Int. J. Life. Sci. Scienti. Res., 3(6): 1522-1526 November 2017 Copyright © 2015-2017| IJLSSR by Society for Scientific Research is under a CC BY-NC 4.0 International License Page 1522 Assessment for Variation of Air Pollution Tolerance Index of Selected Plants in Bengaluru Urban Manjunath B.T 1 , Jayarama Reddy 2* 1 Research Scholar, Department of Botany, Bharathiar University, Coimbatore, India 2 Professor, Department of Botany, St. Joseph’s College, 36, Langford Road, Bengaluru, India * Address for Correspondence: Dr. Jayarama Reddy, Professor, Department of Botany, St. Joseph’s College, 36, Langford Road, Bengaluru, India Received: 05 August 2017/Revised: 23 August 2017/Accepted: 19 October 2017 ABSTRACT- To develop the usefulness of Caesalpinia pulcherrima and Catharanthus roseus plants as bioindicators, which entail an utmost importance for a particular situation. This study focuses on the assessment of air pollution tolerance index (APTI) of two selected plant species commonly found along roadsides in Bengaluru, India. The plant species selected for the study were Caesalpinia pulcherrima and Catharanthus roseus. The plants were evaluated in terms of APTI by analyzing four different biochemical parameters: Leaf relative water content (RWC), Ascorbic acid content (AA), Total leaf chlorophyll (TCh), and pH of leaf extract. Based on APTI Caesalpinia pulcherrima was found to be more tolerant compared to Catharanthus roseus. Species with lower APTI value are considered sensitive species, which can be used as a biological indicator for further monitoring of air quality. Species with higher APTI value are tolerant species and thus, can be planted for pollution abatement in order to control and reduce environmental pollution. Key-words- Air pollution tolerance index (APTI), biochemical parameters, roadside plants, Biomonitors INTRODUCTION Air Pollution can be simply defined as an undesirable change in the physical, chemical and biological properties of air due to anthropogenic or any other cause. An air pollutant is a substance in the air that can have adverse effects on humans and the ecosystem. The substance can be solid particles, liquid droplets, or gases. Air pollution is a serious problem throughout the world. Rapid industrialization and vehicular traffic especially in the urban areas of India lead to the deterioration of air quality by adding toxic gases and other substances to the atmosphere. All combustion releases gases and particulate matter into the air, which includes SO 2 , NO 2 , CO and soot particles as well as smaller quantities of toxic metals, organic molecules, and radioactive isotopes etc. The degradation of air quality is the major environmental problem that affects many urban and industrial sites and the surrounding regions worldwide. Although various efforts have been done for environmental restoration in India still it seems to be a formidable task. A pollutant can be of natural origin or manmade. Air Pollution results in huge harm to the living organisms. Access this article online Quick Response Code Website: www.ijlssr.com DOI: 10.21276/ijlssr.2017.3.6.16 There are several morphological, behavioral, physiological and anatomical changes in plants and animals due to air pollution. But the effect is different in different organisms depending on the chemical the substance causing the pollution [1-3] . The responses of plants to the severity of their environment have attracted the attention of a man long before the establishment of the science of Biology. To a lay man, plants that survive in a harsh environment are ‘hardy’; those which do not are ‘tender’. Biologists have adopted the term stress for any environmental factor potentially unfavorable to living organisms and stress resistance for the ability of the plant to survive the unfavorable factor and even to grow in its presence. A biological stress can be defined as any environmental factor capable of inducing a potentially, injurious strain in living organisms. The living organisms may show a physical strain or change or a chemical strain [4] . Air pollutions can directly affect plants via leaves or indirectly via soil acidification. It has also been reported that when exposed to air pollutants, most plant experience physiological changes before exhibiting visible damage to leaves. Studies have also shown the impacts of air pollution of Ascorbic acid content chlorophyll content, leaf extract pH, and relative water content. These separate parameters gave conflicting results for same species. However, the air pollution tolerance index (APTI) based on all four parameters has been used for identifying tolerance levels of plant species. Several contributors agree that air pollutants affect plant growth adversely. These urban air pollutants not only represent a threat to human health and the urban environment but it RESEARCH ARTICLE