A morphological and molecular analysis was performed on 25 individuals of Phaeoacremonium isolated from diseased European and Californian grapevines (Esca disease). An unexpectedly high intra-generic molecular divergence was evidenced by partial rDNA sequencing between P. chlamydosporum isolates on one hand and an aggregate including P. angustius and P. aleophilum isolates and some undescribed ones on the other. These two groups show 26% nucleotide differences within the 26S rDNA fragment sequenced and were unalignable within the ITS2, suggesting distant phylogenetic relationships. Moreover, P. chlamydosporum appeared more closely related to Phialophora verrucosa (supposed to be an anamorph of the Herpotrichiellacae), than to the type species of the genus, P. parasiticum (more related to Magnaporthaceae).

Dactylella huisuniana sp. nov., is described and illustrated from decaying leaves. It is characterized by tall, simple, erect, hyaline, septate conidiophores which bear denticulate, terminal or subterminal to lateral conidiogenous cells. The conidiogenous cells elongate and elaborate and become somewhat geniculate or candelabrelloid in age. The conidia are predominantly fusoid, 3-septate, widest at the distal second cell. The organism traps nematodes by adhesive knobs at the apex of erect, flexuous, unicellular pedicels arising from hyphae. The differences between D. huisuniana and D. arcuata, D. asthenopaga, D. drechsleri, D. ellipsospora, D. lysipaga, D. multiformis, Dactylaria candida, D. haptotyla, and D. sclerohypha are briefly discussed.

Chlorophenols have been commonly used as disinfectants and preservatives but their recalcitrant nature, persistence and toxicities make them priority pollutants for treatment. The ability of various fungi (Armillaria gallica, A. mellea, Ganoderma lucidum, Lentinula edodes, Phanerochaete chrysosporium, Pleurotus pulmonarius, a Polyporus sp., Coprinus cinereus and Volvariella volvacea), and the spent mushroom substrate of P. pulmonarius (SMS) to remove pentachlorophenol (PCP) was compared using a batch cultivation system. The PCP content was monitored by reversed phase HPLC, and the breakdown products were determined by GC-MS. Possession of ligninolytic ability was determined by ability to decolourize the dye Poly-R478 at two N levels. Not all the fungi tested decolourized the dye, and for those that did, not all showed N-modulation response on dye decolourization. All these fungi showed active breakdown in addition to biosorption as their PCP removal mechanisms. The tolerance level of the fungus towards PCP did not correlate with its degradative capacity, nor to its ability to decolourize Poly-R478. The A. mellea strain showed the highest degradative capacity (13 mg PCP g−1 mycelium; D.W.) while the Polyporus possessed the greatest biosorption capacity (31 mg PCP−1 mycelium, d.w.). In comparison, Pleurotus SMS harbouring both bacteria and fungi functioned over a wide range of initial PCP concentrations and reached a higher degradative capacity (19 mg PCP g−1) in only 3 d. GC-MS chromatograms revealed only residual PCP peaks in SMS extracts, a contrast with the mycelial incubations in which a variety of breakdown products were detectable. Use of SMS for bioremediation of biocide-contaminated sites seems promising.

The ability of Botrytis cinerea to produce cutinolytic, pectolytic and cellulolytic enzymes was re-examined in vivo and in vitro. In liquid culture, B. cinerea produced both constitutive and inductive forms of hydrolytic enzymes. The constitutive levels were 44 mU, 720 mU, 1820 mU, 12·0 U and 22·4 mU for cutin esterase, endopolygalacturonase (endoPG), exopolygalacturonase (exoPG), pectin methyl esterase (PME) and pectate lyase (PL), respectively. Unlike the other enzymes, however, carboxymethyl cellulase (CMCase) production was found to be entirely inducible. The enzymes secreted at the germination and germ-tube growth stages, and during subsequent disease development, were quantified simultaneously. Complete germination was observed within 9 h of incubation of B. cinerea on the surface of bean leaves and disease symptoms gradually increased during days 1–6 of the incubation. Significant amounts of all hydrolytic enzymes studied in the early hours and monitored during 6 d of incubation were detected, supporting the possibility of a major role for the enzymes produced by B. cinerea in the development of disease. The amount of cutinase was found to be uniform from the beginning, indicating that this enzyme may have an important role in penetrating the impervious cutin layer. The exoPG level increased from the beginning of incubation whereas that of endoPG started to rise later. PL and PME were also detected on the leaf surfaces. The patterns of in vitro production of exoPG, endoPG and PL correlated with the in vivo production of these enzymes, but there was only partial correlation in the production of PME and no correlation in the patterns of cutinase and CMCase production.

Arbuscular mycorrhizal fungi (AMF) are obligate symbionts which can only be propagated in association with intact plants or root explants. Molecular study of these fungi has been hampered by the inability to grow them in vitro and to obtain protoplasts. With the advent of advanced gene transformation systems, the opportunity has arisen to use biolistic technology to introduce foreign DNA linked to molecular markers into these fungi. The biolistic transformation system chosen for the AMF was GUS-based as this system was shown to work effectively for ectomycorrhiza. In this study the plasmid pNOM102 was used for transformation of Gigaspora rosea and transient GUS gene expression was detected in 40–50% of spores by colorimetric and immunological based methodologies.

Sixteen highly branched (colonial) mutants of Fusarium graminearum A3/5 were isolated at the end of 11 Quorn® myco-protein production fermentations. These ranged from the highly branched C134-3 to the sparsely branched C145, which was similar to A3/5 in liquid culture. Although allelic complementation was observed to occur between some of the mutants, heterokaryon analysis revealed that all the highly branched mutants belonged to a single complementation group. Mixed cultures of A3/5 and six of the colonial mutants were grown in glucose-, ammonium-, magnesium- and sulphate-limited chemostat culture. One mutant (C153) had a selective advantage over A3/5 in all nutrient limitations tested; four mutants (C134-1, C134-3, C137-1, and C135) had a selective advantage over A3/5 in all except one nutrient limitation; and one mutant (C139) had a selective advantage over A3/5 in magnesium-limited chemostat culture only. Four mutants (C134-3, C139-1, C153 and C135) had a selective advantage over A3/5 when the dilution rate was increased above the critical dilution rate (0·22 h−1) and nutrients were present in excess. These results suggest that the growth conditions in the Quorn® production plant (which is operated as a glucose-stat) favour mutations that confer general growth rate advantages, but these mutations may result in growth disadvantages when nutrient limitations are imposed. As all of the mutations appear to occur in one gene or gene cluster, the differing patterns of selective advantage/disadvantage for the six mutants studied suggests that regulatory genes may also be involved or that different sites of mutation can lead to a variety of pleiotropic effects.

Meliola icacinacearum and M. kerichoensis spp. nov. are described and illustrated from Apodytes dimidiata and Croton alienus, respectively. C. alienus is a new host record for Meliola.

Four DNA sequences (ARSs) that are able to initiate DNA replication in yeast were isolated from mitochondrial DNA of Phytophthora nicotianae and localized on its physical map. Nuclear sequences from P. nicotianae were shown to initiate DNA replication in yeast only very rarely. Minimal regions necessary for replication catalysed by mitochondrial ARSs were delimited by DNase I digestion and sequenced. Transformation efficiencies were estimated for full-length ARS-carrying DNA fragments. Segregation rates and mitotic stabilities in S. cerevisiae were determined for the two shortest subclones of each of the three delimited ARSs. Replication properties of all three ARSs were similar to those of a yeast nuclear ARS sequence. Sequence analysis revealed the presence of many copies of the motif (T/G)ATATTTT, which is related to the ARS core consensus sequences, in all three elements. In two of them, four copies of the motif and its reverse complements were arranged in palindromes. In addition, whole ARS core sequences and long segments consisting exclusively of A and T nucleotides were found in all ARS analysed. These features indicate that an HMG-like (high mobility group) DNA-binding protein similar to ABF2 from yeast may participate in DNA packaging also in non-fungal mitochondrial lineages.

Internally transcribed spacer (ITS) regions of the rRNA gene cluster in isolates of Ascochyta spp. were amplified and digested with restriction endonucleases. Addition of fragment sizes from conventional gel electrophoresis gave anomalous sizes which suggested the presence of more than one PCR product. Separation in HA-Yellow containing agarose gel allowed the detection of fragments of the same size but with different sequences. Isolates of Ascochyta spp. were shown to possess multiple PCR-amplification products of the same sizes, but with significant sequence differences.

The antifungal activity of five substituted flavones and their mixtures with unsubstituted flavone or a flavanone was tested on malt extract agar against five Fusarium spp. 4′-Methylflavone and 2′,6′-dichloroflavone showed the highest activity while 4′-benzyloxyflavone caused the lowest inhibition of all test substances. A significant increase in the antifungal effect of the substituted flavones could be observed if mixtures in combination with the unsubstituted flavone or flavanone were used. Some aspects of structure–activity relationships are discussed.

Mycosphaerella vespa sp nov. is described from diseased leaves of Eucalyptus from south-eastern Australia. It is associated with small, circular to irregular lesions that have red-brown margins and amphigenous pseudothecia. These characters, in combination with ascospore morphology and germination, distinguish M. vespa from previously described species of Mycosphaerella on eucalypt leaves. Lesions associated with this pathogen were often found to be harbouring wasps and this observation is discussed.

Syncephalastrum racemosum RR 96, MTCC 2774, synthesized extra-cellular β-amylase (EC 3.2.1.2) when cultivated with starch as sole carbon source. The strain showed maximum β-amylolytic activity on the fourth day of cultivation, and the partly purified enzyme showed highest activity at 60° and pH 5. About 60% of the activity was found to be retained within the range pH 4–7. The enzyme activity was not increased in presence of exogenous thiols and remained unaffected in presence of heavy metals and the thiol inhibitor p-chloromercuribenzoate, indicating the absence of thiols at the active site of the enzyme. Absence of substrate cross specificity and ability to hydrolyse waste starches made the enzyme competent for industrial application.

Xylem tissues of eight pip fruit, two stone fruit and one willow cv. exhibited similar seasonal variations in susceptibility to colonisation by hyphae of Chondrostereum purpureum following monthly inoculation and incubation of cuttings in the laboratory. Xylem tissues of all hosts exhibited maximum resistance during May/June/July. Generally, susceptibility increased in spring/early summer, peaked in November and declined over late summer to autumn. During June, cv. Golden Delicious apple cuttings prevented host colonisation by immersion of hyphae in tannin-like deposits in xylem vessels. Such deposits were not observed in Nashi pear where hyphae in vessels were also severely disrupted. Hyphae of C. purpureum were bi-nucleate, contained glycogen deposits and readily penetrated starch granules and cell walls.

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.

Linocarpon smilacis sp. nov., Nitschkia phaeospora sp. nov., Ophiodothella cyclobalanopsidis sp. nov., Physalospora palmicola sp. nov., Physalospora smilacis sp. nov. and Tubeufia miscanthi sp. nov. from Taiwan are described and illustrated by microphotographs. Each is compared with related taxa.

This listing covers the period March 1, 1997 through to April 30, 1997. Citations are arranged in groups which roughly correspond with the British Mycological Society's Special Interest Committees. All correspondence about this item should be addressed to the Executive Editor. Reprints of this feature will not be available.

Three new species of Rotiferophthora (R. minutispora, R. amamiensis and R. lacrima) were isolated from samples of soil, rabbit dung and farmland waste in Japan. All species infected bdelloid rotifers and produced dictyochlamydospores in addition to conidia, but their modes of conidiogenesis differed. R. minutispora had small spherical conidia and long tapered conidiogenous cells which formed in verticils around the conidiophores; R. amamiensis had ovoid conidia produced from flask-shaped conidiogenous cells and aphanophialides, and R. lacrima produced long tear-shaped conidia enveloped in a mucoid sheath from short conidiogenous cells produced in a Drechmeria-like formation. A summary table of all known species of Rotiferophthora is shown.

This listing covers the period May 1, 1997 through to June 30, 1997. Citations are arranged in groups which roughly correspond with the British Mycological Society's Special Interest Committees. All correspondence about this item should be addressed to the Executive Editor. Reprints of this feature will not be available.

As one of the endangered breed of mycologists to have maintained an interest in oomycetes, I am compelled to defend the rationale in continuing to refer to these micro-organisms as fungi. This paper is stimulated by recent communications in which my mycological colleagues have, with apparent relish, pointed to what they perceive as inaccurate references to oomycetes as fungi. David Moore (1997) provides a prime example in his review of The Growing Fungus edited by N. A. R. Gow & G. M. Gadd (1995). Moore criticizes the editors for allowing so many pages of their book to be devoted to these micro-organisms, when ‘…Neurospora is probably more closely related to a cow's nose than it is to Saprolegnia’. While a phylogenetic chasm separates the oomycetes from other fungi, I shall argue that it is impractical to restrict the usage of the term fungus to those micro-organisms that qualify as members of the Phylum Fungi (Alexopoulos, Mims & Blackwell, 1996, provide a contemporary overview of fungal systematics). This argument should have been settled by a series of clear-sighted articles published after molecular genetic analyses confirmed the polyphyletic nature of the fungi (Christensen, 1990; Bruns, White & Taylor, 1991; Hawksworth, 1991; Barr, 1992). For example, Donald Barr (1992) suggested that oomycetes are fungi in the colloquial sense of the term and that it is the colloquial sense of the term that will continue to be most meaningful to mycologists. But since the message of these articles was apparently missed by many mycologists, I hope that this note will clarify a practical definition of the fungi that includes the oomycetes but which does not conflict with a natural classification of the Phylum Fungi that excludes them.

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.