氮素类型对盐胁迫下小麦种子萌发及幼苗生长的影响

氮素是植物种子萌发和幼苗生长的重要营养素，盐胁迫是广泛存在的非生物环境胁迫因子，探究氮素添加对盐胁迫下植物种子萌发和幼苗生长的影响具有重要意义。因此，本研究基于水培方法，设置了不同类型的氮(氨氮、硝氮、有机氮和混合氮)和盐胁迫水平，拟探究两者复合对小麦种子萌发、幼苗生长和生理生化指标产生的影响。结果表明：氮素类型对盐胁迫下小麦幼苗的影响与氮素类型和盐胁迫水平有关，与低盐相比，氨氮添加显著降低了小麦幼苗叶绿素a含量和叶绿素b含量，硝氮添加显著增加了小麦幼苗的株高；与高盐相比，氨氮添加显著降低了小麦幼苗的叶宽、叶绿素a含量和叶绿素b含量，硝氮添加均显著降低了小麦幼苗的叶宽；所有混合氮素添加均没有对盐胁迫下小麦种子萌发和幼苗生长产生明显。由此表明，硝氮与低盐复合对小麦幼苗生长产生了拮抗效应，硝氮和氨氮与高盐复合对小麦幼苗生长产生了协同效应，而有机氮和混合氮与盐胁迫符合对小麦种子萌发和幼苗生长均没有影响。因此，在低度盐碱地水平下施用一定水平的硝氮育苗可能会取得较好的效果。

Effect of Nitrogen Types on Seed Germination and Seedling Growth of Wheat under Salt Sstress

Nitrogen is an important nutrient for plant seed germination and seedling growth. Salt stress is a widespread abiotic environmental stress factor. It is of great significance to explore the effects of nitrogen addition on plant seed germination and seedling growth under salt stress. Therefore, based on hydroponic method, this study setted up different types of nitrogen (ammonia nitrogen, nitrate nitrogen, organic nitrogen and mixed nitrogen) and salt stress levels to explore the effects of their combination on wheat seed germination, seedling growth and physiological and biochemical indicators. The results showed that the effect of nitrogen type on wheat seedlings under salt stress was related to the type of nitrogen and the level of salt stress. Compared with low salt, the addition of ammonia nitrogen significantly reduced the content of chlorophyll a and chlorophyll b in wheat seedlings, and the addition of nitrate nitrogen significantly increased the plant height of wheat seedlings; Compared with high salt, ammonia nitrogen significantly reduced the leaf width, chlorophyll a content and chlorophyll b content of wheat seedlings, and nitrate nitrogen significantly reduced the leaf width of wheat seedlings; All mixed nitrogen additions did not significantly affect wheat seed germination and seedling growth under salt stress. The results indicated that the combination of nitrate nitrogen and low salt had an antagonistic effect on the growth of wheat seedlings, while the combination of nitrate nitrogen and ammonia nitrogen and high salt had a synergistic effect on the growth of wheat seedlings, the organic nitrogen and mixed nitrogen had no effect on wheat seed germination and seedling growth in accordance with salt stress. Therefore, applying a certain level of nitrate nitrogen to raise seedlings in low saline alkali soil may achieve better results.