Influx of 137Cs into hyphae of basidiomycete fungi

Short-term radiocaesium influx into fungal hyphae was measured for eighteen fungal species by experiments in which hyphal mats were incubated in 137Cs-labelled medium. The fungal species investigated included saprotrophic and mycorrhizal basidiomycete fungi, together with examples of non-basidiomycete mycorrhizal species. When results were expressed on a dry weight basis the range of influx values was 85 to 276 nmol Cs g−1 dry weight h−1, with saprotrophic species tending to have the highest values, and non-basidiomycete mycorrhizal species the lowest. When results were expressed on a surface area basis, however, the relationship between species type and Cs influx was less obvious. Influx was measured both in fungi which had had no Cs pre-treatment before the experiment, and in replicate samples which were given a 24 h pre-treatment period in medium containing 5 μm-CsCl. No significant differences were found between values of Cs influx measured in the two sets. The wide range of observed Cs influx values obtained here may help to explain the large differences in radiocaesium levels observed in fruiting bodies of different fungal species collected in field surveys after the Chernobyl reactor accident.