外源2,4-表油菜素内酯对NaCl 胁迫下垂穗披碱草种子萌发及幼苗生理特性的影响

Effects of exogenous 2,4-epibrassinolide on seed germination and seedling physiological characteris⁃tics of Elymus nutans under NaCl stress

摘要:

【目的】 探究外源2，4‐表油菜素内酯（2，4‐epibrassinolide，EBR）对NaCl 胁迫下垂穗披碱草（Elymus nutans）种子萌发和幼苗生长伤害的缓解效应。【方法】 试验以垂穗披碱草种子为研究对象，在100 mmol/L NaCl 胁迫处理下，添加不同浓度（0. 001，0. 010，0. 100，1. 000，10. 000 μmol/L）EBR，研究外源EBR 对NaCl 胁迫下垂穗披碱草种子萌发和幼苗生理特性的影响。【结果】 100 mmol/L NaCl 胁迫显著抑制了垂穗披碱草种子萌发和幼苗生长。NaCl 胁迫下添加0. 001~1. 000 μmol/L EBR 可显著提高垂穗披碱草种子的发芽势、发芽率、发芽指数和活力指数，促进NaCl 胁迫下垂穗披碱草种子萌发和幼苗生长。添加0. 001~1. 000 μmol/L 外源EBR 处理能够显著提高NaCl 胁迫下垂穗披碱草幼苗脯氨酸、可溶性糖、可溶性蛋白含量和抗氧化酶活性，降低丙二醛含量，从而有效降低NaCl 胁迫导致的氧化损伤，提高垂穗披碱草种子萌发期的耐盐性。其中，添加0. 010 和0. 100 μmol/L EBR 对NaCl 胁迫下垂穗披碱草种子萌发和幼苗生长的促进效果最显著。【结论】 添加外源EBR 能够有效缓解100 mmol/L NaCl胁迫对垂穗披碱草种子萌发和幼苗生长的抑制作用，并以0. 010 和0. 100 μmol/L EBR 处理效果最佳。

Abstract:

【Objective】 To investigate the mitigating effect of exogenous 2，4‐epibrassinolide（ EBR） on seed germinationand seedling growth of Elymus nutans under NaCl stress.【Method】 E. nutans was chosen as the researchobject，and we examined the effects of exogenous EBR （0. 001，0. 01，0. 10，1. 00，10. 00 μmol/L） on seed germinationand seedling physiological characteristics of E. nutans under 100 mmol/L NaCl stress.【Result】 The results revealedthat the seed germination and seedling growth of E. nutans were significantly inhibited under 100 mmol/LNaCl stress. Adding 0. 001~1. 00 μmol/L exogenous EBR significantly improved the germination energy，germinationpercentage，germination index and vigor indexof E. nutans under NaCl stress，and promoted the seed germinationand seedling growth of E. nutans under 100 mmol/L NaCl stress. Adding 0. 001~1. 00 μmol/L exogenous EBR significantlyincreased the content of proline，soluble sugar，soluble protein and antioxidant enzyme activity of E. nutansseedlings under 100 mmol/L NaCl stress，and reduced the contents of MDA. The oxidative damage caused by NaClstress was effectively reduced and the salt tolerance of E. nutans seeds were improved during the germination period.Notably，adding 0. 01 μmol/L and 0. 10 μmol/L exogenous EBRhad the most significant effect on seed germinationand seedling growth of E. nutans under 100 mmol/L NaCl stress.【Conclusion】 In conclusion，the addition of exogenousEBR can significantly alleviate the inhibitory effect of 100 mmol/L NaCl stress on the seed germination andseedling growth of E. nutans，with the treatment of 0. 01 and 0. 10 μmol/L exogenous EBR perform the best.