Amylase productions from Lyophyllum shimeji, a ectomycorrhizal fungus, in a partly modified matsutake liquid medium were examined using fruit-body forming or non-forming strains on a medium consisting of barley grains. The enzyme activities were assayed by Somogyi-Nelson (amylase), iodine-potassium iodide (α -amylase) and F-kit glucose method (glucoamylase) with soluble starch as a substrate. These activities in culture filtrate were detected to have relatively high values at 15 days after inoculation, and the activities reached a maximum activity at 37〜43 days after inoculation. The activity varied considerably among the test strains, but amylase and glucoamylase in the fruit-body forming strains showed higher activity level than those of the fruit-body non-forming strains. The active fractions obtained from the DEAE-Toyopearl column chromatography were identified. As the results, a glucoamylase and a endo-type amylase activity have been detected from the active fractions. These amylase activities were remarkably activated by the presence of Ca^<2+> ion, but showed no effect on thermal stability.

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Two dikaryotic stocks were prepared by reciprocal crossing of two parental monokaryons of Pholiota nameko carrying different auxotrophic markers. Both of the dikaryons carrying different cytoplasmic genetic factors produced normal fruit bodies. The mean mycelial growth rates of the monokaryons derived from oidia showed a signifycantly higher value than the parental monokaryons of the corresponding nucleus types. Further, the distribution of mycelial growth rates and the dry mycelial weight of the oidium isolates did not follow normal distribution. It is suggested that these phenotypic variations in the oidium isolates from both the reciprocal crossing and the parental monokaryons products may not be caused by the differences in the constitution of the cytoplasmic genetic factors of those test stocks nor by the somatic recombination of the dikaryotic phase.

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The mchanism for re-dikaryotization of the oidium-derived monokaryotic mycelium with the parental dikaryotic mycelium in the cultivation on Pholiota nameko was investigated. The oidium-derived isolate produced dikaryotic mycelium in the dual culture with an other mating type of oidium monokaryon or a parental monokaryon that carried a different incompatibility factor. The rate of redikaryotization in the oidium isolates containing the dominant nucleus that was found to be only 19%. On the other hand, the rate of the dual cultures in the oidium isolates having the recessive nucleus with the parental dikaryons was 89%. These results suggest that the re-dikaryotization of monokaryotic oidium isolates is performed by the Mon-Mon mating in the dual cultures of the oidium isolates having the recessive nucleus with the monokaryotized mycelia from the dikaryotic mycelia. The most of re-dikaryotization products of the oidium-derived isolates with the parental monokaryons and the dikaryon showed the delay of fruiting and the decrease in yields of fruit-bodies as compared with the corresponding results with the parental dikaryotic stocks. These detrimental results might be caused by the variation in phenotypic characteristics produced in the process of monokaryotic oidium formation occurred in the spawn running of this mushroom.

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Wild edible mushrooms, which are sold in markets, and the use of their local names were investigated in the Gifu Prefecture, in the central part of Japan, in September 1998. The two Thelephoraceae species, Sarcodon aspratus and Boletopsis leucomelas, having a slightly bitter taste are esteemed and are commercially the most popular wild mushrooms in this region, as well as the "Matsutake" , Tricholoma matsutake, both which are sold at relatively high prices. Most of the wild mushrooms were called by one or more local names, and were never called by their standard Japanese common names. On the other hand, all the cultivated ones were called by the common names or by the popular commercial names printed on the package of a product. Most people did not know the original local names of the cultivated ones, even if the species have been cultivated a few decades before. This case study suggested that the original local names tend to disappear under the expansion of commercial products.

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