The genus Paraphaeosphaeria (Loculoascomycetes) was described as a segregate of Leptosphaeria for species producing brown, usually punctate ascospores with rounded ends, a submedian primary septum, an inflated cell above the primary septum, and a Coniothyrium sensu lato anamorph. This study evaluated the taxonomic value of the morphological characters, host range, ecology, and anamorphs in relation to DNA sequence data in order to determine the relationship between species described in Paraphaeosphaeria. Nine species were characterized morphologically and the ITS and 18S regions of the rDNA were sequenced and a phylogeny was inferred. Morphological studies and results of the sequence analyses provide strong support for polyphyly of this genus. Based on these analyses, the concept of Paraphaeosphaeria should be narrowed to reflect a monophyletic generic concept. Characters such as spore septation and method of conidiogenesis were found to predict relatedness.

Studies were performed to assess the genetic variation amongst isolates of the aphid-pathogenic fungus Pandora neoaphidis (syn. Erynia neoaphidis). 37 isolates were examined, from a range of pest and non-pest aphid species, as well as 21 from eight other entomophthoralean species. Universal primers were used to amplify the ITS rDNA regions and all of the species tested produced discrete ITS groups, with the exception of Conidiobolus spp. Neighbour-joining analysis of the ITS2 regions from P. neoaphidis, P. kondoiensis and Zoophthora radicans demonstrated that these three species formed distinct groups with sequence identities of 58–82% between the groups. An ITS size of ca 1100 bp was diagnostic for P. neoaphidis, while ca 1450 bp was characteristic of P. kondoiensis. ITS-RFLP analysis failed to yield intraspecific polymorphisms in any of the P. neoaphidis isolates screened, although it was useful in distinguishing between different entomophthoralean species. Some intraspecific variation in the ITS region was detected in a number of isolates of Z. radicans and Conidiobolus spp. We propose that two isolates previously identified as P. neoaphidis based on conidia morphology, are actually P. kondoiensis based on molecular studies. Sequencing analysis of the complete ITS region from P. neoaphidis and P. kondoiensis allowed species-specific primers to be developed for P. neoaphidis and P. kondoiensis. These were used to screen aphids infected in laboratory bioassays and from field-collected samples, without prior isolation of the fungus. The primers are useful tools for quantifying the epizootiology of P. neoaphidis in aphid populations, as well as assessing competitive interactions between these two species.

Alkali-extractable and water-soluble cell-wall polysaccharides were purified from cell walls of some species of Fusarium and Gibberella. Their structures were determined by chemical analysis and NMR. The polysaccharides consisted of a main chain of β-(1 → 6)-linked galactofuranose units almost fully branched at positions O-2 by single residues of glucopyranose or acidic chains containing glucuronic acid and mannose. Individual differences were found, concerning the proportion of neutral and acidic side chains. These polysaccharides showed major differences from those of Microdochium nivale, Plectosphaerella cucumerina, Fusarium ciliatum, F. aquaeductuum and F. cavispermum. Highly specific polyclonal antibodies were raised against this structure, which were used in immunocompetence and immunofluorescence experiments.

Indoor air contamination with mould spores currently experiences an increasing interest with respect to their relevance to health. To assess adverse health effects, epidemiological studies combine the health outcome of individuals with their concomitant exposure to airborne spores, which is observed, for example, during the current month. While the latter is representative for the studied period, health effects might also be the result of long term-exposure or emerge in consequence of a peak of pollution throughout the year. To consider such questions, additional information about the spatiotemporal distribution of airborne spores is necessary.

This paper aims at elucidating the spatial and temporal variation of spore concentrations in Leipzig, Germany. The analysis is based on 1165 matched pairs of indoor and outdoor measurements taken in the period 1998–2002. All data were collected in the frame of previous epidemiological studies and refer to apartments. The analysis comprised spore concentrations (as CFU m−3 in air) of the most important genera, such as Penicillium, Aspergillus, Alternaria, Mucorales, Cladosporium, and also for yeasts.

We found two groups of fungi differing in their spatiotemporal distribution. As this behaviour can be explained by the predominant origin and growing conditions, we call them indoor-relevant and outdoor-relevant genera. Penicillium species are a representative of the former group, while the latter is well represented by Cladosporium. In the studied period we did not observe a clear trend in the spore concentration. Outdoors there is a year-to-year variation of Cladosporium spore concentrations, which follow the prevalent climatic conditions.

For the spore concentration of the outdoor-relevant group a significant annual cycle was observed. Highest concentrations occurred during the summer months and were about 100× the winter burden. That means, for a direct comparison of measurements of spore concentrations taken during different months the season has to be considered. We summarise the findings in a seasonal model, which is fitted to our measurements. Based on the model we developed a procedure for seasonal adjustment, which enabled us to estimate the annual peak spore concentration utilising one monthly observation.

Many species formerly listed in Entyloma have been removed and are now placed in several orders. This study aims to clarify the framework of the genus Entyloma and the phylogeny of these plant parasitic smut fungi with molecular data. Analyses of LSU and ITS sequences are presented and support the monophyly of the order Entylomatales. The sequences show higher similarities within the examined species of Entyloma than within other smut families and genera, suggesting a recent radiation. Within the Entylomatales a cluster of anamorphic Tilletiopsis washingtonensis, T. lilacina and T. cremea collections is the sister group to Entyloma. The phylogenetic relationships in the genus Entyloma are a result of joint evolution with their hosts. The analyses of the sequence data show unresolved groups on Ranunculales and a well-supported group on Asteridae.

Various fungi and myxomycetes have been tested for their synthesis and hydrolytic degradation of β-poly(L-malate) (PMLA), a highly anionic polyester of L-malate-malate. The PMLA content of the culture medium, and also of some cell extracts, has been assayed by L-malate-malate dehydrogenase (EC 1.1.1.83)-catalysed reduction of NAD+ after the alkaline hydrolysis of the polymer. All eight myxomycete isolates were producers. Eight producers were Mitosporic fungi but only one Ascomyete was productive. Aureobasidium pullulans contained PMLA in yeast-like cells but not in hyphae. The polymer was bound to membrane fractions from where it was slowly released during preparation for analysis. Only 12 of the 237 fungi and myxomycetes showed PMLA-hydrolase activity; and two of these were producers of PMLA. Fungi with hydrolase activity were mostly different from those releasing L-malate. The Physarum polycephalum-type unbranched polymer of high molecular mass was not recognized in fungi. Fungi, typically A. pullulans, produced polymer of low molecular mass which seemed to be covalently bound to polysaccharide.

Cladistic analysis of nucleotide characters derived from partial 18S rDNA sequences has been used to infer phylogenetic relationships among five Candida species that exist in nature strictly as intracellular gut endocytobionts of anobiid or cerambycid beetles. Concordant with their assumed taxonomic status, all five species resolve within Saccharomycetales. For both the anobiid-derived taxa, C. ernobii, C. karawaeiwii and C. xestobii, and the cerambycid-derived taxa, C. tenuis and C. rhagii, this phylogenetic position clearly discriminates Candida yeasts from the anobiid yeast-like endocytobionts in Symbiotaphrina which resolve within filamentous ascomycetes. The analyses provide no evidence for a discrete lineage of Candida endocytobionts within Saccharomycetales. Rather, each of the anobiid symbionts and the cerambycid-derived species resolve in separate clades. These data confirm the polyphyletic origins of intracellular symbioses between ascomycetes and Coleoptera and provide another example of convergent evolution in fungal-arthropod associations. The implications of the phylogenetic data for theories on the origins of endocytobiosis are discussed.

Cercospora leaf spot of olives is a serious defoliating disease attributed to Pseudocercospora cladosporioides. Although the disease is well distributed throughout olive growing regions of the world, its epidemiology and population structure remains unknown. The aim of this study was to establish the genetic variability of Spanish isolates of P. cladosporioides using DNA sequence data from the ITS region, as well as two protein-coding genes, actin and calmodulin. Phylogenetic data obtained here support P. cladosporioides as closely related to other Pseudocercospora species that cluster within Mycosphaerella. Spanish isolates clustered in two clades: isolates from Catalonia were different from those collected in Andalusia. However, isolates appeared to be genetically relatively homogeneous, suggesting that chemical control of this disease via a managed spraying programme may prove a viable option for controlling the disease in Spain.

The foliage of Pinus strobus (eastern white pine), as that of all other conifers examined, is occupied by endophytic fungi, the most frequent of which is Lophodermium nitens. The number and extent of endophytic infections and the genetic relationship of individual isolates within living needles as well as their relationship to isolates from forest floor needles is unknown. To examine these and related questions, forest floor isolates and foliar endophytes from needle segments were obtained for ribosomal DNA sequencing and randomly amplified polymorphic DNA (RAPD) analysis. Molecular and morphological data were compared and infection frequency determined as a function of position along the needle. Ribosomal DNA sequences of foliar and ascospore isolates showed high levels of genetic similarity (>97% identity) for the internal transcribed spacer region. RAPD profiles were able to distinguish ascospore siblings from non-siblings, and also revealed that many needle isolates belonged to the same genotype as adjacent neighbour isolates, as would be expected from mycelial spread within the needle. Morphotype evaluation and RAPD profiles showed similar patterns: identical morphotypes grouped together and showed little or no genetic difference under RAPD analysis. Both morphological and molecular data indicated that the majority of infections were contained within 1 mm needle segments but could extend to about 4 mm in length. Infection frequency increased along the length of the needle from the proximal (shoot) end to the distal tip, with markedly higher rates in the distal quarter. Thus, endophytic infections of L. nitens in white pine needles consist of many localized, discrete infections, originating from ascospores and differentially distributed along the length of the needle. In the course of this work, it was found that GenBank accession no. AF203470 under the name Meloderma desmaszieresii appeared not to be that species but L. nitens on the basis of the ITS sequences.

Many intimate associations between different species of ectomycorrhizal fungi are inferred on the basis of the consistent co-occurrence of their fruit bodies. Suillus bovinus and Gomphidius roseus, where the latter never occurs without the former, is one example. This association was examined with PCR identification and light microscopy. S. bovinus and G. roseus were unambiguously separated on the basis of RFLPs of the PCR-amplified ITS region of ribosomal DNA. Tuberculate mycorrhizas of Pinus sylvestris sampled under fruit bodies of G. roseus and S. bovinus were investigated and the majority were identified as mixed associations involving both G. roseus and S. bovinus. Tuberculate mycorrhizas, which macroscopically resemble the ones of Suillus species, contained typical chlamydospores of G. roseus and they had haustoria where G. roseus hyphae penetrated the cortical root cells. Pine seedlings collected near the fruit bodies of the two species were mainly colonised by S. bovinus. Mycelial rhizomorphs collected under the fruit bodies of G. roseus were identified as S. bovinus, while both fungal species were present at the base of G. roseus fruit bodies. The significance of these observations and the possibility that G. roseus acts as a parasite are discussed.

We describe a 16 yr dataset of ectomycorrhizal fruit bodies under Scots pine (Pinus sylvestris), starting from seedlings, and explore the effects of a 50% thinning treatment imposed in year 12. The over-riding pattern in the data was of successional development, with Paxillus involutus and Laccaria proxima in the earliest years, followed by Suillus species, while in later years Amanita and Cortinarius species became prominent. The typical pattern was for each species in turn to increase to a maximum count then gradually decline without actually disappearing from the community (an addition succession). For nine out of the 30 species recorded the time profiles were fitted significantly by a log-normal curve, although the best-fit lognormal models consistently under-estimated the peak count. Thinning increased counts of Suillus bovinus, Gomphidius roseus and Cortinarius semisanguineus, but overall its effect on the community was minor. Rainfall in September was weakly correlated with successional advancement (measured as DCA first axis scores). Mean fruiting date increased significantly as the stands aged.

An examination of microscopic and macroscopic vegetative reactions between paired isolated of Rhizoctonia solani AG-8 revealed that pairs of isolates that give a C2 anastomosis reaction at the microscopic level always gives a ’tuft’ reaction at the macroscopic level. Similarly, any pair that gives a C3 anastomosis reaction at the microscopic level always gives a ’merge’ reaction at the macroscopic level. Thus, macroscopic vegetative (’tuft type’) reactions can be used to predict the microscopic (anastomosis) reaction (and vice versa) between paired isolate of AG-8. This pattern also seems to apply to paired isolates of AG-3, AG-7 and AG-10 but not the other AGs of R. solani. The C2 anastomosis reaction is always observed when two isolates from different zymogram groups of R. solani AG-8 are paired. When isolates from within any of the five zymogram groups comprising AG-8 are paired, either a C2 or a C3 anastomosis reaction will result. Many field isolates of AG-8, when paired, give a C3 anastomosis reaction. We propose that a group of field isolates of R. solani that give a C3 anastomosis reaction be designated a ’vegetatively compatible population’ (VCP).

The distribution of the major components of the bolete mycobiota of South East Asia is considered and suggestions made as to their possible origin, mycogeography and relationships. The final number of species of boletes in South East Asia is likely to be well in excess of the number compiled in Corner’s 1972 monograph. Molecular information is incorporated into the theme where of interest.

Pseudotulostoma volvata gen. sp. nov. is described from the south-central Pakaraima Mountains of Guyana. Pseudotulostoma volvata is associated with ectomycorrhizal Dicymbe corymbosa trees (Caesalpiniaceae) and placed in the Ascomycota, Eurotiales, Elaphomycetaceae. Included are a description of the genus and species, illustrations of the macroscopic and microscopic features, and a discussion of the distinctive features and phylogenetic placement of this fungus.

This study aimed at testing the hypothesis that the genetically distinct Tuber aestivum population on the island of Gotland, Sweden, is adapted to habitats different from French T. aestivum populations. The soil structure, soil chemistry, bedrock, climate, vegetation and host tree continuity of 18 T. aestivum sites on Gotland were analysed and compared with data from France. We conclude that T. aestivum can grow in soils with a broad soil structure range and that no striking differences in soil chemistry were found. No T. aestivum indicator plants other than the host trees were found, but the host tree continuity on the T. aestivum sites on Gotland was more than 300 yr. If the T. aestivum population on Gotland constitutes an ecotype it is rather an adaptation to the colder and drier climate on Gotland. Selecting local T. aestivum inoculum for truffle orchards in northern Europe could be important for successfull truffle production.

Various fungi interact with heavy metals (HM) differently regarding their binding ability and their tolerance. Besides the ability of the fungus to form an extensive extramatrical mycelium, its binding and transport properties are the most important factors in ameliorating the effects of HM toxicity on the mycorrhizal symbiosis. The tolerance of seven ectomycorrhizal fungi to elevated lead concentrations was tested using agar cultures and the results were compared to those from liquid culture. Critical toxic concentrations, where the growth of the mycelium was inhibited to 50%, were lower in liquid cultures (around 0·2 mm) in comparison to agar cultures (0·5–2 mm). The less tolerant fungi in agar culture were Amanita muscaria and Laccaria laccata, the most tolerant Lactarius piperatus, Pisolithus tinctorius and two strains of Suillus bovinus, DB83 from a lead polluted area and DB84 from a non-polluted area. Tolerance indices, based on the dry weight of mycelia from liquid culture, differ from the tolerance indices obtained from solid culture. L. laccata growth was limited to a lesser extent than other fungi and the growth of S. bovinus DB83 was strongly stimulated at a Pb concentration of 30 μm, which could indicate lower susceptibility of this strain to low lead concentrations. The uptake, transport and release of Pb were then studied with 210Pb tracer using Conway cells with the active tracer added to the inoculated medium in the centre compartment. The uptake of Pb by P. tinctorius (1·1% of the added activity) was much lower than the uptake by L. laccata and S. bovinus DB83 (6·2 and 5·4% of the added activity respectively). The same situation was reflected in the activity of the tracer transported in the mycelia. Further, the release of transported Pb from mycelia to the outer medium differs between L. laccata and S. bovinus DB83 mycelia, reaching 45 and 10% of the transported activity, respectively, indicating stronger binding of lead to S. bovinus DB83. The results of the tracer study are discussed with respect to various experiments with ectomycorrhizal seedlings and lead.

In the southeastern USA, Armillaria root rot disease on peach (Prunus persica) is caused by Armillaria tabescens, and to a lesser degree by A. mellea. Recent attempts to genetically characterize A. tabescens isolates using rDNA indicated the existence of heterozygosity in diploid isolates. In order to clarify this heterozygosity, DNA from stipe and single spore cultures of A. tabescens isolate SC.MF-1.01 was characterized using RFLP and sequence analysis. Direct sequencing of rDNA amplicons from diploid stipe tissue indicated heterozygosity in the IGS1 and ITS2 regions. IGS1 copies A and B, and ITS copies A and B segregated in a 1[ratio ]1 ratio in single spore progeny, whereby IGS1 copy A always segregated with ITS copy A and IGS1 copy B always segregated with ITS copy B. The results indicate the existence of divergent haplotypes in the two nuclei of SC.MF-1.01 diploid mycelium and a single locus for rDNA tandem repeats. Additional IGS1 copies, designated IGS1 copy C, D, and E, with variable AluI restriction sites were cloned from SC.MF-1.01 diploid mycelium indicating polymorphism within ribosomal tandem repeats in A. tabescens. IGS1 copies C, D, and E were found once each in 100 clones analyzed, and therefore seemed to be rare compared to copies A (44 clones) and B (53 clones). RFLP and sequence analysis of the ribosomal IGS1 and ITS1 regions in North American A. tabescens isolates indicated that heterozygosity is common in A. tabescens diploid mycelium. A PCR-based molecular technique was developed to distinguish A. tabescens from many other North American Armillaria species, including A. mellea.

There were two successive pandemics of Dutch Elm Disease (DED) in Europe, parts of Asia and North America in the last century, caused by two ascomycete fungal species, Ophiostoma ulmi and O. novo-ulmi. A third DED species, O. himal-ulmi, was later discovered in the Himalayas. For each of these three species, we now report on the cloning and analysis of a 2.2 kb sequence containing the coding region and 5′ and 3′ flanking sequences of the mating type B (MAT-B) gene, which is involved in the control of sexual compatibility. The amino acid sequence of the single protein encoded by the gene for each species contained a conserved DNA-binding motif called the high mobility group (HMG) box which showed significant sequence similarity to corresponding sequences in many ascomycete MAT-2 genes. Phylogenetic trees constructed from the MAT-B (renamed MAT-2) nucleotide and derived amino acid sequences showed distinct clades corresponding to the three Ophiostoma species and a clear separation of the O. novo-ulmi clade into the two subspecies americana and novo-ulmi. The 3′ flanking regions have been shown to contain variable numbers of repeated oligonucleotide sequences, the number of which is species-specific and readily distinguished by a simple PCR assay.

The sensitivity to UV-B (290–320 nm) radiation of common phylloplane yeasts from two contrasting UV-B environments was compared in the laboratory using mixtures of white light (PAR: 400–700 nm) and UV-B radiation from artificial lamp sources. Sporidiobolus salmonicolor, Rhodotorula mucilaginosa and Cryptococcus sp., the dominant yeasts on leaves of tea (Camellia sinensis), were isolated in Sri Lanka (SL), while Sporidiobolus sp. and Bullera alba, dominant on faba bean (Vicia faba), were isolated in the U.K. Dose responses were determined separately for each yeast. UV-B reduced colony forming units (due to cell mortality or inactivation) and colony size (due to reduced multiplication) of all yeasts. The LD50 values and doses causing 50% reduction of cells per colony were higher for SL isolates than U.K. isolates. Results indicated that each yeast is somewhat vulnerable to UV-B doses representative of its natural habitat. The relative insensitivity of SL isolates was shown when SL and U.K. isolates were irradiated simultaneously with the same dose of UV-B. Of the two U.K. yeasts, B. alba was significantly more sensitive than Sporidiobolus sp. to UV-B. Except for R. mucilaginosa from SL, all yeasts demonstrated some photorepair in the presence of white light. White light provided relatively little protection for the U.K. isolate of Sporidiobolus sp. although it allowed increased colony size.

The spectral responses of Sporidiobolus sp. (U.K.) and of B. alba (U.K.) were broadly similar. Wavelengths longer than 320 nm had no measurable effect on colony forming units. However, colony survival was significantly reduced at 310 nm and all shorter wavebands. No colonies were counted at 290 nm or below.

The effects of grazing by the collembolan Folsomia candida on mycelial foraging patterns of Hypholoma fasciculare growing from beech (Fagus sylvatica) wood block inocula in trays of non-sterile soil was investigated. The wood inocula differed in size, state of decay (time for which wood has been colonized: 2 yr, 1 yr, 6 and 3 months) and nutrient status (inocula colonized on malt agar or nutrient agar). Mycelia were most luxuriant, had greater hyphal coverage and extended more rapidly from 2 yr old than younger inocula, from 4 cm3 than 1 cm3 inocula, and from inocula colonized on malt extract agar rather than on distilled water agar. Grazing dramatically reduced coverage and extension, especially in the less luxuriant systems characterized by many fine hyphae and fewer mycelial cords. Grazing by collembola often resulted in points of more rapid outgrowth as cords with a fanned margin. Results are discussed in terms of fungal foraging strategies.