The diversity of ectomycorrhizal mycobionts of Pisonia grandis (Nyctaginaceae) from coral cays in the Capricorn-Bunker group, Great Barrier Reef, Australia, was examined. Only two ectomycorrhiza morphotypes (brown and black) were identified in soil from seven cays and DNA from both morphotypes was subjected to ITS-RFLP and sequence analysis. The brown morphotype was present in soil from all cays but the black morphotype was only observed in soil from three cays. ITS-RFLP analysis showed that the brown and black morphotypes were formed by different fungal taxa, with the RFLP pattern for the black morphotype being consistent with that of the culture previously obtained from black ectomycorrhizal roots on Heron Island. Comparison with the GenBank database revealed that closest matches to both morphotypes were sequences for various Thelephoraceae (Basidiomycota), but the brown and black morphotypes had only 80% sequence similarity to each other. Neighbour-joining analysis of these sequences with sequences for other Thelephoraceae grouped the brown and black morphotypes in a well-supported clade with several Tomentella species, suggesting that both belong to this genus. The data are discussed in relation to ectomycorrhizal fungal diversity and the coral cay habitat.

Podospora anserina and Coprinopsis cinerea (syn. Coprinus cinereus) are endowed with a defence system able to differentiate self vs. non-self and involving the generation of peroxide. Indeed, they produce peroxide when confronted with a filamentous fungus, only in non-self confrontations. Both species are not able to recognize yeasts and show a differential response to bacteria. The accumulation of peroxides in the ascomycete Podospora anserina requires an NADPH oxidase and a MAP kinase cascade, previously shown to be involved in fruit body formation, cell differentiation and cell degeneration. Confrontation is accompanied by the death of the contestant hyphae only in specific combinations of species. As in animals and plants, data suggest that peroxide is likely involved in signalling rather than playing a direct toxic role. Fungi display more complex behaviours than generally acknowledged, i.e. they are able to recognize potential contestants and built up defence reactions involving evolutionary conserved enzymes.

This first contribution of a planned series on the morphology of the Ingoldian fungi discusses three aspects useful for conidial identification, something needed principally in stream ecology and biodiversity surveys: (1) types of propagules found; (2) release organ remnants found on propagules; and (3) conidial tails (or caudal appendages).

(1) Propagules can be unexpectedly varied, and difficulty may be encountered in distinguishing, for example, misshapen conidia from expected ranges in conidial form, or in recognizing the outcome of post-release morphogenesis (involving elongation, branching or fragmentation, the latter resulting in part-conidia of several kinds); autonomous hyphal branching systems resembling branched conidia may undergo disorganized in situ fragmentation; propagules may be compound, the components covering more than one generation of the same morph or even more than one morph; conidial aggregations may behave as single dispersal units; and in one case it may be difficult to distinguish between thalli and propagules.

(2) Conidia secede by means of various specialized structures (release organs) which leave behind remnants of diagnostic value. Among ascomycetous anamorphs are scars (half-septa resulting from schizolysis of release septa), basal collars (portions of lateral walls resulting from rhexolysis or fracture of release or separation cells), and in one case mucilaginous masses (probably the result of the gelification of release cells). The location of scars can sometimes only be inferred by means of other diagnostic characters, and in some instances it cannot even be inferred. This may lead to problems in orientating conidial and consequently in their identification. In the case of release cells, the remnants on the conidium frequently disappear or become indistinct. Among basidiomycetous anamorphs are twin scars (the result of paired schizolysis of the two septa, i.e. the axial and bridge septa, in the release clamp), excentric collars (seemingly the result of a combination of schizo- and rhexolysis of clamp components) and basal collars (the outcome of lysed evacuate conidiogenous cells).

(3) The presence of tails is often inconstant, but where recognizable three types occur which may significantly aid in conidial orientation and hence identification.

In addition, three methodological aspects are emphasized: the effect of the position of the conidium on the appreciation of some diagnostic characters, the need to observe spent conidiogenous structures, and in some cases the necessity of directly observing morphogenesis in order to interpret the conidial form.

Strains of Ophiostoma ulmi, O. novo-ulmi subsp. americana, O. novo-ulmi subsp. novo-ulmi and O. himal-ulmi were examined for optional introns/insertions within the following mitochondrial genes: small subunit RNA gene (rns), large ribosomal subunit gene (rnl) and the cytochrome oxidase subunit I gene (coxI). Insertions were noted in the rns and coxI genes in strains of O. ulmi, the less aggressive species, but absent in strains of the more aggressive O. novo-ulmi subsp. americana. Strains of all species examined had a group I intron present in the U11 region of the mitochondrial-rnl gene. In all but two strains of O. novo-ulmi subsp. americana, this rnl-U11 intron was about 1.5 kb in length whereas a 2.6 kb version of this element was present in all strains representing O. ulmi, O. novo-ulmi subsp. novo-ulmi, and Ophiostoma himal-ulmi. Irrespective of size, this intron based on RNA folds is a class IA1 group I intron and it encodes a putative ORF for the rps3 ribosomal protein. The size variation of the rnl-U11 intron was examined in detail for two strains of O. novo-ulmi subsp. americana and sequence data suggests the presence of a complex ORF within the 2.6 kb version of this intron; here a homing endonuclease-like gene has been inserted in frame and fused to the carboxyl-terminus of the putative rps3 coding region. The mitochondrial optional introns/insertions in combination with nuclear markers might be useful in distinguishing among the various species and subspecies of the O. ulmi s. lat. complex.

A survey of Penicillium albocoremium was undertaken to identify potential taxonomic metabolite markers. One major and four minor metabolites were consistently produced by the 19 strains surveyed on three different media. Following purification and spectral studies, the metabolites were identified as the known protein farnesyl transferase inhibitors andrastin A (1) and barceloneic acid A (2) along with barceloneic acid B (3), barceloneic lactone (4), and methyl barceloneate (5). These compounds are significant taxonomic markers for P. albocoremium; moreover this is the first report of a methyl ester of a barceloneic acid being produced as a secondary metabolite. Tissue extracts created following pathogenicity trials involving P. albocoremium and Allium cepa confirmed the production of these five metabolites in planta. Barceloneic acid B was found to be biologically active against a P388 murine leukemia cell line.

Inter-simple sequence repeat (ISSR) markers were used to investigate genetic diversity among 39 isolates of Beauveria spp. (36 B. bassiana, one B. brongniartii, one B. amorpha, and one B. velata) isolated from different insect hosts and geographical origins. Eighteen among 33 primers that contained different simple sequence repeats (SSR) were chosen for their reproducibility and high polymorphism. Considerable intraspecific and interspecific variability among the isolates of Beauveria spp. was revealed. One hundred sixty-eight highly reproducible fragments were amplified in all 39 isolates with an average of 9.3 markers per primer; among these, 161 (95.8%) were polymorphic. For 36 B. bassiana isolates, 8.9 (1–13) markers per primer were scored, and a total of 123 fragments were amplified, in which 102 (82.9%) were polymorphic. Among the 168 polymorphic bands, 7 bands were considered to be specific for B. brongniartii isolate Bbr06, 14 bands for B. amorpha isolate Ba08, and 18 bands for B. velata isolate Bv01. Within 36 B. bassiana isolates, genetic similarity ranged from 0.651 to 0.972. However, the genetic similarity values among different Beauveria species ranged from 0.411 to 0.720, suggesting that ISSR technique was successful in differentiating the three closely related species from B. bassiana. The results also indicated that there was a certain association between B. bassiana isolates and their geographical origins, but no clear correlation between those isolates and their insect hosts. The present study suggested that ISSR markers can be used as robust molecular markers for the population genetics, epidemiological and ecological studies of entomopathogenic fungi.

The interactions between Pythium oligandrum hyphae and two types of sclerotia, i.e. the plano-convexoid sclerotium of Botrytis cinerea and the tuberoid sclerotium of Sclerotinia minor, were investigated by ultrastructural and cytochemical experiments. In the mycoparasitism of P. oligandrum, some differences in relation to sclerotium anatomy and the role of the rind layer in preventing invasion are documented. Both types of sclerotia showed neither alterations of the heavily melanised rind walls, nor direct rind wall penetration by P. oligandrum. This oomycete successfully entered B. cinerea sclerotia only through breaches at the junction of rind cells and corresponding to gaps in melanin deposits. On the other hand, none of these breaches was observed in the small sclerotia of S. minor, and P. oligandrum ingress in the sclerotia stopped at the inner rind layer. After the penetration of B. cinerea sclerotia by the mycoparasite, it extensively colonised the cortical and medulla areas by intercellular growth. The invaded tissues displayed pronounced alterations as well as some disorganisation of tissue in places. Colonisation was associated with severe chitin degradations of all host walls, which occurred even at some distance from P. oligandrum hyphae. The observation of wall thickenings in some P. oligandrum–hyphae suggests that the sclerotial cells constitute a harsh environment unsuitable for survival of the mycoparasite. These wall thickenings could be interpreted as P. oligandrum defence-like reactions.

A PCR-based technique based on the ITS1-5.8s-ITS2 domain of the rRNA gene for identifying five species associated with Mycosphaerella leaf disease (MLD) of eucalypts was developed. Primer pairs MC2F and MC2R; ML1F and ML1R; MM1F and MM1R; MN1F and MN1R; and MP1F and MP1R amplified a product for DNA extracted from their single target species, those being M. cryptica, M. lateralis, M. marksii, M. nubilosa and M. parva, respectively. The possibility of false positive amplification by each primer pair was tested in reactions with DNA extracts from 16 other Mycosphaerella species associated with eucalypts and against non-infected Eucalyptus globulus leaves. Under the PCR conditions used, there were no false positive amplifications of the 16 non-target Mycosphaerella species, or from non-symptomatic E. globulus leaves for the primer pairs ML1F and ML1R; MM1F and MM1R; MN1F and MN1R; and MP1F and MP1R. The primer pair MC2F and MC2R amplified a 402 nt product from both the target M. cryptica and non-target M. nubilosa. However, these two species were differentiated by digesting the product with the restriction enzyme Sacc II which resulted in a single 402 nt product for M. cryptica, and two products of 78 and 324 nt for M. nubilosa. All of the primers were able to detect their target Mycosphaerella species from Eucalyptus globulus lesions. PCR reactions with these primers on DNA extracted from Mycosphaerella lesions confirmed the presence of all five species from leaf material collected from three plantations in Western Australia.

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 Lulworthiales consists of four genera: three that were removed from the Halosphaeriales, namely Lulworthia, Lindra, and Kohlmeyeriella; and Spathulospora, reassigned from the Spathulosporales. However, studies have shown that neither Lulworthia nor Lindra are monophyletic genera. This study was therefore undertaken to re-evaluate the genera of the Lulworthiales based on the SSU and LSU rDNA genes. Taxonomic revisions are proposed here for Lulworthia crassa, L. lignoarenaria, L. uniseptata and Lindra marinera: Lulworthia crassa is transferred into the genus Kohlmeyeriella; Lulwoidea gen. nov. is established for L. lignoarenaria; Lulwoana gen. nov. is established for L. uniseptata; and Lindra marinera is reduced to synonymy with L. thalassiae. Taxonomic descriptions are emended for the genus Lulworthia s. str., and for L. grandispora and Lindra thalassiae. A neotype is designated for Lulworthia grandispora.

A cDNA encoding a chaperone ClpA homologue of Paracoccidioides brasiliensis was isolated and characterized. The ClpA belongs to a group of ClpATPAses proteins, which are highly conserved, and include several heat inducible molecular chaperones. In this study, a 2879 bp cDNA designated as Pbclpa was obtained which encodes a predicted protein of 927 amino acids. Characteristic consensus motifs of the ClpATPases family are present. The PbClpA middle region was compared to other related ClpA and ClpB proteins from fungi and bacteria. Comparative analysis demonstrated in the middle region the presence of a heptad repeat sequence, characteristic of ClpBs from prokaryotes and fungi, which are absent in ClpAs from prokaryotes but were present in all described fungal ClpAs. Our comparative analysis reveals that one of the criteria typically used to distinguish the prokaryotic subfamilies ClpA and ClpB, the size of the middle sequence, may not be useful in fungi. Phylogenetic analyses were performed with the complete sequences of ClpAs from fungi and bacteria and with the middle regions of those ClpAs present at NCBI and Pfam databases. Our results indicated that both types of analysis can be useful as a tool in the determination of phylogenetic relationships.

Claviceps purpurea specific to grasses in salt marsh habitats (Group G3) has previously been identified on Spartina spp. in two locations: New Jersey, USA and southern England. We have identified this subgroup of C. purpurea (G3) in 11 distinct populations including western Europe, South America, and along the Atlantic and Pacific Coasts of the USA. In addition, G3 C. purpurea was discovered on a new host grass genus, Distichlis. Unweighted pair group mean analyses of AFLP and RAPD data reveal distinct structure in G3 C. purpurea populations. Pacific coast populations show little diversity, suggesting they may have been introduced recently in that region. 43 isolates, representing 11 populations were identified as G3 based on the presence of an EcoRI restriction site in the 5.8S ribosomal DNA, and a clear genetic separation from isolates representing the other two C. purpurea subgroups (G1 and G2). In addition, all isolates originating from Spartina densiflora, S. foliosa, S. alterniflora, and S. anglica were identified as belonging to G3. RAPD and AFLP analyses supported the recognition of three discrete groups within C. purpurea and revealed high genetic variability between groups, with only 1.8% of polymorphic markers shared across all isolates. Similarly, analysis of molecular variation (AMOVA) revealed that genetic variability was mainly due to variations between groups (63.5%) rather than within groups (28.5%) or within populations (7.96%). G3 isolates were 35% similar, Pacific coast isolates 83% similar. Ninety percent similarity among isolates from the San Francisco Bay Area suggests this is a recently introduced population.

Although, oxidative stress response, which protects organisms from deleterious effects of reactive oxygen species (ROS), has been extensively studied in pro- and eukaryotes, the information about filamentous fungi is fragmentary. We investigated the effect of two ROS-generating agents (paraquat, PQ, and H2O2) on cellular growth and antioxidant enzyme induction in 12 fungal species. Our results indicate that exposure of fungal spores or mycelia to PQ and H2O2 promoted oxidative stress, as evidenced by remarkable inhibition of spore germination and biomass production; stimulation of cyanide-resistant respiration; accumulation of oxidative modified proteins. Cell responses against both superoxide and peroxide stresses include enhanced expression of superoxide dismutase (SOD) and catalase, however, the extent was different: treatment with PQ increased mainly SOD, whereas exogenous H2O2 led to enhanced catalase. We also found that G6PD has a role in the mechanism of protection against superoxide and peroxide stresses. The activation of antioxidant enzyme defence was blocked by the translation inhibitor, cycloheximide, suggesting that there was de novo enzyme synthesis.

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.

Teliospores, basidia, cultures, hyphal septations, cellular interactions and nucleotide sequences from the D1/D2 region of the nuclear large subunit ribosomal RNA gene of Entyloma ossifragi occurring on Narthecium ossifragum (Nartheciaceae) were examined and compared with findings in the Georgefischeriales and other Ustilaginomycetes. The data show that Entyloma ossifragi is a member of the Georgefischeriales. Among the Georgefischeriales, Entyloma ossifragi morphologically is very similar to Jamesdicksonia species, but differs from this genus and all other Georgefischeriales by the formation of dolipores without striations that become closed during teliosporogenesis. In addition, in our molecular phylogenetic analyses Entyloma ossifragi stands well apart from Jamesdicksonia, forming with some Tilletiopsis specimens a statistically supported cluster. Accordingly, the genus Gjaerumia gen. nov. and the family Gjaerumiaceae fam. nov. are proposed to accommodate Entyloma ossifragi in the Georgefischeriales. The new combination G. ossifragi (syn. Entyloma ossifragi) is made.

More than 90 species are accepted in the xylariaceous genus Rosellinia. Thorough morphological characterisation of all known species will provide a taxonomic hypothesis that can be later tested by DNA sequence analysis. Exploratory analyses of ascospore morphology, shape of ascus apical structure, and anamorph genus suggest six morphological groups in the genus.

21 strains with all typical morphological characteristics of eight Verticillium species (Phyllachorales) were studied in this work, together with representatives from four Hypocreales species (11 strains), that were previously classified as members of the genus. The PCR products from two nuclear genes, i.e. the ITS1-5.8S-ITS2 region and RNA polymerase II largest subunit gene (rpb1), together with four mitochondrial genes, i.e. the small ribosomal rRNA subunit (rns), the two NADH dehydrogenase subunit genes (nad1 and nad3), and the cytochrome oxidase subunit III gene (cox3) were sequenced and analyzed. Similarly, antibodies raised against one strain of each of the species examined (V. nubilum and V. theobromae excluded) were used against the proteins of all other strains. The number and relative area of precipitates formed after crossed electrophoreses served to estimate the degree of immunochemical relatedness. Combined molecular and immunochemical data clarified the phylogenetic relationships of all true Verticillium species and provided a convincing insight into the evolutionary relation of the sect. Nigrescentia with members of the sect. Verticillium and sect. Prostrata that until recently were included in Verticillium.

We examined the phylogenetic position of Omphalina foliacea and its putative closest relative, the lichen-forming basidiomycete Lichenomphalia lobata. Both species are restricted to specific habitats in the high andine regions of tropical America. We generated nuclear ITS and LSU rDNA sequences of two collections of each species and analysed the data together with sequences of omphalinoid basidiomycetes retrieved from GenBank using a Bayesian and a maximum parsimony approach. Our analyses show that both, O. foliacea and L. lobata are lichenized basidiomycetes. L. lobata is related to other species of the genus Lichenomphalia, whereas O. foliacea is not closely related to other Omphalina or Lichenomphalia species, but probably belongs in the hymenochaetoid clade. The analysis of a nuclear LSU data set of a broader sampling of hymenochaetoid basidiomycetes supported the placement of O. foliacea in this clade, but did not reveal any close relative.