Study on the uptake rate of various elements into Dryopteris erythrosora by multitracer technique

Abstract

The radioactive tracer experiments have been carried out to investigate the uptake rates of various 16 elements in fern samples (Dryopteris erythrosora) using the multitracer technique. The procedure of the experiments were briefly presented. The results of the measurement were summarized by dividing the behaviors of 16 elements into four categories, and shown in figures in respect of the uptake rate. The absorbing behavior of Zn and Mn was remarkably different comparing with other elements, and the absorption of Mn on the 14th day has exceeded 100 percent. No or almost no uptake was observed for Be, Zr, Tc and Se. REE (Rare Earth Elements) were absorbed to a higher degree in comparison with those non-essential nutrient elements, such as Be, Zr, Te, Se. The smooth uptake of REE suggested that the fern species absorbed REE aggressively for some use to help them grow, and that some special mechanism was involved in the uptake of REE.

多重トレーサ手法を用いて種々の16元素に対するベニシダ(Dryopteris erythrosora)の取込み率を検討するため放射性トレーサ実験を行った。実験手順を簡単に紹介した。測定結果は16元素の挙動を4種類に分類して要約し、取込み率を図示した。ZnとMnの吸収挙動は他の元素と比較して著しく異なり、Mnの吸収は14日目には100%を越えた。Be、Zr、Tc、Seについては取込み率は零かあるいはほとんどなかった。希土類元素(REE)の吸収はBe、Zr、Te、Seなどの非必須栄養元素に比べて非常に高かった。REEの円滑な吸収はシダ種が自らの成長を助長する何らかの用途に利用するためにREEを積極的に吸収し、また何か特別なメカニズムがREEの取込みに関わっていることを示唆している。