硅对NaCl胁迫下垂穗披碱草种子萌发及幼苗生长的影响

Effects of exogenous silicon on seed germinationand seedling growth of Elymus nutansunder NaCl stress

摘要:

以采自高寒草甸的野生垂穗披碱草(Elymus nutans)种子为材料,采用培养皿发芽法研究了不同浓度NaCl(0、40、60、80 mmol/L)胁迫下,添加不同浓度硅元素(0、1.5、2.0、2.5 mmol/L)对垂穗披碱草种子萌发和幼苗生长的影响。结果表明:单独NaCl胁迫明显抑制垂穗披碱草种子萌发和幼苗生长,而添加硅元素可显著缓解NaCl胁迫对种子萌发和幼苗生长的抑制作用,其中NaCl浓度为40和60 mmol/L时,随添加Si浓度升高种子发芽率呈逐渐升高趋势,Si浓度为2.5 mmol/L时发芽率均达最高,较单一NaCl胁迫分别提高了17.68%和6.49%,Si浓度为2.0 mmol/L时两种NaCl浓度下幼苗株高达最高,分别较单一NaCl胁迫增长了26.55%和18.47%。NaCl胁迫下垂穗披碱草脯氨酸含量高于清水对照,添加Si时脯氨酸含量均显著降低,说明硅添加可以有效缓解NaCl胁迫对垂穗披碱草种子萌发及幼苗生长的抑制作用,但这种缓解作用随胁迫程度和Si添加浓度而异。

Abstract:

The effects of different concentrations of Si (0,1.5,2.0 and 2.5 mmol/L) on seed germination and seedling growth of wild Elymus nutans collected from alpine meadow were studied under the stress of different concentrations of NaCl (0,40,60 and 80 mmol/L) were studied with petri dish germination method.The results showed that NaCl stress significantly inhibited the seed germination and seedling growth,and the addition of exogenous silicon significantly reduced the inhibition effect of NaCl stress.When the salt concentration was 40 and 60 mmol/L,the germination percentage of seeds gradually increased with the increase of Si concentration and it reached the highest when Si concentration was 2.5 mmol/L,increased by 17.68% and 6.49% compared with NaCl stress control.The seedling height reached the highest when Si concentration was 2.0 mmol/L,and it was increased by 26.55% and 18.47% respectively compared with NaCl stress control.Under NaCl stress,the proline content was higher than control.Under Si addition treatment,the proline content was significantly reduced,indicating that Si addition could effectively reduce the stress effect of NaCl,but this effect varied with NaCl stress degree and Si concentration.