The fate of Cs-137 in senescing roots was investigated by deliberately
increasing the proportion of dead roots in half of the root system of
previously Cs-137-labelled Eriophorum vaginatum L. (hare's-tail cotto
n-grass) plants by using peg (polyethylene glycol) to induce a severe
water deficit in a split-root hydroponic system. The rooting solutions
and treated and untreated plants were analysed over a 21-day period s
ubsequent to radiolabelling. The loss of Cs-137 from roots did not inc
rease with increasing proportion of dead root and there was no evidenc
e to suggest that Cs-137 from senescing roots was recovered and transl
ocated to the shoot or to the remaining live roots. Cs-137 present in
roots killed by peg remained in the dead roots. (C) 1998 Elsevier Scie
nce Ltd. All rights reserved.