Inoculum production and inoculation of Gnetum africanum rooted cuttings using a range of mycorrhizal fungi

Abstract

We studied the ability of peat/vermiculite, barley, rye grain, baby corn and nitrocellulose filter paper to serve as carriers for inoculum production using an isolate of Scleroderma sinnamariense, Scleroderma sp., Paxillus involutus and three isolates of Pisolithus tinctorius. Soil collected from the vicinity of some ectomycorrhiza tree species, mycorrhiza root tips, mycelium and spores of S. sinnamariense were also tested as inoculum. Inoculation of Gnetum rooted cuttings was by the use of both dried and fresh sporocarps of the fungus as well as by use of inoculum prepared on the carriers mentioned above. All fungal isolates showed some growth on peat/vermiculite, barley, rye grain, baby corn and nitrocellulose filter paper. The Paxillus and Pisolithus isolates grew better on these carriers as compared to the Scleroderma isolates. The use of viable root
tips, mycelium and spores of S. sinnamariense led to the formation of ectomycorrhiza on the previously uncolonized plants. This method can be successfully used to produce ectomycorrhizal Gnetum rooted cuttings,
which may be used for outplanting thereby increasing their chances of survival.

Keywords: Scleroderma sinnamariense, Pisolithus, Paxillus, ectomycorrhiza, inoculum production.