SEED PRIMING WITH SELENIUM IMPROVES GROWTH, WATER RELATION AND ANTIOXIDANT ACTIVITY OF POT MARIGOLD (Calendula officinalis L.) UNDER DROUGHT CONDITIONS

Abstract

Selenium (Se) seed priming is an effective method for enhancing seed performance and improving tolerance of crops to abiotic stresses particularly drought. A pot experiment was conducted to determine the effect of seed priming of pot marigold (Calendula officinalis L.) with Se on growth, physiology and antioxidant activity grown under both control and drought stress conditions. Treatments included 6 levels of seed priming with Se (0 (control), 0.5, 1, 1.5, 2 and 4 mg L–1) and 2 levels of water stress (well-watered and drought conditions). The results showed that supplemental Se at lower concentrations improved growth parameters like total leaf area, root length and total biomass of control and drought-stressed plants. In addition, relative water content and chlorophyll content of the drought-stressed plants increased with the application of Se at lower concentrations. Treatment with Se mitigated adverse effects of drought stress through enhancement of photosynthetic pigments, improvement of water relations, accumulation of soluble sugars and increased antioxidant activity. Seed priming with Se also increased total phenols, flavonoids and free radical scavenging activity of pot marigold plants both under well-watered and water stress conditions. It was found that seed priming with Se at lower concentrations (especially 1.5 mg L–1) can mitigate the adverse effects of drought stress and improved antioxidant system of pot marigold plants.