Studies on ectomycorrhizal community structure in an Abies firma forest and techniques for restoring natural ecosystems with mycorrhizal associations

Abstract

The community structure of ectomycorrhizal fungi associated with Abies firma was studied focusing on both aboveground fruit-bodies and belowground ectomycorrhizas with morphological and molecular methods. During 3 years of monitoring, 13 genera and 39 species of ectomycorrhizal fungi were found in a 10×30 m plot and Russula sp.1 fruitied most frequently and abundantly. Ectomycorrhizal roots of A. firma were distinguished based on the hyphal arrangement of fungal mantles and on PCR-RFLP analyses amplified the rDNA of the internal transcribed spacer （ITS） region. Abies firma ectomycorrhizas were divided into a total of 48 morphotypes, most of which showed unique RFLP types that indicated that each of these morphotypes was colonized by a single fungal species. The most frequent morphotype had an identical RFLP pattern with that of frutbodies of Russula sp.1. The relative frequency of fruit-bodies and morphotypes showed a geometric distribution pattern. These results indicate that there were a few dominant species, a few rare species, and many intermediately abundant species. In addition, the stress tolerance of ectomycorrhizal fungi to salinity and heavy metals was examined in vitro. The response of the fungi to NaCl varied among species and strains tested. Promising fungal strains for bioremediations can be obtained by mono- and dual-cultural experiments after understandings of mycorrhizal community structures in the field.