RADIOCESIUM IN FRUITBODIES AND MYCORRHIZAE IN ECTOMYCORRHIZAL FUNGI

Fruitbodies of Suillus variegatus and Lactarius rufus and, at a maximu m distance of 50 cm, the corresponding mycorrhizae, were collected on a rocky area in a coniferous forest. The tuberculate mycorrhizae colle cted close to S. variegatus fruitbodies were identified by the RFLP pa ttern to be S. variegatus mycorrhizae. In contrast the smooth brown my corrhizae collected close to fruitbodies of L. rufus were found to be of various species - L. rufus, but also Russula sp. The Cs-137 activit y concentrations in fruitbodies and the fungal part of the tuberculate mycorrhizae of S. variegatus were about the same. A local enrichment of Cs-137 within fruitbodies was studied by collecting fruitbodies gro wing in clusters. Between 13 and 64% of the mean ground Cs-137 deposit ion of the cluster area (400 or 625 cm(2)) was found in the fruitbodie s This indicates that there might be an important fungal redistributio n of Cs-137 in the forest floor during the production of fruitbodies. The distribution of Cs-137 within the fruitbodies was heterogenous. Fo r example in Cortinarious armillatus, the Cs-137 level in the cap was 2.7 times higher compared to in the stripe. (C) 1997 Elsevier Science Ltd.