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

Effect of Melatonin Foliar Spraying on Growth and Physiology Characteristics of Hydroponic Lettuce during High Temperature Season in Hainan

以辛普森精英散叶生菜为试材,设置4个褪黑素预处理浓度(25、50、75、100μmol·L^(-1)),以清水为对照,研究叶面喷施褪黑素对高温季节水培叶用莴苣生长生理的影响。结果表明:叶面喷施褪黑素预处理提高了叶用莴苣叶片抗氧化酶活性和渗透调节物质含量,降低了高温胁迫对细胞质膜的伤害,促进了植株生长。其中,50μmol·L^(-1)褪黑素的处理效果最好,叶用莴苣最大叶长、最大叶宽、地上部和地下部鲜质量、CAT活性、POD活性、SOD活性、可溶性蛋白质含量、可溶性糖含量、Pro含量、根系活力、叶色值均显著高于对照,而相对电导率和MDA含量则显著低于对照。

Taking‘Xinpusenjingyingsanyeshengcai’as test material,this experiment set 4 concentrations of melatonin pretreatment as 25,50,75,100μmol·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 50μmol·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.