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TOXICITY AND TOLERANCE
IN SAMANEA SAMAN (JACQ.) MERR. TO
SOME METALS (Pb, Cd, Cu AND Zn)
M. KABIR, M. ZAFAR
IQBAL AND M. SHAFIQ
Abstract:
In this study toxicity
and tolerance of Samanea saman (Jacq.) Merr. was investigated for
Pb, Cd, Cu and Zn under lab conditions. Germination rate of S.
saman showed that increased concentration of different metals from
25 to 100 ppm, significantly (p<0.05) reduced germination which was more
prominent for Pb treatments. Seedling growth variables i.e. root and
shoot length, seedling size, root/shoot ratio, seedling fresh and dry
weights also declined significantly (p<0.05). Seedlings growth of S.
saman gradually reduced with increasing in concentrations of
metals especially Pb and Cd compared to Cu and Zn. The inhibitory
effects of metals had the following order Pb>Cd>Cu>Zn of sequence at
different concentrations. Tolerance indices determined for different
metal illustrated that increasing concentrations of metals reduced the
tolerance of S. saman but this reduction was more
prominent for Pb and Cd as compared to Cu and Zn treatments.
Department of Botany,
University of Karachi,
Karachi, 75270, Pakistan
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