Spores of ectomycorrhizal fungi as inoculants for Nothofagus pumilio and exotic conifer seedlings in Patagonia, Argentina: Their activity and conservation

Abstract

Ectomycorrhizal (EM) fungi incorporation in nursery production is necessary for afforestation with exotic tree species and native forests restoration programs. The fact that spore use as EM inocula is inexpensive and effective, makes it an option more realistic than vegetative inoculum production for many regions around the world. To determine spore activity from EM species selected as inoculants for Nothofagus pumilio and exotic conifers planted in Patagonia, two conservation methods were applied (i.e., dried fruit bodies and spore slurries), and their change over time was assessed (over 8-9 months). Spore activity decreased significantly with time for both native and exotic EM species. Conservation methods showed no significant differences for N. pumilio EM species considered together or for exotic conifer EM species. However, spore activity of different EM species behaved differently with conservation method and over time when considered separately. Taxa which better kept spore activity over time were Austropaxillus statuum and Setchelliogaster fragilis for N. pumilio, and Inocybe kauffmanii for exotic conifers. However, considering together fruit body spore density and spore activity, the species Hallingea purpurea and Cortinarius sp. also appeared as suitable for N. pumilio and Rhizopogon roseolus, R. villosulus, Suillus luteus and S. lakei for exotic conifers. Spore density found in EM fungal fructifications were also established in order to estimate fructification weights necessary to apply a reference dose of active spores in inoculation programs.