β-glucan is a safe and highly potent biological response modifier that nutritionally activates the immune response through the Macrophage, Dendritic and additional immune cells to yield various therapeutic effects. Shiitake mushrooms (Lentinula edodes) contanining β-glucans may be beneficial for human health; they have been used in the treatment of cancer, hypertension, and high cholesterol levels. The effect of different substrates and various developmental stages (mycelium growth, primordium appearance, and fruiting-body formation) on β-glucan production in the edible mushroom L. edodes was studied. The cap of the mature mushroom showed the highest β-glucan activity, and β-glucan activity seemed to be influenced somewhat by some well-known inducers or sawdust. In this study, we utilized five strains (JMI 10022, 10036, 10077, 10079, 10080) of L. edodes regardless of origin and growth conditions. This experiment showed that the expression of β-glucan was induced by glucose bond, and increased with the growing of L. edodes. Quantitatively, reverse transcription PCR utilized pairs of primers specific for β-glucan gene expression shows that expressed genes were most commonly indentified during the process of fruiting-body formation. We suggest that the results will provide valuable information to assist L. edodes industry.

A new commercial cultivar ‘Hae Sal’ of Hypsizigus marmoreus was developed by the method of mono-mono crossing between monokaryotic strains derived from KNR8047 and KNR8080. The parental strains are characterized by the property of high quality and a short period of time in cultivation respectively. The optimum temperature of mycelial growth was 25°C and that of fruiting body development was 15～16°C. The period of harvesting including primordia formation was 7.0 days shorter than that of control strain ‘Mangadak No.2’. The color of pileus and stipe surface was neutral-brown and pure white, respectively. The yield was 117.6±23.2g/850cc plastic bottle. Analysis of the genetic characteristics of the new commercial cultivar ‘Hae Sal’ showed a different profile as that of the control strain, ‘Mangadak No.2’, when RAPD (Random Amplified Polymorphic DNA) primer was used. This new cultivar ‘Hae Sal’ of Hypsizigus marmoreus is characterized by the improved quality and a short period of time in cultivation after scratching. It would be of much help to expand the cultivation area of Hypsizigus marmoreus.