Isolation and characterization of developmental variants in fruiting using a homokaryotic fruiting strain ofCoprinus cinereus

Developmental variants in fruiting ofCoprinus cinereus were induced by mutagenizing oidia of the homokaryotic fruiting strain CopD5-12 with UV light. Through screening of 2,696 isolates, 1,018 strains exhibited defects in fruiting and were classified into 8 groups: (1) knotless variants, which fail to form hyphal knots, the first visible sign of fruiting; (2) primordiumless variants, which form hyphal knots but fail to develop fruit-body primordia; (3) maturationless variants, which form fruit-body primordia but do not form mature fruit bodies; (4) elongationless variants, which form mature fruit bodies with short stipes; (5) expansionless variants, which form mature fruit bodies with unexpanded pilei; (6) sporeless variants, which fail to produce black basidiospores, resulting in fruit bodies with white pilei after maturation; (7) compound type, which includes variants exhibiting several of the phenotypes described above; (8) others, including variants that produce a “dark stipe” even under in light/dark conditions, which is formed under continuous darkness in the wild-type. Two elongationless variants were characterized histologically.     

A new species of <Emphasis Type="Italic">Cortinarius</Emphasis> sect. <Emphasis Type="Italic">Orellani</Emphasis> from Japan

Cortinarius breviradicatus sp. nov., found in deciduous forests, is described and illustrated from Niigata, Japan. It is characterized by its medium-sized to large dark brown basidiocarp, acutely conical pileus, and rooting stipe, and by subglobose to broadly ellipsoid basidiospores. In addition, the extracting solution from its basidiocarps exhibits a strong fluorescence around 400–430 nm in ultraviolet radiation (250 nm), which was observed in a species of Cortinarius sect. Orellani. The new species belongs to the section Orellani. The differences between the new taxon and similar species are briefly discussed.     

Sequential production of enzymes and basidiospore formation in fruiting bodies of Coprinus macrorhizus

The production of NADP-dependent glutamate dehydrogenase was initiated at the stage of first meiotic prophase in pileus cells but not in stipe cells of dikaryotic and monokaryotic fruiting bodies in Coprinus macrorhizus. The production of chitinase and glucanases assayed with laminarin and lichenan was observed after the completion of meiosis only in pileus cells. The light conditions that were effective for the delay or inhibition of cellular events in the pileus cells were also effective for the delay or inhibition of enzyme production. But all sporeless mutants tested, which were defective at the various stages of basidiospore formation, produced the normal levels of these enzymes. The results indicate that the sequential production of enzymes and cellular events leading to basidiospore formation in pileus cells are independent from each other.Abbreviation GDH_NADP NADP-dependent glutamate dehydrogenase     

The Change of Tropism in Polyporus brumalis Stipes and the Effect of Directional Stimuli on Pileus Differentiation

The directional influences of light and gravity upon the developmentof pileate and epileate sporophores of Polyporus brumalis, producedin pure culture, have been investigated. Growth in the dimiticfruit-body has a considerable subapical component which in thestipe is responsible for tropistic curvature. The stipe is competentto react negatively to unilateral gravitational and positivelyto unilateral photic stimulation throughout development, butwhen both stimulioperate phototropism masks geotropism. If illuminatedfrom one side the growing epileate stipe is strongly positivelyphototropic but as the pileus reaches a characteristic diameterthe stipe becomes negatively geotropic. Experiments with changingdirection of illumination and with artificial pilei of blackpaper suggest that the change of tropism is explicable by theshading action of the expanding pileus on the sub-pilcal photoperceptiveand photoreactive region of the stipe. Developing sporophores continuously rotated with reference tofixed directions of gravitational and light stimulation andothers with stipes inverted as a result of illumination frombelow during development have in common that the morphologicallyupper surface of the pileus always develops towards and approximatelyat right angles to the direction from which the maximum lightintensity is received. Normal but inverted stipes and dissepimentsshow no tendency to geotropic reorientation.     

Influence of light on the morphological changes that take place during the development of the <Emphasis Type="Italic">Flammulina velutipes</Emphasis> fruit body

We show that fruit bodies of Flammulina velutipes can be induced in complete darkness after a sharp temperature reduction (23° to 16°C). However, the fruit bodies that form in complete darkness have a long stipe with an undeveloped pileus on the top (pinhead fruit bodies) and are thinner and whiter than the normal fruit bodies which are formed in the light. This finding suggests that F. velutipes fruit bodies cannot mature in complete darkness. However, when we irradiated the fruit bodies that had formed in complete darkness, a pileus developed immediately, and 4 days later the separation between the stipe and the pileus could be observed. Immediately after light exposure, the stipe also thickened and became increasingly pigmented. The stipe elongation was inhibited until 8 days after light exposure, although stipe elongation progressed very quickly thereafter. Basidospores were also visible in the gills 8 days after light exposure. We consider that the basidiospore development is involved in this rapid stipe elongation, which aids the effective dispersal of basidiospores.     

Stipe elongation during basidiocarp maturation in Coprinus macrorhizus: Mechanical properties of stipe cell wall

Stipe elongation during basidiocarp maturation in the wild-type,#5026+5132, and the elongationless mutant, NG0398, of Coprinusmacrorhizus was studied, and the following results were obtained.

1. In the wild-type the middle zone of the stipe elongated 8.4times in 15 hr during maturation, while in the mutant it elongatedoaiy 2.2 times.
2. Component cells of the stipe elongated inparallel with thestipe elongation in both the wild-type andthe mutant. The widthof stipe cells was almost constant duringelongation in thewild-type, while it increased 2 times in themutant. Cell volumeincreased ca. 8 times in both stocks.
3. Theosmotic value of stipe cells was almost constant (0.45–0.50M) throughout elongation of both the wild-type and the elongationlessstipes.
4. Mechanical properties of the cell wall were examinedby measuringshrinkage, extensibility and minimum stress-relaxationtime(To) of the stipe during maturation. These parameters weredirectlyproportional to the elongation rate to follow.
5. Whenthe wild-type stipes were incubated in various concentrationsof mannitol solution and then in plain buffer solution, theextensibility of the stipe after the incubation in mannitolsolutions changed proportionally with the stipe length afterthe mannitol treatment, and To with the elongation capacityin plain buffer solution.

(Received March 3, 1977; )     

Four new species of <Emphasis Type="Italic">Crinipellis </Emphasis>and <Emphasis Type="Italic">Marasmius </Emphasis>in eastern Honshu,Japan

 Four new species of Crinipellis and Marasmius (Agaricales, Basidiomycetes) in eastern Honshu, Japan, are described and illustrated: (1) Crinipellis conchata sp. nov. (section Excentricinae), forming a conchate pileus and a strongly excentric, short stipe, was found on a dead twig of Trachelospermum asiaticum in Mt. Takao, Tokyo; (2) Marasmius funalis sp. nov. (section Androsacei), forming a densely white-hispid, dark brown stipe bearing numerous setiform caulocystidia, was found on a dead twig of Cryptomeria japonica or on leaf litter in Tokyo and Kanagawa; (3) Marasmius maculosus sp. nov. (section Sicci), having a relatively large, reddish-brown pileus distinctly mottled with pale colored spots and Siccus-type cheilocystidia and pileipellis cells with relatively long setulae, was found on leaf litter in the lowland forest of Kanagawa and Chiba; and (4) Marasmius sasicola sp. nov. (section Marasmius), having a small, plicate-sulcate pileus, a filiform, wiry, blackish stipe, collariate lamellae, and Siccus-type cheilocystidia and pileipellis elements, was found on fallen dead leaves of grass bamboo in Kanagawa. Received: January 30, 2002 / Accepted: May 24, 2002     

Influences of environmental factors on fruiting body induction,development and maturation in mushroom-forming fungi

Mushroom-forming fungi (restricted to basidiomycetous fungi in this review) differentiate by sensing several environmental factors for fruiting body formation. For fruiting body induction, nutrient, temperature and light conditions are critical environmental factors. Higher nitrogen and carbon sources in the media will suppress fruiting body induction in many mushroom-forming fungi, with induction being triggered by lower nitrogen and carbon concentrations. Low temperature or temperature downshift is another critical influencing factor for fruiting body induction in many cultivated mushrooms, such as Flammulina velutipes, Lentinula edodes, and Volvariella volvacea. Fungal response toward starvation and cold involves the production of sexual spores as the next generation. Species like F. velutipes and Coprinopsis cinerea can form fruiting bodies in the dark; however, light accelerates fruiting body induction in some mushroom-forming fungi. Remarkably, fruiting bodies formed in the dark have tiny or no pileus on heads (called dark stipe, pinhead fruiting body, or etiolated stipe). Light is essential for pileus differentiation in many, but not all mushroom species; one exception is Agaricus bisporus. Mushrooms have positive phototropism and negative gravitropism for effective dispersal of spores. Carbon dioxide concentrations also affect fruiting body development; pileus differentiation is suppressed at a high concentration of carbon dioxide. Thus, the pileus differentiation system of mushrooms may allow the most effective diffusion of spores. Full expansion of the pileus is followed by pileus autolysis or senescence. In C. cinerea, pileus autolysis occurs during spore diffusion. Fruiting body senescence, browning of gill, and softening occur after harvesting in several mushroom species. Fruiting body induction, development, and maturation in mushroom-forming fungi are discussed in this review.     

Growth and fruitbody formation ofGanoderma lucidum on media supplemented with vanadium, selenium and germanium

Responses of mycelia ofGanoderma lucidum to vanadium, selenium and germanium were examined over a wide range of concentrations (10–1, 120 μg/ml) in pure culture. Se and V were found to be highly toxic, but Ge was not toxic at the levels tested.Ganododerma lucidum cultivated on substrates of sawdust with V (30–80 μg/g) developed mature fruitbodies, but the bioaccumulation of V was quite low (2.5–7 μg/g in pileus, 12.5–21.5 μg/g in stipe and <1 μg/g in basidiospores). Se as Na₂SeO₄ labeled with⁷⁵Se was effectively taken up from substrates and accumulated in fruitbodies (mainly in pileus), then depleted by discharge of basidiospores. Ge as GeCl₄ labeled with⁷⁷Ge was easily uptaken and translocated into fruitbodies.     

Untersuchungen über die Bildung und Regeneration von Fruchtkörpern bei Hutpilzen

Zusammenfassung Bei Flammulina velutipes läßt sich Fruchtkörperbildung am Mycel durch Zugabe arteigener und artfremder Fruchtkörperstücke stimulieren, wie das für Pleurotus Florida bereits berichtet wurde. Da auch durch Hitze sterilisiertes Material wirkt, kann mit der Existenz einer artunspezifischen, die Fruchtkörperbildung induzierenden Substanz gerechnet werden.Bei F. velutipes nimmt das Regenerationsvermögen der Fruchtkörper am Stiel von unten nach oben zu und fällt im Hut steil ab.Mycel von Agaricus bisporus dagegen reagiert auf Zugabe von Fruchtkörpermaterial nicht. Auch eine Regeneration an Basidiokarpstücken war nicht zu beobachten. Dies unterstreicht die Sonderstellung dieses Pilzes, der lebende Bakterien zur Fruchtkörperinduktion zu benötigen scheint.

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Summary In Flammulina velutipes fruit-body formation on the mycelium may be stimulated by the addition of basidiocarp pieces of the own or of different species as has been reported for Pleurotus Florida. Heat-sterilized material retains the stimulating character. Thus the existence of a fruit-body inducing chemical compound is likely.In F. velutipes regeneration intensity of fruit-bodies is increasing from the bottom to the top of the stipe and decreasing strongly in the pileus.Mycelium of Agaricus bisporus in contrast does not react on the addition of fruit-body material. Regeneration could not be observed on basidiocarp pieces. This emphasizes the isolated position of this fungus, that seems to require living bacteria for basidiocarp induction.

     

Differential scanning calorimetric analysis of fruit-body and mycelium ofLentinula edodes

Differential scanning calorimetric (DSC) analysis was applied to the fruit-body (pileus and stipe) and mycelium, of shiitake mushroom (Lentinula edodes). Thermograms of each sample indicated distinctive patterns. However, chemical and infrared (IR) spectroscopic analyses showed that the compositions of pileus and stipe were similar to each other and different from that of mycelium. Because the DSC thermogram depends not only on chemical composition but also on physical properties such as density, the result of DSC analysis was assumed to indicate a difference in the state of cell wall between pileus and stipe.     

Isolation and characterization of a sporeless mutant in <Emphasis Type="Italic">Pleurotus eryngii</Emphasis>

 A sporeless mutant dikaryon, completely defective in sporulation, was isolated from mycelial protoplasts of Pleurotus eryngii mutagenized by UV irradiation. Newly established dikaryons between one component monokaryon from the mutant, and 12 different wild type monokaryons from 3 other wild type dikaryons, all exhibited the sporeless phenotype, whereas those between the other monokaryon and the same wild type monokaryons all produced normal fruiting bodies. These results indicated that the sporeless mutation was induced in one of two nuclei of the mutant and was dominant. In the wild type basidia, the pattern of nuclear behavior during sporulation corresponded to the pattern C nuclear behavior as defined by Duncan and Galbraith. Cytological observation revealed that in the sporeless mutant meiosis was blocked at the meta-anaphase I in most basidia and hence basidiospores and sterigmata were not produced. Although fruiting bodies of the sporeless mutant showed a somewhat leaning growth, their gross morphology and its fruiting body productivity were comparable to that of the original wild type strain. Based on these results, it was considered that the sporeless mutant could serve as a potential material in breeding of sporeless P. eryngii commercial strains. Received: September 5, 2002 / Accepted: October 16, 2002 Acknowledgments We are grateful to Mrs. Motoe Masuda for her skillful technical assistance. Contribution no. 358 from the Tottori Mycological Institute Correspondence to:Y. Obatake     

Headspace analysis identifies indole and 1-octen-3-ol as the “coal tar” odor of <Emphasis Type="Italic">Tricholoma inamoenum</Emphasis>

The odor emanating from sporocarps of Tricholoma inamoenum has been described as resembling “coal tar”. To characterize the compounds responsible for this odor, volatile chemicals released from T. inamoenum sporocarps were collected using solid phase microextraction (SPME). Subsequent analysis by gas chromatography-mass spectrometry (GC-MS) showed only indole and 1-octen-3-ol, so these compounds must be responsible for the “coal tar” odor of T. inamoenum. Mushroom pileus size was a factor in the amount of indole produced; larger mushrooms released 25-times more indole than smaller ones. A comparison of SPME and CH₂Cl₂ solvent extraction of sporocarps showed major differences in the volatile organic compounds. Benzaldehyde and phenyl acetaldehyde were the major compounds in the solvent extracts, but were not detected in the SPME experiments. Tissue disruption of the mushroom before solvent extraction showed up to a 40-fold increase in the amount of 1-octen-3-ol present.     

Phase change-related variations of dome shape in Eucalyptus urophylla × Eucalyptus grandis shoot apical meristems

Shoot apical meristem (SAM) domes derived from five different outdoor and in vitro sources of juvenile and mature Eucalyptus urophylla × Eucalyptus grandis akin genotypes were compared. Overall measurements of SAM dome height H and diameter D ranged from 2 to 35 μm and 20 to 80 μm, with significant differences according to the various physiological origins of plant material investigated. SAM domes from the mature trees “Mat” were taller than those from the rejuvenated ministock plants “Rej”; from the in vitro microcuttings “IVM” of the same clone and also from the in vitro juvenile seedlings “IVJ”, whereas outdoor seedlings “Juv” exhibited intermediate SAM dome height. SAM domes from the rejuvenated material “Rej”, from the in vitro mature “IVM” and juvenile “IVJ” origins were also narrower than those from the outdoor seedlings “Juv” and to lesser extent than those from the mature trees “Mat”. Overall, the mature source “Mat” displayed bigger and somehow sharper hemispherical domes than those from “Rej” and “Juv”, physiologically more juvenile, or those from the in vitro origins “IVM” and “IVJ” which looked flatter and smaller. SAM dome height, diameter D and H/D values varied also significantly according to the plastochron. More specifically, H, D, and H/D SAM differences between the five origins were not significant during the early plastochron phase corresponding to leaf initiation, to become more salient as leaf structures started to elongate and to differentiate. This was particularly obvious for mature tree “Mat” SAM dome shapes which showed at this stage much higher H/D values than the other SAM sources. A shape index S used for characterizing more accurately dome shape confirmed these trends. These observations provide additional arguments to the view that juvenility in trees becomes more and more time- and shoot-tip restricted as ageing increases in the course of time during the ontogenetical process and could be ultimately confined to the most organogenic phase of SAM, from which shoot characteristics derive.     

Pleurotus Ostreatus — breeding potential of a new cultivated mushroom

Summary Two isolates of Pleurotus ostreatus from North America and one from Germany are interbreedable. Under identical conditions at low temperatures, their fruiting bodies are hard to distinguish. However, shape and colour and several other characters vary with culture conditions. The American stocks fruit well at temperatures from 4 to 24 °C, the German ones only below 15 °C. Four types of hybrids between German and American Pleupotus were obtained: i) The whole fruiting process is temperature sensitive as in German Pleurotus. ii) It proceeds at 4–24 °C as in American stocks, iii) Fruiting initiation is insensitive but sporophore development is sensitive to elevated temperatures, iv) Primordia formation and initial sporophore development depend on temperatures below 15 °C, but pileus expansion and spore discharge continue above 20 °. The involvement of separate genes for the single developmental steps and the use of temperature sensitivity for commercial varieties are discussed. One sporeless strain, F42x11, with considerable fruiting bodies has been obtained. In intrastock di-mon-matings this character was dominant.     

Distribution of free and esterified ergosterols in the medicinal fungus <Emphasis Type="Italic">Ganoderma lucidum</Emphasis>

The fruiting bodies, spores, and lipid from the spores of Ganoderma lucidum have been widely used for medicinal purpose in China. Ergosterol content may be a suitable marker for evaluating the quality of ganoderma spore and ganoderma spore lipid (GSL) products. A gradient reversed-phase high-performance liquid chromatography method was developed for the simultaneous determination of free and esterified ergosterols in G. lucidum. The contents of free and esterified ergosterols in the different parts (the stipe, pileus, tubes, and spores) of G. lucidum and GSL were determined. The results showed that total ergosterol levels in the stipe, pileus, tubes, and spores of G. lucidum were between 0.8 and 1.6 mg/g. The relative abundances of free to esterified ergosterol were different in the different parts of G. lucidum. The spores and the tubes, the hymenophore tissue that contains the spore-producing cells, have a considerably higher percentage of ergosteryl esters (41.9 and 39.7% of total ergosterol) in comparison with the pileus and stipe tissues (3.6 and 6.2%).