Pronase E and tunicamycin, a putative inhibitor of protein glycosylation, strongly reduced the frequency of germlings adhering to smooth polystyrene and completely inhibited appressorium formation of adhering germlings without inhibiting germ-tube growth of the pathogen. Additionally, α-mannosidase or α-glucosidase, but not β-glucosidase or lipase, partly inhibited adhesion to smooth polystyrene and substantially inhibited appressorium formation by germlings adhering to this substrate. Infection structure formation was also reduced by the addition of either lectins binding to mannose or glucose residues (ConA and LCA), or by the addition of IgG. The presence of ConA- and IgG-binding (glyco)proteins among proteins obtained from the germination fluid, or from differentiated germlings, has been confirmed on Western blots. Removal of proteinaceous surface material by pronase E inhibited appressorium formation on smooth polystyrene. After the protease was removed, newly formed ConA-binding glycoproteins have been detected at the germ-tube apex with FITC-conjugated ConA. The (re)appearance of these glycoproteins was correlated with the time period when appressorium formation was observed. Interestingly, removal of proteinaceous materials from the germ-tube surface by pronase E, and also the addition of IgG had no inhibitory effect on appressorium formation on furrows in polystyrene.

Our results suggest ConA-binding surface glycoproteins present at the germ-tube apex as essential factors for infection structure formation on smooth polystyrene. In contrast, these glycoproteins are unlikely to be involved in appressorium induction over grooves in the same substrate.

Exserohilum longisporum sp. nov., isolated from Miscanthus sinensis, is described and illustrated. Its affinity to closely related species is discussed to show the distinguishing morphological features.

The sensitivity to UV-B (290–320 nm) radiation of common phylloplane yeasts from two contrasting UV-B environments was compared in the laboratory using mixtures of white light (PAR: 400–700 nm) and UV-B radiation from artificial lamp sources. Sporidiobolus salmonicolor, Rhodotorula mucilaginosa and Cryptococcus sp., the dominant yeasts on leaves of tea (Camellia sinensis), were isolated in Sri Lanka (SL), while Sporidiobolus sp. and Bullera alba, dominant on faba bean (Vicia faba), were isolated in the U.K. Dose responses were determined separately for each yeast. UV-B reduced colony forming units (due to cell mortality or inactivation) and colony size (due to reduced multiplication) of all yeasts. The LD50 values and doses causing 50% reduction of cells per colony were higher for SL isolates than U.K. isolates. Results indicated that each yeast is somewhat vulnerable to UV-B doses representative of its natural habitat. The relative insensitivity of SL isolates was shown when SL and U.K. isolates were irradiated simultaneously with the same dose of UV-B. Of the two U.K. yeasts, B. alba was significantly more sensitive than Sporidiobolus sp. to UV-B. Except for R. mucilaginosa from SL, all yeasts demonstrated some photorepair in the presence of white light. White light provided relatively little protection for the U.K. isolate of Sporidiobolus sp. although it allowed increased colony size.

The spectral responses of Sporidiobolus sp. (U.K.) and of B. alba (U.K.) were broadly similar. Wavelengths longer than 320 nm had no measurable effect on colony forming units. However, colony survival was significantly reduced at 310 nm and all shorter wavebands. No colonies were counted at 290 nm or below.

A homothallic species of Nectria producing a Cylindrocladium-like anamorph was collected from bark of a fallen tree in the Amazonian forest in Ecuador. The anamorph, which is placed in a new genus, Xenocylindrocladium, is characterized by forming straight, cylindrical, 1-septate conidia borne on penicillate conidiophores with coiled, avesiculate stipe extensions. The teleomorph, which is best accommodated in Nectria, is distinct in forming yellow-orange perithecia with red ostiolar regions, ellipsoidal, smooth, hyaline, 1-septate ascospores, and long-stalked, cylindrical asci with apical discharge mechanisms. Both the teleomorph and anamorph states are newly described as Nectria serpens and Xenocylindrocladium serpens.

Peridermium harknessii, cause of western gall rust of pines, comprises two populations of multilocus electrophoretic types (zymodemes) in the western United States. When stained with a DNA-specific fluorochrome, mature, ungerminated aeciospores from zymodeme I were found to be predominantly binucleate (70%), as were those of the related macrocyclic species, Cronartium quercuum (74%), whereas aeciospores from zymodeme II were predominantly uninucleate (93%). Within each zymodeme, aeciospores with two nuclei had significantly (P=0·01) more DNA than spores with one nucleus, and numbers of nuclei in germlings increased arithmetically over time. These data suggest that aeciospore nuclei in both zymodemes I and II divide mitotically, not meiotically, as is consistent with an asexual life cycle.

Photometric measurements also indicated that the amount of DNA in one nucleus of a uninucleate zymodeme II aeciospore was similar to the total amount of DNA in a binucleate zymodeme I aeciospore. These data, coupled with recent isozyme studies, suggest either that zymodeme II evolved after karyogamy of zymodeme I and an unidentified zymodeme, or that zymodeme I evolved after haploidization of zymodeme II.

The tef1 gene coding for translation elongation factor EF1α was identified by a PCR-based approach using degenerate oligonucleotides derived from conserved regions seen in alignments of other EF1αs. The deduced amino acid sequence was compared to other EF1αs. In Southern blot analyses no evidence for a second gene encoding EF1α in Schizophyllum commune was detected. Abundant transcript levels were detected in Northern blot analyses. The open reading frame is interrupted by seven small introns ; however, the positions of these introns are not conserved between the homobasidiomycete Schizophyllum commune and the heterobasidiomycete Puccinia graminis genes.

Savoryella is reported from wood submerged in rivers and streams in Australia, Brunei, Hong Kong, Malaysia, Mauritius, the Philippines and South Africa. Six species are reported:– Savoryella aquatica, S. curvispora sp. nov., S. fusiformis sp. nov., S. grandispora, S. lignicola and S. verrucosa. A key to Savoryella species is provided and descriptions and illustrations of selected freshwater Savoryella species are given.

Twenty-one Aspergillus strains representing different A. awamori, A. phoenicis and A. foetidus isolates were studied in order to explore the potential of a fast RFLP analysis to identify fungal strains. The patterns were compared with those characteristic for A. niger, A. tubingensis, A. carbonarius, A. japonicus and A. aculeatus represented by A. niger CBS 120.49, A. tubingensis NW 756, A. carbonarius CBS 111.26, A japonicus CBS 114.51 and A. aculeatus CBS 101.43 and also with those of the type strains of A. heteromorphus CBS 117.55 and A. ellipticus CBS 707.79.

Sma I digested chromosomal DNA revealed characteristic rDNA patterns after ethidium bromide staining which were used in combination with hybridization patterns of Pst I/Sal I double digested chromosomal DNA with well-defined probes. This allowed clear distinction of eight separate species within the Aspergillus sect. Nigri group. The probes used were a 0·9 kb fragment of the 28S rDNA from Agaricus bisporus, an internal fragment of the pkiA gene from A. nidulans, and the pelA gene from A. niger. All the strains examined including those indicated as A. awamori and A. phoenicis were shown to belong either to A. niger, A. tubingensis or a group representing isolates of A. foetidus varieties, amongst which A. foetidus var. acidus CBS 564.65 and A. foetidus var. pallidus CBS 565.65.

In Fusarium section Liseola, the teleomorph is used to identify mating populations that represent different biological species when distinguishing morphological characters are absent in the anamorph. The Gibberella fujikuroi mating populations to which strains of Fusarium section Liseola belong were determined for isolates from sorghum grown at Ifakara, Ilonga and Kachiri, Tanzania. Representatives of all of the mating populations (A–F) were recovered at Ilonga, but C and E were absent at Ifakara and C was absent from Kachiri. The frequency of the different mating populations was similar at all three sites with A (21%) and F (49%) being the most frequent and C and E the least frequent, if they were recovered at all. The relative proportions of mating populations A and F in the population were significantly different from each other at Ilonga, but were not significantly different at Ifakara or Kachiri. Female fertile strains were more common within mating population A than within mating population F. The inbreeding effective population sizes for the A and F mating populations, respectively, were 69 and 91% of count based on mating type, and 88 and 53% of count based on male/hermaphrodite ratios.

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.

Cerato-ulmin (CU) presence was monitored on cell surface and quantitatively determined in mycelial extracts of the elm pathogens Ophiostoma novo-ulmi (races EAN and NAN) and O. ulmi and of the non-pathogenic O. piceae. CU was detected on the surfaces of Ophiostoma novo-ulmi (races EAN and NAN) and, for the first time, of the weak Dutch elm disease pathogen O. ulmi and the non-pathogen O. piceae. Quantitative determination of CU content in the mycelial extracts of the three species showed that high CU cellular content is associated with high CU content in culture filtrates. The content of CU in biomasses and in culture filtrates was influenced by temperature, growth phase and fungal species or race. CU synthesis occurred during the stationary phase and in the late logarithmic phase when fungi were grown at 23° and 32°C, respectively. High temperatures of growth (32°) did not have a negative effect on the cellular CU content but severely hampered CU secretion in high CU-producers O. novo-ulmi isolates.

Three new species of smut fungi (Ustilaginales) on grasses from Western Australia are described and illustrated: Sporisorium ordense sp. nov. on Brachiaria pubigera, Sporisorium paraneurachnes sp. nov. on Paraneurachne muelleri and Ustilago xerochloae sp. nov. on Xerochloa imberbis and X. laniflora. Smut fungi new to Australia are: Sporisorium heteropogonicola comb. nov. (based on Sorosporium heteropogonicola) on Heteropogon contortus, Sporisorium iseilamatis on Iseilema vaginiflorum (matrix nova), Tilletia opaca on Spinifex longifolius (matrix nova), Ustilago spermophora on Sporobolus australasicus (matrix nova). Sporisorium mitchellii, known hitherto from South Australia on Iseilema mitchellii, was collected on Iseilema dolicotrichum (matrix nova).

A new ascomycete, Iodosphaeria polygoni sp. nov., is described and illustrated from Taiwan. It is compared with the other known species of Iodosphaeria. A key to species is also given.

As a later homonym of Mycosphaerella aggregata (Schweinitz) Stevenson the name Mycosphaerella aggregata Carnegie & Keane is illegitimate. The name Mycosphaerella gregaria is proposed as a replacement with similar etymology. The original description is revised following further collections and includes new hosts and cultural characteristics. Originally thought to be a saprophyte, this species may be a primary pathogen of leaves of Eucalyptus.

The new ascomycete Chaetosphaeria ampulliformis sp. nov. found on decaying wood of an unidentified angiosperm in Taiwan is described and illustrated. It is closely associated with an Hemicorynespora anamorph which grows mostly on the necks of the flask-shaped ascomata. This anamorph is described as Hemicorynespora multiseptata sp. nov. The relationships of these two species to others in the genera are discussed, and a key to the recognized species of Hemicorynespora is provided.

Corallocytostroma ornicopreoides sp. nov. is described and illustrated from large (up to 3 cm diam.) conidiomata and sclerotia found on the living stems of four perennial grasses, Astrebla elymoides, A. pectinata, A. squarrosa and Dichanthium fecundum, in northern Western Australia and the Northern Territory. It is compared with Corallocytostroma oryzae, the only other species in the genus.

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.

The broad spectrum fungicide mancozeb was applied to monocultured sugarcane soils affected by the growth constraint known as sugarcane yield decline. The constraint is associated with the long-term monoculture of sugarcane and has been shown to decrease sugarcane growth by 20% in commercial crops in Queensland. The fungicide was shown to decrease root colonization by soil fungi, particularly dematiaceous sterile fungi. Higher doses of mancozeb (up to 400 mg kg−1) sometimes led to increased populations of Penicillium spp. The fungicide greatly improved plant growth and root health when applied at doses of 100 mg kg−1 and above. Results suggest that the role of dematiaceous sterile fungi in sugarcane yield decline should be further examined.

Three species of Phaeoramularia, P. indica sp. nov., P. moracearum sp. nov. and P. psidii-guajavae sp. nov. on Acalypha indica, Ficus religiosa and Psidium guajava, respectively, are described and illustrated from material collected in Gorakhpur and the adjoining area.

Intercellular hyphae of Cladorrhinum foecundissimum were observed in a dense layer surrounding the stele of cotton roots and were distinguished inside root hairs of plants grown in substrate containing the endophyte. No damage was observed in the epidermis of roots from infested substrate. At the blossom stage height of plants grown in substrate with the endophyte was 50% greater than in the controls. In the same group of plants growing in phosphorus-deficient substrate the endophyte doubled the phosphorus concentration compared to the control plants. In 25 day-old plants growing in substrate with high phosphorus content, the use of 32P showed a L value [available P (mg P 100 g−1)] 29% greater in soil colonized by the endophyte than in the non-infested substrate, but dry matter and phosphorus content in plants were not significantly different.