Possible role of soil-microbes in plant uptake of radionuclides

Abstract

A possibility of phytoremediation of soils contaminated with radionuclides has been investigated by the use of specific combination of plant and microbe. Tomato and cucumber plant selected through screening for their ability to absorb soil radionuclides have been tested for their uptake behaviors in association of some soil-microorganisms. Four kinds of fungal isolates were used for the inoculation to tomato and cucumber plants. Multitracer containing the radionuclide elements of Mn, Co, Zn, Sr, and Cs-137 was supplied to the inoculated plants for measuring the uptake percentage of the plants with Ge-detectors. The uptake percentages of nuclides per gram dry weight of tomato and cucumber plants were shown in figures. Although by inoculation of fungal isolates the increase of the root growth including adventitious roots was expected, the production of adventitious root did not occur within the experimental period. The differences of uptake behaviors of tomato and cucumber at every fungus were discussed.

放射性核種で汚染した土壌の植物修復の可能性を特定の植物と微生物の組合せを利用して検討した。土壌の放射性核種に対する吸収能力スクリーニングにより選んだトマトとキュウリがある種の土壌微生物と連携した時の取込み挙動を試験した。トマトとキュウリへの接種には4種の培養分離菌を用いた。Ge検知器を用いて植物の取込み率を測定するために菌接種植物に放射性核種元素Mn、Co、Zn、Sr、およびCs-137を含有する多重トレーサを与えた。トマトとキュウリの乾燥重量グラム当たりの核種元素取込み率を図示した。培養分離菌の接種により不定根を含む根の成長の増大を予期したが、実験期間内では不定根の生成は起きなかった。各菌ごとのトマトとキュウリの取込み挙動の違いを論じた。