海三棱藨草对盐、水胁迫的响应特征

Response Characteristics of Scirpus mariqueter to Salinity and Flooding Stress

摘要:

为探明杭州湾潮间带的海三棱藨草(Scirpus mariqueter)种群对盐、水胁迫的响应特征，该研究通过模拟潮间带生境，设置对照、Ca²⁺(0.05、0.10、0.15 mol/kg)、Na⁺(0.10、0.15、0.3 mol/kg)和水淹深度、时长(12 h/10 cm、18 h/20 cm、24 h/30 cm)胁迫，系统分析叶片细胞膜透性、抗氧化酶活性、叶绿素含量和光合生理响应特征。结果表明，随着Ca²⁺浓度的增加，叶片丙二醛(MDA)含量增加，相对电导率、超氧化物歧化酶(SOD)、过氧化物酶(POD)活性和叶片叶绿素含量均呈现先降后升趋势；而随Na⁺浓度增加均逐渐升高。中度以下Na⁺胁迫对叶片的细胞膜透性、抗氧化物酶活性、叶片叶绿素含量和光合特性指标的影响均高于同等浓度Ca²⁺胁迫，海三棱藨草具有高抗Ca²⁺胁迫、低抗Na⁺胁迫的能力。水淹胁迫下，随水淹时长和深度的增加，叶片相对电导率、SOD和POD活性呈先降后升趋势，叶绿素含量与光合参数则表现为先升后降。其中，中度水淹处理可维持最优光合性能和膜系统稳定性，而持续深淹导致生理功能显著衰退。因此，海三棱藨草通过动态调控抗氧化防御和光合能量分配，在低盐贫瘠、间歇性水淹条件下展现强适应性。这为潮间带互花米草除治区的海三棱藨草种群恢复工作，特别是在盐分胁迫管理、淹水时长和深度调控提供理论基础。

Abstract:

To explore the response characteristics of the Scirpus mariqueter population in the intertidal zone of Hangzhou Bay to salt and water stress, this study simulated the intertidal habitat and set up control, Ca²⁺ (0.05, 0.10, 0.15 mol/kg), Na⁺ (0.10, 0.15, 0.3 mol/kg) and waterlogging depth and duration (12 h/10 cm, 18 h/20 cm, 24 h/ 30 cm) stress treatments. The response characteristics of leaf cell membrane permeability, antioxidant enzyme activity, chlorophyll content and photosynthetic physiology were systematically analyzed. The results showed that with the increase of Ca²⁺ concentration, the content of malondialdehyde (MDA) in leaves increased, and the relative conductivity, superoxide dismutase (SOD), peroxidase (POD) activitives and leaf chlorophyll content all showed a trend of first decreasing and then increasing; while with the increase of Na⁺ concentration, they all gradually increased. The effects of Na⁺ stress at moderate levels or below on leaf cell membrane permeability, antioxidant enzyme activity, leaf chlorophyll content and photosynthetic performance indicators were higher than those of the same concentration of Ca²⁺ stress. Scirpus mariqueter has a high tolerance to Ca²⁺ stress and a low tolerance to Na⁺ stress. Under waterlogging stress, with the increase of waterlogging duration and depth, the relative conductivity of leaves, SOD and POD activity showed a trend of first decreasing and then increasing, while chlorophyll content and photosynthetic parameters showed a trend of first increasing and then decreasing. Among them, moderate waterlogging treatment could maintain the optimal photosynthetic performance and membrane system stability, while continuous deep waterlogging led to significant physiological decline. Therefore, Scirpus mariqueter shows strong adaptability under low-salt, poor and intermittent waterlogging conditions through dynamic regulation of antioxidant defense and photosynthetic energy allocation. This provides a theoretical basis for the recovery of S. mariqueter populations in the intertidal zone after the removal of S. alterniflora, especially in the management of salt stress, waterlogging duration and depth.