Distribution of stomata on Lycopersicon esculentum leaves for plants growing in air pollution related to vehicle fumes along Waiyaki Highway Nairobi County Kenya

Abstract

Air pollution is a worldwide environmental negative phenomenon affecting global climate, humans, animals and plants. Vehicle fumes as a leading major source among smoke producing air pollutants, was examined in this study. Nairobi, a mega-city with increasingly high levels of air pollution was studied with special emphasis on one of its roads, i.e. Waiyaki Highway. This road was investigated for scientific understanding of effects of vehicle fumes on plants stomata behavior and distribution. Hotspots of air pollution averaging PM₁₀ 42.6µgm/M³ along this Highway were identified as locations for monitoring of effects of air pollution on plants. A control (at NARL) had similar environmental conditions but no significant air pollution (measured air pollution at environment of control at NARL, had PM₁₀ 0_.6µgm/M³). The control experiment was protected from air pollution related to vehicle fumes by lengthy distance away from the road plus vegetation thriving in between. Sites selected for treated experiments were: ICEA buildings, ABC Place, and Kangemi market. These hotspots were also evidenced by some existing trees/or plants which were moribund and all trees at the sites had darken tree trunks and leaves due to air pollution. Lycopersicon esculentum Mill. (1691), tomato plant that highly susceptible to air pollution was exposed to air pollution at selected sites. The experiments looked at distribution of stomata account after 3 months. Collected data was analysed using Poisson distribution in Genestat software. Means were separated by use of Least Significant Difference (LSD) or Tukey in Genestat software. The stomata were located under leaf mainly with plants in treated experiments exposed to air pollution. Significantly (at F_2,6=3.37, P<0.05) more of open stomata on the treated plants were found on lower epidermis. In the experiment, plants germinated developed normally but differences were experienced in distribution of stomata analysis. The unfavorable atmospheric condition due to air pollution related to vehicle fumes, physiologically plants react by leaf stomata pores distribution. Physiologically plants distribute stomata pores to where there is no obstruction as a way of adoption to air pollution and this case; it happened on treated experiment plants having more stomata and open stomata on lower epidermis upper epidermis.

Keywords Air pollution, Vehicle fumes, Leaf distribution of stomata, Lycopersicon esculentum Waiyaki Highway