Cross breeding was performed among 5 strains of Pleurotus spp. in order to investigate the development of new commercial strains, generating MH006404. MH006404 could be cultivated just like conventional cultivated species such as P. ostreatus or P. eryngii. Morphological observation and genetic analysis revealed that MH006404 possessed similar characteristics to P. ostreatus or P. eryngii.

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In this study, we analyzed two alcohol dehydrogenase (Adh), eight aldehyde dehydrogenase (Aldh) and two mannitol-1-phosphate dehydrogenase (Mpd) genes in Pholiota microspora. The transcription of Aldh1, 2, 3, Adh1, 2, and Mpd1, 2 was unaffected in liquid medium in the presence of 1 mM ethanol. However, Mpd1 expression was promoted by acetaldehyde. Therefore, Mpd1 is a candidate for an ethanol-producing alcohol dehydrogenase. On the other hand, transcription of Aldh1 and Adh2 was promoted with 3 mM veratryl alcohol; therefore, the role of Aldh1 and Adh2 might have evolved from alcohol metabolism to degradation of aromatic compounds. Transcription of Adh1, Mpd1, Mpd2 and Aldh1 was higher in primordia and fruiting bodies than mycelia. This phenomenon suggested that the response of Adh1, Mpd1, Mpd2 and Aldh1 indicates the presence of oxidative stress during fruiting body development.

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We report that autoclaved water extracts from the fruiting bodies of several mushrooms (Lyophyllum decastes, Lentinula edodes, Pleurotus eryngii and Grifola frondosa) can protect rice from blast disease caused by Magnaporthe oryzae. When rice plants pretreated for one week with these extracts were inoculated with M. oryzae, the number of blast lesions on leaves was significantly decreased compared to those treated with distilled water as a control. None of the extracts inhibited the germination of M. oryzae spores. Furthermore, H2O2 generation and PR10a gene expression, which are involved in systemic acquired esistance, significantly increased in the leaves pretreated with the extracts for 24 h. These results suggested that the protective effect of extracts from fruiting bodies of mushrooms was due to enhancing resistance, and that extracts may be a useful tool for protecting rice from blast disease caused by M. oryzae.

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The effect of enhancement of general taste of soy sauce based soup by adding broth of commercial mushrooms was investigated using a sensory evaluation. We evaluated general taste of soy sauce soup with six different mushroom broths using scoring methods. All mushroom broths were found to have enhanced general taste. Investigation of the relationships among saltiness, palatability and sodium chloride concentration revealed that richness was increased and saltiness was suppressed in new mushroom strain, IC1 broth compared to the control soy sauce soup. Taste scores of IC1 broths were significantly higher than those of onion and radish broths, indicating that IC1 was an excellent foodstuff enhancing the general taste of soy sauce soup. Equivalent umami concentration value calculated from the contents of taste components indicated that IC1-mediated enhancement of general taste was related not only to umami compounds, but also to unknown compounds suppressing saltiness and enhancing umami taste.

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Although shiitake sawdust-block cultivation has become popular, it has been accompanied by pest damage. Currently, although cultivation facilities have been disinfected using adhesive sheets or light traps, further extermination methods are in demand from problems about disposal labor time and environmental health. In this study, in order to find fungi suitable as biological control agents, we investigated the fungi isolated from harmful flying insects in shiitake cultivation facilities. As a result, 37 of 52 strains were identified as Lecanicillium spp., and others were parasitic fungi belonging to the Ophiocordycipitaceae and Cordycipitaceae except for one strain. In addition, a tendency for the species of entomogenous fungi to differ depending on the method of shiitake cultivation was observed.

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