Effect of Foliar Application of Sodium Nitroprusside on Some Morphological, Physiological and Biochemical Properties of Marigold Plant (Calendula officinalis L.) under Different Irrigation Regimes

In order to investigate the effect of irrigation as well as foliar application of sodium nitroprusside as a nitric oxide donor compound on some morphological, physiological and biochemical characteristics in marigold (Calendula officinalis L.), an experiment was conducted in a greenhouse and has been carried out as factorial (two factors) based on a completely randomized design with three replications. Experimental factors included different irrigation levels 100, 65 and 30% FC and foliar application of sodium nitroprusside at three concentration levels 0 (control), 200 and 400 µM. The results showed that the highest root dry weight and root to aerial organ dry weight ratio belonged to control and 30% FC, respectively. Chlorophyll a and total concentration were reduced under water deficit stress, while the electrolyte leakage percentage was increased. The highest amount of total phenol content was belonged to 65% FC. Sodium nitroprusside had significant effects on the root dry weight and chlorophyll a and total concentration that this effects was maximum in 400µM. The concentrations of 200 and 400 µM sodium nitroprusside with 65% FC treatment increased the activity of superoxide dismutase and catalase enzymes. In all irrigation treatments, foliar application of 200 µM sodium nitroprusside increased the relative leaf water content. The concentration of 400 µM sodium nitroprusside with 30% FC showed the highest essential oil percentage. Based on the results obtained, sodium nitroprusside treatment protected marigold plant from water deficit stress and decreased its damages.