Development of mycelial slurries containing surfactant for cultivation of the edible ectomycorrhizal mushroom Rhizopogon roseolus (syn. Rhizopogon rubescens)

Abstract

Rhizopogon roseolus (Corda) Th. M. Fr., known as shoro in Japanese, is an edible ectomycorrhizal mushroom. To successfully cultivate ectomycorrhizal mushrooms, inoculation and propagation methods must be developed, and isolates with superior traits must be selected. Pinus thunbergii Parl. seedlings were inoculated with several isolates of R. roseolus using the Petri dish technique and their mycorrhizal abilities were assessed. We selected a superior isolate that rapidly colonized and produced a lot of ectomycorrhizas in the roots of P. thunbergii. The selected strain was cultured in liquid medium, and the resultant mycelia were homogenized in saline solution to make a slurry. Adding surfactant to the mycelial slurry stimulated mycorrhizal formation in host roots. We investigated the effects of mycelial slurry containing surfactant on ectomycorrhizal formation of P. thunbergii and fruiting body formation in mother plant systems. Stimulatory effects of the slurry were observed not only on ectomycorrhizal formation of the seedlings but also on fruiting body formation. These results suggest that the mycelial slurries containing surfactant could serve as mycelial spawns for the cultivation of shoro under greenhouse conditions.