The type species, A. formosa sp. nov., was collected on unidentified decaying leaves in Cuba. Notes on similar genera are given.

Mycosphaerella tasmaniensis is newly described from Mycosphaerella leaf blotch symptoms occurring on Eucalyptus nitens in Tasmania, Australia. Single ascospore cultures produced a Mycovellosiella anamorph, described here as M. tasmaniensis. Both states occurred together, as well as separately on leaf spots. Phaeophleospora epicoccoides (=Kirramyces epicoccoides) is commonly associated with leaf spots of Eucalyptus spp. in Australia. The teleomorph, Mycosphaerella suttoniae, previously known only from Indonesia, was also collected on E. grandis leaves from Australia. A Cylindrocladium leaf blight disease of young E. grandis trees in Indonesia was found to be associated with a new species of Calonectria. Calonectria multiseptata and its anamorph Cylindrocladium multiseptatum is newly described and distinguished from other species based on their larger, multi-septate ascospores and conidia.

Techniques for selective isolation, semiquantification and rapid virulence testing are described for Catenaria anguillulae, an important endoparasitic fungus of nematodes. Selective isolation was achieved by using second-stage juveniles of Anguina tritici as bait in soil aliquots for 48 h. Semiquantitative estimation of the population of the fungus was made by calculating the infection percentage of inoculated juveniles. Rapid virulence testing was done by using second-stage juveniles of Heterodera cajani, Meloidogyne incognita and A. tritici.

Coniochaeta polymegasperma sp. nov. is described from hare dung from Sutherland, Orkney and Inverness. With 64-spored asci, it differs from other Coniochaeta spp. with asci with more than eight spores by its much larger spores. Delitschia trichodelitschioides sp. nov. is described from hare dung from Sutherland and Inverness, differing from other Delitschia spp. in its distinctively setose pseudothecial neck.

The orientation of individual urediniospores and spore clusters of Uromyces viciae-fabae, during fall and after landing in still air, was recorded using high-speed video microscopy. Individual spores and aggregates fell in a variety of orientations. On landing spore clusters attached to the substratum without rebounding or fragmenting and typically retained their orientation during fall. Some aggregates landed and attached in orientations in which their mass was asymmetrical with respect to their point of contact. Attachment also occurred when spores fell onto spore aggregates which had previously landed on the substratum. Rate of fall was influenced by the orientation and size of cluster. When dispersed and collected on substrata under simulated field conditions, the orientation and attachment of urediniospore clusters were similar to those of aggregates deposited in still air.