A method is described for identifying strains of Metarhizium suitable for use in field experiments. It involves the restriction endonuclease digestion of a PCR product derived from the Pr1 protease gene and the analysis of the fragments by electrophoresis. Using this technique, 40 Metarhizium strains produced 15 different profile types and were clustered into four groups. Correlation between the profile of restriction fragments and geographic origin was observed for certain groups of strains. This PCR strategy allowed the identification of fungal strains, using as samples spores scraped from the surface of single insects killed by the fungus or single whole dead insects with external mycelium. The sequence of the Pr1 PCR product from two strains revealed that Pr1 gene has at least three introns.

Saprobic fungi were identified among the material collected during the Benelux Lichenological Expedition to Papua New Guinea in 1992. These include many widespread species, especially those found on high altitude, some of which are reported here for the first time from the Southern Hemisphere. Papilionovela albothallina gen. et sp. nov. is described and illustrated. Xylopezia is referred to the Hyponectriaceae.

Twenty-six isolates representing six morphologically similar taxa of Tilletia occurring in the western U.S.A. were compared using randomly amplified polymorphic DNA (RAPD) markers and restriction fragment length polymorphisms (RFLP) of the 5·8 s rDNA and flanking ITS regions. Two distinct clusters were separated in the dendrogram based on the RAPD analysis. One cluster contained isolates of T. controversa, Apera interrupta-infecting isolates of a potentially new species of Tilletia, and isolates of the Bromus-infecting varieties bromi-tectorum and guyotiana of the T. fusca (=T. bromi) complex. The second cluster contained Vulpia-infecting isolates of T. fusca var. fusca. The separation of the Bromus-infecting varieties from the Vulpia-infecting variety of T. fusca was supported by distinct restriction digest phenotypes. The RAPD analysis was more sensitive than the RFLP analysis, and allowed separation of the Bromus-infecting varieties bromi-tectorum and guyotiana corresponding to host specificity shown in previous studies. The presence of genetically distinct populations of T. fusca var. fusca occurring on V. microstachys and V. octoflora is indicated by RAPD and RFLP analyses. Species status of T. togwatii, a bunt infecting Poa reflexa that was previously removed from the T. fusca complex, is also supported by RAPD and RFLP analyses.

Three new species of Stenella, S. heterophragmae, S. lantanae and S. buteae occurring on Heterophragma sp., Lantana indica and Butea parviflora, respectively, have been described and illustrated.

The process is described of teliospore germination in Tilletia opaca and T. sumatii leading to the production of basidiospores on basidia, and later the development of ballistospores and blastospores on agar. In both species the basidium shows some evidence of being a condensed dichotomously branched structure. The situation in these two smuts is discussed in relation to that in several other species of Tilletia, and some consideration is given to the origin of the basidium and evolutionary trends within the genus.

Isolates of Cylindrocladium floridanum obtained from diseased roots of white and black spruce seedlings and surrounding soil in bareroot nurseries in Ontario, Minnesota and Wisconsin area were compared by mitochondrial DNA (mtDNA) and ribosomal DNA (rDNA) restriction fragment length polymorphisms (RFLPs), human minisatellite DNA fingerprints and polymerase chain reaction. Nucleotide sequences of rDNA ITS regions of selected isolates were also performed. Based on the nuclear DNA fingerprinting patterns, these isolates could be divided into three groups, namely S1, S2 and S3. Isolates of S1 and S2 showed the same mtDNA RFLPs which were slightly different from that of S3. Isolates representing each of the three groups showed an identical nucleotide sequence of rDNA ITS regions. These data suggest that all the isolates tested belong to the same species which may be divided into three biotypes or populations.

Phaeoseptoria peltigerae is described and illustrated from the thallus of Peltigera horizontalis from Norway.

Epichloë typhina is a biotrophic symbiont of grasses with its sexual state on immature host inflorescences. The ectophytic, presexual structure (stroma) of E. typhina produces spermatia and also serves as the female structure in mating. After fertilization there is proliferation of a dense mycelium which has been suggested to be heterokaryotic. Perithecia form in the thickened stroma. We investigated the possible formation of heterokaryons in matings and the role of ascospores in contagious spread of E. typhina. In almost all instances the transfer to a stroma of spermatia of opposite mating type leads to thickening of the stroma; however, ascospores were produced only if the parents were of the same mating population. Fertilization of part of a stroma by one spermatial parent often inhibited fertilization by another strain elsewhere on the stroma depending upon the spermatial isolates used. Tests for heterokaryon formation were performed by culturing stromata after matings that produced no ascospores, to avoid analysing meiotic products. In two instances the female was cultured, and in two the nuclear and mitochondrial haplotypes were primarily of the male. In another instance mitochondrial haplotypes and mitochondrial plasmids from the female became associated with the male nuclear haplotype. These results suggest that, following mating, male hyphae proliferate and heterokaryons may sometimes form and also proliferate. To test how ascospores mediate infection, inflorescences of uninfected perennial ryegrass plants were surrounded by fertilized stromata from which E. typhina ascospores were being ejected, seeds were collected and grown, newly infected progeny plants were identified, and isolates from five progeny plants were analysed genetically. As expected for ascospore progeny the rDNA haplotype of the stromal and spermatial parents had segregated, whereas all five isolates had the stromal profile of mitochondrial DNA. This observation demonstrated that ascospores mediate infection of new host plants.

Investigations of corticolous fungi in Patagonia have revealed the existence of a new species of Hysterium. H. andinense sp. nov. is described and compared to the related species. H. andicola is synonymized with H. insidens.

Preussia aquilirostrata is newly described from submerged plant debris in Iraq. A key to the identification of Preussia species with hairy ascomata is provided. Since Sporormiella is regarded as a synonym of Preussia, the new combinations Preussia lasiocarpa, P. pilosa, P. pilosella and P. chaetomioides are proposed.

A new species of Chaetomium, C. cuyabenoensis, is described from the Ecuador rain forest. It is similar to Chaetomium longicolleum but differs by having smaller and, in face view, strongly limonifom to quadrangular ascospores.

A new rust fungus on Dioscorea, Cerotelium dioscoreae, sp. nov. is described from Ecuador. Similarity with other phakopsoraceous genera and the assignment of the new fungus to Cerotelium is discussed.

The ability of an unidentified mycobiont from Pisonia grandis mycorrhizas to utilize organic nitrogen and phosphorus sources was determined in axenic liquid cultures. The fungus utilized inorganic phosphate and both freely- and poorly-soluble salts of inositol hexaphosphate as sole phosphorus sources. With the exception of uric acid which did not support growth, the yield of the mycobiont on all organic nitrogen sources tested was significantly greater than the yield on either NH4+ or NO3−. It is suggested that the major ecological role of the Pisonia mycobiont in stands of P. grandis on coral cays may be rapid absorption of allantoin and urea produced during degradation of uric acid by the soil microflora. This may be important in retaining nitrogen in the soil[ratio ]plant system prior to loss from the coral cay by further degradation, volatilization and/or leaching.

Linear mycelial aggregates (rhizomorphs) produced by the squamulose lichens Toninia opuntioides, Squamarina cartilaginea, Lecanora rhizinata, and Acarospora scotica were examined by transmission electron microscopy (TEM). Cytological features typical of lichenized mycobionts were present, including concentric bodies and plasmalemma invaginations. Some septa in rhizomorphs of S. cartilaginea and A. scotica appeared to be multipored. Septal pores were usually plugged by an electron-dense structure. Intrahyphal hyphae were common to abundant in the rhizomorphs of all four species examined. The wall of the invasive hypha was continuous with inner wall layers of the cell of origin. Contacts between adjacent hyphae involved wall dissolution and formation of new wall layers, leading to anastomosis and/or possibly to intrahyphal invasion. Differentiation of an outer layer of collapsed cells in rhizomorphs of Squamarina cartilaginea and of extremely thick-walled cells Lecanora rhizinata was evident, but no anatomical specialization comparable to the ‘vessel hyphae’ of non-lichen linear mycelial organs was observed. Enlarged spheroid or ovoid cells with dense cytoplasm, numerous mitochondria and lipid reserves occurred in short chains in rhizomorphs of Acarospora scotica; infrequently, similar cells were observed singly in those of Squamarina cartilaginea. These cells were reminiscent in shape of certain types of oil hyphae found in endolithic lichens, although often the lipid content of the enlarged cells was not particularly pronounced.

Four inhibitors of the lysine biosynthetic enzyme dihydrodipicolinate synthase (DHDPS) were examined for their effects on the late blight fungus Phytophthora infestans. One of these compounds, dipicolinic acid, reduced mycelial growth of P. infestans by 61% and completely controlled blight infection of leaf discs when used at 1 mM. The other inhibitors, chelidamic acid, chelidonic acid and dimethyl cis-piperidine-2,6-dicarboxylate, were less effective against P. infestans in vitro and in vivo. The effects of dipicolinic acid and chelidonic acid on mycelial growth were partly overcome by the addition of lysine to the growth medium. Both of these compounds reduced DHDPS activity and lysine concentrations in P. infestans, although they had no effect on activities of aspartate kinase and diaminopimelic acid decarboxylase. Both dipicolinic acid and chelidonic acid reduced in vitro activity of DHDPS from P. infestans.

A new nematophagous-predacious hyphomycete, Candelabrella shahriari sp. nov., which captures nematodes by means of adhesive networks, is described and illustrated.

Description and illustration of Chaetasbolisia indica sp. nov. collected on Shorea robusta from India is given.

Two new species of Helicoon, H. myosuroides and H. dendroides, are described and illustrated, and their characteristics are outlined in comparison with similar species. Both species belong to the ecological group of the aero-aquatic fungi and are even more specialized as they only inhabit raised bogs. Their ecological characteristics are discussed in detail.

The growth of three wood inhabiting basidiomycetes (Microporus xanthopus, Pycnoporus sanguineus and Schizophyllum commune) isolated from a tropical coastal forest of Papua New Guinea is characterized in relation to temperature and NaCl salinity. P. sanguineus and M. xanthopus present a very similar response to NaCl salinity, but P. sanguineus has a wider tolerance for temperature variations. S. commune withstands wide temperature variations, but it is the only one to present a marked salt resistance. This correlates with its abundance along the sea. The presence of P. sanguineus in the same habitat is rather unexpected since it is very sensitive to NaCl salinity. Its high growth rate probably allows it to take advantage of periods of high rains that limit salt accumulation.

Moelleroclavus is considered to be an anamorphic genus. The teleomorph of M. penicilliopsis is shown through field observations, collection examination, and cultures to represent a previously unnamed species of Xylaria, X. moelleroclavus sp. nov. Xylaria lingua and X. scruposa are also discussed.