Abstract

This study investigated the potential of shading to mitigate the stressful effects of different periods of flooding, favoring the recovery of seedlings in the post-flooding period. Copaifera langsdorffii Desf. seedlings were grown under three different levels of light availability (100%, 70%, and 30%), and two water conditions (control and flooded). During the flooding period, plants were evaluated at 0, 45, and 90 days, and at 45 days after the cessation of each period of flooding to assess post-flooding effects (45 + 45 and 90 + 45 days). There was an increase in internal concentration of CO_2, and increased activity of antioxidant enzymes in both the leaves and roots at all levels of light availability, with more pronounced effects under shady conditions (30% brightness). The plants demonstrated the capacity to survive flooding but did not fully recover within 45 days after the suspension of flooding, as evidenced by an evaluation of physiological and biochemical characteristics. We concluded that shading does not mitigate the stressful effects of flooding. Flooding and cultivation under 30% light availability created stressful conditions for the plants, which presented adjustment mechanisms that allowed the resumption of balance up to 45 days after the suspension of flooding, especially when grown under high light conditions.

摘要

本研究调查了遮荫减轻不同洪水时期压力影响的潜力，有利于洪水后幼苗的恢复。Copaifera langsdorffii Desf. 幼苗在三种不同的光照水平（100%、70% 和 30%）和两种水条件（对照和淹水）下生长。在洪水期间，在 0、45 和 90 天以及每个洪水期停止后 45 天对植物进行评估，以评估洪水后的影响（45 + 45 和 90 + 45 天）。_{CO 2}的内部浓度增加，在各种光照条件下，叶和根中抗氧化酶的活性增加，在阴暗条件下（30% 亮度）效果更明显。这些植物表现出在洪水中生存的能力，但在洪水暂停后的 45 天内没有完全恢复，生理和生化特性的评估证明了这一点。我们得出结论，阴影并不能减轻洪水的压力影响。在 30% 光照条件下进行洪水和栽培为植物创造了压力条件，这提供了允许在洪水暂停后长达 45 天恢复平衡的调整机制，尤其是在高光照条件下生长时。