【摘要】 【目的】探究氮、镁交互作用对杉木幼苗生长和生理特性的影响，确定适合杉木幼苗生长的氮、镁用量。【方法】以1年生杉木品种‘青杉’幼苗为材料，采用盆栽法，设置氮三因素[0（N₀）、1.2（N₁）、2.4（N₂） g·株^-1]、镁三水平[0（M₀）、0.64（M₁）、1.28（M₂） g·株^-1]共9个处理，分别于施肥后的30、60、90、120、150、180 d测定各处理杉木幼苗的苗高、地径、叶绿素含量、可溶性蛋白含量、丙二醛（MDA）浓度、超氧化物歧化酶（SOD）活性、过氧化物酶（POD）活性和过氧化氢酶（CAT）活性等指标。【结果】（1）整个试验期间，杉木幼苗的苗高、地径增长量随着氮、镁用量的增加呈先上升后下降的趋势，N₁M₁处理的苗高、地径增长量显著大于N₀M₀处理（P<0.05）。（2）整个试验期间，随着氮、镁用量的增加，叶绿素含量整体呈先下降后上升的趋势，可溶性蛋白含量整体呈先上升后逐渐趋于稳定的趋势，MDA浓度、SOD活性整体呈先上升后下降的趋势，POD活性、CAT活性整体呈先下降后上升的趋势。（3）整个试验期间，N₁M₁处理的叶绿素含量显著大于N₀M₀处理（P<0.05）;N₁M₁处理的MDA浓度在多数情况下最低；N₁M₁处理的POD活性显著大于N₀M₀处理（P<0.05）,且大于N₂M₁、N₁M₂、N₂M₂处理；处理60～150 d时，SOD活性整体变化较平稳，N₁M₁处理的CAT活性大于N₀M₀处理。【结论】氮、镁交互作用处理N₁M₁可降低细胞膜的损害程度，提高细胞渗透调节能力，增强细胞抗氧化酶活性，促进杉木幼苗生长发育。更多还原

【Abstract】 【Objective】The effect of nitrogen and magnesium interaction on the growth and physiological characteristics of fir seedlings were investigated to work out the application rate of nitrogen and magnesium for fir seedlings. 【Method】Three rates of nitrogen [0（N₀）, 1.2（N₁） and 2.4（N₂） g·plant^-1] and 3 rates of magnesium [0（M₀）, 0.64（M₁） and 1.28（M₂） g·plant^-1]were applied on 1-year-old Chinese fir variety of Cunninghamia lanceolata cv. Glauce′seedlings via factorial design by pot experiment, and indicators on growth（seedling height and ground diameter） and physiological characteristics contents of chlorophyll, soluble protein and malondialdehyde（MDA）, superoxide dismutase（SOD） activity, peroxidase（POD） activity and catalase（CAT） activity were determined at 30, 60, 90, 120, 150 and 180 d after fertilization, respectively. 【Result】（1） The growth of seedling height and ground diameter firstly rose and then declined with the increase of N and Mg dosage, and the significantly higher growth was achieved under N₁M₁ treatment in comparison to the performance under N₀M₀（P<0.05）.（2） With the increase of N and Mg dosage, the overall chlorophyll content, POD and CAT activity decreased first and then increased, while the MDA concentration and SOD activity showed the opposite trend of firstly up and then down, and soluble protein contents rose first and then gradually stabilized.（3） During the entire trial, the chlorophyll content under N₁M₁ treatment was significantly higher than that under N₀M₀ treatment（P<0.05）, accompanied by the lowest MDA concentration most of the time; the POD activity under N₁M₁ treatment was significantly greater than that under N₀M₀（P<0.05）, and greater than N₂M₁, N₁M₂ and N₂M₂ treatment; during 60-150 d, the SOD activity was mostly stable under N₁M₁ treatment, together with higher CAT activity in comparison to that under N₀M₀ treatment. 【Result】The interaction of nitrogen-magnesium under N₁M₁ treatment can alleviate the damage of cell membranes, improve the regulation of cell penetration, and enhance the activity of cell antioxidant enzymes, leading to the enhanced growth and development of fir seedlings.更多还原