Effect of polluted soil extracts on germination and seedling growth of some species

The seeds of Albizia lebbeck, Leucaena leucocephala and Peltophorum pterocarpum show a high rate of germination in the soil extract of control (campus) as compared to polluted areas (city). Germination percentage was lowest in the soil extracts of Guruminder and M. A. Jinnah road. The seedling length of A. Lebbeck and P. pterocarpum was not significantly altered by the soil extract of city areas, whereas L. leucocephala showed significant results. Reduction in root length was high in P. pterocarpum; similarly, it also showed a reduction in dry weight. This would indicate that P. pterocarpum was found to be the most susceptible species to automobile pollution. It showed reduction in germination, root and seedling length and biomass production. Tolerance of this species was also lowest as compared to other species.