Investigating of the effect of the smoke from gasoline combustion in engine on some physiological and biochemical characteristics of Scheffleraarboricola, Euphorbia pulcherrima and Dieffenbachia amoena

Quantification of plant tolerance to air pollution (APTI) besides other criteria can be helpful in order to reduce air pollution and developing green space. The goal of this study was to investigate the effect of smoke from gasoline combustion in engine on some physiological and biochemical characteristics, especially the Air Pollution Tolerance Index of three species of houseplants. This laboratory study was performed in a factorial arrangement in a completely randomized design in two control and treatment groups. At first, houseplant plants of Scheffleraarboricola, Euphorbia pulcherrima and Dieffenbachia amoena were exposed to pollution due to motor fuels. Then, by measuring two physiological factors of relative water content and the PH of leaf extract, as well as the two biochemical factors of total chlorophyll and ascorbic acid, APTI values were determined in control and treatment plants. In addition to these factors, two parameters of proline and soluble sugar were measured to evaluate the physiological responses of plants. Results showed that among the studied species the highest acidity and relative water content were found in Dieffenbachia amoena and the highest proline, ascorbic acid and APTI were measured in Euphorbia pulcherrima. There was also no significant difference in the amount of soluble sugar and chlorophyll among the three species. The degree of APTI in Scheffleraarboricola, Euphorbia pulcherrima and Dieffenbachia amoena were respectively measured as 10.37, 15.63 and 10.55. The amount of APTI value in treated plant of Dieffenbachia amoena was lower than the control plants. Also, the amount of proline and relative water content in treated plants of Scheffleraarboricola was lower than the control plants. Since Euphorbia pulcherrima plant had the highest air pollution index compared to the other two plants of Scheffleraarboricola and Dieffenbachia amoena in the exposure to the smoke due to gasoline fuel combustion in engine, the development of green space in apartments with Euphorbia pulcherrima plant compared to the other two plant species has more priority.