The genus Agaricus encompasses the cultivated mushroom A. bisporus, and includes both unifactorial heterothallic and homothallic species. The intractable nature of their life cycles and an absence of diagnostic morphological features, hinder analysis of breeding systems in Agaricus and some other homobasidiomycete species. We utilised RAPD markers to assess genetic variation in single spore progeny from different Agaricus species and to confirm heterokaryon formation in matings. Single spore progeny from heterothallic species should be more heterogeneous than those from homothallics. Homokaryotic progeny from the secondarily homothallic A. bisporus were less variable (12%) with fewer segregating loci than the known heterothallic species, A. bitorquis (50%) and A. nivescens (32 %). Variation in the progeny of A. campestris (36%) was similar to that for the heterothallics. Heterothallism in the field mushroom was confirmed by RAPD analysis of putative matings; the first time A. campestris heterokaryons have been constructed. No variation was observed in progeny from two collections of A. subfloccosus. Homogeneity in RAPD profiles, absence of matings and self-fertility of single spores shows that A. subfloccosus is homothallic. In progeny from A. arvensis very low variation (5%) occurred and proportions of segregating loci were around half of those for A. bisporus. However, matings were observed and RAPD characterised within the A. arvensis progeny. RAPD analysis of genetic variation within spore progeny should have general utility in the characterisation of fungal breeding systems.

The genus Tulasnella is surveyed in the Patagonian Andes forests of southern Argentina based on specimens collected from Austrocedrus chilensis, Nothofagus antarctica, N. betuloides and N. pumilio. Five species are recorded, namely T. robusta sp. nov., T. allantospora s.lat., T. calospora, T. helicospora and T. violea, all of which represent new records for Argentina.

Two distinct and unrelated groups of ophiostomatoid fungi are associated with Protea infructescences. Two species, Gondwanamyces proteae and G. capensis, have unique anamorphs that reside in Knoxdaviesia. This anamorph genus is infrequently found amongst species of Ceratocystis sensu lato. The second group includes Ophiostoma splendens and O. protearum that have Sporothrix anamorphs typical of Ophiostoma. During recent collections of Protea gaguedi infructescences from the Northern Province in South Africa, an apparently new species of Ophiostoma with a Sporothrix anamorph was discovered. It can be distinguished from O. splendens and O. protearum based on its short ostiolar hyphae and its associated plant host. This teleomorph is described as O. africanum and the anamorph as S. africanum. Five species of ophiostomatoid fungi are now known from Protea infructescences and a key is presented for them.

The haplophase of the pine blister rust Cronartium flaccidum was used to grow mycelial clones axenically from single genotypes. Single telia were suspended over the media in order to obtain a direct cast of uninucleate basidiospores, providing nurse cultures from a mass basidiospore inoculum. Nurse culture and medium composition were crucial factors in successful germination and establishment of single-spore colonies. Significant differences in percentage germination between treatments and controls suggested that an extracellular matrix secreted by high density seeded basidiospores could be involved in the germination of single propagules. Proteins present in this matrix could exert a surface contact stimulus triggering germination of newly seeded basidiospores. Pre-production of extracellular enzymes in the medium could also initiate early substrate catabolism and thus create a favourable environment to support subsequent colony establishment. Growth was good on various media, and excellent on HG1Y+BSA medium. Primary mother colonies were divided into several smaller ones, re-grown axenically, then macerated. Aliquots of the resulting mycelial fragments were dispensed with a micropipette into fresh agar media. Clones derived from each pure culture were in general morphologically similar in texture, margin, compactness, and surface topography. These genetically pure lines grew at a faster rate and rapidly produced a considerable amount of mycelium. The significance of culturing rust fungi from single genotypes is discussed in relation to potential applications and new directions of research.

Englerodothis oleae and Lepteutypa tropicalis spp. nov., Pellucida pendulina gen. et sp. nov., and Pseudorhynchia mauritiana sp. nov., collected from the Mauritian native plants Cordemoya integrifolia, Olea lancea and species of Pandanus, are described, illustrated and compared with related taxa. A key is provided to the currently accepted species of Lepteutypa.

A taxonomic and ecological reassessment of the genus Cresporhaphis is presented, with a key to all 7 species currently known, including C. ulmi sp. nov. from Spain, on twigs of Ulmus minor. Species are facultatively lichenized with chlorococcoid algae, Trentepohlia and other algae, or saprobic.

A new ascomycete, Antarctomyces psychrotrophicus gen. et sp. nov., characterised by naked asci, hyaline, thick-walled, ellipsoidal to fusiform, echinulate ascospores, and blastoconidia, isolated from Antarctican soil samples, is described and illustrated. Analysis of the nuclear rDNA ITS region sequences showed that this taxon is related to Thelebolaceae.

Ascogenous hyphae of foliicolous members of the Arthoniaceae, including the genera Arthonia, Eremothecella, Amazonomyces, and Cryptothecia, were studied by epifluorescence microscopy. Two additional representatives of Opegrapha were included. The ascogenous hyphae in Arthonia, Eremothecella, Amazonomyces, and Opegrapha arise from a central region of the ascoma and form a dense and branched tree-like structure. The asci of Cryptothecia are not connected by such structures and arise singly. Differences of measurements, structures and branching patterns of ascogenous hyphae indicate that these are species-specific characters. Typical ascogones were not observed. The fusion of tips or croziers of ascogenous hyphae and haploid mycelium were seen in several species. The systematic significance of the observations is discussed.

If is with deep regret that we announce the sudden, tragic, and unexpected death of Dr Stephen Moss, President of the British Mycological Society for 2001-2002. Stephen, aged 58 years, died at his home in Portsmouth on Friday 26 October 2001. He was a caring and conscientious person who dedicated his life to mycology, and in particular the Society, throughout his career. Our thoughts are with his wife Jan and all the family at this dificult time. A full obituary will appear in a future issue of Mycological Research.

Teleomorphic, or sexual, phases have not been described for many deuteromycetous fungi and it is debated whether these phases actually exist, or are even necessary for some fungi. Muller's Ratchet is a population genetical mechanism, hypothesized in 1964 by H. J. Muller, which describes how certain asexual populations may undergo an unavoidable and progressive decline in fitness, eventually leading to population extinction. With respect to deuteromycetous fungi, Muller's Ratchet could operate because clonally reproducing populations are not able to reduce their mutational load with each generation. Here we used a model to investigate and quantify some of the potential effects of the lack of sexual recombination on the accumulation of deleterious mutations using parameters derived from two species of deuteromycetous entomopathogenic fungi, Metarhizium anisopliae and Beauveria bassiana. Our results suggest that, under certain realistic conditions, Muller's Ratchet may not play a critical role in the fitness of these deuteromycetous entomopathogenic fungi and it is at least theoretically possible that these fungi could reproduce through exclusive clonal lineages.