Pinus sylvestris Can Form Ectomycorrhiza with Phialocephala fortinii

The ectomycorrhizal fungal community associated with Pinus sylvestris (Scots pine) in a Mongolian forest was investigated in this study. The fungal strain was isolated from roots of Scots pine and identified as Phialocephala fortinii. Inoculation experiments showed that Phi. fortinii could form ectomycorrhizae with Scots pine seedlings. Hartig nets, external hyphae, and mantle structures of ectomycorrhizae were observed in pine seedlings roots. The morphology and ultra-structure of the fungal-host plant association and characteristics of Phi. fortinii colonies developed on MEA, MMN, and PDA media are described. Phialocephala fortinii inoculation significantly increased the growth, biomass accumulation, and P, K, Ca, Mg, Na, and N concentrations in roots, stems, and needles of pine seedlings. These results demonstrated that Phi. fortinii could effectively form ectomycorrhizae with Scots pine and improve its growth, presumably through enhanced nutrition acquisition.