Coniophora eremophila and Antrodia sinuosa cause brown heartrot in living lemon trees in southern Arizona and California. They can be distinguished in the field by differences in rot characteristics. Both have a high optimum growth temperature of approximately 35°C. Coniophora eremophila has a cultural morphology typical of other Coniophora species and did not fruit in culture. Antrodia sinuosa cultures were morphologically similar to previous reports and fruited readily under laboratory conditions. Mating tests with homokaryotic single spore isolates showed it to have a heterothallic bipolar mating system. The decay capacity of C. eremophila on lemon wood test blocks under laboratory conditions was low compared to that of A. sinuosa, five other brown rot fungi, and three white rot fungi.

An evaluation was made of the genotypic diversity (DNA fingerprinting) of 269 A. flavus strains, including subpopulations isolated from grain sampled at harvest (91 unique ‘fingerprints’ or genotypes/128 strains), field soil (26 genotypes/31 strains), maize insects (49 genotypes/52 strains) and air-spora (56 genotypes/58 strains), from a maize field near Kilbourne, Illinois. Eight A. flavus genotypes were isolated from grain samples harvested in different years (1988–1991). Genotype 36, isolated from three maize samples, matched the DNA fingerprint of a K. E. Papa strain NRRL 19997, isolated from maize grown in Georgia. Ninety-eight percent of the A. flavus genotypes produced sclerotia and 53% produced aflatoxin. Contrasts of DNA fingerprints revealed two matches involving subpopulations from grain and soil, one match for grain and maize insects, and no matches for grain and air-spora. The high genotypic diversity recorded for each subpopulation, in addition to a limited sample size, precluded any assessment of the relative importance of these subpopulations as sources of A. flavus infective inoculum. Aspergillus parasiticus was routinely isolated from soil samples.

Faecal samples collected from the Mountain brushtail possum (Trichosurus caninus) at several sites in eastern Australia showed the presence of spores from at least 21 hypogeous fungi, and several epigeous species. Most were found in faeces of animals at one site, where samples were collected in different seasons. Further collections are needed from the other sites at different times of the year to clarify how widespread the mycophagous habits of T. caninus are. Many of the hypogeous fungi identified are either known or presumed to form mycorrhizal relationships with the roots of forest trees and shrubs and T. caninus may disperse their spores in its faeces.

Twenty-four strains of six Cylindrocladiella spp. were compared with respect to their morphology, nuclear ribosomal DNA (nuclear rDNA) polymorphisms, and restriction fragment length polymorphisms of A+T-rich DNA (AT-DNA). Two distinct DNA profiles were observed for the ten strains of C. camelliae/peruviana-complex studied. One profile corresponded with the type strain of C. peruviana, which was earlier regarded as a synonym of C. camelliae. Based on Southern analyses and AT-DNA, C. parva, C. elegans and C. lageniformis were confirmed to be distinct species with little intraspecific variation. Although C. infestans was shown to have some variation among the four strains studied, they could not clearly be distinguished as separate taxa. Based on general morphology, nuclear rDNA and AT-DNA polymorphisms, seven species of Cylindrocladiella are recognized.

Colletotrichum xanthorrhoeae sp. nov. causes leaf spots on Xanthorrhoea preissii and X. platyphylla in south-western Western Australia.

Thirty-one clonal isolates of U. necator were taken from diseased grapes from three different vineyards in France and Germany. Samples were collected in April from typical ‘flagshoot’ symptoms, and in July and August from the same plants. The mating-type and the sensitivity to the fungicide triadimenol were determined for all isolates. Techniques for obtaining and characterizing isolates are described. Two isolates in the first sampling and eight in the second were resistant to triadimenol, with resistance factors ranging from 3·4 to 11·8. All isolates in the first sampling and nine out of the 21 isolates in the second were mating-type (+), the remaining isolates were mating-type (−). Genetic variation between all isolates was assessed using the RAPD technique. Phenetic analysis based on the 364 RAPD fragments obtained revealed two very distinct groups, one group containing nine out of the 10 isolates from the first sampling, the second group containing all the remaining isolates. Isolates clustered in the first group displayed 58 RAPD fragments specific to them. These isolates did not exhibit 60 RAPD fragments present in all other isolates. Molecular and biological data suggested that isolates clustering in the two groups represent two different biotypes of U. necator, which are likely to be genetically isolated.

Ophiostoma europhioides and O. huntii are two very similar fungi known to cause blue-stain of timber. Both species have been isolated from pine and spruce in Canada and are characterized by Leptographium anamorphs and hat-shaped ascospores. The aim of this study was to compare isolates of O. huntii and O. europhioides from various parts of the world. These isolates were compared morphologically using light and scanning electron microscopy. Sexual compatibility was determined using mating studies. O. huntii isolates from the different geographical areas were similar to each other but distinct from O. europhioides. A new Ophiostoma species, O. aenigmaticum, is described for the Japanese isolates; Leptographium aenigmaticum, its anamorph, is described as a new species.

A field study was conducted to determine the size and spatial distribution of mycelial individuals of Pisolithus tinctorius at a site in NSW, Australia. Following collection and mapping of carpophores and isolation of the fungi into axenic culture, genomic DNA was extracted and combined data from RAPD and microsatellite analyses used to identify and map mycelial individuals. Thirty-three genetically distinct individuals were recognized at the field site and, while one large individual (at least 30 m diam.) was identified, most individuals appeared relatively small (<3 m diam.). The size and distribution of individuals is discussed in relation to growth of P. tinctorius mycelia through soil.

Twenty-one isolates of the nematode-vectored plant pathogen, Dilophospora alopecuri, were examined by allozyme electrophoresis. The study focused on isolates from Australia, including those associated with populations of the seed-gall nematode, Anguina funesta, in Western Australia (W.A.), where the fungus apparently provides natural control of the A. funesta–Clavibacter toxicus association responsible for annual ryegrass toxicity, and a range of Anguina populations in south-eastern Australia. Reference strains from international culture collections were included. Variation was found in 26 of 27 presumptive loci and 10 electrophoretic types were identified. All Australian isolates fell into six electrophoretic types that formed two groups of three that differed by less than 13% within each group, but differed by over 70% between the groups. Of the isolates from W.A., six fell into one electrophoretic type and one into a second electrophoretic type that differed at one locus only. Three exotic isolates varied from Australian ones by 27–74%. Dilophospora alopecuri exhibited greater within-species allelic variation than previously reported for asexually-reproducing halophase fungi. The lack of variation within W.A. suggests that (i) a teleomorph does not occur under local conditions, (ii) the W.A. population has arisen from a single introduction and (iii) selection of strains suitable for biocontrol of Anguina funesta and Clavibacter toxicus should include material from eastern Australia.

Conioscypha is reviewed, with a discussion on generic concepts and conidiogenesis. A new genus, Conioscyphopsis, is described from submerged wood in Australia, and a key to species in both genera is provided. Conioscyphopsis australiensis sp. nov. is similar to species of Conioscypha in lacking conspicuous conidiophores, but its dematiaceous, unicellular conidia are produced from ampulliform conidiogenous cells borne on semi-immersed hyphae. Conioscyphopsis differs from Conioscypha mainly in its conidiogenesis. Conidiogenesis in Conioscypha is intermediate between ‘annellidic’ and ‘phialidic’, single conidia being produced endogenously within indeterminate, percurrently proliferating conidiogenous cells. In Conioscyphopsis, conidiogenesis is ‘enteroblastic-phialidic’, solitary conidia being produced exogenously from determinate, but percurrently regenerating conidiogenous cells.

Secretion of a constitutive endopectinase was detected in cultures of Venturia inaequalis grown in complex and defined media. Pectinylase or pectinesterase activity was not present. The attainable level of extracellular pectinase was present after 5–10 d post inoculation, when only about 5–10% of mycelial mass had developed. Time course culture experiments with conidial and mycelial inoculum indicated that enzyme secretion did not depend on physiological effects within or shortly after conidial germination. Cellulosic substrates did not affect pectinase production. Catabolite repression or repression by glucose was not detected and there was no stimulation of enzyme production in media supplemented with pectic substrates. Inhibition of enzyme activity by galacturonic acid was not detected. Nineteen isolates of V. inaequalis were tested, all of which displayed constitutive pectinase production. All isolates were able to grow in the defined media with galacturonic acid or the pectic substrates as the sole carbon source. Mycelial pectinolytic activity was only detectable in substantial quantities when the fungus was grown in media supplemented with 1% pectin. The pectinase preparations displayed a long-term stability at temperatures up to 20°C and within a pH-range of 5–7·5. Activity was very low at 5 and 10° and there was a distinct increase at 15 and 20°. Enzyme activity was highest at pH 4 and decreased with increasing pH. Time course viscometric assays and hplc analyses of liberated galacturonic acid indicated an endo-type degradation of pectin and polygalacturonic acid. Di- and trigalacturonic acid were released from pectin with high enzyme concentration and long incubation. Pectin with a degree of esterification of 93% showed reduced degradability. Pectinase preparations had a macerating activity on solvent extracted apple leaves and caused galacturonic acid release. Isoelectric focusing followed by a zymogram technique revealed a single activity band at pI 10. The pectinase preparations from culture filtrates or mycelia of 19 isolates did not show any differences in characteristics of degradative activity or the activity band detected after isoelectric focusing.

A fluorometric-based method for the kinetic measurement of conidia growth of Botrytis cinerea in liquid culture is described. The method involves an oxido-reduction dye, Alamar blue, as an indicator of growth. The effect of nystatin, a non-specific antifungal agent, was studied on conidial germination. An excellent correlation was found between the IC50 obtained by the fluorometric method, and by microscopic measurement. The method is rapid and quantitative, and requires only a small amount of chemicals and fungal material. Since the measurements were performed in a 96-well plate, it is possible to test many different parameters in parallel.

This is the first report demonstrating Amorphotheca resinae to be a natural member of the soil mycobiota in Germany. The fungus was detected at 19 out of 68 collection sites and was most frequently isolated from soil under or in the vicinity of yew trees (Taxus baccata). This finding is in contrast to reports from other countries, where no correlation was found between the presence of the fungus and the kind of soil or vegetation. A. resinae could not be re-isolated by standard methods like the soil dilution technique or the soil plate method, unless the fungus was present in high numbers of colony forming units. By a modification of the creosoted matchstick method it was possible to detect the fungus when as few as 11 viable spores were present in a plate with 20 g of soil.

Seventeen species of Rickia are reported from Sulawesi. Five are described: R. corylophidorum, R. mammillata, R. pocadii, R. serrulata, and R. sphindidorum. The slime mould feeding beetle family Sphindidae is reported for the first time as host for a species of the Laboulbeniales and R. minuta is recorded for the first time from a beetle, this species previously being known to parasitize only mites. For each of the reported species a detailed description with information on the known geographical distribution and host range is presented along with illustrations and a key to identification.

Three new species of Corynespora: C. morindae-tinctoriae, C. nana and C. rosacearum on Morinda tinctoria, Lantana indica and Eriobotrya japonica respectively, are described and illustrated from Gorakhpur (U.P.) India.

A new species of Cryptosporiopsis is described. It was isolated frequently from roots of healthy-looking and declining oaks (Quercus robur and Q. petraea). The relationship to C. radicicola, a similar species also occurring on oak roots, is discussed. The new species is separated from C. radicicola by means of morphological and physiological characters, genomic analysis by the PCR-based RAPD technique as well as by the production of metabolites.

In experiments where groundnut plants with sporulating late leaf spot lesions were exposed to increasing ‘gusty’ and ‘steady’ wind speeds, conidia were more effectively removed by gusty winds than by steady winds of the same mean wind speed. Rain drops dislodged conidia more efficiently than wind, with large drops dispersing conidia more effectively than small ones. No conidia were caught in still air. After most of the conidia had been removed by exposure to high wind speeds, rain was found to remove additional conidia. When plants were exposed to continuous wind or rain, most of the conidia were dispersed during the first few minutes, and the concentration of conidia then declined exponentially with time. From field observations on rain-free days, airborne concentrations of conidia tended to increase as the wind speed increased during the day and with a further increase in wind speed, concentrations decreased. On rainy days, the onset of the first shower coincided with a phenomenal increase in the airborne concentrations of conidia.

Collybia fusipes is the cause of a root rot of oak trees. We studied the structure of C. fusipes populations in two infected oak stands by using somatic incompatibility and DNA amplification. Isolates were obtained from different oak root systems or from within the same root system and somatic incompatibility groups (SIG) were identified. Many small SIGs that seldom encompassed more than one root system were present in both stands. More than one SIG was usually present on an individual root system: there were 3·1±1·3 SIGs on the pedunculate oaks and 2·2±0·6 on the red oaks. The largest SIG contained more than 70% of the isolates obtained from the root system of 14 of the 20 trees studied. Isolates that belonged to the same SIG usually had the same ribosomal intergenic spacer. It is concluded that C. fusipes spreads poorly from tree to tree by vegetative means.

Conidiogenesis in Septoria chrysanthemella was studied in vitro with light and transmission electron microscopy (TEM). For the first time, proof is given with TEM that both percurrent and sympodial proliferation can occur in a single conidiogenous cell. Ontogeny of conidia is holoblastic. After delimitation by a transverse, uniperforate septum, each conidium is liberated schizolytically. Three kinds of conidiogenous cells occur in S. chrysanthemella: (i) annellides, proliferating only percurrently; (ii) sympodulae, proliferating only sympodially, and (iii) cells proliferating either way. No influence of illumination by diffuse daylight or nuv, or medium was observed on qualitative aspects of conidiogenesis. The annellations in S. chrysanthemella seen with TEM are not resolved by light microscopy (LM). It is concluded that LM is not sufficient to assess conidiogenesis in species of Septoria with equally minute conidiogenous cells.

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.