Influence of Ectomycorrhizal Infection on the Rhizosphere pH Around Roots of Maritime Pine (Pinus pinaster Soland in Ait.)

This study examined the influence of mycorrhizal infection on ionic exchanges by roots, by measuring rhizosphere pH and the quantities of protons released by roots of mycorrhizal and non-mycorrhizal pine (Pinus pinaster x Suillus collinitus). The effect of inoculation was measured around individual roots and compared with the effect on the root system as a whole, with root heterogeneity thus being taken into account in structural terms and in terms of functioning. Inoculation enhanced significantly the capacity of roots to release protons in a medium with a neutral pH, but the strength of reaction varied with the part of the root involved. This enhancement could possibly be used to improve the bioavailability of compounds not readily soluble in particular chemical conditions of the soil.