Accumulation of toxic metals in citrus plants due to heavy traffic pollution in industrial areas

Abstract

Sargodha is famous for the production of different citrus varieties due to its quality throughout the country. Keeping in
view the importance of citrus, this experiment was done to evaluate the effect of air contamination/pollution on growth of
Citrus limon (Lemon) and Citrus sinensis (Kinu) and accumulation of heavy metals in their leaves in industrial areas of
Tehsil Shahpur Sadar, Sargodha, Pakistan. Various biochemical and physiological parameters (chlorophyll a and b,
relative water contents) were studied. Lessening of fresh and dry weight of lemon (23.38% and 2.19%) and kinu (12.16%
and 1.49%) was noted. In lemon, values of 16.63%, 13.95% and 2.41% were noted for chlorophyll a, b and total while
37.07%, 3.48% and 6.24% for kinu. Copper (lemon = 0.175 & kinu = 0.789 mg L-1
) and nickel (lemon = 0.345 & kinu =
0.450 mg L-1
) concentrations were analyzed. Same trend for Ca (2.42 and 2.27 mg g-1
in lemon and kinu respectively), N
(1.93 and 2.96 mg g-1
in lemon and kinu respectively) and P (0.064 and 0.58 mg g-1
in lemon and kinu respectively)
contents were noted. It is concluded that contamination of polluted site significantly reduced the growth and physiological
attributes of Citrus limon (Lemon) and Citrus sinensis (Kinu).