Functional ectomycorrhizae between Tuber umbilicatum and Quercus glauca: Implications for seedling performance and phosphorus acquisition

Abstract Tuber is a typical ectomycorrhizal fungus with significant economic value and essential ecological roles in maintaining ecosystem stability. Here, we demonstrate the first successful synthesis of ectomycorrhizae between the near-threatened species T. umbilicatum and Quercus glauca under controlled conditions, with molecular confirmation and detailed morphological characterization. Systematic assessment of mycorrhization effects revealed significant growth enhancement in inoculated hosts. Seedling height increased by 20.8%, while aboveground biomass rose by 27.1% at 6 months and 16.9% at 8 months. Belowground biomass was 25.4% greater at 8 months. Photosynthetic performance improved, with a 136.8% increase in the net photosynthetic rate and a 36.5% increase in stomatal conductance at 6 months. Mycorrhizosphere available phosphorus rose by 10.9% at 8 months. These findings underscore the potential benefits of inoculating T. umbilicatum for the cultivation of Q. glauca, while advancing the conservation and cultivation efforts of this threatened fungus.