六种沉水植物对盐胁迫的生理响应及耐盐性评价

目的]为了在进行滨海及盐碱地湿地修复时筛选出耐盐的沉水植物,本文研究了六种常用沉水植物,苦草、轮叶黑藻、金鱼藻、穗花狐尾藻、篦齿眼子菜、小茨藻的耐盐性及四项生理指标。方法]在室内模拟条件下,分别用不同浓度的NaCl溶液对六种沉水植物进行盐分胁迫,每周进行盐害症状的观测,并测定叶片叶绿素a、叶绿素b、脯氨酸、可溶性蛋白及丙二醛的含量。结果]结果表明,在六种沉水植物中,耐盐性为小茨藻>篦齿眼子菜>金鱼藻>苦草、轮叶黑藻>穗花狐尾藻。其中小茨藻和篦齿眼子菜能在盐度为15‰和8‰的盐胁迫条件下存活。金鱼藻的最高耐受盐度为6‰,苦草和轮叶黑藻的盐度胁迫能力较弱均为4‰,穗花狐尾藻的盐度胁迫能力最弱,仅为2‰。结论]该实验为沿海及盐碱化地区的水生态系统修复提供理论依据,为项目工程实践及沉水植物的抗盐生理学研究奠定基础。

6 Submerged Plants: The Physiological Response to Salt Stress and Salt Tolerance Evaluation

To select the salt-tolerant submerged plants in coastal and saline-alkali wetland restoration, we studied the salt-tolerance ability and 4 physiological indexes of 6 kinds of submerged plants commonly used in water, including Vallisneria natans, Hydrilla verticillata, Ceratophyllum demersum, Myriophyllum spicatum, Potamogeton pectinatus and Najas minor. Under the condition of indoor simulation, we carried out salt stress on the 6 kinds of submerged plants with NaCl solution of different concentrations, observed the salinity symptom every week, and determined the content of chlorophyll a, b, proline, soluble protein and MDA in leaves. The results showed that: among these plants, the salt-tolerance ability was Najas minor>Potamogeton pectinatus> Ceratophyllum demersum>Vallisneria natans, Hydrilla verticillata>Myriophyllum spicatum. Najas minor and Potamogeton pectinatus could survive in salinity of 15‰ and 8‰ , the lethal salinity of Ceratophyllum demersum was 6‰, while Vallisneria natans and Hydrilla verticillata had a week salt-tolerance ability, whichwas 4‰ , and Myriophyllum spicatum had the worst salt-tolerance ability, which could only survive under salinity of 2‰. This study provides a basis for water ecosystem restoration in coastal and salinization areas, and lays a foundation for project practice and salt-resistant physiology research of submerged plants.