YAMADA, AKIYOSHI.
Ibaraki Prefectural Forestry Center, 4692 Toh, Naka-machi, Naka-gun, Ibaraki, 311-0122, JAPAN.
Tricholoma matsutake has been reported to form ectomycorrhizas with Pinus densiflora in the field condition. The present study aimed to tested the ability of mycorrhizal formation of T. matsutake isolates with axenic seedlings of P. densiflora in vitro. Seeds of the pine were germinated axenically on nutrient agar media, and two seedlings were transplanted on autoclaved peatmoss/vermiculite mixture in a polycarbonate bottle. The ligand was saturated with nutrient media containing glucose. At the same time, mycelia of a T. matsutake isolate were inoculated within the bottle. Two months after the fungal inoculation these pine seedlings were growing more vigorously than the control plants (without fungal inoculation), and the root systems were covered with the vigorously growing mycelia. However, neither inter and intra cellular penetration on the lateral roots were confirmed. Three months after the fungal inoculation intercellular penetration, i.e. Hartig-net, was confirmed on the pine lateral roots with fungal sheath around the roots. Such fungus-infected roots, i.e. ectomycorrhizas, were also confirmed on 4 - 6 months old seedlings which showed better growth than that of the control plants. These results indicate that cultured mycelia of T. matsutake isolated can form symbiotic ectomycorrhizas with axenic seedlings of P. densiflora in vitro.