Ectomycorrhiza synthesis and basidiome formation of an orchid symbiont of the genus Thelephora on Quercus serrata

Abstract

We induced basidioma formation of a fungus belonging to the Thelephoraceae that was isolated from the orchid Cephalanthera falcata. The mycobiont was isolated from root, cultured on modified Melin-Norkrans medium, and then inoculated onto fine roots of a Quercus serrata (Fagaceae) seedling. After observation of ectomycorrhiza formation, the Q. serrata seedling was grown in a pot. Thirty-six mo after ectomycorrhiza formation, basidioma formation was confirmed at the bottom of the pot. From comparisons in morphological characteristics between the mycobiont and known related Thelephoraceae species, and sequence similarities of internal transcribed spacer region in ribosomal DNA, we identified the mycobiont as Thelephora ellisii sensu lato in Thelephoraceae (Basidiomycota). Phylogenetic analysis indicated that the related sequences came from ectomycorrhizae of trees of the Salicaceae, Pinaceae, and Fagaceae distributed in East Asia, the USA, central Africa, and Europe.