Air pollution impact on micromorphological and biochemical response of Tabernaemontana divaricata L. (Gentianales: Apocynaceae) and Hamelia patens Jacq. (Gentianales: Rubiaceae)

Abstract. In the present investigation an attempt was been made to assess the air pollution effects on micromorphological and biochemical parameters of Tabernaemontana divaricata (Gentianales: Apocynaceae) and Hamelia patensi (Gentianales: Rubiaceae). In polluted area the number of stomata and clogged stomata were found to be higher then control, where as the number of unclogged stomata are found to be very less in the control site. The stomatal breadth and pore length were found to be decreased in polluted area in both the plants when compared to control. The number of subsidiary cells, trichome length values was found to be less then control plants. However trichomes are absent in T. divaricata. The stomatal index was found to be higher in both the plants is when compared to control. The chlorophyll a, chlorophyll b, and total chlorophyll content were found to be maximum in control samples when compare to polluted samples. But ascorbic acid, relative water content, pH and Air Pollution Tolerance Index (APTI) were found to be maximum in polluted samples when compare to control. Based on the present study both the plant species were categorized as tolerant to air pollution