The response of seed germination and seedling growth of Chamerion angustifolium to drought stress

Introduction: by evaluating its physiological responses at both seed germination and seedling growth stages. Methods: Seed germination assays were conducted under osmotic stress induced by polyethylene glycol (PEG-6000) at six specific concentrations: 2%, 4%, 6%, 8%, 10%, and 12% (w/v), with ultrapure water serving as the control. Germination parameters, including germination rate, vigor, index, relative drought damage rate, and post-germination radicle and plumule lengths, were recorded. Additionally, the contents of soluble sugars and soluble proteins in the seeds were quantified. For the seedling experiments, drought stress was then initiated by precisely controlling and maintaining the soil water content (SWC) at three deficit levels: 30% ± 5%, 50% ± 5%, and 70% ± 5%, representing mild, moderate, and severe stress, respectively. Each stress level was applied for 5, 10, or 15 days, corresponding to short-, medium-, and long-term exposure. Seedlings maintained at 90% ± 5% SWC throughout the experiment served as the wellwatered control. Results: seedlings were significantly higher (P< 0.05) than in the control group. With prolonged stress duration, osmotic regulator content showed an upward trend, while antioxidant enzyme activity exhibited a downward trend. Conclusion: possesses a certain degree of drought tolerance, and short-term mild drought stress does not significantly affect seed germination or seedling growth.