The Journal of Indian Botanical Society

Air pollutants including the gaseous and particulate matters are accountable for poor consequences on health of living beings at local, regional and global level. Sulfur dioxide (SO₂) is one of the most common harmful air pollutants in relation to its negative effect on the variety of living beings including plant growth and productivity. Leaves of the plants are the primary receptors of air pollutant gases viz. SO₂, NO_x, CO₂, O₃ etc. As soon as pollutant gases enters through stomata, plants have the ability to absorb and assimilate these gases in its natural metabolic pathway. Generally, the assimilatory pathways are common in almost all higher plant life forms. However, the rate of response to variety of air pollutant gases may differ and governed by certain external and internal factors. The phytotoxicity of SO₂ depends on multiple factors including genetic factors, environmental factors, age of plants, growth factors, concentration of pollutants, and exposure time. Based on the response towards exposure, the plants can be categorized as “sensitive” and “tolerant” species. Sensitive species are early indicators of pollution, and the tolerant species help in reducing the overall pollution load. The study reports the effect of exposure of SO₂ gas on a range of physiological parameters of the selected wheat cultivars exposed to SO₂. Stress Response Index (SRI) and Recovery Index (RI) of wheat cultivars were calculated in order to judge the tolerance and resilience nature of different cultivars.