摘要
研究了大灰藓(Hypnum plumaeforme)对2种不同形态的氮--硝态氮(KNO3)和混合态氮(NH4NO3)处理的生理响应。结果显示,在20～60kg N·hm-2·a-1范围内,2种形态氮均导致大灰藓体内淀粉和可溶性糖含量下降,总氮、可溶性蛋白、精氨酸、脯氨酸含量上升。2种氮处理条件下,大灰藓体内的总氮含量与淀粉和可溶性糖含量均呈显著负相关,反映了氮同化过程对碳架的竞争利用,但NH4NO3处理条件下的负相关系数远高于KNO3处理,据此推测,KNO3处理下大灰藓体内淀粉含量下降除由于氮同化过程中对碳骨架的消耗外,亦与其在高浓度时导致的光合速率下降、碳化合物合成减少有关。与KNO3处理相比,NH4NO3处理导致大灰藓精氨酸的上升幅度较大而脯氨酸上升幅度较小,显示大灰藓具有较强的NH4+去毒能力。
This paper studied the physiological responses of Hypnum plumaeforme to two kinds of inorganic nitrogen,i.e.,KNO3 and NH4NO3.The addition of KNO3 or NH4NO3 within the range of 20-60 kg N·hm-2·a-1 caused the starch and soluble sugar contents in H.plumaeforme decreased,while the total nitrogen,soluble protein,free amino acid,arginine,histidine,and proline contents increased.With the addition of KNO3 or NH4NO3,the total nitrogen content in H.plumaeforme had significant negative correlations with the starch and soluble sugar contents,suggesting the competition for carbon skeleton between the H.plumaeforme＇s nitrogen-and carbon assimilation.The coefficients of the negative correlations under NH4NO3 addition were far higher than those under KNO3 addition,suggesting that the decrease in the starch and soluble sugar contents under KNO3 addition was also related to the decrease of net photosynthesis rate and carbohydrate production,besides the carbon skeleton consumption during nitrogen assimilation.As compared with KNO3 addition,NH4NO3 addition resulted in a greater increase of arginine but a less increase of proline in H.plumaeforme,indicating that H.plumaeforme possessed a well-developed NH4＋ detoxification system.
出处
《生态学杂志》
CAS
CSCD
北大核心
2012年第11期2823-2827,共5页
Chinese Journal of Ecology
基金
国家自然科学基金项目(31070470)
广东省自然科学基金项目(06300472)资助
关键词
大灰藓
氮沉降
铵态氮
硝态氮
生理响应
Hypnum plumaeforme
nitrogen deposition
ammonium nitrogen
nitrate nitrogen
physiological response.
