春季低温下底质氧化还原电位对沉水植物苦草和菹草生长的影响研究

Study on the influence of sediment oxidation-reduction potential on the growth of submerged aquatic plants Vallisneria natans and Potamogeton crispus under low-temperature conditions in spring

  • 摘要: 为研究底质不同氧化还原电位(ORP)条件对沉水植物生长生理的影响,以沉水植物菹草和苦草为研究对象,通过改变底质ORP,分析不同ORP对菹草和苦草株高、鲜重以及生理生化指标的影响。结果表明,当底质ORP大于−70 mV时,有利于苦草和菹草的生长;而当ORP小于−100 mV时,苦草和菹草的生长受到抑制。随着ORP的降低,苦草和菹草株高和鲜重的增长速率减缓,过氧化物酶(POD)活性、丙二醛(MDA)含量升高,总叶绿素含量和可溶性蛋白降低。主成分分析显示,苦草的株高、鲜重及总叶绿素含量与ORP呈显著正相关,POD活性、MDA含量与ORP呈显著负相关。菹草的总叶绿素含量与ORP呈显著正相关,POD活性、MDA含量和及可溶性蛋白含量与ORP呈显著负相关。随着底质厌氧程度增强,对苦草和菹草的胁迫也随之增强,且苦草的耐受性较菹草更差。研究显示,为了恢复沉水植物的生长,应改善底质的氧化还原条件,为沉水植物提供更加适宜的生长环境,以促进湖泊生态系统的稳定发展。

     

    Abstract: Potamogeton crispus and Vallisneria natans were used as the research objects to study the effects of different oxidation-reduction potential (ORP) conditions in sediment on the growth and physiology of submerged aquatic plants. The effects of different ORP on the plant height, fresh weight, and physiological and biochemical indexes of Potamogeton crispus and Vallisneria natans were analyzed by changing the ORP of sediment. The results indicated that a sediment ORP greater than −70 mV was conducive to the growth of both Vallisneria natans and Potamogeton crispus, whereas an ORP below −100 mV inhibited their growth. With the decrease of ORP, the growth rate of plant height and fresh weight of Vallisneria natans and Potamogeton crispus slowed down, accompanied by increased peroxidase (POD) activity and malondialdehyde (MDA) content, and decreased total chlorophyll content and soluble protein levels. Principal component analysis showed that the plant height, fresh weight, and total chlorophyll content of Vallisneria natans were significantly positively correlated with ORP, and POD activity and MDA content were significantly negatively correlated with ORP. The total chlorophyll content of Potamogeton crispus was significantly positively correlated with ORP, while POD activity, MDA content, and soluble protein content were significantly negatively correlated with ORP. With the increase of the anaerobic degree of sediment, the stress on Vallisneria natans and Potamogeton crispus also increased, and the tolerance of Vallisneria natans was worse than that of Potamogeton crispus. The research shows that in order to restore the growth of submerged plants, the oxidation-reduction environment of the sediment should be improved to provide a more suitable growth environment for submerged plants to promote the stable development of the lake ecosystem.

     

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