褪黑素浸种对盐碱胁迫下大豆种子萌发的影响

为研究褪黑素浸种对盐碱胁迫下大豆种子萌发的影响,以大豆品种垦丰16为试验材料,研究100μmol/L褪黑素浸种对不同浓度混合盐碱（NaCl和NaHCO₃物质的量按1:1混合,配制为0、25、50、100、200mmol/L的盐碱溶液）胁迫下大豆种子萌发的影响。结果表明：与对照相比,随盐碱浓度提升,大豆种子发芽率、发芽指数、芽鲜重和芽干重呈不断降低趋势,超氧化物歧化酶、过氧化物酶、过氧化氢酶、谷胱甘肽还原酶和谷胱甘肽过氧化物酶活性呈现先升高后降低的趋势,抗坏血酸过氧化物酶活性呈不断上升趋势;渗透调节物质可溶性糖、可溶性蛋白和脯氨酸含量呈现先升高后降低的趋势;膜脂过氧化产物丙二醛、H₂O₂含量、$\mathop{{O}}_{2}^{{\mathop{}_{\ .}^{-}}}$产生速率呈不断上升趋势。褪黑素浸种可提高不同浓度盐碱胁迫下大豆种子发芽率、发芽指数、芽鲜重、芽干重和抗氧化酶活性以及渗透调节物质含量,降低丙二醛、H₂O₂含量和$\mathop{{O}}_{2}^{{\mathop{}_{\ .}^{-}}}$产生速率。综上所述,褪黑素浸种可以缓解不同浓度盐碱胁迫对大豆种子发芽的抑制作用,并能提高抗氧化酶活性和渗透调节物质含量,降低膜脂过氧化程度。

Effects of Melatonin Soaking on Germination of Soybean Seeds under Saline-Alkali Stress

In order to study the effects of melatonin soaking on the germination of soybean seeds under salt-alkali stress, the soybean variety Kenfeng 16 was used as experimental material to study the effects of 100μmol/L melatonin soaked on the seeds germination of soybean under different concentrations of mixed saline-alkali stress. The results showed that compared with the control, with the increase of concentration, the saline-alkali stress continuously reduced the germination rate, germination index, bud fresh weight and dry weight of soybean seeds, and the antioxidant enzymes superoxide dismutase, peroxidase, catalase, glutathione reductase, glutathione peroxidase activities rised first and then decreased. The activity of APX increased continuously. The content of soluble sugar, soluble protein and proline osmotic adjustment substances increased first and then decreased. The content of membrane lipid peroxidation products malonaldehyde (MDA), H₂O₂, and $\mathop{{O}}_{2}^{{\mathop{}_{\ .}^{-}}}$ rate of production was on the rise. Melatonin soaking could increase the germination rate, germination index, bud fresh weight, bud dry weight and antioxidant enzymes activity, as well as the content of osmotic adjustment substances, and decrease the content of MDA, H₂O₂ and $\mathop{{O}}_{2}^{{\mathop{}_{\ .}^{-}}}$ production rate under different concentrations of saline-alkali stress. In summary, melatonin soaking can alleviate the inhibition of soybean seed germination under different concentrations of saline-alkali stress, and can increase the activity of antioxidant enzymes and osmotic adjustment substances, and reduce the degree of lipid peroxidation on membrane.