Currently, mycopesticide development for locust and grasshopper control depends on aerial conidia or submerged spores of entomopathogenic fungi. In our study, the production of submerged conidia of Metarhizium anisopliae var. acridum (IMI 330189) was investigated in a liquid medium containing 3% biomalt and 1% yeast extract (BH-medium). The effects of freeze and spray drying techniques on the quality of submerged conidia were determined. The influence of different additives on the viability of fresh submerged conidia and their suitability for oil flowable concentrate formulation development was assessed. In a BH medium maintained at 180 rev min−1, at 30 °C for 72 h, IMI 330189 produced a green pigmented biomass of submerged conidia whereas in Adámek medium it produced a yellowish biomass of submerged spores. The spore concentration was high in both media; however, the size of the spores produced in the BH medium was significantly lower than those produced in Adámek medium (P<0.001). Submerged conidia can be effectively dried using either freeze or spray drying techniques. The viability and speed of germination were significantly affected by the drying and pulverizing process (P<0.001). The initial viability was significantly higher for spray-dried submerged conidia than for freeze-dried spores. Pulverizing of freeze-dried submerged conidia reduced the speed of germination and the viability by 63–95%. Dried submerged conidia can be stored over 45 wk at low temperatures (<10°) without suffering a significant loss in viability. Furthermore, we have identified carriers that are suitable for oil flowable concentrate formulation development.

The phylogenetic relationship between Epicoccum nigrum and Phoma epicoccina has been assessed by means of sequencing of the ITS regions of rDNA. The analysis of the sequences from five isolates of E. nigrum and four of P. epicoccina suggests that both entities represent the same biological species.

On water agar, hyphae of many fungi are attracted to viable pollen grains of Pinus nigra. Hyphae of 41 of 157 species tested could penetrate the pollen grains, ramify within the interior and consume the contents. It is proposed that pollen serves as a supplementary seasonal source of nutrients, particularly nitrogen, for litter- and wood-decaying members of the Basidiomycota.

The effects of different temperatures and pH on the growth and solubilization of insoluble calcium phosphate, cobalt phosphate, manganese phosphate, strontium hydrogen phosphate and zinc phosphate by Rhizoctonia solani on solidified media were assessed. Solubilization of the metal phosphates was monitored by the production of a clear zone around or underneath the fungus. R. solani efficiently solubilized all five metal phosphates except cobalt phosphate when grown on medium at pH 7. Solubilization activity by R. solani decreased with increasing pH on medium containing calcium phosphate but increased on strontium hydrogen phosphate-amended medium. The uptake of metals by the mycelia was unaffected by the pH of the medium or the growth temperature. Small quantities of crystals were produced in the agar when R. solani was grown on calcium phosphate- and strontium hydrogen phosphate-amended media and these were identified as calcium or strontium sulphates respectively: there appeared to be little or no production of insoluble oxalates although a role for oxalate in the overall solubilization process cannot be discounted. These results are discussed in relation to their physiological and environmental significance, and the important roles of fungi in effecting transformations of insoluble metal-containing compounds in the environment.

The antifungal activity of five substituted flavones and their mixtures with unsubstituted flavone or a flavanone was tested on malt extract agar against five Fusarium spp. 4′-Methylflavone and 2′,6′-dichloroflavone showed the highest activity while 4′-benzyloxyflavone caused the lowest inhibition of all test substances. A significant increase in the antifungal effect of the substituted flavones could be observed if mixtures in combination with the unsubstituted flavone or flavanone were used. Some aspects of structure–activity relationships are discussed.

The present work reports the development of a PCR assay to detect the ascomycete Biscogniauxia mediterranea in asymptomatic tissues of Quercus cerris. To this purpose, two specific primers (MED1 and MED2) were designed by comparison of sequences comprised between ITS1 and ITS4 generic primers of 21 isolates of B. mediterranea and related species. Specificity of the primers was tested against 19 isolates of B. mediterranea and 20 isolates of related and unrelated genera, and against Quercus cerris DNA. The reliability of the results was confirmed by Southern Blot analysis. The 2 specific primers MED1 and MED2 were able to detect B. mediterranea DNA in the host tissues at picogram quantity of target DNA. This assay would greatly enhance the possibility to study the presence and localization of B. mediterranea during its latent phase in Quercus species.

The fluG gene proved to be essential in the initialisation of autolysis in Aspergillus nidulans (teleomorph Emericella nidulans) cultures, while a loss-of-function mutation in only one out of the flbB-E genes had only minor effects on autolysis. In contrast to its important role in sporulation, brlA regulated only some, but not all, elements of the autolytic process. The tightly coupled autolytic events (chitinase and proteinase production, hyphal fragmentation, disorganisation of pellets, autolytic loss of biomass) observable in ageing cultures of A. nidulans were disconnected by loss-of-function mutations in some genes of the FluG-BrlA regulatory network. The tight correlation between pellet morphology and size and hydrolase production was also erased by these mutations. On the other hand, the mutations studied did not affect the glutathione metabolism of the fungus.

Characteristics of hyphal septation, cellular interaction, sporulation, cultures and/or nucleotide sequences from the 5′ terminal domain of the nuclear large subunit rRNA gene of some species of Exobasidium, Microstroma and Muribasidiospora were examined and compared. Our analyses show that the order Microstromatales comprises Microstroma, Muribasidiospora triumfetticola and the anamorphic species Rhodotorula bacarum, R. phylloplana and Sympodiomycopsis paphiopedili, whereas Muribasidiospora hesperidium and Muribasidiospora indica are members of the Exobasidiales. Because of the high degree of morphological divergence between Muribasidiospora triumfetticola and Microstroma, a new genus, Volvocisporium, and a new family, Volvocisporiaceae, of the Microstromatales are proposed. Apart from the phylogenetic implications, the most interesting observations in the present work are the unusual development of the basidia, especially of the basidiospores, and the nutrient transport system from the host attacking hyphae to the basidia in Muribasidiospora triumfetticola.

In an in vitro study, interactions between ectomycorrhizal fungi, saprotrophic basidiomycetes and soil microfungi known from pine forests were examined in relation to different ammonium concentrations. The saprotrophic basidiomycetes Clitocybe marginella and C. vibecina and the soil microfungi Penicillium pinetorum, Oidiodendron flavum and Torulomyces lagena were grown against the ectomycorrhizal Cenococcum geophilum, Laccaria bicolor and Rhizopogon luteolus. Interactions were species specific and overgrowth was the most common (43%), followed by inhibition at distance (26%) and contact inhibition (16%). Ammonium concentrations affected the type and strength of the interactions. The competitive strength of the ectomycorrhizal fungi was relatively high and only the growth of the mycelia of L. bicolor was clearly suppressed by the Clitocybe spp. The interactions are discussed in relation to the ecology of the fungi and potential future studies.

Uptake of 75[Se]-selenite by Saccharomyces cerevisiae has been characterized. At a 0.5 mM selenite, ~0.14 nmol Se (106 cells)−1 was rapidly accumulated by the cells at a rate of ~56 pmol.min−1 (106 cells)−1 which was independent of temperature and glucose. This rapid phase was followed by a slower uptake phase which was sensitive to glucose, temperature and metabolic inhibitors [2,4-dinitrophenol (DNP), carbonyl cyanide m-chlorophenyl hydrazone (CCCP), potassium cyanide (KCN) and sodium azide (NaN3)] and therefore presumed to be metabolism-dependent. Two transport systems appeared to be involved in selenite uptake. At the low range of selenite concentrations used (0.025–0.1 mM), a high affinity transport system occurred with apparent Km and Vmax values of 54.0 μM and 3.14 pmol.min−1 (106 cells)−1 respectively. A low affinity system was present at higher concentrations (0.1–1.0 mM) with apparent kinetic parameters of Km=435 μM and Vmax=11.6 pmol.min−1 (106 cells)−1. Elevated sulphate concentrations (up to 2.5 mM) did not affect the accumulation of selenite. However, the transport rate from 0.5 mM selenite was stimulated by sulphite, with the maximum effect occurring at 0.5 mM sulphite. Methionine had a detectable inhibitory action on selenite uptake whereas cystine and cysteine completely inhibited active transport of selenite. Transmission electron microscopy of 5 mM selenite-grown cells revealed the presence of abundant small cytoplasmic vesicles containing electron-dense granules which could represent an intracellular selenium-detoxification mechanism.

Isolates of Pisolithus and Scleroderma species from different northern temperate and tropical geographical regions were subjected to analyses of pure culture morphology, colony growth rates, isozyme (allozyme) variation and ribosomal DNA (rDNA) restriction fragment length polymorphisms (RFLPs). Cultural characteristics enabled clear species separation of isolates and together with growth rates suggested geographically-linked intraspecific variability in the Pisolithus populations. Combined or method-specific hierarchical cluster analyses of allozyme polymorphisms and RFLPs of the fungal internal transcribed spacer (ITS) and intergenic spacer (IGS) sequences confirmed the Scleroderma species groupings and considerable geographical and host-linked variation in the Pisolithus population. Isolates of Pisolithus from the Philippines were genetically very homogeneous and distinct from less related isolates from Europe, Scandinavia and North America. Based on the ITS–RFLP and isozyme polymorphism data, the isolates investigated probably represent four different ‘species groupings’ which supports similar findings from recent taxonomic and genetic studies of Australian Pisolithus species.

In Finland and Norway, a uninucleate Rhizoctonia sp. is causing a root dieback disease on nursery-grown Norway spruce and Scots pine seedlings. This Rhizoctonia can be fruited under laboratory conditions and the basidial characters fit well in the species concept of Ceratobasidium bicorne, a species originally described as a moss parasite under forest conditions. Further comparison using traditional methods (cultural morphology, nuclear condition, anastomosis) has not been possible as the forest population of C. bicorne has apparently never been cultured. In the present study, we isolated DNA from a herbarium sample of C. bicorne grown on the moss Polytrichastrum formosum. Sequence analysis of the PCR-amplified rDNA region containing the internal transcribed spacer (ITS) regions and the 5.8S rDNA gene was used to examine the conspecificity of the herbarium sample and the uninucleate Rhizoctonia sp. The nucleotide sequence of the 5.8S rDNA gene was identical between the herbarium sample and five sequenced uninucleate Rhizoctonia strains. Within the uninucleate Rhizoctonia sp., the sequence identity ranged from 96.1 to 100% in ITS1 and from 99.6 to 100% in ITS2. The sequence from the herbarium sample fits well within these limits, strongly suggesting that the uninucleate Rhizoctonia sp. and C. bicorne are conspecific. Interestingly, two of the uninucleate Rhizoctonia strains produced two ITS alleles: the genetic implications are also discussed.

Species delimitation within the core group of Peziza is highly controversial. The group, typified by P. vesiculosa, is morphologically coherent and in previous analyses of LSU rDNA sequences it formed a highly supported clade. Phylogenetic diversity and species limits were investigated within the group using sequences from the complete ITS region (ITS1-5.8S-ITS2). Eighty-three specimens were selected for molecular study from a larger sample of material studied morphologically to explore the intra- and interspecific variation of each putative species. The sister group taxon, P. ampelina was used as the outgroup and two specimens of P. subcitrina were additionally included. Seven independent lineages of rDNA were identified (I–VII), each representing one to several species. These lineages form two larger clades, A (II, and I or III) and B (IV–VII), supported by macromorphology: small (generally <2 cm), shallowly cup- to disc-shaped apothecia (A) and large (up to 15 cm), deeply cup-shaped to expanded apothecia (B). The overall exciple structure (a stratified or non-stratified medullary layer) and to some degree spore surface relief, likewise support the groupings. Clade A contains taxa with smooth or nearly smooth spores (except for P. lohjaënsis), while clade B contains taxa with a range of spore ornamentations, from smooth, finely warty to distinctly warty, and spiny. The position of groups I (P. vesiculosa and P. ammophila) and III (P. lohjaënsis) are uncertain, and these taxa also deviate morphologically from the other clade A members. The following species are recognized based on morphology and ITS rDNA analyses: P. ammophila and P. vesiculosa (I); P. alcis, P. ampliata, P. domiciliana, P. fimeti, P. nivalis, and a number of putative species or intraspecific entities (II); P. lohjaënsis (III); P. sp. c (IV); P. arvernensis (V); P. echinispora and P. sp. d (VI); and P. varia (VII). The nomenclature of these species is analyzed and taxa are typified as necessary. Based on ITS and morphology, we found no justification for recognizing more than one species in the ‘P. varia complex’, including 27 specimens that have been referred to under the names P. cerea, P. micropus and P. repanda, from an array of substrates and different geographical areas. Morphological characters previously used to delimit species within this complex, such as colour variation of the apothecia, presence or absence of a stipe, stratified or non-stratified medullary exciple (or thickness of the excipular layers), cell types in the outermost exciple and moniliform vs filiform paraphyses were not correlated with the subgroups supported by ITS analyses and appeared to be plastic. Therefore, P. cerea and P. micropus are placed in synonymy with P. varia. The name P. repanda is rejected. Levels of sequence divergence were low within group II, comprising 33 small apothecial specimens. Twelve fine-scale lineages were identified, but the analyses did not resolve relationships among these. P. granulosa sensu Boudier is considered a synonym of P. fimeti. These have previously been distinguished mainly by occurrence on various soil types, including burnt soil and soil mixed with sawdust or woodchips vs on dung. The substrate and habitat have been much emphasized in the taxonomy of Peziza, but the results obtained here indicate that populations on a diverse array of substrates may be closely related, or indeed, conspecific.

A phylogenetic analysis based on internal transcribed spacer regions of the nuclear ribosomal RNA region (ITS) sequences has been undertaken for species in the genus Schizopora. Four known species were studied, viz. S. radula, S. paradoxa, S. flavipora, S. nothofagi, and a hitherto undescribed species from Taiwan. Allopatric differentiation was apparent in S. radula, for which several geographically representive samples were available. Among these, ITS sequence data obtained from S. radula isolates from British Columbia and Australasia were identical. All previously recognised Schizopora species were well separated from each other with respect to their ITS sequences. Mating compatibility tests also showed complete reproductive separation between species, but intercompatibility between cultures from the same species, irrespective of geographical origin. Overall, the morphology of basidiomes of S. radula from New Zealand differs only in minor respects from those of European and Argentinean origin, but shows a higher degree of variability than described for European specimens.

Genetic relationships of the complex of Fusarium species associated with crown rot and head blight in cereals and some species associated with plant diseases in general were examined by distance and maximum parsimony algorithms of their internal transcribed spacer sequences. The analysis clustered the complex of Fusarium species that causes root and crown rot and head blight of cereals and three other clusters of F. sambucinum, F. venenatum and F. poae into one clade. This group of Fusarium species was also found in this study to correspond to the group defined by the presence of the tri5 gene. The tri5 gene was recently reported to co-segregate with the locus governing the type of trichothecene produced, and probably maps in the trichothecene gene cluster. The other clusters of F. avenaceum, F. tricinctum, F. torulosum, F. oxysporum, F. verticillioides and F. solani did not have the tri5 gene. Although, F. pseudograminearum was phylogenetically close with the cluster of F. graminearum, F. culmorum and F. cerealis, it could be distinctly separated from them. The distinct genetic status of F. pseudograminearum from F. graminearum corroborated with other published molecular data and isozyme findings. The molecular analysis provided a simple diagnostic tool to differentiate fungi causing crown rot from those involved in head blight.

Epifluorescence microscopy and low temperature scanning electron microscopy were used to document the development of Uncinula necator on vine leaves and the antifungal effects of kresoxim-methyl and penconazole. Post-germinational growth and development followed a regular time course which was classified into 10 stages.

Kresoxim-methyl was applied at a range of concentrations and at different times before and after inoculation. In glasshouse trials at moderate relative humidity (60%), all pre-infectional applications completely inhibited conidial germination. Lower efficacies were observed with detached leaves at high humidity in Petri dishes. Post-infectional applications of at least 8 mg a.i. l−1 inhibited sporulation and mycelial growth and 67 mg a.i. l−1 caused a partial collapse of surface structures.

Penconazole applied at 17 mg a.i. l−1 did not inhibit germination, but prevented hyphal development and caused growth distortion with hyphal tip swelling. Pre- and post-infectional treatments had similar effects. Applications made 3 d after inoculation increased multiple appressoria and conidiophore formation.

Zoospores of the nematode-parasitic Catenaria anguillulae (Chytridiomycota) were studied by videomicroscopy in sealed films of water on microscope slides in the presence or absence of freeze-inactivated nematodes (Panagrellus redivivus). Zoospores swam for more than 1 h at a mean velocity of 104 μm s−1, interspersed with repeated phases (1–2 min) of amoeboid crawling on glass or nematode surfaces. They were attracted to and encysted near the mouth, excretory pore, and anus of nematodes, or eventually encysted at random on glass and nematode surfaces. The single posterior flagellum was immobile during amoeboid crawling but resumed rapid beating when the last pseudopodium was being retracted. Zoospores encysted by adhesion of the anterior of an amoeboid cell to a surface; then the cell posterior was raised above the anterior so that the flagellum projected perpendicular to the surface, and the flagellum was retracted by rotation of the cell contents. Cysts germinated within 20–60 min by a narrow germ-tube at the site of adhesion. The germ-tube grew a short distance, then formed an intercalary vesicle into which the cyst contents emptied by expansion of a cyst vacuole. In several cases the germ-tube penetrated a nematode and formed the vesicle inside the host. Rhizoids or assimilative hyphae developed from the vesicle or by growth of the germ-tube tip. An increasing proportion of zoospores that remained motile after 1 h in water films had a globose body in contrast to the normal elongated form. This seemed to be caused by damage during repeated transitions between the amoeboid and swimming phases, because pseudopodia sometimes remained firmly attached to a glass surface.

C. anguillulae showed consistent orientation (polarity) of zoospore encystment and cyst germination. This parallels the behaviour of other zoosporic fungi or fungus-like organisms (Plasmodiophora brassicae, Rozella allomycis, Pythium, Phytophthora and Saprolegnia spp.) suggesting that it is a common feature of zoosporic parasites. Surface-recognition for encystment by C. anguillulae was mediated by the zoospore soma, not the flagellum. In addition, we redefine the early development of C. anguillulae, including flagellar retraction by rotation of cell contents, non-specific adhesion of zoospores and cysts to surfaces, and evacuation of cyst contents into a vesicle from which further growth occurs.

The phylogenetic position of the marine ascomycete genus Spathulospora was investigated using partial SSU and LSU DNA sequences obtained from dried herbarium specimens. Spathulospora was represented by the two species S. adelpha and S. antarctica. Phylogenetic analyses using Bayesian, parsimony, and neighbour-joining algorithms on SSU and LSU data sets agreed with the placement of Spathulospora. Both Spathulospora species are each others closest relatives, and group within the Lulworthiales (Sordariomycetes, Ascomycota) with support in all analyses. Members of the morphologically similar insect parasites in the Laboulbeniomycetes are not closely related to Spathulospora. Despite several striking morphological differences between Spathulospora and Lulworthiales, an important shared morphological character was found that until now had not been recognized. Ascospores of Spathulospora and some members of the Lulworthiales have apical chambers containing mucus believed to be involved in ascospore attachment. A closest relative to Spathulospora could not be determined.

Production of lignin-modifying enzymes by 10 white-rot fungi, as measured by decolorization of Poly R 478 dye, varied in response to different carbon and nitrogen regimes. Fastest decolorization rates were achieved with wood polysaccharide monomers (glucose, xylose) as carbon source, although cellulose was the only carbon source to facilitate decolorization by all test fungi. Enzyme production by most isolates was strongly dependant on nitrogen levels, with high nitrogen conditions generally suppressing enzyme production. One unidentified isolate (HKUCC 4062) displayed apparent nitrogen deregulation of enzyme production. A cellulose-low nitrogen growth medium is recommended for agar-based screening procedures of lignin-modifying enzyme production by white-rot fungi.

The performance of isolates of the ectomycorrhizal fungi Coltricia perennis, Laccaria bicolor, Lactarius hepaticus and Paxillus involutus originating from Scots pine stands was studied on solid media with different concentrations of ammonium, glycine and glucose as inorganic nitrogen, organic nitrogen and carbon source. Laccaria bicolor was able to grow on both ammonium- and glycine-containing media. Biomass and growth rate of L. hepaticus and P. involutus on media with ammonium were generally higher than on media with glycine as nitrogen source. Coltricia perennis did not clearly show preference for either ammonium or glycine. Fractal dimensions, calculated from the biomass and radii of the fungi, were in the range 1–3. Fractal dimensions provided extra information about the foraging strategy of mycelia not obtained from growth rate and biomass production measurements, but cannot replace those because the use of fractal dimensions alone may lead to misinterpretation.