Basidiome Development Research Articles

Yerba mate residue (Ilex paraguariensis – Aquifoliaceae) in the production of edible mushroom Pleurotus ostreatoroseus

Mushrooms are cultivable on various plant substrates and the yerba mate residue may be one of the most promising, especially if domestic cultivation techniques are developed. As a large producer and consumer of yerba mate, southern Brazil also presents a large production of this residue. In this sense, this work aimed to test the cultivation of Pleurotus ostreatoroseus on yerba mate residue, seeking a technique for its domestic cultivation. Three substrates were prepared: a) partially decomposed yerba mate; b) recently discarded yerba mate; c) yerba mate recently discarded and added with eucalyptus sawdust. Cultivation of P. ostreatoroseus in yerba mate just after disposal and partially decomposed proved to be unviable, with good mycelial colonization of the substrate, but without basidioma production. In cultivation with sawdust, all concentrations tested showed the formation of primordia, with 70% of sawdust, being the first to form primordia and having the largest basidiome in diameter. It is believed that aeration is an important factor for mycelial and basidiome development in P. ostreatoroseus, contrary to what has already been mentioned for P. djamor, contributing to the differentiation of both species in cultivation situations. The mycelium of the species growing on yerba mate residue was able to reduce the inoculum of pathogenic fungi, indicating that it is an adequate practice for the treatment of the final residue. Thus, the yerba mate residue added with sawdust proved to be a possible substrate for the cultivation of P. ostreatoroseus, in addition to eliminating pathogenic fungi from plants. Keywords: Cultivation; Alternative substrates; Shimeji; Mycelial growth.

A new corticolous species of Mycena sect. Viscipelles (Basidiomycota: Agaricales) from the bark of a Living American elm tree in Texas, U.S.A.

A Mycena species new to science was obtained from moist chamber cultures of trunk bark of a living American elm tree (Ulmus americana) located in the Fort Worth Botanic Garden, Tarrant County, Texas. This discovery was part of an ongoing study of corticolous myxomycetes on larger American elm trees occurring in Fort Worth nature parks. More than 15 American elm trees were sampled for trunk bark but only a single tree yielded Mycena basidiomes. Collections of bark began in the summer of 2017 and continued until the beginning of 2020. Bark samples from the north, south and west side of the tree yielded fruit bodies of the mushroom in moist chamber culture. No fruit bodies were observed in nature nor were early formation stages on the underside of the bark. Crystals previously described in another study were present on the bark surfaces, edges, and undersides. Habit and morphological development were photographed using light microscopy applying multifocal imaging and computer stacking to increase depth of field. Basidiome development was observed and photographed from the earliest primordial beginning stage, the button stage, intermediate stage and the final emerging stalk elongation and mature cap formation stage. Mature mushroom development took from 9 to 21 days after wetting the bark in moist chamber cultures. Scanning electron microscopy was used to illustrate development of the button stage, emerging stalk and pileus stage, and the fully mature pileus, lamellae, and pseudocollarium. Morphological features and DNA sequence data confirmed that this Mycena species was undescribed and distinct from other Mycena taxa. Morphological features suggest placement of the novel taxon in Mycena sect. Viscipelles, distinct from other members based on morphological characters and phylogenetic analysis.

In Vitro Studies of Secondary Metabolite-Related Responses in Some Species of Genus Grifola (Agaricomycetes) from Argentina.

Grifola gargal Singer and Grifola sordulenta (Mont.) Singer mushrooms are related to Grifola frondosa (Dicks.) Gray, which is well known for its medicinal properties. In vitro studies were performed to find a useful guide for optimizing the environmental parameters through biotransformation of lignocellulosic materials and basidiome development, also considering secondary metabolism-related responses (SMRRs) associated with these processes and the variability among species and strains; this optimization is necessary to make the mushroom's industrial cultivation profitable. Morphological features of mycelial cultures revealed that intraspecific variability was of taxonomic relevance. A low ligninolytic capacity in studied Grifola species was observed when compared with 2 control species: G. frondosa and Ganoderma lucidum. Experiments with nutrient media containing different carbohydrate sources indicated that G. gargal mycelia grew better in xylulose and G. sordulenta, in xylulose or cellulose; in addition, the latter species presented cellobiose dehydrogenase activity. An additional study of SMRRs under different light conditions (aroma, pigmentation, and morphogenic manifestations) showed that white light was better than blue, green, or red-filtered light at inducing advanced SMRRs. The results of SMRR stimulation are proposed as useful guidance for optimizing the environmental parameters for bioprocesses aimed at metabolite production.

Modeling Grifola frondosa fungal growth during solid‐state fermentation

AbstractGrifola frondosa (maitake) is an edible and medicinal mushroom. Considering its increasing popularity, there are limited references for its cultivation. Previous studies demonstrated that carpophore formation is correlated directly with mycelial biomass. The development of a mathematical model for its growth under solid‐state fermentation (SSF) may help to predict the potential of different substrates for maitake production. G. frondosa growth and basidiome development was studied, using oak sawdust and corn bran as substrates. The fungal biomass content was determined by measuring N‐acetyl‐D‐glucosamine (NAGA). It increased steadily for the first 80 days, to a maximum in coincidence with the first fruiting (60.5 μg NAGA/mg dry sample). Two mathematical models were selected to evaluate G. frondosa development, measuring reducing sugars consumption and NAGA synthesis, as an indirect assessment of fungal growth. Both models showed a good fit between predicted and experimental data: logistic model (R2=0.8896), two‐stage model (R2=0.8878), but the logistic model required a minor number of adjustment parameters.

Effect of culture parameters on the production of the edible mushroom Grifola frondosa (maitake) in tropical weathers

Hitherto, little effort has been directed to improve culture conditions for commercial development of maitake (Grifola frondosa), an edible and medicinal fungus, due to the short history of cultivation, particularly in tropical weathers. The purpose of this research was analyzing the environmental factors required for successful basidiome development on synthetic substrates in Colombia. We evaluated different cereal grains (corn, barley, sorghum and rice) for spawn production; and industrial by-products (such as coffee spent-ground and oak-sawdust) as substrates for mushroom production. Exploiting these residues for G. frondosa solid culturing would primarily provide edible mushroom and simultaneously help in resolving their disposal problem. The use of corn grains as substrate for spawn production results an important factor for reducing crop cycle time. A cold shock to 10°C was requisite for basidiome formation. Coffee spent-ground was a good substrate for mycelial growth, but not for mushroom production. When using oak sawdust plus corn bran as substrate, we obtained consistent yields with combined high biological efficiency (BE) (35.3%), best quality mushrooms, and a crop cycle of 12–14 weeks. The results achieved in this investigation contribute to expand the knowledge on this fungus, and compare favorably with previous works in the northern hemisphere with respect to BE, mushroom quality and crop cycle time.

New species of Torrendia (Fungi, Agaricales) from remnant woodlands in the wheatbelt region of Western Australia

Two new species of sequestrate (truffle-like fungi) Basidiomycetes of the putatively ectomycorrhizal genus Torrendia Bres. with contrasting basidiome morphology are described from remnant patches of eucalypt woodland in the wheatbelt of Western Australia: Torrendia grandis Bougher and Torrendia inculta Bougher.Like other species of Torrendia, they have basidiomes which develop and mature mostly underground but may break through to the soil surface at a late stage of maturity. The gleba of Torrendia species does not become powdery. A comparison of the main diagnostic features of all known taxa of Torrendiais provided. T. grandishas stocky basidiomes with an agaric-like pileus. T. inculta has a gleba which fragments during stipe elongation. The basidiome development of T. incultaisdescribed and illustrated, and some possible mechanisms of spore dispersal are discussed.

Notes onTremella mesentericaand allied species

Some aspects of development and biology of Tremella mesenterica and two closely allied species are discussed; some associated fungi are noted. Tremella brasiliensis, previously known only from neotropical areas, is reported from Japan; an extended description is provided. One North American species, Tremella mesenterella Bandoni & Ginns, is described as new, and other taxa with superficially similar basidiocarps are discussed.Key words: Tremellaceae, Tremella, T. mesenterica, T. mesenterella, T. philippinensis, T. rufobrunnea, conidium ontogeny, basidiome development.

Observations on development, morphology and biology in Phaeocollybia

Investigation of Phaeocollybia in British Columbia, Washington, Oregon and California has led to a better understanding of the characters and biology of the genus as a whole. Generically significant characters – pseudorhizas, pellicular veil, tibiiform diverticula, and sarcodimitic tissues – are examined in depth with four variations of branched and unbranched pseudorhizal patterns outlined. Basidiome development is traced from subterranean initiation to fully mature emergent basidiomes. Hypotheses on the ontogeny of Phaeocollybia basidiomes and biological associations are developed based on extensive observations of primordia and numerous field excavations. Comparisons between rhizomorphs and the thread-like pseudorhizal extensions of certain species are made and the term ‘rhizomorphic pseudorhiza’ is introduced. Possible biological strategies are explored and evidence for consideration of Phaeocollybia as a mycorrhizal genus is presented.

Notes on <I>Tremella mesenterica</I> and allied species

Some aspects of development and biology of Tremella mesenterica and two closely allied species are discussed; some associated fungi are noted. Tremella brasiliensis, previously known only from neotropical areas, is reported from Japan; an extended description is provided. One North American species, Tremella mesenterella Bandoni & Ginns, is described as new, and other taxa with superficially similar basidiocarps are discussed.Key words: Tremellaceae, Tremella, T. mesenterica, T. mesenterella, T. philippinensis, T. rufobrunnea, conidium ontogeny, basidiome development.

Dependence of Laccariabicolor basidiome development on current photosynthesis of Pinusstrobus seedlings

Development of the Laccariabicolor (Maire) Orton basidiome in association with container-grown Pinusstrobus L. seedlings was influenced by photosynthetic photon flux densities (PPFD). Three growth patterns were observed. At a PPFD of 330 μmol•m−2•s−1, basidiome growth was rapid, and complete development was achieved after 16 days. At a very low PPFD (20 μmol•m−2•s−1), the basidiome development ceased, although some residual growth was observed for a few days. At an intermediate PPFD (50 and 90 μmol•m−2•s−1), basidiome growth was less rapid than that observed at 330 μmol•m−2•s−1. Significant differences in the net photosynthesis of the host plant resulted in corresponding changes in basidiome biomass. The effect of basidiome removal on the photosynthetic response of the host plant was evaluated at three stages of basidiome development (2- to 4-, 6- to 8-, and 10- to 15-mm pileus diameter). At each developmental stage, removal of the basidiome induced a very rapid decrease in both net photosynthesis and stomatal conductance of the host plant. This decrease in net photosynthesis indicates that the growth and development of the basidiome are dependent on the host plant's current rate of net photosynthesis.

Phenotypic variation of Pseudomonas putida and P. tolaasii affects the chemotactic response to Agaricus bisporus mycelial exudate

The chemotactic response of wild-type Pseudomonas putida and P. tolaasii, and a phenotypic variant of each species, to Agaricus bisporus mycelial exudate was examined. Both P. putida, the bacterium responsible for initiating basidiome development of A. bisporus, and P. tolaasii, the causal organism of bacterial blotch disease of the mushroom, displayed a positive chemotactic response to Casamino acids and to A. bisporus mycelial exudate. The response was both dose- and time-dependent and marked differences were observed between the response time of the wild-type strains and their phenotypic variants. Phenotypic variants responded rapidly to both attractants and reached a maximum response after 10-20 min, whereas the wild-types took 45-60 min. The differences are partly explained by the more rapid swimming speed of the phenotypic variants. Both variants responded maximally to similar concentrations of Casamino acids and mycelial exudates. Investigations into the nature of the attractants contained in the mycelial exudate indicated that they are predominantly small (Mr less than 2000) thermostable compounds. Sugars present in the exudate did not elicit a chemotactic response in any isolate, but a mixture of 14 amino acids detected in the exudate accounted for between 50 and 75% of the chemotactic response of the fungal exudate.

Cultural control of basidiome formation in Laccaria bicolor with container-grown white pine seedlings

Container-grown Pinus strobus seedlings inoculated with a wild strain of the ectomycorrhizal fungus Laccaria bicolor , were raised under the same controlled growth conditions for 14 wk after which conditions were varied. Lowering the temperature from 24/18 °C (day/night) to 18/12° inhibited the fruiting of L. bicolor associated with P. strobus . A short photoperiod as well as a low level of nitrogen and phosphorus fertilization stimulated basidiome development. Less fruiting of L. bicolor occurred at 24/18° with the host plants Picea glauca or Pinus taeda . However some basidiomes did form at 18/12° with P. glauca and P. taeda contrary to P. strobus .

Development of the basidiome of Volvariella bombycina

Basidiome development of Volvariella bombycina was examined with optical and scanning electron microscopy. Primary gills arose as ridges on the lower surface of the cap, projecting into a preformed annular cavity. Secondary and tertiary gills were added whenever space became available by bifurcation of an existing gill either from one side or at the free edge, or by folding of the palisade layer near or at the roots of existing gills. These processes gave rise to sinuous, labyrinthiform hymenophores as a normal transitional stage to the mature regularly radial gill pattern. Although many cystidia spanned the gill space at the early stages, their tips causing depressions in the opposing hymenium, cryo-SEM examination showed that marginal and facial cystidia of mature gills bore droplets, suggesting that these cells are more likely to act as secretory elements than as structural members. Transformation of the convoluted gills into regularly radial ones is probably accomplished by cell inflation in the gill trama. Marking experiments and consideration of cystidial distribution suggest that V. bombycina gills grow at their root, not at their margin.

Pattern of pore morphogenesis in the resupinate basidiome of Phellinus contiguus

On malt agar in Petri dishes in the light, basidiome development of the resupinate polypore Phellinus contiguus proceeded centrifugally after a minimum but variable colony diameter had been attained. Dissepiments were initiated as more or less separate islands of aerial hyphae approximately 3 mm behind the mostly submerged mycelial margin. Localized aerial fascicles of apically-extending hyphae grew from these island initials both horizontally, where they coalesced with fascicles from adjacent initials and delimited pores, and vertically, resulting in lengthening of dissepiments. On dilute (0.2%) malt agar and towards the edge of dishes containing more concentrated malt agar, initials tended to fail to unite laterally and grow as vertical spines. Horizontal growth of branching and interconnecting aerial fascicles also occurred at the margins of more mature poroid basidiome patches, increasing the poroid area. Time lapse studies of development from widely spaced initials transferred to fresh medium weekly showed that on 0.2% malt agar, areas with basidia and lacking extending aerial hyphae remained as the bases of developing primary tubes. On 2 % malt agar secondary tubes were formed at a later stage by differential vertical growth within dissepiment areas. Where groups of initials were removed poroid basidiome tissue was regenerated mainly by lateral fascicle development from the surrounding basidiome tissue.

Effects of environmental factors on basidiome development in the resupinate polypore Phellinus contiguus

A strain of Phellinus contiguus changed during subculturing to abundant formation of basidiome tissue. The resupinate poroid basidiome was initiated within 4 mm of the colony margin in the light. Virtually no basidiome formation occurred in the dark but after light for 20 min initials developed over an annulus consisting of the youngest part of the exposed colony and adjacent subsequent growth. Initiation did not occur when aeration was restricted by parafilm or polythene seals but was restored by inclusion of potassium hydroxide within sealed dishes. After initiation normal pore development only occurred if well-aerated cultures with the agar uppermost with respect to gravity were supplied with further light. Abnormal hymenophore growth occurred in dishes which were inverted. Pore density was increased by slightly reduced aeration and by a higher concentration of malt in the agar medium.