Physiological and Biochemical Response of Rice Cultivars (<i>Oryza Sativa</i> L.) To Elevated Ozone
Ambikapathi Ramya, Periyasamy Dhevagi, Sengottiyan Priyatharshini, C. N. Chandrasekhar, K. Valliappan, S. Venkataramani
Abstract
A study was carried out to evaluate the effect of elevated tropospheric ozone concentration on 15 rice cultivars. The cultivars were exposed to a weighted average ozone concentration of 51 ppb ±10% (10:00–17:00 h) for 30 days on its reproductive stage. On an average, elevated ozone significantly affects photosynthetic rate (−19.23%), stomatal conductance (−21.35%) and the contents of chlorophyll (−27.19%), malondialdehyde (+121.43%), proline (+98.38%), and ascorbic acid (−20.99%) over the control. Linear multiregression 3D model significantly fits the leaf traits related to leaf injury percentage which in turn affects all photosynthetic traits. The maximum R2 = 0.85*** was observed between photosynthetic rate, chlorophyll content, and leaf injury percentage. Rice cultivars exhibited significant interspecies variation in physiological and biochemical traits under elevated ozone. Among the tested rice cultivars, the multivariate analysis confirmed the Rice CO51, Anna(R)4, CO47, PMK(R)3, and Rice TPS5 were ozone tolerant. For the first time in South India, the study on response of rice cultivars to elevated ozone was done, which might support the rice breeders for selecting suitable donor parents for future climate change scenarios.