外源褪黑素对盐碱胁迫下小黑麦种子萌发幼苗生长、抗氧化能力的影响

为了解外源褪黑素对盐碱胁迫条件下小黑麦种子萌发、幼苗生长及抗氧能力的影响,以小黑麦品种东农96026为材料,通过种子萌发试验和水培试验分析了盐碱胁迫(NaCl、NaHCO3摩尔比1∶1混合)条件下外源褪黑素(浓度200μmol·L^-1)添加后,小黑麦种子萌发指标、生长指标、渗透调节物质含量、抗坏血酸-谷胱甘肽(AsA-GSH)循环系统相关酶活性和物质含量的变化。结果表明,外源褪黑素可显著提高盐碱胁迫条件下小黑麦的种子发芽率、发芽势和发芽指数,增加幼苗地上部分和根系的生物量,提高根系可溶性糖和可溶性蛋白含量。褪黑素可显著增强盐碱胁迫下小黑麦幼苗单脱氢抗坏血酸还原酶、脱氢抗坏血酸还原酶、抗坏血酸过氧化物酶及谷胱甘肽还原酶活性,提高AsA和GSH含量及AsA/DHA和GSH/GSSG比值。由此说明,外源褪黑素能促进盐碱胁迫下小黑麦种子萌发和幼苗生长,提高渗透调节能力和抗氧化能力,从而有效地缓解盐碱胁迫对小黑麦生长发育的抑制效应。

Effect of Exogenous Melatonin on Seed Germination,Seedling Growth and Antioxidant Ability of Triticale under Saline-Alkali Stress

In order to understand the effect of exogenous melatonin on the seed germination,seedling growth and antioxidant capacity of triticale under saline-alkali stress,Triticale Dongnong 96026 was used as the material and seed germination test and hydroponic test were conducted.After the addition of exogenous melatonin(200μmol·L^-1)under stress(NaCl,NaHCO3 mole ratio 1∶1),we measured the triticale seed germination indicators,growth indicators,osmotic adjustment substance content,ascorbic acid-glutathione glycine(AsA-GSH)circulatory system related enzyme activities and changes in substance content.The results showed that exogenous melatonin significantly increased the germination rate,germination potential and germination index of triticale seeds under salt-alkali stress conditions,increased the biomass of seedlings and roots,and increasedsoluble sugar and soluble protein content in root.Melatonin significantly enhanced the activities of monode hydroas corbate reductase,dehydroascorbate reductase,ascorbate peroxidase and glutathione reductase of triticale seedlings under saline-alkali stress,and increased the content of AsA and GSH and AsA/DHA and the ratio of GSH/GSSG.Taken together,exogenous melatonin can promote seed germination and seedling growth of triticale under saline-alkali stress,improve osmotic regulation and antioxidant capacity,and thereby effectively alleviatethe inhibitory effect of saline-alkali stress on the growth and development of triticale.