This is a report on the radiocesium monitoring of wild mushrooms after the Chernobyl accident. The radiocesium density before the Fukushima accident was high in wild mushrooms growing at high altitudes near Mt. Fuji, and the density after the Fukushima accident was high in wild mushrooms growing at low altitudes. Similar results were confirmed for the surface soil of the forests of Mt. Fuji. Some contribution ratios for the cesium (Cs) -137 density in wild mushrooms were calculated as a test for the Fukushima and Chernobyl accidents. The contribution ratio for the former (73％) was found to be higher than that for the latter (17％). Long-term monitoring of changes in radiocesium distribution will be necessary in future.

　Simuliomyces microsporus (Legeriomycetaceae, Harpellales) was collected from the hindguts of the larvae of Simulium aokii (Simuliidae: Diptera). This is the first report of this species (genus) from Japan. A thick cell wall was produced between each zygospore and zygosporophore, which was remarkably recognized on the surface of the detached zygospores. The apical cell wall was absent in the remaining zygosporophores on thalli. Solitary detachment of zygospores from zygosporophores was observed for the first time in this species. Host insects were immediately dissected after collection (ordinal method) or dissected after preservation in the frozen condition (new method). In defrosted specimens, dissection of the abdomen and derivation of the mid- and hind-gut was easy, and the harpellalean fungus could be observed. Preservation by freezing of host insects appeared to be a suitable method for studying Harpellales.

　Effects of bacteria on the basidiospore germination of the ectomycorrhizal fungus Tricholoma matsutake were investigated. The bacteria used in this study were identified as a species of the genus Pseudomonas. The basidiospore germination rate of T. matsutake reached 14.38% as a result of inoculation of the basal medium (containing 30μl/L n-butyric acid) with the bacteria. Furthermore, the germination rate was high when bacteria were incubated far from spores. However, the basidiospore germination rate did not improve when they were inoculated in the medium without n-butyric acid or the water agar medium with n-butyric acid. These results indicate that bacterial proliferation with n-butyric acid is important for basidiospore germination．

　Inhibitory effects of charcoal particle-immobilized Trichoderma spp. (ANCT-05013 and ANCT-05103) on wood degradation by five basidiomycetes (Fomitopsis palustris, Trametes versicolor, and three other wood-decaying fungi) were examined. Furthermore, Japanese white birch (Betula platyphylla var. japonica) blocks were exposed to Trichoderma spp. at 25°C for 12 weeks to measure the mass loss and compressive strength. The immobilized Trichoderma sp. ANCT-05103 showed superior inhibition effects at the same level as ANCT-05013 for all the basidiomycetes. ANCT-05103, however, did not produce a significant strength decrease in the blocks in comparison with ANCT-05013.

　The fungal parasites Harpellales live in the digestive tracts of aquatic insects. To observe this group, dissection of hosts is required. Dissection methods to obtain digestive tracts of Simuiidae larvae are described. Simuliidae larvae are suitable host insects to study Harpellales because of the following reasons: (i) collection is easy because of slow movement; (ii) larvae are infected with Harpella melusinae in high ratio; (iii) the two families comprising Harpellales (Harpellaceae, Legeriomycetaceae) can be observed in one larva; and (iv) infection-site specificity (a remarkable feature of this order) is shown if both families are observed. To obtain digestive tracts, the head and part of the abdomen at the base of anal gills were transversely cut out. Inner tissue was pinched with forceps and removed. The hindgut and midgut were removed in a line. After dividing the guts, followed by rinsing the contents of each gut in a water droplet on glass slides, each translucent gut was prepared as a separate glass slide. The simplest method to obtain the midgut was to cut out the thorax of the larva. The midgut was expelled by shrinking the abdomen after the incision.