Degeneration of cultivated strains of Flammulina velutipes is a serious problem. We developed a simple colorimetric method to detect degenerate strains by using a liquid medium supplemented with bromothymol blue and lactose. The ability of a strain to develop normal mushrooms could be determined by the color of the medium.The primary objective of this study was to develop a simple method for detecting degenerate Flammulina velutipes (Enokitake) cultures. Cultural degeneration of cultivated strains of Enokitake similar to the degeneration observed for Agaricus bisporus (1, 2) has become a serious problem in Japan. Previous efforts to evaluate the fruiting potential of Enokitake have been made using isozyme electrophoresis profiles, randomly amplified polymorphic DNA, and mitochondrial DNA restriction fragment length polymorphism, but there was no clear correlation between the results of these experiments and the degenerate symptoms. Normal and degenerate strains differ in the ability to decolorize synthetic dyes, such as bromothymol blue (BTB), which changes from blue-green to yellow. The underlying cause of degeneration is not known, so a simple bioassay that distinguishes degenerate and productive strains of Enokitake would be of use for both researchers and commercial spawn producers.Commercial cultivation of Enokitake began in Japan in the 1930s with sawdust and rice bran as the substrate. In 2003, the total yield of Enokitake was 110,185 tons, which is much greater than the 65,363 tons of Lentinula edodes (Shiitake) or the 5,210 tons of Pleurotus ostreatus produced in Japan (annual statistics for mushroom production in Japan from the Forestry Agency [http://www.rinya.maff.go.jp/puresu/h16-8gatu /0805tokusan.htm]). The degenerate symptoms of Enokitake reported in the 1980s were malformed fruiting bodies, reduced numbers of primordia, and in some cases complete loss of fruiting body development. However, degenerate mycelia are morphologically indistinguishable from normal mycelia, and the symptoms of degeneration are not apparent until the final stage of mushroom cultivation, which may result in major financial losses.Four cultivars (TK,YO, JB, and G5) developed at Nagano Vegetable and Ornamental Experiment Station were used in the present study. The first symptom of degeneration usually is the development of undifferentiated, callus-like tissue in normal fruiting bodies. TKd, YOd, and JBd were isolated from malformed portions of fruiting bodies. TKd mycelia can produce malformed abnormal fruiting bodies, but TKm and JBm are even more severely degenerate and can develop very few primordia. Field strains in our culture collection that produced normal fruiting bodies on potato dextrose agar (Nissui, Tokyo, Japan) (FV wild a, FV wild b, and FV wild c) or that formed no fruiting bodies (FV wild d and FV wild e) also were examined. None of the strains used in this study contained detectable double-stranded RNAs (3).Each strain was inoculated onto malt extract agar (10 g/liter malt extract, 18 g/liter agar) in 9-cm ...

Photocatalytic disinfection of six bacteria and fungi, including pathogens of four mushroom diseases, Trichoderma harzianum, Cladobotryum varium, Spicellum roseum, and Pseudomonas tolaasii, and Escherichia coli and Bacillus subtilis, was studied. The photocatalyst reduced the number of viable microorganisms sufficiently by near-UV irradiation. Efficiency of disinfection was increased for P. tolaasii and E. coli, but not for T. harzianum, when the superhydrophilic properties of the photocatalyst were induced by 16 h irradiation of the photocatalyst by near-UV light just before treatment of microorganisms. Efficiency of disinfection was also affected by the state of the microorganisms, temperature, and the thickness of suspensions of organisms. Tests of disinfecting ability of the photocatalyst in mushroom growing rooms indicate that it can be used effectively for reducing numbers of environmental bacteria and fungi under black light, and that it was also effective under white light.

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Breeding of European Hobby Falco subbuteo was observed in Nagano City in a golf training field was used. On June 25, 1994, female began to sit in the nest. On July 28, chicks were fed for the first time. On August 3, two chicks and one egg were confirmed. A chick was fledged on August 29 and another on August 30. This report forms the southernmost breeding record of European Hobby in Japan.