Antioxidant Defence System in Chickpea (Cicer arietinum L.): Influence by Drought Stress Implemented at Pre- and Post-anthesis Stage

Significant differences in the antioxidant system of the leaves of four chickpea (Cicer arietinum L.) genotypes differing in tolerance to drought were observed in a pot experiment. Drought stress was imposed at pre- and post- anthesis stage (50 and 65 days after sowing). We studied the effect of drought stress on hydrogen peroxide (H2O2) content, lipid peroxidation and antioxidant enzyme activities in four chickpea genotypes viz., Tyson, ICC 4958, JG 315 and DCP 92-3. Drought treatment significantly increased hydrogen peroxide accumulation and lipid peroxidation, which indicated the extent of oxidative injury posed by stress conditions. Enzyme activities of Superoxide Dismutase (SOD), Peroxidase (POX), Catalase (CAT) and Ascorbate Peroxidase (APX) increased in chickpea leaves as a consequence of drought conditions and all the enzyme activities were significantly higher in drought stressed genotypes i.e., Tyson and ICC 4958 than in JG 315 and DCP 92-3. Relationship between Lipid Peroxidation (LPO), Hydrogen peroxide (H2O2), Superoxide Dismutase (SOD), Catalase (CAT), Peroxidase (POX) and Ascorbate Peroxidase (APX) was determined in order to find out whether these parameters can be used as selection criteria for drought tolerance in this crop. Early drought stress (pre-anthesis drought) was found to be more damaging than the late drought stress (post-anthesis drought).