Flammulina velutipes (Curt. ex Fr.) Sing. was grown on potatoglucose solution freed of most starch. Glucose uptake and dry weight changes in the colony indicated that the large fruitbodies derived their substrates partly from glucose remaining in the medium and partly from cellular constituents stored in the mycelium and small fruitbodies. Changes in the amounts of low molecular weight carbohydrates, glycogen, and four cell wall polysacchande fractions were followed in the mycelium and fruitbodies. Trehalose, arabitol, and smaller amounts of mannitol were the main stored low molecular weight carbohydrates. A large net loss of these compounds occurred in the mycelium and small fruitbodies after their growth ceased. The carbohydrates accumulated in the large fruitbodies, but were also partly metabolized in the colony.Reducing sugars were minor components, and induded about 30 to 50% glucose and a small undetermined quantity of fructose. Glycogen was the main storage carbohydrate in the mycelium, and was also stored in the small fruitbodies. It was broken down in both structures during growth of the large fruitbodies which accumulated only small amounts. During the same period, almost 45% of the maximum amount of cell wall polysaccharides were degraded in the small fruitbodies, but not in the mycelium.By feeding 14C-glucose in replacement medium, incorporation of radioactivity into carbohydrates was foRowed in the colony during fruitbody development. Total incorporation was highest in trehalose, next highest in glycogen, and the rest was found in polyols and cell wall polysaccharides except for a few per cent which remained in endogenous glucose. In the large fruitbodies, specific radioactivity in glucose was much lower than in trehalose and mannitol. The labeling patterns in the mycelium and large fruitbodies suggested that trehalose, mannitol, and possibly arabitol were translocated into the stipes and pilei.Stipe elongation in the fruitbodies of Flammulina velutipes (Agaricales) requires a supply of water and nutrients from the vegetative mycelium during most of the growth period (9, 10). The identity of the translocated nutrients was not determined, but the elongation of isolated whole fruitbodies is promoted by glucose and other low mol wt carbohydrates (10). Stipe elongation also depends on the lamellae in the pileus (7), and excised lamellae release a diffusate into agar which promotes stipe growth. Production of this diffusate is stimulated by glucose (8). These results indicated that a knowledge of the nature and distribution of cellular carbohydrates would contribute to a better understanding of the relationship between fruitbody growth and the mycelium. Few reports have been published on the quantitative distribution of cellular carbohydrates during the development of the vegetative mycelium and fruitbodies of Hymenomycetes. Most of the available information has been obtained for Schizophyllum commune (Aphyllophorales) where changes in total alcoholsoluble carbohydrates and especially in several...

Mating compatibility of 25 Pleurotus species collected mainly from Asia was tested by either the Mon-Mon mating or the Di-Mon mating tests. The results showed 5 intersterility groups (P.

In the current studies, we sequenced and characterized the gene for the homeodomain protein (hox1) in a bipolar mushroom, Pholiota nameko, which is a putative homologue of A mating type genes in the tetrapolar basidiomycete, Coprinopsis cinerea. We also sequenced and characterized the gene for the pheromone receptor (rcb1) in P. nameko, which is a putative homologue of the B mating type genes in C. cinerea. Restriction fragment length polymorphism (RFLP) and linkage analyses indicated that the both genes are present as a single locus on the different chromosome. Moreover, in P. nameko, the hox1 gene was mapped to the A mating type locus in linkage group I. However, rcb1 was not linked to the A mating type locus and was mapped to the other linkage group. These results strongly suggest that hox1 regulates with incompatibility in the bipolar mushroom, and that rcb1 may not affect the mating function in P. nameko. This is the first report regarding the structure of the mating type genes in bipolar mushrooms.

A novel type of trehalose phosphorylase was found in a basidiomycete. Flammulina velutipes. The enzyme catalyzes both the reversible phosphorolysis of trehalose to form α‐glucose 1‐phosphate and glucose and also the synthesis of trehalose. Comparison of the specific activity of trehalose phosphorylase with that of trehalase suggested that the function of the former enzyme was more important in the fruit‐bodies of this fungus.

Recovery of 66 fungus stock cultures including Oomycota, Zygomycota, Ascomycota, Basidiomycota, and mitosporic mycetes were examined after cryopreservation. Almost all the stock cultures remained viable when the mycelia that had grown over the sawdust medium containing 10% glycerol as the cryoprotectant (65% moisture content, W/W) were frozen rapidly at Ϫ85°C and then allow to thaw naturally at room temperature. Test stock cultures were preserved for more than 10 years by this preservation method without any programmed precooling and rapid thawing for their cryopreservation. Most of the test fungi could survive for 5 years in medium containing 10% glycerol even after alternate freezing and thawing at intervals of 6 months. When a strain of Flammulina velutipes was tested for mycelial growth rate and productivity of fruit-bodies after cryopreservation for 3 years, the fungus reproduced with its initial capability. These results demonstrate that the sawdust-freezing method using a cryoprotectant is expected to be a reliable and easy preservation method for fungus stock cultures.

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