INSTYTUT DENDROLOGII

Abstract: Mycorrhizal syntheses of pine seedlings were conducted with Suillus luteus (L.) S. F. Gray, the strain No 14 characterised by high tolerance to Al³⁺ ions and strain No 62, sensitive to aluminium. The experiment was performed as a semi-sterile culture in peat-perlite medium with Al³⁺ ion concentration of 11 mM. Abundant coralloid and cluster mycorrhizas of S. luteus were formed on roots of inoculated plants at the beginning of experiment. Aluminium treatment limited mycorrhizal morphotypes to single and dichotomous and significantly reduced the total number of mycorrhizal tips but had no effect on extramatrical mycelium development in the potting substrate. Al treatment did not affect growth of the above-ground part of tested plants but significantly reduced root growth of mycorrhizal seedlings. Effect of Al on the internal nutrient status was variable and not very much pronounced. A considerable amount of Al was absorbed on/in roots and translocated to shoots. Mycorrhiza formation with both strains of S. luteus did not prevent Al³⁺ translocation to the upper part of the tested seedlings. The results suggest that low pH and high Al availability may harmfully influence mycorrhizal symbiosis of Scots pine (Pinus sylvestris L.) by negative effect on fine-root production and fewer short root tips available for colonisation rather than through direct negative effect of Al³⁺ ion concentrations on extramatrical mycelium in the soil.

Additional key words: ectomycorrhizal fungi, extramatrical mycelium, ergosterol