"Shimeji" mushrooms include at least three species: hon-shimeji (Lyophyllum shimeji), shaka-shimeji (L. fumosum), and Hatake-shimeji (L. decastes). Of these, hon-shimeji is the most prized as a delicacy. The Latin names of these three shimeji mushrooms were established in the mid-1970s. Recently, the biological species of L. shimej has been discussed based on results of mating tests, and its phylogenetic analysis has also been conducted. In this paper, We review the taxonomic treatment of L. shimeji in Japan over the previous several decades and discuss the needs for future taxonomic studies of shimeji mushrooms.

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Marbre 219, a variety of Hypsizygus marmoreus, was cultivated on larch (Larix kaempferi) sawdust-based substrates substituting for 0-40% supplemental rice bran. Taste component analysis of harvested fruit bodies, including soluble sugars, free amino acids and 5'-nucleotides, was conducted. On substrates with 10% or 40% soybean curd residue substituted for rice bran, and on substrates with more than 10% soybean shell substituted for rice bran, fruit-body yields were significantly higher than in controls supplemented with rice bran only. At substitution ratios of 20% and 40% soybean shell for rice bran, the content of soluble sugars was higher than in controls. At a substitution ratio of 20% soybean curd residue for rice bran, the content of monosodium glutamate-like components that contribute to umami taste was higher than in controls. In the case of substitution ratios of more than 10% soybean curd residue for rice bran, the content of sweet components increased. Since the equivalent umami concentration value of fruit bodies formed on larch sawdust-based substrate was significantly higher than on Japanese cedar (Cryptomeria japonica) sawdust-based substrates, larch sawdust-based cultivation would be preferable for the cultivation of H. marmoreus.

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In Japan, a fungus described as Mucidula mucida ("Japanese M. mucida", Japanese name: "Numeritsubatake") was identified as M. mucida var. asiatica based on morphological features and phylogenetic analysis of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA. This variety differs macromorphologically from M. mucida var. venosolamellata (Japanese name: "Numeritsubatakemodoki") mainly in that the latter possesses reticulate, anastomosed veins on the lamellae. However, mating compatibility tests between M. mucida var. asiatica (="Japanese M. mucida") and var. venosolamellata appeared compatible in all pairings. Furthermore, the basidiomata derived from the mating-compatible mycelia possessed intermediate macro- and micromorphological features between M. mucida var. asiatica and var. venosolamellata. In our molecular phylogenetic tree, the two fungi formed a clade of "Japanese M. mucida"/M. mucida var. asiatica/M. mucida var. venosolamellata, and specimens of the two fungi were randomly scattered within this clade. These results strongly suggest that fungi belonging to the clade should not be divided into intraspecific taxa. Mucidula mucida var. venosolamellata (= var. asiatica) differed from M. mucida var. mucida in their pileipellis structure, basidiospore size and ITS-based phylogenetic analysis. These differences indicate that M. mucida var. venosolamellata and var. mucida are different at the specific level.

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