Micropeltopsis cannabis sp. nov. and Orbilia luteola (Roum.) comb. nov. are proposed. New Cannabis host associations include binucleate Rhizoctonia spp., Curvularia cymbopogonis, Sphaerotheca macularis, Glomus mosseae, and Pestalotiopsis sp. The geographic ranges of Pseudoperonspora cannabina, Septoria neocannabina and Fusarium graminearum are expanded.

Sequences of the intergenic spacer between the 28S and the 5S rDNA genes (IGS 1) were compared for three European isolates belonging to three Puccinia striiformis f. sp. tritici races, of different geographic origins and virulence spectra. Two PCR products (IGS 1-1 and IGS 1-2, of 1.3 and 1.1 kb, respectively) were recovered from all spore multiplications. The analysis of IGS 1-1 or IGS 1-2 showed that a low mutational polymorphism existed between the three isolates (from 0.7 to 1.1%) and that each IGS 1 type was characterised by a succession of repetitions. The comparison of IGS 1-1 and IGS 1-2 to each other showed that the polymorphism between the two types of IGS was due to a length polymorphism consisting of a 216 bp insertion/deletion located in the repeated region. Two hypotheses can be proposed to explain the coexistence of two different IGS 1 types within one isolate: either each nucleus of this dikaryotic fungus contains one type of IGS 1 or there are two discrete ribosomal units resulting from recombination in the same nucleus.

Extracts from entomopathogenic fungi of the genus Hypocrella (7 species) and its anamorph Aschersonia (11 species) were screened for cytotoxicity to Sf9 and C6/36 insect cells and L929, BHK(21)C13 and HepG2 mammalian cells. Cytotoxic extracts to insect cells (ID50's[les ]10 μg ml−1) but not to mammalian cells (ID50's[ges ]10 μg ml−1) conformed to the criteria of the project and were considered ‘lead’ extracts for further investigation. ‘Leads’ were found in two of the Hypocrella species: H. discoidea, and H. tamurai and in three of the Aschersonia species: A. samoensis, A. badia, and A. tamurai. Bioassay-guided fractionation of the cell extract of the fungus A. samoensis BCC 1393 led to the identification of two known anthraquinone dimers, (+)rugulosin (1) and skyrin (2) which showed selective toxicity towards insect cells. (+)Rugulosin (1) and skyrin (2) exhibited strong cytotoxic activity against the insect cell line Sf9 with respective ID50 values of 1.2 and 9.6 μg ml−1, but showed weak activity toward mammalian cells. This first report of (+)rugulosin (1) and skyrin (2) in A. samoensis is confirmed and demonstrated in another four strains of A. samoensis isolated in Thailand. The preferential cytotoxicity against Sf9 insect cells gives evidence that these insect-pathogenic fungi of the Hypocrella/Aschersonia group might be useful as an agent for pest control.

Tuberculina species are mitosporic parasites of rust fungi. Phylogenetically they belong to the Urediniomycetidae, therefore being closely related to their rust fungal hosts. We reveal by means of molecular analyses, ultrastructural and morphological features, observations in the field, and infection experiments that species of the genus Tuberculina and the violet root rot (Helicobasidium/Rhizoctonia crocorum) are stages of the life-cycle of one holomorph. This opens up new perspectives on parasitic life strategies as the resulting life-cycle is based on interkingdom host jumping between rusts and spermatophytes. In addition, we point at the consequences for any practical application dealing with Helicobasidium as an economically important plant pathogen and Tuberculina as a biological agent in rust control.

A thermostable extracellular glucoamylase from Thermomyces lanuginosus in static culture was purified to SDS–PAGE homogeneity by fractional ammonium sulphate precipitation, ion-exchange chromatography on DEAE–Toyopearl, Butyl–Toyopearl hydrophobic interaction chromatography, gel filtration on Sephacryl S-300 and ion-exchange chromatography on FPLC MonoQ. The molecular weight of the enzyme, consisting of a single polypeptide, was estimated to be 72000 by SDS–PAGE. The glucoamylase exhibited maximal activities at pH 5·0. The optimum temperature for the activity was 70°C. The enzyme was thermostable at 60° with half-lives at 70° of 20 min and 80° of about 6 min. The glucoamylase was a glycoprotein with 11·4% carbohydrate content. The enzyme hydrolysed soluble starch, amylose, amylopectin, dextrin, glycogen, maltotroise and maltose. Starch was the best substrate.

The identity of strains identified as Trichoderma aureoviride/Hypocrea aureoviridis was reconsidered. Trichoderma aureoviride was isolated originally from a specimen identified as H. aureoviridis and thus is H. aureoviridis. The morphological and molecular characters of most strains identified as T. aureoviride differ from those of the ex-type but are more typical of T. harzianum, a member of sect. Pachybasium. Molecular data do not support inclusion of T. aureoviride in sect. Trichoderma, nor was there strong phenotypic similarity between H. aureoviridis and H. rufa. In the ITS phylogeny the T. aureoviride ex-type and other collections of H. aureoviridis form a strongly supported clade that is separate from any other recognized section of Trichoderma. Hypocrea vinosa, which was originally included in the T. aureoviride aggregate species concept, is distinct from T. aureoviride, but closely allied with H. rufa/T. viride. Trichoderma aureoviride/H. aureoviridis is a rare species, restricted to the UK and the Netherlands. We redefine T. aureoviride, limiting it to strains with very slow growth rate, effuse conidiation, and the ITS-1 and 2 sequence type D.

Sarcodon imbricatus has long been used to extract blue and greenish pigments for wool dyeing. We found that fruit bodies growing with Pinus sylvestris seemed to be superior for dyeing compared to fruit bodies growing with Picea abies, and macroscopical differences between the forms indicated that they are different taxa. By studying sequences of rDNA ITS and macroscopical characters, two species were recognized. Sarcodon imbricatus grows in association with Picea, and S. squamosus with Pinus. The latter species, described by Schaeffer in 1774, has been lumped with S. imbricatus during the past 50 years, creating great confusion among wool dyers.

Colletotrichum acutatum is cosmopolitan and causes diseases in many crops including Hevea brasiliensis. It sporulated freely on PDA at 10–40 °C with peaks at around 15° and 25°. Self-inhibition of spore germination occurred at concentrations above 8×106 spores ml−1. Ultraviolet radiation (especially 254 nm) inactivated the spores. Spore germination was around 90% between 15–35°. Free water promoted spore germination but was not essential; high relative humidity (95%) was sufficient. Spores could also withstand temperatures up to 35°. It is concluded that the most favourable conditions for the spread of C. acutatum are prevalent in the major rubber growing areas in Sri Lanka throughout the monsoons.

Although several new techniques for isolating and culturing lichens have been reported in recent years, there is little information available concerning the variability in development of species from different taxonomic groups. A comparison of the early stages of the germination and growth of Xanthoria parietina (Teloschistaceae), Parmelia saxatilis (Parmeliaceae), Physconia distorta and two Diplotomma species (Physciaceae) was performed on two different media: one inorganic, and the other containing 4% glucose (LBM; Lilly-Barnett medium). Different germination and development rates, and isolation success rate (single- and multispore cultures) are reported. The new combination Diplotomma rivasmartinezii (Barreno & A. Crespo) Barreno & A. Crespo is made.

Cryopreservation of ectomycorrhizal fungi is often difficult, but needed for patent deposits and for enabling experiments on model strains with constant characteristics. In this study we report a protocol for successful cryopreservation of the ectomycorrhizal mushroom Cantharellus cibarius, together with a brief summary of some unsuccessful attempts. A slow freezing rate (0.3°C min−1) of agar cubes carrying the mycelium, and a gentle addition of the cryoprotectants sorbitol and DMSO were important features. This protocol was successfully repeated by ATCC who used it to deposit a patented strain of C. cibarius, and therefore the protocol should also be tested for other ectomycorrhizal basidiomycetes.

Macro- and micromorphology of 124 specimens and 11 holotypes of South American taxa of subgenus Elfvingia (= G. applanatum complex) were examined, and were compared with isoenzymic data previously obtained. Two major dermis types were defined and illustrated. Spore ornamentation was inspected under SEM. Sixty-four per cent of the specimens had an anamixodermis, 80% had spores with longitudinal furrows under SEM and 83% had a context layer without streaks of melanoid deposits. Some of our South American collections could be ascribed to G. lipsiense, G. tornatum, G. testaceum and G. lobatum. Other taxa are critically discussed. The position adopted in this work was to join under synonymy closely related taxa on the grounds of morphology and geographical distribution. In general, correlation between morphological features and isoenzymic patterns could not be established. In this group, phenotypic plasticity appears to be great.

Analysis of 18S rDNA sequence and morphological data indicate that Achlya s. lat. is polyphyletic. Aplanopsis spinosa and Achlya species with subcentric oospores and laterally applied antheridia are transferred to Newbya gen. nov. The relationship of Calyptralegnia and Aplanes androgynus to Newbya is discussed. Molecular data support morphologically based conclusions concerning the relatedness of Pythiopsis and Aplanopsis terrestris. Achlya truncatiformis nom. nov., is provided for material previously identified as Achlya recurva. The following new combinations within Newbya are made: N. pascuicola (type species), N. apiculata, N. braziliensis, N. curvicollis, N. megasperma, N. oblongata, N. oblongata var. gigantica, N. oligacantha, N. polyandra, N. recurva, N. spinosa, and N. stellata combs nov.

Zoospore cysts of four isolates of Aphanomyces euteiches with different host-specific pathogenicity germinated in response to peptone, pea root extract, CaCl2 or gum arabic but, in tests on one isolate, did not respond to several individual sugars, amino acids or polysaccharides. A. euteiches showed differential responses to substances applied at different times in the encystment process. Gum arabic triggered germination only when added to motile zoospores, which it caused to encyst. CaCl2 triggered germination when added to motile zoospores or during vortex-encystment of zoospores, but seldom immediately (<2 min) after encystment. Peptone and pea root extract triggered germination when added to motile zoospores, during vortex-encystment or immediately after encystment, but not ca 20 min after encystment. In comparative tests, Phytophthora parasitica was less stage-specific than A. euteiches, because it germinated in response to gum arabic applied to motile zoospores, during encystment and immediately after encystment.

Zoospore taxis, encystment and germination of A. euteiches and P. parasitica cysts were recorded on pea roots by video microscopy. The speed of germination and pattern of sporeling development on roots were most closely matched by treatment of motile spores with gum arabic in pure culture. The behaviour of A. euteiches conformed to a previous model for Pythium and Phytophthora spp., in which zoospores encyst by recognition of root surface components (simulated by gum arabic), germinate autonomously by a calcium-mediated process (simulated by calcium treatment during vortexing), and the germ-tube produces an assimilative hypha (simulated by peptone or pea root extract).

Aflatoxins (AFs) are secondary metabolites produced mainly by Aspergillus parasiticus and A. flavus. To study AF regulation, previously isolated non-toxigenic A. parasiticus sec− (for secondary metabolism minus) variants were genetically analysed. In parasexual crossing, the sec− strains failed to form heterokaryons and diploids with other sec− strains. Heterokaryon test results suggested that involvement of cytoplasmic elements in the formation of sec− phenotype was unlikely. At the molecular level, the coding sequence of the sec− aflR (the only known positive regulator of AF pathway) was identical to that of their toxigenic sec+ (for secondary metabolism plus) parents. However, the sec− aflR expression was 5- to 10-fold lower compared to that in the sec+ forms. RT–PCR analysis demonstrated that the AF pathway genes were expressed in the sec− forms but in trace amounts and in their unprocessed forms. Combined, these results suggest that aflR is necessary but not sufficient for AF production and that elements involved in fungal development directly or indirectly influence its proper function.

Anaerobic fungi were isolated from both the rumen and faeces of nine sheep and a cow. A reliable and simple method for the isolation of anaerobic fungi using 24 h rumen incubated milled straw as the inoculum source was developed. We also evaluate the use of chitin measurements as an assay of rumen fungal biomass. Chitin levels were determined from various sample sources (milled barley straw used as the fungal culture substrate in vitro; plant particulate digests from the rumen (PLP) and centrifuged strained rumen fluid (CSRF) using both HPLC and colorimetric methods. Both methods were highly correlated and consequently the simpler colorimetric method was adopted for subsequent studies. There was also a high degree of correlation between anaerobic fungal cellulase activities with the assayed chitin content of milled barley straw cultures over 12 d of an in vitro experiment. The colorimetric chitin assay protocol was then used to assess the diurnal variation and abundance of rumen fungi in in vivo assays. We assessed the distribution of chitin (mg g−1 dry matter) in various fractions of the strained rumen fluid (SRF) and PLP samples from the rumen of sheep. Chitin was detected in all fractions of strained rumen fluid but the main source of chitin in the samples may be attributed to the fungal biomass. We did not detect any significant differences in chitin levels over a 24 h sampling period. Finally, an SEM study on subsamples of milled straw and plant particulate matter used in the chitin assays, revealed that the pattern of the fungal development on substrate material differs from the culture medium to the rumen.

The composition and concentration of airborne fungal propagules are probably determined by many interrelated environmental factors, such as temperature, relative humidity, atmospheric pressure, wind speed, rainfall and gas pollutants. The importance of these variables was assessed in an outdoor sampling survey conducted at regular intervals for 12 months at a single site in Turin. Samples were collected with a single-stage volumetric sieve sampler on potato dextrose agar supplemented with 15 mg l−1 streptomycin and 50 mg l−1 chloramphenicol.

Canonical Correspondence Analysis showed that the four ordination axes accounted for 93·5% of the variance in relationships between fungal entities present in more than 20% of samples and the environmental variables. The Monte Carlo permutation test demonstrated that the ordination was highly significant (P=0·01). The community's qualitative and quantitative composition mainly depended on the factors that have the greatest influence on Turin's climate, i.e., in descending order, temperature, relative humidity and rainfall. The relative importance of these environmental variables on different groups of fungi was assessed. Wind speed positively correlated with the fungi producing conidia of larger sizes.

The shelled grains of glutinous broomcorn millet, Panicum miliaceum, were used as solid substrate to prepare granular cultures of Zoophthora radicans, an entomophthoralean biocontrol agent against numerous insect pests. Steamed millet grains were inoculated by mixing 15 g millet grains (D.W.) with mashed pieces of half a 60-mm-dish colony in 3 ml modified Sabouraud dextrose broth and incubated at 15 °C and L[ratio ]D 12[ratio ]12 for up to 24 d. 20 grains were sampled at 3 d intervals from day six onwards and individually assessed for their sporulation capacity using a self-designed device for spore collection. The millet cultures after [ges ]12 d incubation produced 12.0–14.9×104 spores grain−1 during a 7 d period. The maximal sporulation capacity associated with the 21 d-old culture was about half of that of Z. radicans-killed Plutella xylostella larvae (28.7×104 spores cadaver−1), which individually were at least three times larger than the millet grains. Based on the time–concentration–mortality responses of second-instar P. xylostella larvae to Z. radicans in three independent bioassays, the spores ejected from the cultured millet grains, from the mycelial mats from liquid culture, and from larval cadavers displayed insignificant variations in infectivity to the host species, and yielded similar LC50 and LT50 estimates. Conclusively, the millet-based technology for production of granular cultures of Z. radicans was easy, inexpensive and highly efficient, and it could be superior to previous methods used in mass production of mycelium-based preparations of Entomophthorales since this new approach requires no special additives, drying, freezing and milling. This technology may suit to mass production of culturable but nutritionally fastidious entomopathogens from the Entomophthorales.

A protocol for the generation of high yields of viable protoplasts has been developed for several highly branched (colonial) strains of the Quorn® myco-protein fungus, Fusarium graminearum A3/5. Driselase was found to produce higher protoplast yields (ca 109 g−1 wet weight) than the other lytic enzymes tested (Glucanex, Novozyme, β-glucuronidase, Sigma lytic enzyme, or ICN lytic enzyme), although yields differed for the various strains. Protoplast regeneration frequencies of 25–50% were observed when glucose (1·0 M) or sucrose (1·0 M) was used as the osmotic stabilizer. A highly branched strain of F. graminearum CC1-5, which grows better in submerged culture than the more sparsely branched wild-type strain (A3/5) was transformed using the hygromycin B resistance plasmid pAN7-1.

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.