Fruit-body production of an ectomycorrhizal fungus in genus <Emphasis Type="Italic">Boletus</Emphasis> in pure culture

Mycelial growth and fruit-body production of an ectomycorrhizal Boletus sp. were examined in pure culture. Mycelia of the strain Bo1 grew well on a medium consisting of sawdust and barley grains. Mature fruit bodies bearing basidiospores were produced after incubation at 22°C for 90 days in the dark, followed by incubation at 26°C for 30–46 days under conditions of high humidity and illumination. The addition of porous stone as a casing on the medium increased fruit-body yield. Deposited spores germinated well on an agar medium and formed mycelial colonies, thus completing the life cycle of Bo1 without a host plant and under axenic conditions. The ability of Bo1 to form ectomycorrhizas was confirmed by axenic resynthesis of mycorrhizas on Quercus serrata. Cultured fruit bodies of Bo1 resembled Gyroporus castaneus and Boletus subcinnamomeus, but its taxonomic position was not elucidated at the species level.     

矿质元素对北虫草继代培养不同菌落子实体产量及菌丝生长速度的影响

主要研究矿质元素对北虫草继代培养中形成的不同类型菌落子实体产量及菌丝生长速度的影响, 旨在探讨矿质元素与子实体产量以及菌丝生长速度的关系。采用正交试验, 将北虫草优良菌株L20在不同矿质元素培养基上进行12次继代培养。结果表明菌株L20在不同培养基中继代培养后形成7种菌落类型, 有子实体形成能力的菌落为Ⅰ、Ⅱ、Ⅲ、Ⅴ型, 其中Ⅰ型菌落产量最高、Ⅲ型中等、Ⅱ型最低, Ⅴ型形成的子实体均为畸形; Ⅳ、Ⅵ、Ⅶ型无子实体形成能力。菌丝生长速度依次为Ⅴ型 > Ⅳ型 > Ⅶ型 > Ⅵ型 > Ⅲ型 > Ⅱ型 >Ⅰ型, 高产型菌落生长速度最慢, 而低产型菌落菌丝徒长, 表明菌落生长速度与子实体产量成负相关。优型菌落——Ⅰ型菌落子实体高产及高产保持代数最多的矿质元素配方为K3Mg2Ca4Mn3Zn2, 其中Mn和K促进子实体高产, K、Mg、Ca有利于高产保持多代。抑制Ⅰ型菌落菌丝徒长的最佳配方为K3Mg2Ca2Mn3Zn2, 其中Mn对其抑制作用最为显著。     

Sustainable fruit-body formation of edible mycorrhizal <Emphasis Type="Italic">Tricholoma</Emphasis> species for 3 years in open pot culture with pine seedling hosts

Three edible mycorrhizal mushrooms, Tricholoma portentosum, T. saponaceum, and T. terreum, that had formed ectomycorrhizas with Pinus densiflora seedlings in vitro, were maintained in open pot culture for 3 years under laboratory conditions. Tricholoma portentosum and T. saponaceum produced fruit bodies several times. For T. terreum, which produced a single fruit body in the third year, this is the first report of mushroom production under controlled conditions. Morphological observation of fruit bodies indicated that they were mature, i.e., well-organized cap, stem, and gills, and basidiospores. These results suggest that cultivation of these three edible Tricholoma mushrooms is feasible.     

Dynamics of fruit-body production and mycorrhiza formation of ectomycorrhizal ammonia fungi in warm temperate forests in Japan

To investigate the quantitative correlation between dynamics of ectomycorrhiza (ECM) formation and fruit-body production of the ammonia fungi, we treated forest soils in two ECM forests, a Castanopsis cuspidata forest and a Quercus serrata forest, in warm temperate Japan with urea to induce fruiting of ammonia fungi. We identified the ectomycorrhizae of two known species of ammonia fungi, Alnicola lactariolens and Hebeloma vinosophyllum, using morphological typing and PCR-RFLP. ECM initiation, increase, and subsequent decrease preceded the start, increase, and decrease of fruit-body production for each species. We also found many kinds of ECM fungi that did not develop fruit bodies after urea treatment during the observation period, which suggests that it is necessary to expand the definition of ammonia fungi from one that refers solely to the species reproducing on the ground to one which includes those in somatic forms in the soil.     

Changes in phenol oxidases and superoxide dismutase during fruit-body formation of Pleurotus on sawdust culture

Peroxidase and laccase activities increased rapidly up to the formation of primordia and then declined throughout the entire stage of fruiting. In the case of Pleurotus ostreatus, the level of Mn-dependent peroxidase was very low in primordia and fruiting stages but gradually increased with the growth of the fruit-body, whereas no activity was detected in Pleurotus sajor-caju during all growth stages. Superoxide dismutase activity was observed mainly at the fruiting stages. These results show that changes in concentration of lignin-related enzymes are associated with the fruiting process.     

Changes in phenol oxidases and superoxide dismutase during fruit-body formation of <Emphasis Type="Italic">Pleurotus </Emphasis>on sawdust culture

 Peroxidase and laccase activities increased rapidly up to the formation of primordia and then declined throughout the entire stage of fruiting. In the case of Pleurotus ostreatus, the level of Mn-dependent peroxidase was very low in primordia and fruiting stages but gradually increased with the growth of the fruit-body, whereas no activity was detected in Pleurotus sajor-caju during all growth stages. Superoxide dismutase activity was observed mainly at the fruiting stages. These results show that changes in concentration of lignin-related enzymes are associated with the fruiting process. Received: December 11, 2000 / Accepted: March 28, 2002