不同施氮水平下盐胁迫对灵武长枣幼苗生理生化指标的影响

目的]探究灵武长枣的耐盐性及氮素对盐胁迫的影响。方法]以2年生灵武长枣嫁接苗为试验材料，对盆栽幼苗进行盐胁迫（0、50、150、200mmol／L）与施氮（100、200、300mg／kg）交互处理，研究其对植株叶片丙二醛（MDA）含量、过氧化物酶（POD）活性以及质膜透性的影响。结果]低盐处理下，外施氮素增加叶片MDA的含量，降低POD活性，当施氮为300mg／kg时，叶片MDA含量高于其他施氮处理，表明高氮加剧叶片膜质过氧化，使胁迫伤害加重；高盐处理下，外施氮素减少叶片MDA积累，提高POD活性，当施氮为300mg／kg时，叶片MDA含量低于其他处理，表明高氮缓解了盐胁迫的伤害。结论]该研究为灵武长枣的栽培实践与良种选育提供参考。

Effects of Salt Stress on Physiological and Biochemical Index of Lingwu long Jujube Seedlings under Different Nitrogen Application Levels

Objective] The study aimed to explore the salt tolerance of Lingwu long jujube and the effect of nitrogen on the salt stress.Method] With 2-year-old grafted seedlings of Lingwu long jujube as the tested materials,the potted seedlings were treated interactively with salt stress at 0,50,150,200 mmol/L and nitrogen application at 100,200,300 mg/kg to study the their effect on malondialdehyde(MDA) content,peroxide enzyme(POD) activity,and membrane permeability of Lingwu long jujube leaves.Result] Under the low salt stress,nitrogen application induced the increase of leaf MDA content and decrease of POD activity,and the MDA content in leaf treated with nitrogen application at 300 mg/kg was higher than that with other treatments,showing that high nitrogen application could aggravate the leaf lipid peroxidation and exacerbate the damage caused by salt stress.Under the high salt stress,the nitrogen application would decrease leaf MDA content and increase POD activity,and the MDA content in leaf treated with nitrogen application at 300 mg/kg was lower than that with other treatments,indicating that high nitrogen application could alleviate the damage caused by salt stress.Conclusion] This study provided reference for cultivation and breeding of Lingwu long jujube.