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INVERSTIGATION INTO THE EFFECTS OF AUTOMOBILE POLLUTANTS ON GROWTH AND METAL CONTENTS OF SOME ROADSIDE PLANTS

Shafiq, Muhammad (2002) INVERSTIGATION INTO THE EFFECTS OF AUTOMOBILE POLLUTANTS ON GROWTH AND METAL CONTENTS OF SOME ROADSIDE PLANTS. PhD thesis, University of Karachi, Karachi.

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Abstract

The phenology of Astonia scholaris, Pongamia pinnata, Cassia siamea and peltophorum pterocarpum was significantly (p<0.05) affected in the Karachi city polluted environment. Plants were more affected to pollutants at Gulshan-e-Iqbal, Nazimabad, Shahrah-e-Faisal and M.A Jinnah Roadm as compared to Karachi University Campus. Leaf length, width and area of A. Scholaris were found lowest in summer at M.A Jinnah Road, as compared to Shahrah-e-Faisal, Nazimabad, Gulshan-e-Iqbal and Karachi University Campus, respectively. Leaf length and area of P. pinnata were Significantly (p<0.05) reduced in autumn at the highly polluted sites of M.A Jinnah Road as compared to Karachi University Campus. Leaf width and area of C.siamea were significantly (P<0.05) reduced in autumn at the highly polluted sites of M.A Jinnah Road, as compared to Karachi University Campus. Leaf length of P. pterocarpum was also found significantly (P<0.05) reduced at M.A Jannah Road in winter as compared to other less polluted sites of the city. Autoemission showed toxic effect on seed germination and seedling growth of plants. The seeds of P.Ptercarpum and C. siamea collected from the trees growing along the busy roads of the city showed low percentage of germination. Seedling dry weight of the plants also decreased significantly (P0.05). In pot experiments, the seed germination and seedling growth of C. siamea was badly affected in seeds collected from the polluted areas of the city as compared to Karachi University Campus. Lead and cadmium treatment produced toxic effects on seed germination and seedling growth of Peltophorum pterocarpum and Leucaenal leucocephala. Root length of L leucocephala and P. pterocarpum was significantly (P<0.05) reduced at 50 ppm treatment of lead. The treatment of Pb at 25 ppm suppressed the seedling dry weight of P. pterocarpum. Cadmium treatment of 50 ppm produced significant (p<0.05) effects on seed germination of L. leucocephala as compared to control. The seed germination, seedling length and dry weight of C. siamea were significantly affected by 25 ppm cadmium treatments as compared to control. The trees of all species (A. scholaris, P. siamea and P. pterocarpum) growing along the busy roads of the city showed significantly higher concentration of Pb and Cd. The concentration of Pb and Cd in leaves of all the species was quite high at M.A Jinnah Road as compared to Shahrah-e-Faisal, Nizamabad, Gulshan-e-Iqbal and Karachi University Campus. Higher level of Pb and Cd in leaves of A. scholaris and P. pinnata might be due to the large surface area that is available for exposure to any pollutant as compared to any pollutant as compared to C siamea and P. pterocarpum. Low vehicular traffic activities at the campus showed lowest Pb and Cd contents for all the tree species investigated. In this study, pletophorum pterocarpum was found affected to automobile pollution of the city as compared to other species. It is therefore suggested that P. pterocarpum shuld be given more preference for future plantation in the city areas, particularly along the roads.

Item Type:Thesis (PhD)
Uncontrolled Keywords:automobile, pollutants, roadside, plants, growth of plants, seed germination, metal accumulation, autoemission, toxic
Subjects:Biological & Medical Sciences (c) > Biological Sciences(c1) > Paleo-botany(c1.9)
ID Code:549
Deposited By:Mr. Muhammad Asif
Deposited On:05 Aug 2006
Last Modified:04 Oct 2007 21:01

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