褪黑素引发对干旱胁迫下黄瓜幼苗生理特性的影响

Effects of Melatonin Priming on Physiological Characteristics of Cucumber Seedlings Under Drought Stress

研究褪黑素(MT)种子引发对干旱胁迫下黄瓜幼苗生长的影响,以期为MT作为黄瓜种子引发剂或包衣剂物料筛选提供理论依据。以‘津研4号’为试验材料,用50、100、150μmol/L MT对种子进行6、12、15 h引发处理,以未引发种子为对照,设置50%田间持水量的干旱胁迫,采用基质盆栽,探究MT引发对干旱胁迫下黄瓜幼苗生长的影响。结果表明,50~100μmol/L的MT引发15 h时对黄瓜幼苗耐旱性增强有显著作用,其中50μmol/L时提高幼苗的光合速率达85.5%,超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性增幅分别为5.1%、42.4%、38.8%,根系活力提高154.0%,说明适宜浓度的MT引发可以通过增强幼苗的抗氧化酶活性及根系活力来提高黄瓜幼苗的耐旱性。

The purpose is to study the effect of melatonin(MT)seed priming on cucumber seedling growth under drought stress,so as to provide a theoretical basis for selecting MT as cucumber seed priming agent or coating agent.The seeds were treated with 50,100,150μmol/L melatonin(MT)priming for 6,12 and 15 h,and the unprimed seeds were used as a control,the drought stress was set at 50%of field moisture capacity,and the substrate pot cultivation was used.The results showed that 50-100μmol/L of MT priming for 15 h triggered a significant increase in drought tolerance of cucumber seedlings.Compared with the control,50μmol/L MT priming increased the photosynthetic rate of the seedlings by 85.5%,and SOD,POD and CAT activities by 5.1%,42.4%and 38.8%,respectively,and the root vigor was improved by 154.0%,indicating that suitable concentration of MT priming could improve the drought tolerance of cucumber seedlings by enhancing the antioxidant enzyme activities and root vigor of the seedlings.