Physiological Adaptation Strategies and Comprehensive Waterlogging Tolerance Evaluation of Alpine Swamp Wetland Plants under Waterlogging Stress

To investigate the effects of waterlogging stress on the morphological structure, physiological characteristics, and adaptation mechanisms of alpine wetland plants, five representative alpine swamp wetland plant species with similar specifications and healthy growth were selected as test materials.Potbased waterlogging experiments were conducted, including a control group (CK) and a waterlogging stress treatment group (MW), with treatment durations of 20, 40, and 60 days.The growth status and physiological-biochemical indicators of the five plant species were recorded and measured.A comprehensive evaluation was performed using waterlogging tolerance coefficients, significance analysis, correlation analysis, principal component analysis (PCA), and subordinate function methods.The results showed that: with prolonged waterlogging stress, the contents of chlorophyll and carotenoid first increased and then decreased, while the malondialdehyde content first decreased and then increased; the activities of antioxidant enzymes and the contents of osmotic adjustment substances exhibited varied trends over time; correlation analysis revealed D-values of 0.739, 0.616, 0.660, 0.200, and 0.534 for the five species; and the ranking of waterlogging adaptability was as follows: Hippuris vulgaris > Halerpestes tricuspis > Poa psilolepis > Blysmus sinocompressus > Pedicularis chinensis.