Accumulation of 137Cs in trefoil (leaf and stem), “Mitsuba”, Cryptotaenia japonica Hassk, with or without root was investigated to prepare higher radioactive plant in hydroponic culture medium (140-150 Bq/ml) .
It was found that 137Cs concentration in plant tissue was increased with time, as high as 1.6 times of that in the culture medium after 4 days.
On the other hand, 137Cs concentration was affected by carrier element (Cs > 6ppm) and coexistent elements in the medium.
Radioactivity of the plant after 4 days was shown to be sufficient for successive experiments.
