不同盐生境下硅对高羊茅生物量及生理生化特征的影响

利用水培实验研究了不同盐生境下硅对高羊茅幼苗生物量及生理生化特征的影响。研究结果表明,高羊茅幼苗生物量随着盐浓度增加而逐渐降低,200mmol/L的盐浓度为高羊茅幼苗的临界盐浓度,盐浓度小于该临界值时,添加硅显著增加了高羊茅幼苗生物量;盐浓度大于该临界值时,硅对高羊茅幼苗生物量没有明显影响,说明硅调节盐生境下高羊茅的生长能力与环境内的盐浓度密切相关。在盐浓度临界值之内,水培条件下硅通过增加盐胁迫下高羊茅幼苗体内SOD、CAT、POD活性,降低盐胁迫条件下高羊茅幼苗体内的丙二醛、脯氨酸、可溶性糖含量和相对电导率,其中盐浓度为100mmol/L时,丙二醛含量降幅最大,为18.05%,当盐浓度为50mmol/L时,脯氨酸含量降幅最大,为23.63%。这不仅说明了硅可增强高羊茅幼苗适应盐生境的能力,而且证明了硅直接参与了盐胁迫条件下高羊茅的生理生化过程。

Effects of silicon supply on the biomass and physiochemical features of tall fescue seedlings under different salinization conditions

The effect of silicon supply on the biomass and physiochemical features of tall fescue seedlings was in-vestigated under different salinization conditions using a water culture experiment.Biomass decreased as salt concentration increased,with 200 mmol/L proving to be the critical concentration for tall fescue seedlings. When salt concentration was less than 200 mmol/L,silicon addition significantly increased seedling biomass, indicating that the effectiveness of silicon on tall fescue is closely related to salt concentration.If the concentra-tion was more than 200 mmol/L,there was no significant effect of silicon addition on biomass.Under water culture,the activities of SOD,CAT and POD were increased and the contents of malondialdehyde,proline and water soluble sugars,and relative conductivity,were decreased by adding silicon to seedlings under salt stress below the critical concentration.The most significant reduction in MDA content (18.05%)was when salt con-centration was 100 mmol/L.The most significant decline in proline content (23.63%)was when salt concen-tration was 50 mmol/L.The results indicate that the adaptability to salinization of tall fescue seedlings is im-proved by adding silicon and that silicon may be directly involved in the seedlings’physiochemical processes.