Effect of ozone and antioxidants on wheat and its pathogen — Bipolaris sorokininana

Tropospheric ozone (O₃) adversely affects growth and productivity of crops and also influences crop—pathogen interactions. Adverse effects of O₃ on crops can be mitigated by antioxidants application. In the present study through lab and field experiments impact of O₃ and antioxidants treatment to wheat was assessed on growth of Bipolaris sorokiniana (BS-75 strain) pathogen responsible for Spot blotch disease, pathogenesis related (PR) proteins and chitinase content. Results showed that growth of Bipolaris was significantly higher in elevated ozone (EO₃) exposed plants as compared to control plants. Antioxidants — ascorbic acid (AA), tagetes extract (T) and quercetin (Q) application on culture media and wheat plants, respectively, retarded the growth of Bipolaris sorokiniana. Among the three antioxidants minimum growth of Bipolaris was observed in AA-treated plants as compared to control plants. Reduction in chitinase activity and PR proteins content due to EO₃ treatment in wheat plants was 18% and 78%, respectively, as compared to control plants. Increase in chitinase activity and PR proteins content due to antioxidants treatment in wheat plants was 45% and 60%, respectively, as compared to control plants