© 1996 Heron Publishing—Victoria, Canada
Influence of ectomycorrhization and cesium/potassium ratio on uptake and localization of cesium in Norway spruce seedlings
Ivano Brunner (1), Beat Frey (1) and Thomas K. Riesen (2)
1. Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), CH-8903 Birmensdorf, Switzerland / 2. Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland / Received August 8, 1995
Summary
Norway spruce (Picea abies (L.) Karst.) seedlings growing in a growth pouch system were used to investigate the effects of the ectomycorrhizal fungus
Hebeloma crustuliniforme (Bull. ex St. Amans) Quél. and various Cs/K ratios on the uptake of 134Cs, expressed as a percentage of the total amount of 134Cs supplied. The amount of 134Cs taken up by seedlings increased with increasing Cs/K ratio. At a Cs/K ratio of 0.1, uptake of 134Cs ranged between 7.2 and 7.3% and was independent of ectomycorrhizal status, whereas at Cs/K ratios ≥ 1 uptake of 134Cs varied from 8.1 to 11.1% for ectomycorrhizal and from 10.4 to 14.4% for non-inoculated plants. Ectomycorrhizal seedlings
contained a lower concentration of 134Cs than non-inoculated seedlings. Among plant parts, the amount of 134Cs was significantly lower in needles and lateral roots of ectomycorrhizal seedlings compared with non-inoculated seedlings.
Among fungal and seedling tissues, highest X-ray net counts of 133Cs were measured in fungal hyphae of ectomycorrhizal mantles. X-Ray net counts of 133Cs in lateral roots of ectomycorrhizal and non-inoculated plants were similar, but 5 to 10 times higher than in main roots
and needles, suggesting an accumulation of 133Cs in lateral roots and slow translocation to other plant parts. In contrast, X-ray net counts of K indicated that K was readily
mobilized from lateral roots to main roots and needles. Elemental mapping showed a relatively homogeneous distribution of
133Cs within the root.
Keywords:
gamma spectrometry, growth pouch, Hebeloma crustuliniforme, low-temperature scanning electron microscopy, Picea abies, X-ray microanalysis.
