秋季施氮对油松幼苗游离氨基酸贮存策略的影响

Effect of Fall Nitrogen Fertilization on the Free Amino Acid Storage Strategy of Chinese Pine

本试验以1年生油松播种苗为对象,在秋季苗木顶芽形成后采用^(15)NH_4^(15)NO_3肥料,以0、5、10、15 mg·株-1的施氮量进行处理。结果表明:秋季施氮处理下,油松苗木各器官游离氨基酸质量分数均显著提升,且各个器官间游离氨基酸质量分数随秋季施肥剂量增大而提高,游离氨基酸质量分数由大到小的顺序为茎、根、叶;油松苗木体内游离氨基酸质量分数由多到少的顺序为谷氨酰胺、精氨酸、γ-氨基丁酸、脯氨酸。对于不同秋季的施肥处理,施氮水平越高各游离氨基酸质量分数越大,但种类不变;秋季施肥处理下,加载氮主要贮存为占总游离氨基酸质量分数超过88%的谷氨酸族氨基酸与超过70%的中性氨基酸。综上,秋季施肥手段通过提高苗木体内游离氨基酸质量分数进而提高苗木生理抗性,是解释秋季施氮提高苗木质量的重要途径。

With the seedlings of 1-a Chinese pine,15NH415NO3 fertilizer was used after the seedlings,the buds were formed in autumn and seedlings were treated with the nitrogen rates of 0,5,10 and 15 mg per plant. Under the nitrogen application in autumn,the contents of free amino acids in the organs of Chinese pine seedlings increased significantly,and the content of free amino acids in different organs increased with the increase of fertilizer application in autumn. The main storage of free amino acids in Chinese pine seedlings was in the descending order of glutamine,arginine,γ-aminobutyric acid,and proline. For different fall fertilization treatments,the higher the level of nitrogen fertilizer was,the greater the amount of free amino acid storage was,but not the same species. Under fall fertilizer application,nitrogen was mainly stored as glutamic acid amino acids with more than 88% total free amino acids and more than 70% neutral amino acids. Therefore,the fall fertilization by raising free amino acids in seedlings and thus improving the physiological resistance of seedlings is to explain the fall nitrogen fertilizer to improve the quality of seedlings an important way.