Exogenous Application of Melatonin Alleviates Drought Stress in Ranunculus asiaticus by Improving Its Morphophysiological and Biochemical Attributes

Melatonin (MT) controls various physiological functions and enhances plant drought tolerance. This study aimed to evaluate the effect of exogenous MT on morpho-physiological biochemical attributes Ranunculus asiaticus under normal conditions. A completely randomized design was used with two factors, stress concentration (0, 50, 100, 200 μM), assess foliar application R. seedlings. The experiment conducted a total groups: group control group. carried out four times during period. exhibited considerably decreased shoot length by 26.0%, leaf number 31.03%, area 62.2%, fresh dry vegetative weights 34.5% 52.9%, respectively, chlorophyll carotenoid contents 68.29% 51.72%, relative water content 7.1%; early emergence flower stalks observed within 29 days; increased electrolyte leakage 20.5% compared well-watered plants. Conversely, notably growth parameters their no-treatment counterparts. Foliar treatment µM resulted in most significant response Moreover, stressful conditions no treatment, exogenously applied induced appearance buds 21 days 6.4%, proline 32%, peroxidase activity 58% while reducing 14.3%. Regarding tolerance index percentages, higher indicated suitability for use as markers tolerance, supporting effective role enhancing adaptability stress.