Nitrogen isotope fractionation during nitrogen transport from ectomycorrhizal fungi, Suillus granulatus, to the host plant, Pinus densiflora

The N-15 natural abundance in Pinus densiflora Sieb, et Zucc. that had been inoculated and not inoculated with ectomycorrhizal fungi (Suillus granulatus (L.:Fr.) O. Kuntze) was compared. The inoculated pine needles showed a lower delta(15)N value, while the uninoculated ones showed a higher delta(15)N value. Higher delta(15)N values in the mycelial mat of the ectomycorrhizal fungi compared to those of the inoculated pine needles were also observed. These facts indicate that nitrogen isotope fractionation occurred during the nitrogen transport from mycorrhizal fungi to the host plants.