不同盐胁迫水平下硅对高羊茅幼苗生物量、酶活性和渗透调节物质的影响

Effect of silicon supplies on biomass and antioxidase and osmolytes of tall fescue seedlings under different salt concentration conditions

采用盆栽试验研究了高羊茅(Festuca arundinacea)幼苗在不同盐浓度胁迫下生物量、抗氧化酶活性和渗透调节物质对硅的响应。结果显示,随盐浓度增加高羊茅生物量逐渐降低,而盐浓度小于50 mmol·L^(-1)或大于250mmol·L^(-1)时,硅对高羊茅生物量没有明显影响,盐浓度介于50到250mmol·L^(-1),硅显著提高了高羊茅生物量(P<0.05)。随着盐浓度增加过氧化氢酶(CAT)活性呈上升趋势,过氧化物酶(POD)和超氧化物歧化酶(SOD)活性先上升后下降,添加硅虽然提高了POD、SOD和CAT活性,但不同酶显著增加时盐浓度存在一定的差异。可溶性糖和可溶性蛋白含量随着盐浓度的增加呈先上升后下降的趋势,丙二醛含量呈上升趋势,盐浓度为200和250mmol·L^(-1)时,可溶性糖和可溶性蛋白含量达到峰值,添加硅均降低了高羊茅体内可溶性糖、可溶性蛋白和丙二醛含量。上述结果表明,硅对高羊茅适应盐胁迫能力的影响在盐浓度间存在分异,过低或过高盐浓度时,硅对高羊茅适应性没有显著影响,中盐浓度时,硅能通过增强高羊茅体内的抗氧化酶活性、改善渗透调节过程和降低膜质氧化来增强其对盐胁迫的适应性。

In this study,apot experiment was conducted to determine the response of biomass,antioxidant enzyme activities,and osmotic regulators to silicon in tall fescue seedlings under different salt stress condition.The results showed that with an increase in salt concentration,the biomass of tall fescue decreased gradually.When the salt concentration was less than 50 mmol·L^-1 or greater than 250 mmol·L^-1,silicon had no obvious effect on the biomass of tall fescue;when the salt concentration was between 50 and 250 mmol·L^-1,the biomass of tall fescue increased significantly（P〈0.05）with silicon.With an increase in salt concentration,CAT activity increased,and POD and SOD first increased and then decreased.Although the addition of silicon increased the activity of POD,SOD,and CAT,there are some differences in the salt concentrations when the different enzymes increased significantly.With an increase in salt concentration,MDA content increased,soluble sugar and soluble protein content first increased and then decreased,and when the salt concentration reached 200 and 250 mmol·L^-1,soluble sugar and soluble protein contents reached their highest values.The addition of silicon reduced the contents of soluble sugar,soluble protein,and MDA in tall fescue.The above results showed that the effect of silicon on the salt tolerance of tall fescue varied under different salt stresses.When the salt concentration was too low or too high,the silicon had no significant effect on the adaptability of tall fescue,but when the salt concentration was in a middle range,the silicon enhanced the adaptability to salt stress of tall fescue by increasing the antioxidant enzyme activity in the plants,improving the osmotic adjustment process and reducing membrane oxidation.