As part of an inventory of mycodiversity in the Brazilian Cerrado new coelomycetes were collected and are herein described: Phyllosticta xylopiae-sericeae sp. nov., Dinemasporium duguetiae sp. nov., Harknessia salvertiana sp. nov., Harknessia qualeae sp. nov. on living leaves of Xylopia sericea, Duguetia furfuracea, Salvertia convallariodora, and Qualea grandiflora, respectively. Pseudothiopsella hirtellae is reported on a new host, Hirtella gracilipes, and for the first time illustrated in detail.

A new species of Zoophagus, Z. cornus, capturing loricate rotifers on short peg-like traps, was isolated from paddy field mud in Ibaraki, Japan. The fungus produced long, narrow, cylindrical, aseptate conidia. Azygospores containing a large vacuole were produced directly from the hyphae.

Several isolates of the entomopathogenic Metarhizium anisopliae that harboured dsRNA viruses of similar electrophoretic band sizes (1.8 and 2.0 kbp) were assessed for homologies of the dsRNA by Northern analysis. The isolates were also characterised genetically by RAPD and VCG. Similarly sized dsRNA, as visualised by electrophoresis, were not always homologous, suggesting that the comparison of dsRNA based solely on electrophoretic banding patterns is an unreliable method of dsRNA characterisation. Several isolates, but not all, harbouring multiple dsRNA patterns, including a 1.8 and 2.0 kbp doublet, also showed homologies to strains harbouring only the dsRNA banding doublet. This suggests that mixed infections of different dsRNA elements are found in M. anisopliae. Genetically similar fungi, based on RAPD banding patterns and vegetative compatibility, were more likely to harbour genetically related dsRNA. The findings suggested that dsRNA elements in M. anisopliae are horizontally transferred to genetically related isolates or are maintained through clonal lineages.

Phomopsis cucurbitae is a latent infection fungus which causes muskmelon fruit decay only after harvest. It can cause severe losses during fruit storage and marketing in the U.S.A., Japan and some Central American countries. Previous studies showed that P. cucurbitae produced polygalacturonase (PG) in both culture and muskmelon fruit tissue. In this study, a prominent PG isozyme (PG1) produced by P. cucurbitae in decayed fruit was purified to homogeneity by a procedure of extraction, ultrafiltration, preparative isoelectric focusing, anion exchange, and gel filtration chromatography. The isozyme had a primary endo-activity, a relative molecular weight of 54 kD according to SDS-PAGE, and a pI of 4·2 based on IEF-PAGE. The isozyme was active in a low pH range from 2 to 6, and was optimum at pH 5. Optimum temperature for the activity of PG1 was 40–45°C. The Km and Vmax on polygalacturonic acid were 44·7 μg ml−1 and 0·14 U μg−1 enzyme, respectively. The purified PG1 effectively macerated mature fruit tissue, suggesting that the isozyme may be involved in the pathogenesis of Phomopsis fruit rot of muskmelon.

The objectives of this study were to examine genetic variation, physiological dissimilarities and diversity in pathogenicity between Verticillium fungicola var. aleophilum and var. fungicola and within a population of six V. fungicola var. fungicola strains responsible for dry bubble outbreaks on mushroom farms. Genetic variability was investigated using random amplification of polymorphic DNA (RAPD). Mycelial growth rate, extracellular enzyme production and susceptibility to hydrogen peroxide were used to examine physiological dissimilarities. Variation in pathogenicity was studied both in vitro and during mushroom cultivation. All the physiological properties studied indicated that var. aleophilum isolates were potentially more efficient than var. fungicola isolates for rapid colonisation of the mushroom cultivation medium. They could then interact more efficiently with Agaricus bisporus to produce dry bubble disease. RAPD analysis confirmed that all the French isolates belonged to var. fungicola, and two isolates were distinguishable from the homogeneous group constituted by the others. These isolates had a higher mycelial growth rate and lower extracellular enzyme activities in liquid media, except for chitinases. Their spores were more susceptible to germination inhibition by hydrogen peroxide, and they were responsible for higher levels of affected mushrooms. The two varieties might be regarded as pathotypes that are geographically isolated, and variation in isolates of var. fungicola might have consequence for mushroom growers.

A 3193 bp contiguous sequence has been cloned from the oleaginous fungus Mucor circinelloides, that contains a full-length gene encoding a putative NADP+[ratio ]dependent malic enzyme (EC. 1.1.1.40). The cloned DNA contains a 2154 bp putative open reading frame containing five introns and encoding a protein of 616 amino acids. The gene encoded what appeared to be an anaerobic isoform of malic enzyme (isoform II); this conclusion is supported by transcript analysis and by the fact that the ORF contains an N-terminal mitochondrial target sequence (a similar cellular location was identified for the anaerobic malic enzyme in Saccharomyces cerevisiae; Boles et al. 1998). The cloned gene did not encode either isoform III (the isoform associated with active growth) or isoform IV (associated with lipid accumulation) previously identified. M. circinelloides therefore must possess (at least) two structural genes for malic enzyme.

The phylogenetic relationships of Tholurna dissimilis were investigated in relation to a phylogeny of twenty-three species in Caliciaceae and eighteen species from Physciaceae. ITS and LSU regions of the nuclear ribosomal DNA were used for the reconstruction of phylogenies by maximum parsimony methods. Calicium adaequatum was shown to be the closest relative of and possibly congeneric with Tholurna. Calicium is thus not monophyletic unless Tholurna is included. Calicium in the molecular phylogeny contains several distinct clades, which to some extent can be characterized morphologically. Cyphelium in a traditional sense is probably not monophyletic. Cyphelium s. str. has immersed apothecia, large smooth spores and a very thin excipulum throughout. C. inquinans and C. karelicum, which form a distinct and highly supported clade, may be accommodated in Acolium, possibly along with other Cyphelium and Calicium species. The phylogenies presented here do not support the recognition of neither Physciaceae nor Caliciaceae in a narrow sense, but they also do not exclude this. Numerous spliceosomal and unclassified insertions were found in the LSU sequences. They to some extent offered phylogenetic information both with respect to location and by their sequence similarities.

The entomopathogenic fungus Metarhizium anisopliae is generally considered to be mesophylic, although some isolates have the ability to grow at 8 °C. In two cold-active isolates (DAT-1 from Tasmania and CLB2-1vi from Ontario, Canada) and one non-cold-active isolate (Ma 2575 from South Carolina), we (1) analyzed cold-induced intracellular proteins, using two-dimensional (2D) gel electrophoresis, and (2) analyzed cold-active transcripts, using a polymerase chain reaction (PCR) based subtractive hybridization technique. Protein differences, as observed by 2D gel electrophoresis, were observed in cold active isolates grown at 8 ° when compared with 25 °, but such differences were not observed in the non-cold active isolate. Fungi were also subjected to various stresses (45 °, pH, and salinity) to determine how proteins induced under these conditions compared to proteins induced under low temperature growth. Proteins induced were either specific to cold-active growth or were general stress proteins and differences were also observed in 2D patterns between the two cold-active isolates. Transcripts upregulated during growth at 8 ° and isolated by a PCR based subtractive hybridization technique also differed between the two cold-active isolates. Analysis of the transcripts showed several novel sequences but also included transcripts with similarities to actin, NADPH quinone oxidoreductase, a thiamine biosynthesis protein and a yeast-like membrane protein. The potential role of these proteins in cold-active growth is discussed.

The 29 spore-ball-forming smut fungus genera (of the total 58 recognized genera) are analysed, grouped, briefly characterized and illustrated. Problems within the genera, similarities, possible relationships and differences between genera are discussed. The following groups and genera are treated: genera with spores in pairs (Schizonella, Mycosyrinx, Geminago), genera with permanent spore balls composed of colourless spores and sterile cells and/or modified mycelia (Burrillia, Doassansia, Doassansiopsis, Heterodoassansia, Nannfeldtiomyces, Narasimhania, Pseudodoassansia, Tracya), genera with permanent spore balls composed of pigmented spores and sterile cells (Urocystis, Moesziomyces, Dermatosorus, Testicularia), and genera with spore balls containing only spores and lacking sterile cells between the spore balls. Within the latter group, the two sub-groups were distinguished: one with light, brownish spores (Sorosporium, Thecaphora, Glomosporium, Fulvisporium), and another one with dark, blackish spores (Tolyposporium, Tolyposporella, Clintamra, Orphanomyces). Heterotolyposporium has small, hyaline spores between the pigmented spore balls. Sporisorium and Macalpinomyces have sterile cells between the true or pseudo spore balls. Odd genera are: Ustacystis, Mundkurella and Uleiella. A key to the spore-ball-forming genera of smut fungi is given. The value of the spore balls in the taxonomy of the Ustilaginales is discussed. The arrangement of the genera in groups is based on the most important characters of the spore balls. It has a practical, didactic purpose and in many cases the groups do not reflect natural relationships.

Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis of the first intergenic region (IGR1) of nuclear ribosomal DNA was used to clarify the relationship between IGR1 variations and six Japanese biological species of Armillaria: A. gallica, A. nabsnona, A. ostoyae, A. cepistipes, A. mellea and Nagasawa's E (Nag. E: taxonomically unknown species). The procedure was then used to identify Armillaria species associated with Wynnea species (W. americana and W. gigantea) and Entoloma abortivum. By combining the RFLP patterns obtained using three endonucleases, HaeIII, HinfI and MspI, the IGR1s from 18 isolates of six Armillaria species were assigned to nine different RFLP phenotypes and the six species were distinguished from each other. Each of the RFLP phenotypes from the Armillaria isolates associated with Wynnea species or E. abortivum matched a corresponding phenotypes observed among the six Armillaria species. Based on this, all four isolates from W. gigantea were identified as A. mellea, two from W. americana as A. cepistipes, and all three from E. abortivum as Nag. E. These results provide new information on the biological species of Armillaria associated with Wynnea and E. abortivum.

The identification of Trichoderma strains is important for their application as biocontrol agents. We used a two-dimensional analysis, in which extracellular proteins of Trichoderma harzianum strains T-35, Y and TM were first separated according to their isoelectric point and then according to their molecular mass. Chitinase activities were detected in situ after the second separation. Each of the three strains exhibited a unique pattern of 3–5 different chitinases (1 or 2 N-acetyl-β-glucosaminidases, and 2 or 4 endochitinases). These unique profiles can be used to differentiate among strains within this species. The suggested procedure makes use of a property of T. harzianum that is directly involved in the mycoparasitic interaction, making it suitable for specific biocontrol applications.

To test the validity of R. tauricus as a separate species, its carbon source utilization, isoenzyme patterns and PCR-coupled RFLP of the ITS of its rDNA were analysed. Whilst R. tauricus differed considerably from R. pusillus and R. miehei in morphological traits as well as its ability to row on single carbon sources, the results obtained from all other experimental approaches suggest extensive similarity between R. tauricus and R. pusillus. These findings lead us to believe that R. tauricus is a mutant heterothallic strain of R. pusillus.

Urediospore-derived infection structures of Phakopsora apoda, a rust fungus on kikuyu grass (Pennisetum clandestinum), penetrate the host leaf directly through the cuticle and not through the stomata. A urediospore germinates on the leaf to form a short germ tube which is delimited from a terminal appressorium by a septum. Most appressoria form at the junctions between epidermal cells. Appressoria are often sessile to the urediospores. From the base of the appressorium, a penetration peg develops, which penetrates through the host cuticle and epidermal cell wall. Penetration of the epidermal cell wall occurs approx. 6 h post inoculation. Once inside the epidermal cell, the penetration peg expands to form a penetration hypha, which traverses the epidermal cell and emerges into the intercellular space of the mesophyll tissue. A septum is formed in the intercellular portion of the penetration hypha, delimiting a primary hypha which extends further into the mesophyll, before branching to form two secondary hyphae. This penetration process appears to be very similar to that of Phakopsora pachyrhizi on soybean.

Haptoglossa dickii is a biflagellate zoosporic parasite of bactivorous nematodes. The walled encysted zoospores germinate more or less synchronously to produce specialised infection cells known as gun cells. This paper documents the changes in the main cytoplasmic organelles, namely the nucleus, Golgi body, mitochondria, lipid droplets and dense-body vesicles, from the onset of encystment until the formation of the mature gun cell. The septum-delimited gun cells show a marked polarity in the distribution of their organelles from their inception, which seems in part determined by the temporal order by which the main organelles migrate out of the cyst and into the gun cell initial. In this species the majority of dense-body vesicles and mitochondria precede the nucleus and lipid droplets. The nucleus remains more or less central throughout the remaining course of gun cell differentiation. The single nucleus associated Golgi body changes its orientation to track (possibly even determining) the spatial position of the ingrowing injection tube. The mitochondria fuse to form one or more complex reticulate structures which are aligned close to the injection tube throughout its formation and which in the mature cells form a fine network entwined around the fully differentiated tube. The vesicles containing electron-dense inclusion granules (dense-body vesicles) are initially concentrated towards the gun cell anterior, but later migrate to the posterior end of the cell and fuse to give rise to the basal vacuole. Some of the likely functional aspects of these cytoplasmic changes are discussed.

Beauveria bassiana is an entomopathogenic fungus with a growing potential for pest control in different agro-ecosystems worldwide. Such potential brings the necessity of developing a strain specific typing system. In a previous study, we reported the identification of molecular variants in mitochondrial DNA (mtDNA) polymorphism in 15 North American isolates. Results indicated a highly conserved mitochondrial genome showing only two mitochondrial genotypes (mitotypes). In this study we used whole genomic DNA from 18 isolates of B. bassiana, two unidentified Beauveria spp., and one each of B. amorpha, B. cylindrospora and B. nivea from more diverse origins. By doing single- and double-restriction enzyme digestion of total genomic DNA with EcoRI, and HindIII and then probing with BbmtE2, the predominance of mitotypes A and B was observed again, along with three newly described mitotypes (C to E). Additionally, by using whole B. bassiana mtDNA digested with HpaII as probe, we further demonstrate up to nine different mitotypes within B. bassiana. With either of the two probes, distinguished between members of the genus Beauveria and from Paecilomyces farinosus and Metarhizium anisopliae. Phylogenetic analysis could not however distinguish B. amorpha and B. nivea isolates from B. bassiana, suggesting a close genetic relation between the three species of the genus. Altogether, these results show high variability in mitochondrial genome, which can be useful as a reliable tool for the biopesticide industry for both species and isolate specific identification.

The following foliicolous fungi on Tabebuia species are described and illustrated: Anhelia tabebuiae sp. nov. and Dictyonella tabebuiae sp. nov. (ascomycetes), Fumagospora tabebuiae sp. nov., Polychaeton tabebuiae sp. nov. and Septoria tabebuiae-impetiginosae sp. nov. (coelomycetes), Cercospora tabebuiae-impetiginosae sp. nov. and Pseudocercospora tabebuiae-roseo-albae sp. nov. (hyphomycetes). Uncinula peruviana was found and described on T. impetiginosa as a first record for Distrito Federal, Brazil.

Heterothallism was confirmed in Mortierella umbellata from Japan. Anisogamic zygospore formation is described and illustrated with time-lapse light micrographs. The anisogamic behaviour of the species is discussed with reference to previous studies on anisogamic zygospore and azygospore formation in Zygomycetes.

Myconymphaea yatsukahoi gen. sp. nov. is described in the Kickxellaceae (Kickxellales, Zygomycetes). The fungus is characterised by unicellular sporocladia formed on apical vesicles of sporangiophores, conspicuously long sporangiospores and peculiar septal plugs with prominent protuberances. In addition, a key to all known genera of the Kickxellales is provided.

Paraphaeosphaeria barrii, a new species of the genus found on Agavaceae, is described from leaves of Yucca schidigera collected in Baja California, Mexico. The Coniothyrium anamorph is briefly described from cultured ascospores. This species was found to be most closely related to P. conglomerata, P. filamentosa, and P. quadriseptata all of which are from Agavaceae, produce 3 or 4 septate ascospores and pigmented, non-septate conidia from holoblastic, percurrently proliferating conidiogenous cells.

Crossing and selfing experiments were carried out with six field collections and five isolates belonging to three formae speciales, larici-epitea typica (LET), larici-daphnoides (LD), and larici-retusae (LR), of willow rust, Melampsora epitea. European larch (Larix decidua) was inoculated with basidiospores produced on overwintered telial leaves and the resulting spermagonial lesions on larch needles subsequently paired in vitro. In two crosses between LR and LD involving a total of 439 lesion pairs, only two cultures obtained were identified as hybrids. These two cultures were non-pathogenic to the maternal host Salix burjatica cv. Korso and weakly pathogenic to the paternal host S. daphnoides cv. Meikle. No identifiable hybrids were obtained from 56 lesion pairs between LET and LD. In a cross between LET as receptor and LD as donor, one-third of the lesions formed aecia. In the reciprocal combination, however, less than 1% developed aecia. All F1 cultures between LET and LR were weakly pathogenic to the parental hosts S. viminalis cv. Mullatin and S. burjatica cv. Korso. When three of the F1 cultures were used to produce telia, only one developed mature teliospores. Subsequent selfing experiments showed that this culture was predominantly self-sterile, with only 1% of lesions producing aecia. In selfing and crossing two pathotypes within the same f. spp., 20–40% of needles produced aecia and the rate of aecial formation was similar in both directions. The results obtained suggest that M. epitea is heterothallic and the sexual compatibility is controlled by a pair of alleles at a locus. It is concluded that the three f. spp. are genetically different populations and ecologically fit new pathotypes cannot arise easily as a result of hybridization between them. Within a f. sp., however, many pathotypes exist or will occur due to exchange of genes for virulence during the sexual life-cycle.