研究了杨树在不同程度盐胁迫下加硅处理30d后，叶片细胞超微结构的变化。结果表明,无硅条件下,随着盐胁迫浓度的增加和时间的延长,杨树叶肉细胞内叶绿体类囊体扭曲、变形、松散,嗜锇颗粒增多,外膜逐渐断裂解体,局部消失,细胞核固缩,核物质凝聚,核膜不清晰。盐质量浓度为40g／L比盐质量浓度为20g／L和30g／L的处理对叶片细胞结构的损伤程度更为严重。盐胁迫下加硅后杨树叶肉细胞细胞器损伤得到明显改善,表现为叶绿体类囊体排列有序,嗜锇颗粒略有增多,细胞核基本完好,局部核物质凝聚。施硅质量浓度为05g／L比施10g／L的效果显著,且对盐质量浓度为20g／L和30g／L的缓解效果比质量浓度为40g／L的更为明显。

The effects of silicon on cell ultrastructure of poplar leaves were investigated under salt stress for 30 days. The results showed that in the salt treatments without adding silicon, the slices of basal granule distorted or even disintegrated, the quantity of osmiophilic granule increased, the membrane of chloroplast became disintegrated and some of them disappeared with increasing external NaCl concentration and prolonging treatment time. Under salt stress，the cell nucleus were also condensed, and the nuclear membrane could not be seen clearly. The phenomena mentioned above was more obvious in the treatment with 4.0g/L NaCl than that in the 2.0g/L and 3.0g/L salt treatment. However, in the salt treatments with the addition of silicon, the degeneration of membrane systems decreased, and the lamellae were lined regularly, while the chloroplast grana lamellae just began to degenerate and the number of osmiophilic granule were increased more or less，even if some cell nucleus were condensed. The study also indicated that effects on mitigating salt stress were more significant in the treatment with silicon addition of 0.5g/L than in the addition of 1.0g/L. Moreover, the mitigating effects were more obvious in the 2.0，3.0g/L salt treatments than that in the 4.0g/L treatment.