Oxidative status of Moringa oleifera Lam. seeds during storage

The aim of this study was to evaluate oxidative damages and antioxidative defences during loss of viability and vigour in Moringa oleifera Lam. seeds stored under controlled conditions. Seeds were packed in semipermeable plastic bags, maintained in a refrigerator (4 +/- 2 degrees C and 20-25% RH) or in a growth chamber (27 +/- 2 degrees C and 60-65% RH) for 18 months, and harvested every 6 months. The seeds stored in the growth chamber lost viability and vigour earlier than those stored under refrigeration. Irrespective of the storage environment, the H2O2 levels did not increase, lipid peroxidation remained almost unchanged, and protein carbonylation decreased in the course of the experiment. The reduced glutathione levels and the phenol peroxidase activity decreased faster in the seeds maintained in the growth chamber than in those kept under refrigeration. The reduced ascorbate levels and the activities of ascorbate peroxidase and catalase increased during storage in both tested conditions. Hence, loss of viability and vigour in M. oleifera seeds during storage could not be attributed to oxidative damages, in terms of H2O2 accumulation, lipid peroxidation, and protein carbonylation. The preservation of antioxidative defences, specifically the reduced ascorbate levels and the activities of superoxide dismutase, ascorbate peroxidase, and catalase, does not result in the maintenance of seed vigour.(C) 2019 SAAB. Published by Elsevier B.V. All rights reserved.