Effect of low pH and aluminium on growth of pinus sylvestris L. Seedlings mycorrhizal with Suillus luteus (L.ex Fr.) S.F. gray

Mycorrhizal syntheses of pine seedlings were conducted with the strain of Suillus luteus No 14 characterized by high tolerance to Al3+ ions. The experiment was performed as a semi-sterile culture in peat-perlite medium with Al3+ ion concentration of 4.0 mM. Three mycorrhizal morphotypes were distinguished on the pine roots: single, dichotomously branched and coralloid. The coralloid mycorrhizas were rare on plants treated with Al. Mycorrhizal plants. However mycorrhizas from seedlings treated with Al revealed a thinner mantle and a lack of the Hartig net as compared with the untreated control. There was no growth reduction of tested seedlings by the Al3+ concentration used. Mycorrhiza formation with the selected S. luteus strain caused lower Al3+ translocation to the upper part of the tested seedlings compared with the nonmycorrhizal control. It may be concluded that Al3+ ion concentrations that appear in the moderately polluted fine-root layers of forest soil may in certain condition negatively influence mycorrhiza formation of young Scots pine trees.