Effects of exogenous melatonin on seed germination and seedlings of rescuegrass under NaCl stress

The effect of exogenous melatonin on the germination and the morphological and physiological characteristics of the seedling stage of Bromus catharticus ‘Chuanxi’ (rescuegrass) under salt stress was investigated in the current study, providing a theoretical basis for improving the salt-resistance of ‘Chuanxi’. The experimental results indicated that the highest germination rate and salt resistance were obtained when 100 μmol·L^–1 melatonin was added. In this case, the germination rate, germination energy, soluble protein, free proline (Pro) content, and peroxidase (POD) activity of ‘Chuanxi’ seedlings increased by 22.39%, 58.83%, 21.78%, 121.44%, and 81.02%, respectively. The malondialdehyde (MDA) content decreased by 45.43% compared to the salt stress treatment. The results suggested that exogenous melatonin (MT) can improve the antioxidant enzyme activity and decrease the membrane peroxidation, thereby improving the adaptability of ‘Chuanxi’ under salt stress. The research results provided technical improvements for the cultivation and utilization of the ‘Chuanxi’ in the saline area.