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以杂交鹅掌楸体胚再生苗为试验材料,分别采用0、50 mmol/L、100 mmol/L、150 mmol/L、200 mmol/L浓度的NaCl处理,初步探讨了杂交鹅掌楸的耐盐能力,并研究了100 mmol/L NaCl盐胁迫处理对杂交鹅掌楸植株表型、叶绿体超微结构的影响及生理变化,以探讨杂交鹅掌楸在盐胁迫下的响应机制。表明:(1)在不同浓度NaCl胁迫处理中,杂交鹅掌楸受盐害程度随着NaCl浓度的增加而明显加重,在同一NaCl浓度下,杂交鹅掌楸受盐害指数随胁迫时间的延长而逐渐加剧;植株叶片从基部往上逐渐萎蔫卷曲,但顶芽无明显变化,可能是由于下部叶片的保护以适应盐胁迫环境。(2)100 mmol/L NaCl盐胁迫处理过程中叶绿体膨大变形,膜系统严重损伤,甚至降解,基粒片层排列松散、紊乱,淀粉粒呈现体积增大、数量增加的趋势,嗜锇颗粒电子密度增大,胁迫后期出现聚集现象,说明虽然盐胁迫导致杂交鹅掌楸叶绿体超微结构遭受严重破坏,但杂交鹅掌楸存在适应盐胁迫的结构特征。(3)100 mmol/L NaCl盐胁迫处理过程中过氧化物酶(POD)活性和游离脯氨酸含量先快速升高,后缓慢下降;丙二醛(MDA)含量先缓慢增加,后加快上升,表明盐胁迫条件下,POD和游离脯氨酸能有效减少膜脂质过氧化,使杂交鹅掌楸对盐胁迫具有一定耐受性。100 mmol/L NaCl盐胁迫处理7 d后恢复处理2 d均不能恢复为正常状态,表明杂交鹅掌楸受到中度盐害后短期内难以恢复。
The seedling of Liriodendron hybrid seedlings were used as materials to study the effects of 0, 50 mmol / L, 100 mmol / L, 150 mmol / L and 200 mmol / L NaCl on the tolerance Salt tolerance and the effects of 100 mmol / L NaCl stress on plant phenotype and chloroplast ultrastructure of Liriodendron hybrids were studied in order to investigate the response mechanism of hybrid tulip tree under salt stress. The results showed as follows: (1) Under salt stress of different concentrations, the degree of salt damage of Liriodendron hybrida increased significantly with the increase of NaCl concentration. Under the same NaCl concentration, the salt damage index of Liriodendron hybrids increased with the increase of stress time But gradually increased. The plant leaves gradually wilted and curled upwards from the base, but there was no obvious change in the terminal buds, which may be due to the protection of the lower leaves to adapt to the salt stress environment. (2) The chloroplast was swollen and deformed during 100 mmol / L NaCl stress treatment, and the membrane system was seriously damaged and even degraded. The stratum granulosum was loosely arranged and disorganized. The starch granules showed an increase in volume and the number increased. The results showed that although the ultrastructure of Chloroplast ultrastructrue severely damaged under salt stress, the structure characteristics of the hybrid Liriodendron hybrids adapted to salt stress existed. (3) Peroxidase (POD) activity and free proline content increased rapidly at 100 mmol / L NaCl stress and then decreased slowly; MDA content increased slowly at first and then increased rapidly , Indicating that under salt stress, POD and free proline can effectively reduce membrane lipid peroxidation, so that the hybrid Liriodendron has a certain tolerance to salt stress. 100 mmol / L NaCl salt treatment for 7 d did not recover to normal condition after 2 d recovery treatment, indicating that it is difficult to recover in the short term after moderate salt damage.