Abstract：Taking‘Xinpusenjingyingsanyeshengcai’as test material，this experiment set 4 concentrations of melatonin pretreatment as 25，50，75，100 μmol · L-1；took clean water as the contrast；and studied the effects of melatonin foliar spraying on growth，physiology characteristics of lettuce during high temperature season under hydroponic condition．The results showed that pretreatment with melatonin spraying on leaves had increased the antioxidant enzyme activity and osmotic adjustment substance content of hydroponic lettuce，alleviated the damage of high temperature stress to cell plasma membrane，and promoted the growth of lettuce．The 50 μmol · L-1 melatonin pretreatment had the best effect．The maximum leaf length，maximum leaf width，above-and below-ground fresh weight，CAT，POD and SOD activities，soluble protein，soluble sugar and Pro contents，root system vigor，and leaf color value of lettuce were all significantly higher than those of the contrast．While，the relative conductivity and MDA content were significantly lower than that of the contrast．
王博伟，陈艳丽*，朱国鹏，杨雨，刘金伟，周铎航. 叶面喷施褪黑素对海南高温季节水培叶用莴苣生长生理的影响[J]. 中国蔬菜, 2022, 1(11): 80-85.
WANG Bowei，CHEN Yanli*，ZHU Guopeng，YANG Yu，LIU Jinwei，ZHOU Duohang. Effect of Melatonin Foliar Spraying on Growth and Physiology Characteristics of Hydroponic Lettuce during High Temperature Season in Hainan. China Vegetables, 2022, 1(11): 80-85.
