Changes in the antioxidant enzyme efficacy in two high yielding genotypes of mulberry (Morus alba L.) under NaCl salinity

Changes in the activity of antioxidant enzymes such as superoxide dismutase (SOD: EC 1.15.1.1). peroxidase (POD: EC 1.11.1.7), catalase (CAT: EC 1.11. 1.6), glutathione reductase (GR: EC 1.6.4.2), glutathione S-transferase (GS T: EC 2.5.1.18), cell membrane stability (CMS) and the rate of lipid peroxi dation in terms of malondialdehyde (MDA) content in two high yielding genot ypes (SI and ATP, salt tolerant and salt susceptible, respectively) of mulb erry under NaCl salinity were studied. After salt stress. antioxidative enz ymes were altered in mulberry and the extent of alteration varied between t he cultivar S1 and ATP, leading to the higher amounts of antioxidative enzy mes in S1 supporting its salt tolerance. The levels of lipid peroxidation a s indicated by MDA formation was high in the sensitive variety (ATP), while the tolerant variety (Sl) showed no change in MDA content under NaCl salin ity. Further, the salt tolerance of SI was supported by CMS, having compara tively lower amounts of electrolyte leakage. The relative tolerance of thes e two cultivars is discussed. (C) 2001 Elsevier Science Ireland Ltd. All ri ghts reserved.