It cannot be denied that recent developments in sophistication, availability and cost of molecular biology techniques have had a profound effect on mycology. The ready availability of DNA sequence data has led to major developments in the study of the systematics, biochemistry and ecology of fungi. The introduction of molecular techniques has allowed significant steps to be made in genomics, and in many areas of applied mycology molecular based approaches have become routine for strain characterisation, pathogen detection and identification. Molecular methods are now starting to give major insights into how fungi function in the environment, where they are present, and how they interact with associated organisms.

The 'Ling-zhi' (formerly 'Ling-chih') is familar to the whole of China, and it has played an important role in Chinese and Japanese culture for at least two thousand years. Images of the mushroom can be seen frequently depicted in the ancient, oriental art. It is used medicinally, with many claims of health-stimulating properties, and believed to have an effect on long life. Ling-zhi means the 'Mushroom (or herb) of Immortality' or the 'Celestial Herb', and it symbolises happiness, good fortune, good health and even immortality. In Japan it is called 'Mannen-take' ('10,000 year old Mushroom') or 'Reishi' ('Divine Mushroom'). The fungus is a hard bracket-fungus, which grows on oak, maple, elms and willows, often from the tree-roots. It is long been identified with the European 'Varnished Polypore' (Ganoderma lucidum (W. Curtis: Fr.) P. Karst.) but it is now known that this name has been applied to a number of closely related species.

The striking reddish-pink colour of the phylloplane yeast Sporobolomyces roseus was found to be due to three major carotenoid pigments which were identified by UV and mass spectra as β-carotene, torulene and torularhodin. Simple protocols for the extraction of these pigments and their visual separation by thin-layer chromatography are presented. Ultrastructurally, the pigments were localized within numerous small lipid droplets. Putative physiological roles and the biotechnological relevance of carotenoids from red yeasts are discussed.

Early in the nineteenth century John Curtis (1833) investigated flies attracted to a phalloid fructification in England. The fungus was found in some abundance on “the sand-hills near Lowestoft, Suffolk, in the middle of October”. It had a scent like violets at a distance, in the field, but was very offensive when dried. Curtis stated that it seemed “to differ materially from the Phallus foetidus Lam. (P. impudicus Linn.)”. Flies of all descriptions were much attached to the fungus and, as well as bees and beetles, seemed very fond of the “shining matter which dropped from the pileus”. The bees were not identified. A pale pinkish flush over the volva was visible in the original illustration. The fungus seems to represent Phallus hadriani Vent. (syn. P. iosmus Berk.) the basal volva of which becomes pinkish to reddish when exposed. It is also said to smell sweeter than P. impudicus, often of violets. It is the less common of the two Phallus species in Britain, being more or less restricted to coastal dunes (Pegler et al., 1995).

Two Indonesian agarics described from Mount Kinabalu in Borneo, Mycena rimosacuta Corner, and Mycena rimosacuta var. alba Corner, are now known to be the Australasian species Hygrocybe lewelliniae (Kalchbr.) A. M.Young and Hygrocybe mavis (G.Stev.) E.Horak respectively.

The occurrence of the American Horse Chestnut mildew, Uncinula flexuosa, is reported from Europe, including Great Britain, for the first time (New British Record 210). A key is provided for the identification of powdery mildews on horse chestnuts in Europe.

When a major wild bird food producer advised, in their catalogue for the year 2000, that they could not offer peanuts because of the high levels of aflatoxin, the phenomenon of mycotoxins had really come into the public domain. In 2001 the same company was able to advise that 'Although present in some peanut crops this season, aflatoxin is not currently creating any major peanut supply problems'. Mycotoxins, and specifically peanuts and the health of wild birds, were reviewed in earlier volumes of this journal (Isaac 1994 a, b) but the passage of time has not led to any reduction in the problems associated with the presence of mycotoxins in foods and animal feeds. Indeed, the improvement in analytical methods, and the implications of legislation in many countries have served to increase awareness of mycotoxins.

Name of fungus

Teleomorph: Rhytisma acerinum (Pers.) Fr. (order Rhytismatales, family Rhytismataceae)

Anamorph: Melasmia acerina Lév.

Introduction: Features of interest

Tar-spot disease on leaves of sycamore (Acer pseudoplatanus L.) is one of the most easily recognised foliar plant diseases caused by a fungus (Figs 1 and 4). First described by Elias Fries in 1823, knowledge of it had become well-established by the latter half of the 19th century (e.g. Berkeley, 1860; Massee, 1915). The causal fungus, Rhytisma acerinum, occurs in Europe and North America on A. pseudoplatanus throughout its distribution range and also on other species of Acer (Sutton, 1980; Farr et al., 1989), but it is less frequent in urban and industrial areas.

The black tar-spots visible in late summer and autumn are stromata containing many apothecial rudiments, but these only mature to form asci during the winter on fallen leaves (Jones, 1925; Duravetz & Morgan-Jones, 1971). Maturing apothecial stromata develop linear or convoluted ridge-like swellings which raise the thick black layer (clypeus) on the upper surface of the stroma (Fig 1). Eventually, the surface breaks along the ridges (Fig 2), exposing a greyish hymenium (Fig 3) which contains club-shaped asci and filamentous paraphyses with curved or recoiled tips (Figs 8 and 9). The ascospores are unicellular and needle-shaped, with an apical mucilage pad (Fig 10). In Britain and Europe, ascospore discharge from overwintered stromata takes place in March and April, just as the new sycamore leaves unfold.

Opportunistic fungal infections have emerged in the past ten to twenty years as some of the most significant and potentially lethal infectious diseases to confront contemporary medicine. Fungi such as Candida albicans, Aspergillus fumigatus and Cryptococcus neoformans have emerged from obscurity to threaten many patient groups. Although the latter of these, the yeast C. neoformans, was identified as a potential pathogen as early as 1894, it was not until the 1950s that a systematic appreciation of its potential as an opportunistic pathogen began. During this decade the association between the heightened risk of C. neoformans infection (cryptococcosis) and various cancers of the blood became obvious. Fortunately, just as the risk posed by this yeast to human health was being clearly defined (in the late 1950s), the first effective therapy to treat cryptococcosis appeared - the drug amphotericin B. This was particularly timely since it had been recognised that C. neoformans infection often led to a rapidly fatal form of meningitis if untreated.

Throughout the 1960s the infection remained relatively rare, being largely confined to the patient group described above. However, by the late 1970s the incidence of C. neoformans infection began to rise rapidly. Cases were now being seen in patients undergoing organ transplantation, in those with autoimmune diseases and in others who were receiving immunosuppressive drugs to treat various cancers. Cryptococcosis had suddenly become 'the awakening giant' amongst fungal infections (Kaufman & Blumer,1977); but quite how much of a ‘giant’ would only become clear in the next two decades with the development of the human immunodeficiency virus (HIV) epidemic.

In October 2001, Sir Paul Nurse and Dr Tim Hunt of the Imperial Cancer Research Fund became the first Britons since 1988 to win the Nobel prize for Physiology or Medicine. The prize was shared with Dr Leland Hartwell, director of the Fred Hutchinson Cancer Research Center in Seattle, and acknowledged the extraordinary progress made by the three scientists in identifying the molecules that orchestrate the growth and division of cells. Two British scientists winning a Nobel prize is reason enough to celebrate, but what made this achievement particularly pleasing was that many of the key experiments were carried out in fungi.

In the early 1970's, Hartwell recognised the potential for studying the cell cycle with genetic methods, using as his model the baker's yeast, Saccharomyces cerevisiae (Hartwell, Culotti & Reid, 1970). He isolated yeast cells in which genes controlling the cell cycle were mutated and thereby identified over 100 "CDC" (cell division cycle) genes. One of these (CDC28) was shown to control a key step in the progression from G1 to S-phase, a point known as 'Start' (Fig 1). Inspired by Hartwell's work, Paul Nurse took a similar approach using another fungal model, the fission yeast Schizosaccharomyces pombe (Nurse, Thuriaux & Nasmyth, 1976). In the mid-1970's, he showed that a gene dubbed cdc2 had a key function in controlling the transition from G2 to M-phase. DNA sequencing of the gene revealed that cdc2 was very similar to the CDC28 gene that Hartwell had shown to control the transition through Start. In other words, a single gene regulates progression through two key points in the cell cycle in organisms that separated from each other during evolution more than one billion years ago.

Since most mycologists work on ascomycetes or basidiomycetes it is easy to forget chytridiomycetes when thinking about fungi, let alone anaerobic chytridiomycetes. So it was hardly surprising that more than one hundred years ago scientists did not recognise the motile spores in a rumen sample as being fungi. Since it was general knowledge that the rumen was infested with bacteria and ciliates the flagellated cells seen by Liebetanz and Braune (1913; 1910) were considered to be flagellates (see Fig 1). About 50 years later there are some careful remarks in the literature about this Callimastix species by Vavra and Joyon (1966) but they do not explicitly mention that it might be a fungus. It took until the seventies before Colin Orpin finally dared to suggest that those strange anaerobic flagellates that live in the rumen might actually be fungi (Munn et al., 1981; Orpin, 1975; 1977). That scientific dogmas are enormous barriers is obvious from the fact that even the great rumen microbiologist Robert Hungate did not believe that fungi could be anaerobic. The late Rudolf Prins told me that in the sixties, when he and Hungate discovered 'fluffy' colonies in anoxic tubes, they always threw them away because oxygen must have seeped in!

Careful examinations by Heath (1983; 1988b) and Barr (1980; 1988) morphologically linked the anaerobic chytrids to the fungi. Modern phylogenetic analyses have confirmed these findings and reveal the chytrid fungi to be the earliest fungal branch (Bowman et al., 1992; Doré and Stahl, 1991; Li and Heath, 1992; Van der Auwera and De Wachter, 1996).