NUKLEONIKA 2004, 49(Supplement 1):s13-s16

The plants of three species (Zea mays L., Panicum miliaceum L. and Panicum maximum Jacq.) were grown on the soil contaminated with 0.3 mM CsCl solution traced with ¹³⁷Cs, in the greenhouse. For all the species, the fresh-to-dry weight ratio was equal in the caesium-treated plants and in the control group after 3 weeks of culture.
The shoot-to-root fresh weight and dry weight ratios were decreased in maize, unchanged in Panicum miliaceum and increased in Panicum maximum, comparing to the control without caesium treatment. The shoot/soil and also root/soil transfer factors (TF) for ¹³⁷Cs (measured by means of NaI gamma spectrometer) were always the highest in maize, then lower in Panicum miliaceum and the lowest in Panicum maximum. All the plants seem to be hyperaccumulators of caesium. The root/soil TF was especially high in maize, i.e. 55 (kBq kg^-1 biomass)/(kBq kg^-1 soil). The shoot/root concentration factor (CF) for ¹³⁷Cs was the lowest in maize, higher in Panicum miliaceum and the highest in Panicum maximum.
The hyperaccumulation of ¹³⁷Cs in the whole plant was the highest in maize, lower in Panicum miliaceum and the lowest in Panicum maximum. The proved ability of the investigated plants for phytoextraction of the soil caesium points to the possibility to utilise these plants in the soil bioremediation. From this point of view, Panicum maximum seems to be the most useful plant because it accumulates caesium mainly in the shoot, and maize would be the least useful species since it has the highest accumulation in the root.