Survival in the soil of the ectomycorrhizal fungus Laccaria bicolor and the effects of a mycorrhiza helper Pseudomonas fluorescens

摘要: In disinfected forest nursery soils, inoculating Douglas fir (Pseudotsuga menziesii) seedlings with the ectomycorrhizal fungal strain Laccaria bicolor S238N significantly increases tree growth after outplantating. However, success of inoculation depends on survival inoculum in soil during pre-symbiotic life fungus. We followed L. autoclaved glasshouse, and under gnotobiotic conditions or γ-irradiated soil. also studied effect mycorrhiza helper bacterium Pseudomonas fluorescens BBc6R8, which promotes fir-L. symbiosis, viability. viability was assessed by trapping seedlings. showed that fungus retained its a state at least for 23 weeks, is much longer than reported literature other fungi. The did not modify experiments, ergosterol, specific membrane component, used to quantify biomass. Fungal behaviour differed disinfection technique used, modified chemical characteristics initial There no but there rapid increase biomass irradiated varied significant stimulation vs. inhibition Our results show beneficial condition fungus, i.e. greatest benefit occurs when growing unfavourable conditions.