Various fungi and myxomycetes have been tested for their synthesis and hydrolytic degradation of β-poly(L-malate) (PMLA), a highly anionic polyester of L-malate-malate. The PMLA content of the culture medium, and also of some cell extracts, has been assayed by L-malate-malate dehydrogenase (EC 1.1.1.83)-catalysed reduction of NAD+ after the alkaline hydrolysis of the polymer. All eight myxomycete isolates were producers. Eight producers were Mitosporic fungi but only one Ascomyete was productive. Aureobasidium pullulans contained PMLA in yeast-like cells but not in hyphae. The polymer was bound to membrane fractions from where it was slowly released during preparation for analysis. Only 12 of the 237 fungi and myxomycetes showed PMLA-hydrolase activity; and two of these were producers of PMLA. Fungi with hydrolase activity were mostly different from those releasing L-malate. The Physarum polycephalum-type unbranched polymer of high molecular mass was not recognized in fungi. Fungi, typically A. pullulans, produced polymer of low molecular mass which seemed to be covalently bound to polysaccharide.

The development of the peridioles of a Mycocalia sp., and the primordia of Scleroderma verrucosum and S. areolatum, has been studied, particularly in view of the presence of metamorphosed basidia. In the Mycocalia sp. and S. verrucosum spore-like bodies were formed exclusively by transformation of whole basidia. The ontogeny of S. verrucosum has been compared with that of S. areolatum. The structure of the exoperidium of S. verrucosum is much more complicated: hyphal knots play an important part in its construction. The processes giving rise to the exoperidium may be homologous with those constituting universal veils in Agaricales.

Multivariate analyses (cluster and correspondence) were used to assess the taxonomic structure of 34 isolates of Penicillium miczynskii scored for 95 binary characters. Six isolates of P. raistrickii and P. rolfsii were added solely for the purpose of comparison. The characters used were 38 micromorphological, 15 cultural and 42 secondary metabolite characters. With just one exception, allocation of isolates to clusters was equal in the separate analyses using morphological and secondary metabolite data. The combined data set, using 95 characters, resulted in clearly-defined clusters interpretable as species on the basis of the distribution of ex-type cultures. Four species were accepted: P. miczynskii, P. manginii, P. soppii and P. atrosanguineum. Two additional species, P. syriacum and P. chrzaszczii, represented only by ex-type cultures, were interpreted as a nomen ambiguum and a form of uncertain taxonomic status, respectively.

Brief descriptions, illustrations and a synoptic key are included to aid identification of the accepted species.

Cladistic analysis of nucleotide characters derived from partial 18S rDNA sequences has been used to infer phylogenetic relationships among five Candida species that exist in nature strictly as intracellular gut endocytobionts of anobiid or cerambycid beetles. Concordant with their assumed taxonomic status, all five species resolve within Saccharomycetales. For both the anobiid-derived taxa, C. ernobii, C. karawaeiwii and C. xestobii, and the cerambycid-derived taxa, C. tenuis and C. rhagii, this phylogenetic position clearly discriminates Candida yeasts from the anobiid yeast-like endocytobionts in Symbiotaphrina which resolve within filamentous ascomycetes. The analyses provide no evidence for a discrete lineage of Candida endocytobionts within Saccharomycetales. Rather, each of the anobiid symbionts and the cerambycid-derived species resolve in separate clades. These data confirm the polyphyletic origins of intracellular symbioses between ascomycetes and Coleoptera and provide another example of convergent evolution in fungal-arthropod associations. The implications of the phylogenetic data for theories on the origins of endocytobiosis are discussed.

The time course of release of an extracellular matrix (ECM) from conidia of the barley powdery mildew pathogen Blumeria graminis was investigated by scanning electron and light microscopy. Conidia released the ECM material preferentially onto a hydrophobic surface and release was detected within 20 s of contact of a conidium with the substratum. No such rapid release of an ECM could be detected when conidia were deposited onto the hydrophilic surface of clean glass. A limited amount of ECM was, however, released from conidia onto the hydrophilic surface of a hydrated cellulose membrane. A time study on hydrophobic plastic revealed that although the ECM was clearly present within the first hour after contact of the conidium with the substratum, it was much reduced in quantity after 12 h incubation. The ECM was demonstrated by micromanipulation and light microscopy to be present as a liquid at the contact interface of the conidium and the substratum. The ECM could not be detected by SEM beneath conidia on leaves, but light microscopy and micromanipulation demonstrated that the ECM could be detected beneath some conidia on the waxy surface of an epidermal strip taken from the abaxial surface of a barley leaf. The ECM material stained positively for protein and could not be removed from the conidium interface by vacuum desiccation in the scanning electron microscope indicating that the ECM is not simply water.

Annulatascus species are common freshwater ascomycetes in the tropics. In this paper, the type species, Annulatascus velatisporus, and a new species, A. triseptatus, are described and illustrated at light and electron microscope levels. Annulatascus triseptatus differs from A. velatisporus in having three-septate ascospores surrounded by a thin sheath. The asci of both species have bilamellate ascus walls and a bipartite apical ring. The upper part of the apical ring differentiates from the inner ascus wall layer and the lower part elongates downwards during maturation. The mesosporium is the first formed ascospore wall layer followed by the episporium, which is covered with verruculose ornamentations. The mucilaginous sheath of the ascospores is fibrillar or amorphous depending on the fixation methods employed, and appears to be derived from the episporial verruculose ornamentations.

An EcoRI 1428 bp A+T-rich, DNA element (MYCDIRE: MYCorrhizal fungus DIspersed Repetitive Element) has been identified in the genome of Scutellospora castanea, an arbuscular mycorrhizal fungus. After sequencing, primers were designed and used in PCR reactions to amplify portions of this element in five species of arbuscular mycorrhizal fungi belonging to four genera of Glomales. Southern hybridizations and partial analysis of the main PCR products confirmed that this element was highly conserved in all the species. Southern blot analysis of single and double digested DNA from two of the glomalean fungi gave smears suggesting that MYCDIRE is scattered throughout the fungal genome. Sequence analyses revealed three copies of a previously reported autonomously replicating sequence (ARS) from Saccharomyces cerevisiae and comparisons indicated similarities of MYCDIRE with the autonomously replicating, A+T-rich element (ACARS) from Acremonium chrysogenum.

The biotrophic species of Phyllachoraceae associated with the angiosperm family Erythroxylaceae are examined, and five new species and one new subspecies proposed. Five species of Phyllachora are accepted, including the four undescribed taxa P. occultans from Mexico, P. usteriana subsp. piliformis and P. reticulata from Brazil, and P. tanensis from Madagascar. The new genus Fremitomyces is introduced for two undescribed species from East Africa and the Seychelles, which have initially brightly coloured stromata.

Medusoides gen. nov. is described from North Carolina, U.S.A. The fungus reproduces sexually, with oogonia and antheridia, but no asexual stage has yet been found. The fungus has not yet been obtained in culture. The vegetative growth is mycelial but the hyphae are very narrow (<3 μm) with vesiculate nodes. The oospores are strictly plerotic. Oogonial and oospore walls are distinctive with unique ultrastructure. The peronosporomycete is a typical aero-aquatic fungus, having markedly buoyant propagules, due to the possession of long, recurved, oogonial outgrowths covering the oogonium sufficiently densely so as to retain air between them and the oogonial surface after exposure and reimmersion. Its habitat, in the lower layers of submerged deciduous leaf litter, suggests survival in an anaerobic environment and a fermentative capacity. An affinity with Pythiogeton is proposed, and Pythiogeton is made the type genus of a new family, the Pythiogetonaceae.

Six species of Mycosphaerella and eight anamorphs with unknown Mycosphaerella states occurring on myrtaceous hosts other than Eucalyptus are treated in the present study. Eight additional species that have recently been described elsewhere are discussed, while a further six species remain unconfirmed, and two are excluded from Mycosphaerella. New species are described in Mycosphaerella, Mycovellosiella, Passalora, Pseudocercospora and Stenella, and new combinations proposed in Eruptio and Microthyrium. Keys are provided to distinguish the accepted species occurring on Myrtaceae other than Eucalyptus, while their morphological similarities with taxa known from this host are discussed.

Antrodia taxa sp. nov. and Perenniporia celtis sp. nov. found growing saprotrophically on the decayed stems of Taxus mairei and Celtis sinensis, respectively, in Taiwan, are described and illustrated. A. taxa is distinguished by effused-reflexed to pileate basidiomes and small oblong ellipsoid basidiospores 4×2·5 μm. P. celtis is characterized by large, subglobose to tear-shaped, non-truncate basidiospores 8·5–10×5–7 μm and encrusted cystidia. Cultural characteristics are described for the two species.

Twenty-seven Fusarium oxysporum isolates were studied by RAPD-PCR and isozyme analyses. Thirteen isolates were from barley and the rest from different hosts, most of which were dicotyledonous plants. All isolates could be distinguished from each other by RAPD-PCR analysis, and clustered into seven groups in NJ and parsimony consensus trees. Isozyme analysis detected polymorphism in five of the six enzymes and the isolates could be divided into 26 different electrophoretic groups. Five groups were supported by high branch support and bootstrap values in the approximate support tree of combined RAPD-PCR and isozyme data. These five groups were found also in NJ and parsimony consensus trees. The matrices from RAPD-PCR and isozyme data proved to be incongruent, but they did not totally disprove each other. Some correlation was found between geographical origin and phylogenetic relationships of isolates collected from barley. Representatives of the main clades of phylogenetic trees, were further studied by rDNA RFLP and rDNA sequence analyses, together with isolates of other Fusarium species. Isolates of F. oxysporum and F. avenaceum formed distinct groups in the phylogenetic analyses, except for two isolates of F. oxysporum which were grouped with isolates of F. redolens.

The hydrophobin SC4 was isolated from the medium of a dikaryon from Schizophyllum commune with disrupted SC3 genes. Although not glycosylated, its biophysical properties were similar to those of SC3. As the hydrophobins SC3 from S. commune and ABH1 and ABH3 from Agaricus bisporus, SC4 self-assembled at hydrophilic-hydrophobic interfaces into an SDS insoluble amphipathic film with a typical rodlet structure at its hydrophobic face, and also proved to be a powerful surfactant. Similar rodlet structures were observed in the fruiting body plectenchyma. By immunodetection SC4 could be localized lining air channels within this tissue. A similar localization was found for the ABH1 hydrophobin in fruiting bodies of A. bisporus. Probably, these hydrophobin coatings prevent collapse of air channels allowing efficient gas exchange even under wet conditions.