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 (GST: EC 2.5.1.18), cell membrane stability (CMS) and the rate of lipid peroxidation in terms of malondialdehyde (MDA) content in two high yielding genotypes (SI and ATP, salt tolerant and salt susceptible, respectively) of mulberry under NaCl salinity were studied. After salt stress. antioxidative enzymes were altered in mulberry and the extent of alteration varied between the cultivar S1 and ATP, leading to the higher amounts of antioxidative enzymes in S1 supporting its salt tolerance. The levels of lipid peroxidation as indicated by MDA formation was high in the sensitive variety (ATP), while the tolerant variety (Sl) showed no change in MDA content under NaCl salinity. Further, the salt tolerance of SI was supported by CMS, having comparatively lower amounts of electrolyte leakage. The relative tolerance of these two cultivars is discussed. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.