The content of phenolic substances in freshly collected fruit bodies of several basidiomycete genera varied in the range 2·35–9·05 mg g−1, following closely the trend of a normal function.

It was necessary to use a polyphenoloxidase-inhibiting substance to obtain reliable analysis. The content of phenolics decreased, during 3 d at room temperature and following freezing at −20°C.

Delortia, represented by the type, D. palmicola, is redescribed from fresh decaying palm material collected in north Queensland, Australia. Two new species, D. tumidoapicis and D. aquatica, collected from wood submerged in a freshwater stream, also in north Queensland are described. The three species are illustrated with light micrographs and line diagrams and discussed in relation to each other.

Phaeoseptoria peltigerae is described and illustrated from the thallus of Peltigera horizontalis from Norway.

The current distribution and host range of the Sclerotiniaceae indicate that the family originated in the Northern Hemisphere. The ancestors were possibly present on earth during the Tertiary period when, in most northern areas, environmental conditions were wet, warm and uniform until the approach of the Pleistocene epoch. It seems from present-day host–pathogen relationships that some ancient groups of plants and a variety of angiosperms were hosts. The teleomorph of early genera was well adapted to wet conditions, with ascospores the only dispersive spore and microconidia probably serving a spermatial function. Macroconidia were probably later evolutionary developments associated with colonization of habitats drier than the original one. The onset of the Pleistocene Ice Age would have exerted considerable environmental pressures on early genera resulting in selection of adaptations which enabled survival of the gradually changing conditions, particularly sub-zero temperatures and unavailability of hosts during the harsh winter months. The major adaptations in the Sclerotiniaceae have been a range of multihyphal, reserve-rich resting structures which survive harsh environmental conditions and provide nutrients and protection for the teleomorphs, which are highly sensitive to cold and desiccation. The resting structures are useful indicators of phylogenetic relations within the family. Information on stromata and sclerotia of the Sclerotiniaceae is reviewed and then used to discuss evolution of these structures. The first type of resting structure to evolve was probably an indeterminate stroma which developed by branching and interweaving of infection hyphae within host tissues. Several, better differentiated forms were produced with their morphology related to type of host and tissue infected and to characteristics of the pathogens. The different stromata could have evolved along a common pathway or independently. The general anatomical similarity of the various structures could be accounted for because of the limited structural forms that can be produced by interweaving of filamentous hyphae. It seems that sclerotia may have developed from hyphal tissue which had the ability to produce sclerotia when the climate was cold and wet, and macroconidia when conditions were warmer and drier. Two main types of sclerotia are distinguished, tuberoid sclerotia and plano-convex sclerotia. The literature relating to the morphology and ontogeny of macroconidia is reviewed and used for speculation on the effects of environmental conditions on evolution of macroconidia, the origin of macroconidial anamorphs and stages in the evolution of botrytoid spores. It is concluded that in the Sclerotiniaceae there are at least two main pathways along which resting structures have evolved, one leading to a variety of stromata and the other to two types of sclerotia. Sclerotia predated macroconidia and both anamorphs could have originated from common generative tissue.

Eighty-eight isolates of Gremmeniella abietina var. abietina belonging to the Asian, European and North American races were cultivated on agar plates and their fatty acids and sterols were extracted and analysed.

Fourteen fatty acids and seven sterols were detected by gas chromatography. Multivariate discriminant analysis revealed distinct differences between the contents of fatty acids and sterols (FAST-profiles) of the three races; the most distinct was the Asian race. Additionally, the presence of two ecologically different types in Finland, the large tree and small tree type (LTT and STT, respectively) was confirmed on the basis of their significantly different FAST-profiles. The FAST-profiles of European STT more closely resemble the American race than the European LTT. The diversity of North American isolates of the European race, which were supposedly initially introduced from Europe in the 1960s, were considerably higher than the diversity of the European LTT or STT isolates.

Fungi were isolated from the beetles, Ips typographus f. japonicus and Yezo spruce (Picea jezoensis) trees infested with the beetles in Hokkaido, Japan. Nine species of ophiostomatoid fungi including one new species were identified. They were Ceratocystiopsis minuta, Ceratocystis polonica, Ophiostoma ainoae, O. bicolor, O. cucullatum, O. europhioides, O. penicillatum, O. piceae, and a new species described here as O. japonicum. Based on frequencies of occurrence, O. ainoae, O. bicolor, O. penicillatum, and O. piceae were regarded as dominant associates of I. typographus japonicus, and C. minuta, C. polonica, O. europhinoides, and O. japonicum were subdominant. The species of ophiostomatoid fungi associated with I. typographus japonicus in Japan are almost identical to those associated with I. typographus infesting Norway spruce (P. abies) in Europe. This study improves our knowledge of the biogeography of the ophiostomatoid fungi and the insects with which they are associated.

Spatial characteristics of Suillus variegatus populations, including the size, distribution and number of genets, were measured in four naturally regenerated stands of Scots pine, Pinus sylvestris in Sweden that were more than 100 years old. In the oldest forest, a continuous tree-layer had been present at least since the last forest fire in 1647. Genets were identified based on somatic incompatibility reactions performed on mycelial cultures from sporocarps. In total, 38 genets were identified from 120 tested sporocarps. The maximal extension of a genet, as reflected by its outermost sporocarps, was 27 m in the oldest stand and ranged between 10 and 17 m in the other stands. On average, genet size was 20 m in the oldest stand and 10 m in the other stands. Other genets were not found within the domains of established genets. The closest detected distance between genets was 1·5 m, and the average distance was 4 m. The number of genets ranged between 56 and 74 ha−1 at the studied sites. Possible reasons for the high degree of resemblance in characteristics in old forests between S. variegatus, the dominant bolete in mature forests, and S. bovinus when present, more a characteristic for younger forests and only scarcely occurring in older forests, are discussed.

Twenty-one Aspergillus strains representing different A. awamori, A. phoenicis and A. foetidus isolates were studied in order to explore the potential of a fast RFLP analysis to identify fungal strains. The patterns were compared with those characteristic for A. niger, A. tubingensis, A. carbonarius, A. japonicus and A. aculeatus represented by A. niger CBS 120.49, A. tubingensis NW 756, A. carbonarius CBS 111.26, A japonicus CBS 114.51 and A. aculeatus CBS 101.43 and also with those of the type strains of A. heteromorphus CBS 117.55 and A. ellipticus CBS 707.79.

Sma I digested chromosomal DNA revealed characteristic rDNA patterns after ethidium bromide staining which were used in combination with hybridization patterns of Pst I/Sal I double digested chromosomal DNA with well-defined probes. This allowed clear distinction of eight separate species within the Aspergillus sect. Nigri group. The probes used were a 0·9 kb fragment of the 28S rDNA from Agaricus bisporus, an internal fragment of the pkiA gene from A. nidulans, and the pelA gene from A. niger. All the strains examined including those indicated as A. awamori and A. phoenicis were shown to belong either to A. niger, A. tubingensis or a group representing isolates of A. foetidus varieties, amongst which A. foetidus var. acidus CBS 564.65 and A. foetidus var. pallidus CBS 565.65.

A study on the mangrove leaf litter fungi of two tropical mangroves in Singapore was carried out. Five Halophytophthora species and four isolates which did not fit the descriptions of known species were isolated from leaves of Avicennia alba, A. rumphiana, Rhizophora apiculata and R. mucronata. Halophytophthora exoprolifera, H. kandeliae, H. operculata, H. spinosa var. lobata and H. vesicula are new records for Singapore; the first three also being new records for tropical mangroves. The isolate of H. exoprolifera sporulated at 28 °C and may be a tropical strain. H. operculata is reported for the first time outside of Australia. The results of this study contribute to the little known distribution of the Halophytophthora in the Indian Pacific region. Thirteen deuteromycetes were also isolated from the mangrove leaf litter and represented both phylloplane fungi as well as possible marine fungi.

Strains (47) of 14 genera isolated from soil and woody chips were tested for their ability to oxidize dibenzofuran, a model compound for highly chlorinated dibenzofuran pollutants. Thirty strains formed one or more isomers of monohydroxylated dibenzofurans identified by chemical structure analysis with hplc and GC-MS, indicating an active monooxygenase system widely distributed in filamentous fungi. Dihydroxylated derivatives were detected in only very low amounts and some degradation products were observed. A few fungi metabolized dibenzofuran only to intermediates with hydrophilic characteristics (eight strains) and nine strains showed no transformation capability. The transformation reactions were not inducible and seemed to be strain-specific.

Intact ungerminated spores or germinating swollen spores of Mucor circinelloides were biolistically transformed to leucine prototrophy with the autonomous replicating plasmids pLeu4 and pMCL1302. The former developmental stage was efficiently transformed with both plasmids. The existence of pLeu4 sequences, as selfreplicating elements, within Leu+ transformants was established by Southern analysis and by the recovery of plasmid pLeu4 in bacteria transformed with total DNA from M. circinelloides transformants. This is the first report of the transformation of intact cells of a member of the Zygomycetes.

Epichloë typhina is a biotrophic symbiont of grasses with its sexual state on immature host inflorescences. The ectophytic, presexual structure (stroma) of E. typhina produces spermatia and also serves as the female structure in mating. After fertilization there is proliferation of a dense mycelium which has been suggested to be heterokaryotic. Perithecia form in the thickened stroma. We investigated the possible formation of heterokaryons in matings and the role of ascospores in contagious spread of E. typhina. In almost all instances the transfer to a stroma of spermatia of opposite mating type leads to thickening of the stroma; however, ascospores were produced only if the parents were of the same mating population. Fertilization of part of a stroma by one spermatial parent often inhibited fertilization by another strain elsewhere on the stroma depending upon the spermatial isolates used. Tests for heterokaryon formation were performed by culturing stromata after matings that produced no ascospores, to avoid analysing meiotic products. In two instances the female was cultured, and in two the nuclear and mitochondrial haplotypes were primarily of the male. In another instance mitochondrial haplotypes and mitochondrial plasmids from the female became associated with the male nuclear haplotype. These results suggest that, following mating, male hyphae proliferate and heterokaryons may sometimes form and also proliferate. To test how ascospores mediate infection, inflorescences of uninfected perennial ryegrass plants were surrounded by fertilized stromata from which E. typhina ascospores were being ejected, seeds were collected and grown, newly infected progeny plants were identified, and isolates from five progeny plants were analysed genetically. As expected for ascospore progeny the rDNA haplotype of the stromal and spermatial parents had segregated, whereas all five isolates had the stromal profile of mitochondrial DNA. This observation demonstrated that ascospores mediate infection of new host plants.

The edible mushroom, Agaricus bisporus, when cultivated commercially derives its nitrogen from the proteins present in compost, much of which is firmly bound to the lignin-humic complex. The proteinases involved in mobilization of nitrogen were studied in both the filtrates of liquid culture and mushroom compost. Proteinase activities were detected in liquid culture filtrates with a range of substrate specificities. One activity with chymotrypsin-like specificity was found by Western blotting to be the 27 kDa serine proteinase previously purified from senescent sporophores. Serine proteinase activity and level in the filtrates rapidly increased during mycelial growth on liquid medium containing humic fraction (extracted from mushroom compost) as sole nitrogen source. Activity and level remained low in filtrates of cultures grown on glutamate or casein. Non-denaturing gel analysis revealed the serine proteinase to be the most prominent proteolytic activity in compost filtrates. Regulation of the activity in compost was indicated by a doubling during the early stages of sporophore growth.

Nia globospora sp. nov., a marine basidiomycete, provisionally put in the Melanogastrales, producing fruit bodies on dead culms of Spartina maritima is described. The species grew on baits that were submerged for a period of 6 months in the Mira River estuary, Portugal. Comparisons with other species of Nia are made.

Two new tropical species of Lachnum with red or reddish hymenia are described. Lachnum euterpes occurs on fronds of the palm Prestoea (= Euterpe) and L. victoriani is described from coriaceous leaves of dicotyledonous trees. A full description of each new species is given along with a brief discussion of the morphological differences distinguishing it from other species with which it could be confused. New combinations in Lachnum are made for the tropical fern-inhabiting species Dasyscyphus ulei and D. chermisinus.

A mathematical model is presented which qualitatively describes the growth kinetics of the aphid-pathogenic Erynia neoaphidis in liquid culture. An essential feature of the model is that it allows for the presence of a toxic component within the growth medium which may be broken down by an extracellular enzyme released by the biomass. In this investigation, the toxin was oleic acid which had previously been shown to be essential for the growth of E. neoaphidis, but only at low concentration.

The model reproduces a number of unusual features of the kinetics of growth of E. neoaphidis in liquid culture. These include: the requirement for a high inoculum concentration to successfully initiate growth in liquid culture; failure to grow in continuous culture under conditions similar to those supporting successful batch culture; a reduced growth yield in continuous culture compared to batch culture; a depressed apparent specific growth rate in continuous culture compared to batch culture and, deviation from the usual exponential decrease of biomass concentration during washout. Through the development of the model, and the application of predictions derived from it to the laboratory situation, continuous culture of E. neoaphidis was achieved for the first time.

Hainesia marsdeniae sp. nov. is described and illustrated from dead leaves of ?Cornus sp. collected in the U.K. It is compared with known Hainesia species and those coelomycetes with cupulate conidiomata that it resembles.

A study of the macroscopic and microscopic characters of type material of Tulostoma leiosporum, T. exitum, T. operculatum and T. puncticulosum showed their heterogeneity. An attempt was made to resolve the taxonomic problems involved in the selection of lectotypes, and new synonymies are proposed. SEM photographs of spore ornamentation are provided.

The organic soil horizons of heathland and temperate forest ecosystems are characteristically rich in phenolics, which present barriers to organic N availability to the microflora. The abilities of ectomycorrhizal (ECM), ericoid mycorrhizal and wood decomposing saprotrophic fungi to degrade model compounds representing the insoluble phenolic lignin, and soluble phenolics, which provide physical and chemical barriers respectively to organic N availability, were compared. No clear relationship was found between ability to degrade lignin and soluble phenolics. The presumptive assays indicated that most mycorrhizal fungi have only low abilities to degrade these compounds relative to the wood decomposing fungi. In general, ericoid mycorrhizal fungi were capable of greater phenolic degradation than most ECM species, and degradative ability was associated with production of phenol-oxidizing enzymes. In no case was presumptive degradation of lignin or soluble phenolic, or production of phenol-oxidizing enzymes by mycorrhizal fungi as great as that of the wood decomposing fungi. In the case of the ericoid endophyte Hymenoscyphus ericae, phenol-oxidation was associated with production of an extracellular o-polyphenol oxidase (tyrosinase) which showed optimal activity at a pH of 5–5·5 and temperature of 30°C. The ecological significance of the results is discussed.

In a soil survey, nematophagous fungi were recovered less from agar plates sprinkled with forest soil (Quercus ilex subsp. rotundifolia) than from those incubated with agricultural (Citrus orchards) soil. Nematodes were present in all soils. The organic matter was higher in forest soils. Water extracts from forest soils with high levels of phenols, leaf litter and Q. rotundifolia fresh leaves affected the development and growth of common species of nematophagous and entomopathogenic fungi. These results show that phenolics from leaf letter could play an important role in the ecology and biology of these invertebrate pathogens in soil.