【摘要】 [目的]研究外源褪黑素对高粱幼苗干旱胁迫下的生长影响和筛选适宜浓度。[方法]以高粱品种辽糯11为材料，采用15%PEG模拟干旱胁迫，设置0、60、120、180、240和300μmol/L等6个不同浓度梯度浸种，研究干旱胁迫下不同褪黑素浓度对高粱种子芽苗表型参数、渗透调节参数等指标的影响。[结果]不同褪黑素浓度处理下，渗透调节参数中游离氨基酸含量、脯氨酸含量、可溶性糖含量在180μmol/L褪黑素处理下含量最高，质膜透性在0～180μmol/L间不会受到损伤；抗氧化酶指标中，POD、SOD、CAT等活性指标在180μmol/L与300μmol/L达到最高，MDA含量与褪黑素浓度呈负相关，在180～300μmol/L处于较低水平。[结论]外源褪黑素180μmol/L的浓度处理对干旱逆境下高粱芽苗生长改善效果最佳。更多还原

【Abstract】 [Objective]To study the effects of exogenous melatonin on the growth of sorghum seedlings under drought stress and screen the appropriate concentration.[Method]The sorghum variety Liaonuo 11 was used as the material,and 15%PEG was used to simulate drought stress.Six different concentration gradients of 0,60,120,180,240 and 300μmol/L were set up to study the effects of different melatonin concentrations on the phenotypic parameters and osmotic adjustment parameters of sorghum seed buds and seedlings under drought stress.[Result]Under different melatonin concentrations,the contents of free amino acid,proline and soluble sugar in osmotic adjustment parameters were the highest under 180μmol/L melatonin treatment,and the plasma membrane permeability was not damaged between 0-180μmol/L.Among the antioxidant enzyme indexes,POD,SOD,CAT and other activity indexes reached the highest in 180μmol/L and 300μmol/L,MDA content was negatively correlated with melatonin concentration,and was at a low level from 180μmol/L to 300μmol/L.[Conclusion]The concentration of exogenous melatonin 180μmol/L had the best effect on the growth of sorghum seedlings under drought stress.更多还原