The nitrogen source-requirement and preference of ectomycorrhizal fungi (42 strains belong to 13 genera) collected from Korean forests were investigated by incubating mycelial cells in four nitrogen source test media for 56 days. The nitrogen requirement was relatively high in five strains (Heimioporus japonicas (KFRI 1224), Suillus luteus (KFRI 1232), Tylopilus castaneiceps (KFRI 1383), Suillus granulates (KFRI 1997), Rhizopogon sp. (KFRI 1434)) in comparison with other strains. Forty-five percent of ectomycorrhizal strains including Boletus griseus (KFRI 1362) preferred the ammonium-form of inorganic nitrogen source for mycelial growth, whereas thirty-six percent of tested strains including Suillus grevillei (KFRI 1125) preferred the nitrateform as an inorganic nitrogen source.

No abstract

Chaga mushroom (Inonotus obliquus), which has invaluable medicinal uses, grows only on living trees. To date, it is still harvested from its natural habitat and is not cultivated artificially. We artificially cultivated chaga mushrooms by inoculating its sawdust spawns on Betula platyphylla var. japonica in 2007, and monitored mushroom growth on the inoculated trees for 9 years. The mushrooms grew less than 1 cm per year, with the largest mushroom growing up to 9 cm in the 9 years of study. There was no difference in the growth (diameter at breast height) of trees with viable and non-viable I. obliquus. In conclusion, artificial cultivation of chaga mushroom was successful. Our findings suggest that selection of large B. platyphylla var. japonica as host tree could lead to better I. obliquus productivity. Further improvements of the method are needed to increase the success rate of I. obliquus inoculation.