Abstract:
Brassica rapa ssp. pekinensis seedlings were exposed to
heavy metal (lead and mercury) stress to determine the
effect of heavy metal uptake on root elongation and to
detect if heavy metal uptake induces genetic damage in root
cells. The heavy metal concentrations which resulted in
50% reduction of seed germination (750 ppm for lead and
500 ppm for mercury) were used as basis for the sowing
concentrations (500, 750, and 1000 ppm for lead and 250,
500, and 750 ppm for mercury). Five-day old seedlings
were observed for root elongation and tissues were assessed
for genetic damage. Greater concentrations of either lead or
mercury resulted in lower percentage germination and
seedlings with shorter roots. Compared to lead, mercury is
noted to exert more toxic effects on seedling germination
and root elongation. No genetic damage was detected, even
with increased amounts of heavy metals.
