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.

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.

Radiata pine (Pinus radiata) lumber from Australia, Chile, and New Zealand is imported into Korea where it represents one of the most important sources of timber. Blue stain of this timber is a serious problem for which an integrated control strategy is being developed. One of the fungi that has been isolated from stained radiata pine sapwood in Korea is a Leptographium sp. that has a distinct Sporothrix synanamorph. The aim of this study was to classify this fungus. Morphological comparisons showed that this fungus is distinct from all other species of Leptographium and especially L. elegans and L. francke-grosmanniae that also have Sporothrix synanamorphs. Comparisons of sequence data for the ITS2 and part of the 28S rDNA genes as well as the β-tubulin gene also confirmed that this fungus represents an undescribed taxon, described here as Leptographium bistatum sp. nov.

Eleven new intertidal fungi Aniptodera intermedia, Anthostomella nypae, Anthostomella nypensis, Anthostomella nypicola, Helicorhoidion nypicola, Herpotrichia nypicola, Leptosphaeria nypicola, Lignincola nypae, Phomatospora nypicola, Trichocladium nypae, and Vibrissea nypicola spp. nov., are described from Nypa fruticans. These new species are compared with existing species in the genera and illustrated with interference light micrographs.

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.

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.

The relation between the pattern of fumonisin production and the mating population and mating type of Fusarium isolates from maize in Argentina at different maturity stages has been evaluated. Fifty-one isolates of Fusarium species belonging to the Liseola section were identified to mating population and tested for their ability to produce fumonisins (FB1, FB2 and FB3). Only mating populations associated with maize, A (Fusarium moniliforme, 23 isolates), D (F. proliferatum, 24 isolates) and E (F. subglutinans, 4 isolates) were found. All but two isolates of populations A and D produced, when grown on maize substrate, high levels of fumonisins ranging from 0·01 to 3·99 mg g−1 (mean 2·00 mg g−1 and 1·69 mg g−1, respectively), whereas isolates of population E yielded less than 0·02 mg g−1 (mean 0·01 mg g−1). Five isolates of F. proliferatum, all belonging to mating type D−, produced more FB2, than FB1, which is consistent with finding a relatively large amount of FB2 (0·01 mg g−1; FB2/FB1=2·27) in one of the maize samples from which these isolates were obtained. Amounts of FB3 were similar to FB2 in cultures of mating population A (mean FB3/FB2=0·89), but much lower than FB2 in cultures of mating population D (mean FB3/FB2=0·21).

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.

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.

The teleomorph of Phoma medicaginis var. pinodella is reported for the first time. A single isolate, collected from infected plant material in Australia, produced asci and ascospores in culture. The anamorph was identified as Phoma medicaginis var. pinodella on the basis of axenic colony morphology, symptoms on the foliage of a susceptible pea line and characteristic hybridization banding patterns observed during RFLP analysis. The ascospores and asci, although similar in morphology to those produced by Mycosphaerella pinodes, were considerably larger. Therefore, the binomial assignment of the teleomorph remains open to speculation. The potential impact on disease dissemination and effectiveness of control measures against P. medicaginis var. pinodella are discussed.

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.

During the course of a survey of sapstaining fungi in Korea, a Leptographium was isolated from Pinus densiflora and P. koraiensis logs, infested with the bark beetle Tomicus piniperda. The fungus grew optimally at 25 °C on 2% malt extract agar and showed a high level of tolerance to cycloheximide. The Leptographium has unusually short conidiophores and is morphologically similar to L. pini-densiflorae, L. lundbergii, L. yunnanense, and the Leptographium anamorph of Ophiostoma crassivaginatum. Comparisons of DNA sequence data for three gene regions, as well as morphological characteristics, confirmed that this fungus represents an undescribed taxon. We consequently provide the name Leptographium koreanum sp. nov. for it here.

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.

Podosphaera tridactyla (Ascomycota: Erysiphales) is a morphologically variable species occurring on Prunus s. lat. In order to assess the genetic variation within this species, the rDNA ITS region was amplified from 29 specimens from a range of Prunus species collected in Australia, Switzerland, and Korea. RFLP analysis of the PCR products revealed six groups, and a comparison of sequences from representatives of these groups revealed three clades: Clade 1 contained all specimens from Prunus subgen. Prunus; Clade 2 specimens from a variety of Prunus subgenera, except subgen. Prunus, and Podosphaera longiseta was closely allied to this clade; and Clade 3 contained two specimens, from Japan and Korea. Phylogenetic analysis comparing P. tridactyla with of a range of Podosphaera species suggests that P. tridactyla is paraphyletic.

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.

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.

Accurate identification of Alternaria spp. is dependent upon the production of diagnostic morphological characters under defined cultural conditions and the proper assessment of character variation. This process is often compromised by variation in laboratory facilities and technical expertise. To assist taxon identification and phylogenetic studies, restriction site information from the intergenic spacer (IGS) region of nuclear rDNA was evaluated. Restriction maps were constructed from 15 species of Alternaria and Stemphylium botryosum (telemorph Pleospora herbarum) for 11 restriction enzymes using a new method for restriction mapping based on differential priming of IGS amplicons. IGS fragment size varied among species from 2.2–3.9 kb. Based upon restriction site homology among closely-related and more distantly related species, the IGS region could be divided into conserved and variable domains. The conserved domain was approximately 0.75 kb in size and was located at the 3′ end of the IGS region. Restriction site homology within this region was very high, especially among closely related taxa. The remainder of the region comprised the variable domain, which encompassed considerable differences in size and restriction sites among taxa. The presence or absence of restriction sites among taxa was analyzed using methods of neighbor-joining. Phylogenetic relationships based on this method were concordant with those previously resolved based upon other methods and other genomic regions.

Nine species of Trametes and five other wood inhabiting basidiomycetes, were collected from the indigenous forests of Zimbabwe and analysed for cellulases, ligninases, extracellular phenolases and wood degrading ability for the first time. Cellulase enzyme activities varied widely among the species. After 15 d growth exo-glucanase activity had increased in the majority of species whilst filter paper activity showed the opposite trend, being greatly reduced in all species on day 15 compared to day 10. Endo-glucanase activity was relatively uniform at both sampling times. The fungi were more active against water soluble cellulose derivatives than filter paper cellulase. In all the fungi tested, cellulose activity on filter paper was significantly less than endo- and exo-glucanase activities. The highest cellulase activity was expressed by Cerrena meyenii (683 U mg−1) Phaeotrametes decipiens, Trametes modesta, and T. pocas also expressed relatively high cellulase activity on all types of cellulose tested. All Trametes species tested positive for extracellular phenol oxidases whilst Fomotopsis spragueii and Irpex stereoides tested negative. All but one of the Trametes species in the study were able to degrade two different lignin preparations in tests for lignin degradation. T. menziesii was unable to degrade both lignin preparations although it had tested positive for production of extracellular oxidase. The species in this study degraded hardwood to a greater extent than softwood. Eight of them caused more than 80% dry weight loss of wood blocks during 70 d incubation. Those fungi that expressed high cellulase activity also caused high weight loss on wood.