Ecology, Environment and Conservation Paper

EFFECT OF AUTOMOBILE POLLUTION ON FEW ORNAMENTAL PLANTS

T.N. RANGARAJAN, M.C. ARJUNAN AND N.R. PONNAMMAL

Abstract

Effect of automobile pollution on four ornamental species, Acalypha wilkesiana eul muell Arg., Bougainvillea spectabilis Wind: Hibiscus rosasinensis L. and Ixora singaporansis were studied. As compared to the control, aerial parts of all the plants growing near the bus terminals were fully coated with black or dark brown colour dust. The dust deposition on the adaxial side of the leaves was more than on the abaxial side. Anatomically epidermal cell frequency is decreased on both the sides in A. wilkesiana and H. rosasinensis. But in B. spectabilis and I. singaporansis the epidermal cell frequency is increased on both the sides. The frequency of trichomes is increased on the adaxial side of the leaf in all the four plants. Stomatal frequency increased in B. spectabilis and!. singaporansis on both the surfaces. It is reduced in the other two species when compared to normal plants. There is no change in the type, length and width of stomata in all the species. Affected stomatal percentage was found to be more in the case of I. singaporansis on both the sides. Xylem elements show a reduction in length in all the species except I. singaporansis where it is increased. The leaf thickness was reduced in all the species. when compared to normal plants. Among the four species studied B. spectabilis seems to be a less affected species due to automobile pollution. The most affected species in terms of leaf epidermal characters were I. signaporansis, H. rosasinensis and A. wilkestana.