This issue of Mycological Research News features a 21 year study of the occurrence, abundance and timing of macromycete fruit body production in a Swiss forest plot reported on this month.

This part of Mycological Research includes 15 other papers. These examine fruiting times in different genets of two Laccaria species, and report on differences in Microbotryum violaceum from North America and Europe, and also variation in Athelia rolfsii (Sclerotium rolfsii) and S. delphinii found by incompatibility and RAPD analyses. The EAN and NAN races of Ophiostoma novo-ulmi are named as subspecies, and molecular studies suggest that an unnamed Rhizoctonia attacking conifers is an anamorph of Ceratobasidium bicorne.

The effectiveness of surface sterilization methods for plant material is compared, an ELISA method for the quantification of Ulocladium atrum in plant tissues developed, and the efficacy of different storage regimes for Beauveria bassiana assessed. The fungicide oxycarboxin differentially suppresses Hebeloma sinapizans and not Tuber borchii.

A major study of the macrofungi and slime moulds on decaying beech logs uses gradient analysis to discern the effects of different parameters on species found. Different types of oidium formation in Coprinus cinereus strains are also described.

Taxonomic papers in this issue focus on novel marine and freshwater ascomycetes from the tropics, and describe a new gall-forming lichenicolous ascomycete.

The following new scientific names are introduced: Aqualignicola, Brunneosporella and Lichenopyrenis gens. nov.; A. hyalina, B. aquatica, Jobellisia viridifusca, L. galligena, Porosphaerellopsis bipolaris, and Trematosphaeria malaysiana spp. nov.; Ophiostoma novo-ulmi subsp. americana subsp. nov.

Fungal fruit bodies were surveyed on a plot area of 1500 m2 from 1975–99 (excluding 1980–83) in the fungal reserve La Chaneaz in western Switzerland. Fruit bodies were identified and counted on a weekly basis. Species richness and abundances varied strongly between years. More than 400 species were encountered. Many species were transient; particularly rich years showed species occurring for only one year. This indicates that the number of species will substantially increase if the survey is continued. Within years, the species richness, abundances and periods of fruiting were tightly correlated. The abundance data of species within a year seemed symmetrically distributed over their fruiting period. The relation between species richness and abundances within years was studied by fitting species-abundance plots, known from numerical ecology. The surface area under the curves was taken as a parameter for ecological/fungal diversity. Productivity was correlated with the precipitation from June until October. The time of fruit body appearance was correlated with the temperatures in July and August. As groups, mycorrhizal and saprotrophic species behaved similarly over the years. The productivity of species was compared with their distribution in The Netherlands indicating a correlation between the level of local abundance and the geographic range of species.

Laccaria bicolor and L. laccata are ectomycorrhizal basidiomycetes which fruit abundantly over 1 or 2 months in autumn and sometimes in summer. We investigated the phenology of fruiting of the various Laccaria spp. genets in a Douglas fir plantation in the Nièvre (France), in which all genets had been identified by molecular methods. During the fruiting period of the population, the genets did not fruit synchronously: some fruited early, others later, and some over the whole period. For some genets that survived over 2–3 years (1995–97), the fruiting phenology remained similar from year to year, even when fruiting occurred in summer. We took advantage of the presence of a L. bicolor genet, which had been used to artificially inoculate Douglas firs in this plantation, to assess whether the timing of fruiting was influenced by microsite differences in the plantation (soil, host tree, etc.). In summer 1997, fruit bodies of this genet appeared synchronously everywhere at the beginning of the fruiting period. We conclude that the timing of Laccaria fruiting may be genetically determined, rather than explained by the size and position of the genet or the environmental conditions. The consequences for population studies are discussed.

Microbotryum violaceum (anther-smut) from Silene caroliniana and S. virginica produced promycelia that frequently appeared to contain more than three cells according to the number of septations. This is in contrast to samples from S. latifolia and to previous descriptions of this species. Apparent four-celled promycelia contained three nucleate cells and one anucleate zone. Anucleate zones were usually positioned between the first and third cells of the promycelium. Their presence was negatively correlated with the occurrence of intra-promycelial conjugation. Also, unlike isolates from Silene latifolia, isolates from S. caroliniana and S. virginica produced hyphae in the absence of an inducing agent.

The genetic relationships among 132 isolates of Sclerotium rolfsii (teleomorph Athelia rolfsii) collected during 1967–97 from 36 different host species over a wide geographic range representing 13 countries were investigated using mycelial compatibility groupings and RAPD analysis. A smaller group of 15 Sclerotium delphinii isolates from five host species and a limited geographic distribution was also studied. The development of aversion reactions following mycelial pairings of isolates in all possible combinations on potato dextrose agar was used to differentiate 71 mycelial compatibility groups (MCG) in S. rolfsii and five MCG in S. delphinii. Many MCG were unique single-member groups and these generally were found in widely separated geographic regions or countries. There was no clear relationship between host of origin and MCG, except for a majority of isolates of S. rolfsii from turfgrass that belonged to MCG 1. Within a specific geographic region, e.g. California, there usually were several different MCG present, some of which were recovered from the same host species. In addition, specific MCG of S. rolfsii were recovered from widely separated geographic regions as well as different host species, e.g. MCG 1 was recovered from turfgrass, carrot, tobacco, and tomato in California, Georgia, North Carolina, and Mexico, respectively. The extent of genetic diversity within and among MCG of S. rolfsii and S. delphinii was studied using RAPD analysis. Isolates from different MCG could be differentiated by their unique banding patterns using six primers. There were no discernible relationships among the various MCG using UPGMA analysis. Isolates within a particular MCG were also genetically diverse, but shared greater numbers of common bands and clustered together. Only a few members of some MCG in S. rolfsii and S. delphinii that had identical RAPD patterns were considered to be clonally derived. The extent of genetic diversity among isolates of S. delphinii was lower than that observed in S. rolfsii.

The two subpopulations of the Dutch elm disease pathogen Ophiostoma novo-ulmi, previously known as the Eurasian (EAN) and North American (NAN) races, are redesignated as subspecies novo-ulmi and americana. In addition to their partial reproductive isolation, wide range of physiological and molecular differences and different geographic ranges, the two subspecies can be discriminated by their perithecial form and dimensions. These perithecial differences are described, using perithecia produced in multiple intra-subspecies crosses. Perithecia of subsp. novo-ulmi have an average neck length of ca 450 μm, base width of ca 103 μm and neck length:base width ratio ca 4.4. Perithecia of subsp. americana have an average neck length of ca 295 μm, base width ca 116 μm and neck length:base width ratio ca 2.6. The average shape and dimensions of subsp. americana perithecia is similar to that of O. ulmi. The average perithecial form of subsp. novo-ulmi, as well as of O. himal-ulmi, is rather distinctive. The current known geographical distribution of subspecies novo-ulmi and americana, based on > 6500 samples, is presented.

In Finland and Norway, a uninucleate Rhizoctonia sp. is causing a root dieback disease on nursery-grown Norway spruce and Scots pine seedlings. This Rhizoctonia can be fruited under laboratory conditions and the basidial characters fit well in the species concept of Ceratobasidium bicorne, a species originally described as a moss parasite under forest conditions. Further comparison using traditional methods (cultural morphology, nuclear condition, anastomosis) has not been possible as the forest population of C. bicorne has apparently never been cultured. In the present study, we isolated DNA from a herbarium sample of C. bicorne grown on the moss Polytrichastrum formosum. Sequence analysis of the PCR-amplified rDNA region containing the internal transcribed spacer (ITS) regions and the 5.8S rDNA gene was used to examine the conspecificity of the herbarium sample and the uninucleate Rhizoctonia sp. The nucleotide sequence of the 5.8S rDNA gene was identical between the herbarium sample and five sequenced uninucleate Rhizoctonia strains. Within the uninucleate Rhizoctonia sp., the sequence identity ranged from 96.1 to 100% in ITS1 and from 99.6 to 100% in ITS2. The sequence from the herbarium sample fits well within these limits, strongly suggesting that the uninucleate Rhizoctonia sp. and C. bicorne are conspecific. Interestingly, two of the uninucleate Rhizoctonia strains produced two ITS alleles: the genetic implications are also discussed.

The effectiveness of surface sterilization methods were compared using root tissue of barley (Hordeum vulgare) colonized by two Chaetomium species in an aseptic plant growth system. The reliability of different sterilants to inhibit ascospore germination was tested. Ascospores on nitrocellulose membranes were either treated directly or ascospores adhering to axenic barley seedlings were treated on plant tissue. Inhibition of ascospore germination on nitrocellulose membranes was achieved with lower concentrations of sterilants than when the spores were on plant surfaces. A 10% peracetic acid treatment was necessary if experiments were conducted ad planta. The sterilants penetrated into epidermal root tissue and caused damage to this area, as shown by the vital dye DiOC7(3). It was concluded that effective surface sterilization techniques for ascospores adhering superficially to plant tissue were not appropriate for the detection of fungi growing within the epidermis.

Five murine hybridoma cell lines secreting monoclonal antibodies (MAbs) with similar binding specificities were raised to extracts from cyclamen leaves colonized with Ulocladium atrum, a saprotrophic fungus used for biological control of Botrytis cinerea. One of the cell lines produced a MAb, UA–PC3, which was used to develop a quantitative ELISA to determine the biomass of U. atrum in extracts from colonized leaves. The antigen, which is water soluble, was present on the surface of conidia and hyphae and was secreted into culture fluids. Production of the antigen was much greater in vivo than in vitro. Germination of conidia took place in saline buffers at 4 °C after 6 h. To avoid amplification of the antigen in biomass assays of the fungus in extracts from sporulating tissues, coating of microtitre wells in ELISA was reduced to 1 h.

The occurrence of fungi and slime moulds on 70 decaying beech logs was surveyed based on the presence/absence of sporocarps. In total 277 species of fungi and 25 of slime moulds were recorded and summarised in a log/species datamatrix. The structure of the datamatrix was analysed using detrended correspondance analysis (DCA). The ecological nature of the gradients expressed by the first three DCA-axes was then investigated by environmental and log related variables. The first and strongest gradient corresponded to changes in the community development during the decay process. The second gradient was complex and corresponded to both decay rate and microclimatic stress. The third, rather weak, gradient was influenced by soil conditions. The gradients are discussed in a context of fungal ecological strategy theories. A model generalised from the community development on the studied logs is proposed.

The effect of air-dry storage environment on the longevity of conidia from seven isolates of Beauveria bassiana produced at different times and locations was determined by estimating the parameters of a viability equation. Conidia were stored hermetically at six to 11 moisture contents between 2.3 and 32.0% with one (50±0.5 °C) to five constant temperatures (10, 20, 30, 40 and 50±0.5 °) for various periods up to 372 d and then tested for viability. All isolates behaved similarly (P > 0.25) in terms of the relative effect of moisture content (CW) and temperature (CH and CQ) on conidial longevity; common values were CW = 3.05 (SE = 0.07), CH = 0.0293 (SE = 0.0078), and CQ = 0.00081 (SE = 0.00011). Estimates of the low-moisture-content limit to the negative logarithmic relation between conidial moisture content and longevity were 4.6 and 5.0% at 50° and 40°, respectively, for isolate I98-1140ss, and 5.2 and 5.1% moisture content, respectively, for isolate I97-1111. Absolute longevity (KE) varied considerably (P < 0.005) among isolates, even within an isolate when conidia were produced at different locations. Among the eight samples of seven isolates, two cohorts were identified with respect to KE (P < 0.005): conidia of three isolates which were produced at Ascot had a common estimate of KE of 6.696 (SE = 0.170), whereas those produced at Nairobi or Carolina provided a lower estimate (6.203, SE = 0.029). This difference in KE means that for any given viability period in any given environment, the conidia produced in Ascot provided about three times the longevity of the other samples.

Oidiophores with uninucleate oidia are produced on the aerial mycelium of Coprinus cinereus and occasionally also on the submerged mycelium. Oidiophore development starts with the formation of a stem cell and proceeds with stem cell elongation, followed by the formation of oidial hyphae at the tip of the stem cell and subsequent release of matured oidia. However, analysis of more than 20 different C. cinereus strains revealed that oidiophore formation is a flexible process. Based on morphological variations, we defined four main types of oidiophores. Types 1 and 2 oidiophores produced oidia at the tip(s) of simple (type 1) or branched stems (type 2). Types 3 and 4 oidiophores were characterized by the absence of stem cell elongation (type 3) or stem cell formation (type 4). All strains examined produced types 1 and 2 oidiophores and some produced also types 3 and 4 oidiophores but the frequency of the different oidiophore types varied strongly from strain to strain.

Competing ectomycorrhizal fungi can cause problems during the commercial production of edible Tuber species infected plants in greenhouses and later when infected plants are transplanted to the field. We investigated the effect of selective fungicides on Tuber borchii, in the presence of Hebeloma sinapizans, both in vitro and during the production of T. borchii infected Quercus pubescens. Oxycarboxin completely suppressed the growth of H. sinapizans but had only a weak fungitoxic effect on the growth of T. borchii both in vitro and on Q. pubescens roots. In contrast, other fungicides either suppressed both fungi or T. borchii more than H. sinapizans.

Trematosphaeria malaysiana sp. nov. is described based on light microscope and ultrastructural studies. It was found on driftwood, exposed test blocks of Avicennia marina and Rhizophora apiculata, and split twigs of R. apiculata exposed in Kuala Selangor and Morib mangroves, Malaysia. T. malaysiana is characterized by striate, pale brown ascospores and trabeculate pseudoparaphyses. Ascospore cell walls are two layered, an outer thick layer comprising fibrillar mucilaginous material, and an inner bilamellate layer (the inner layer electron-transparent; the outer electron-dense and containing melanin). Both T. malaysiana and Leptosphaeria pelagica were examined at the transmission electron microscope level and their structure compared with that of other bitunicate ascomycetes. T. malaysiana and L. pelagica were similar in that the mucilaginous sheath was the outer most layer, in the former the spore wall was two layered, while in L. pelagica it was three layered. In L. pelagica the spore wall was smooth, while in T. malaysiana it was longitudinally striate.

Brunneosporella aquatica gen. et sp. nov., Aqualignicola hyalina gen. et sp. nov., Jobellisia viridifusca sp. nov. and Porosphaerellopsis bipolaris sp. nov. are described and illustrated from wood submerged in freshwater collected in Hong Kong. Both Brunneosporella and Aqualignicola have characteristic features of the Annulatascaceae and their placement within this family is discussed. Jobellisia viridifusca sp. nov. differs from all described species in having an ascomatal wall with a bright orange middle wall layer and fusiform, greenish-brown ascospores. Porosphaerellopsis bipolaris sp. nov. is unique in producing multiseptate ascospores with bipolar mucilagilous pads.

The new genus Lichenopyrenis is described for L. galligena, a cecidiogenous species parasitic on the lichen Leptochidium albociliatum. This genus is characterized by perithecioid ascomata with a cellular wall, formed by relatively large, somewhat compressed cells, fissitunicate, I- asci, wide hamathecium filaments, and 1-septate, pale orange brown ascospores with distoseptate thickenings which at maturity are seemingly bulging out of the exospore wall at the septum and apices. The conidia have a rhexolytic type of secession, and are attached to the conidiogenous cells by a separating cell. Lichenopyrenis is referred tentatively to the family Pleomassariaceae.

The Mycota. A comprehensive treatise on fungi as experimental systems for basic and applied research. Edited by Karl Esser & Paul A. Lemke. 1994–2001 [ongoing]. Springer Verlag, Berlin. 12 vols (9 published to date).

I Growth, Differentiation and Sexuality. Edited by Joseph G. H. Wessels & Friedhelm Meinhardt. 1994. Pp. xv+433, figs 112, tables 22. ISBN 3 540 57781 5. Price: DM 429, £148, US $235.

II Genetics and Biotechnology. Edited by Ulrich Kück. 1995. Pp. xv+375, figs 67, tables 31. ISBN 3 540 58003 4. Price: DM 399, £137.50, US $321.

III Biochemistry and Molecular Biology. Edited by R. Brambl & G. A. Marzluf. 1996. Pp. x+449, figs 89, tables 27. ISBN 3 540 58004 2. Price: Out of print.

IV Environmental and Microbial Relationships. Edited by Donald T. Wicklow & Bengt E, Söderström. 1997. Pp. xvii+373, figs 82, tables 31. ISBN 3 540 58005 0. Price: DM 329, £113.50, US $251.

V Plant Relationships. Edited by George C. Carroll & Paul Tudzynski. 1997. Part A. Pp. xviii+253, figs 74, tables 18. ISBN 3 540 58006 9. Price: DM 289, £99.50, US $181. Part B. Pp. xix+288, figs 81, tables 13. ISBN 3 540 62018 4. Price: DM 299, £103, US $192.

VI Human and Animal Relationships. Edited by Dexter H. Howard & J. D. Miller. 1996. Pp. xiv+399, figs 61, tables 24. ISBN 3 540 58007 7. Price: DM 329, £113.50, US $251.

VII Systematics and Evolution. Edited by D. J. McLaughlin, E. G. McLaughin & Paul A. Lemke. 2000 [2001]. Part A. Pp. xx+366, figs 217. ISBN 3 540 58008 5. Price: DM 379, £130.50, US $215. Part B. Pp. xx+259, figs 120. ISBN 3 540 66493 9. Price: DM 279, £96, US $159.

[VIII Biology of the Fungal Cell. Edited by R. J. Howard & N. A. R. Gow. In preparation.]

IX Fungal Associations. Edited by B. Hock. 2000 [2001]. Pp. xiv+250, figs 69, tables 16. ISBN 3 540 62872 X. Price: DM 279, £96, US $159.

[X Industrial Applications. Edited by H. D. Osiewacz. In preparation.]

[XI Agricultural Applications. Edited by F. Kempen. In preparation.]

[XII Human Fungal Pathogens. Edited by J. E. Domer & G. S. Kobayashi. In preparation.]