seedlings were of uniform size and free of any
disease symptoms. Nickel and Lead were selected
for the study , the uptake was estimated in root,
stem and leaves for every 20 days for a total period
of 60 days. In addition a set of control blank
experimental pots was also maintained. The metal
solutions prepared by dissolving in distilled water to
prepare stock solution of 1000 ppm for each metal.
The calibration curves for each metal were also
prepared. A blank reading was taken to incorporate
necessary correction factor. The heavy metal
solutions of 5mg/L was prepared from the stock and
administered to the plants and care was taken to
avoid leaching of water from the pots. The metal
uptake was estimated once in every 20 days. The
sample plants were removed from the pots and
washed under a stream of water and then with
distilled water. The collected plants were air dried,
then placed in a dehydrator for 2-3 days and then
oven dried for four hours at 100 ºc. The dried
samples of the plant were powdered and stored in
polyethylene bags. The powdered samples were
subjected to acid digestion. 1gm of the powdered
plant material were weighed in separate digestion
flasks and digested with HNO3 and HCl in the ratio of
3:1. The digestion on hot plate at 110ºc for 3-4 hours
or continued till a clean solution was obtained. After
filtering with Whatman No. 42 filter paper the filtrate was analyzed for the metal contents in AAS.
(Simarzdu 6800).
3.0 Results and Discussion
In the present investigation, Catharanthus roseus
plant accumulated both the metals. By 20th day Lead
content was high in roots and low in leaves. While in
stem it was 67.31 mg/kg biomass. There was no
change in lead accumulation in leaf after 40th day.
Stem concentration increased to 68.09 mg/kg and
root concentration was increased to 88.74 mg/kg
biomass much change observed in the roots (Table
1). In the 60th day only minimum change was
observed in leaf, stem and root. Finally, after the
total experimental period it was concluded that root
accumulation was higher compared to stem and
leaves.
From the above information, write the main points
1. The study focused on the uptake of Nickel and Lead in Catharanthus roseus plants over a period of 60 days.
2. The seedlings used in the study were uniform in size and free of any disease symptoms.
3. Metal solutions of Nickel and Lead were prepared at a concentration of 5mg/L and administered to the plants, with uptake estimated every 20 days.
4. The plants were removed from the pots, washed, dried, powdered, and subjected to acid digestion for metal analysis using Atomic Absorption Spectrometry.
5. Lead content was found to be higher in roots, followed by stems and leaves, with no significant change in lead accumulation in leaves over the experimental period.
6. By the 60th day, there was minimal change in metal accumulation in leaves, stems, and roots, with root accumulation being higher compared to stems and leaves.
7. The study concluded that Catharanthus roseus plants have a higher accumulation of metals in the roots compared to stems and leaves.