PHYSIOLOGICAL EFFECTS OF WATER LEVEL FLUCTUATIONS ON THE SUBMERGED PLANT POTAMOGETON CRISPUS

Water level fluctuations in lakes are a fundamental feature of wetland hydrology, influencing the growth and development of wetland plants, species composition, and community succession.To study the effects of different water level fluctuations on the morphology and physiological characteristics of the submerged plant Potamogeton crispus.Experiments were conducted to investigate how varying intensities and durations of rising and falling water levels influence the growth and physiology of Potamogeton crispus.We analyzed the changes in the physiological indicators of the plant, such as antioxidant enzyme activity (peroxidase, superoxide dismutase, catalase), osmoregulatory substances (soluble sugars, soluble proteins), superoxide anion and malondialdehyde under different water-level conditions.The results showed that water level fluctuations lead to higher malondialdehyde and superoxide anion contents, which cause damage to the plant, while the plant responds to unfavorable environments by adjusting the activities of antioxidant enzymes as well as the content of osmoregulatory substances.The antioxidant system of Potamogeton crispus was limited by the duration and intensity of water level fluctuation.And in the later stages of the experiment, the scavenging capacity of reactive oxygen species in the plant was reduced and malondialdehyde content increased.