外源褪黑素对低温胁迫下玉米幼苗生长和生理特性的影响

以玉米品种‘郑单958’为试验材料,在幼苗长至三叶一心时,利用5个浓度(0、10、50、100、500μmol/L)的外源褪黑素进行叶面连续喷施3 d后,转入人工气候箱中进行低温胁迫处理,旨在探究外源褪黑素对低温胁迫下玉米幼苗生长特征、叶绿素含量、可溶性糖含量及过氧化物酶活性的影响。试验结果表明,褪黑素有利于缓解低温胁迫对玉米幼苗株高及叶片含水量特性影响,SPAD值升高,增强了叶片叶绿素合成能力,可显著提高玉米叶片过氧化物酶活性;可溶性糖含量随低温胁迫时间增加而增高,低温胁迫7 d后,对照组和处理组间可溶性糖含量存在显著差异。综合来看,外源褪黑素对低温胁迫下玉米幼苗受到的伤害可以起到缓解作用。

Effects of Exogenous Melatonin on Maize Seedlings Growth and Physiological Traits under Low Temperature Stress

Here, the corn variety "Zhengdan 958" was used to investigate the effects of exogenous melatonin on growth characteristics, chlorophyll content, soluble sugar content and peroxidase activity of maize seedlings under low temperature stress. The seedlings with three leaves were sprayed continuously with 5 different concentrations(0,10, 50, 100, 500 μmol/L) of exogenous melatonin for 3 days, and then transplanted to an artificial climate chamber for low temperature stress. The results showed that exogenous melatonin alleviated the effects of low temperature stress on the characteristics of maize seedlings, such as plant height and leaf water content, also increased the SPAD value in leaves. Further, exogenous melatonin significantly increased the peroxidase activity of maize leaves. The soluble sugar content also increased with the continuously low temperature stress. After 7 days of low temperature stress, there was a significant difference in the soluble sugar content between the control group and the treatment group. Therefore, exogenous melatonin alleviated the damage to maize seedlings under low temperature stress.