Growth Performance and Antioxidant Enzyme Activities of Advanced Mutant Rice Genotypes under Drought Stress Condition

Abstract

Drought stress affects various physiological and metabolic processes in rice (Oryza sativa L.) plant. Non-availability of high-yielding varieties suitable for cultivation under drought condition lead towards a sharp decline in rice yield. Induce mutation is an essential auxiliary approach to counterpart conventional breeding to produce stress-tolerance rice variety. The current study was aimed to identify two advanced mutant rice genotypes as drought-tolerant using growth parameters and antioxidant enzyme activities. The advanced mutant rice genotypes, MR219-4 and MR219-9, showed a minimal reduction on all growth parameters, yield, and yield components measured for drought tolerance. MR219-4 had a slight reduction on total dry weight and chlorophyll content under drought stress condition. Proline content increased significantly in drought-tolerant rice genotypes and the highest proline content was obtained from MR219-4 followed by MR219-9 under drought stress. Catalase, ascorbate peroxidase, and guaiacol peroxidase activities were significantly increased in drought stress treatment in all the rice genotypes. MR219-4 and MR219-9 were identified as high-yielding drought-tolerant genotypes as they maintained good performance under drought stress condition for all the measured traits compared to the drought-tolerant check varieties, Aeron1 and MR219, thus, this might be underlying selection criteria for a drought tolerance rice breeding programme.