不同氮处理下速生柳对水体氮的吸收、分配及生理响应  

Nitrogen absorption / distribution and physiological characteristics of Salix matsudana seedlings grown in hydroponic solution

作　　者：汪庆兵[1] 张建锋[1] 陈光才[1] 孙慧[1] 吴灏[1] 张颖[1,2] 杨泉泉[1] 王丽[1] 

机构地区：[1]中国林科院亚热带林业研究所,富阳311400 [2]青岛农业大学,青岛266109

出　　处：《生态学报》2015年第16期5364-5373,共10页Acta Ecologica Sinica

基　　金：林业公益性行业科研专项(201104055);国家科技支撑专题(2012BAJ24B0504);中央级公益性科研院所基金重点项目(RISF2013001)

摘　　要：采用水培法,研究了旱柳苗在外源添加不同氮水平(贫氮、中氮、富氮、过氮)的铵态氮(NH+4-N)和硝态氮(NO-3-N)的生长、氮吸收、分配和生理响应。结果表明:一定范围氮浓度的增加能够促进旱柳苗的生长,但过量氮会抑制其生长,且NH+4-N的抑制作用大于NO-3-N;两种氮处理下,旱柳表现出对NH+4-N的吸收偏好,在同一氮水平时,旱柳各部位氮原子百分含量Atom%15N(AT%)、15N吸收量和来自氮源的N%(Ndff%)均为NH+4-N处理大于NO-3-N处理,且随着氮浓度的增加,差异增大,且在旱柳各部位的分布为根﹥茎﹥叶;2种氮素过量和不足均会对旱柳根和叶生理指标产生不同的影响,其中在过氮水平时,NH+4-N和NO-3-N处理下根系活力比对照减少了50.61%和增加了19.53%;在过氮水平时,NH+4-N处理柳树苗根总长、根表面积、根平均直径、根体积和侧根数分别对照下降了30.92%、29.48%、19.44%、27.01%和36.41%,NO-3-N处理柳树苗相应的根系形态指标分别对对照下降了1.66%、5.65%、1.49%、5.06%和25.72%。可见,高浓度NH+4-N对旱柳苗的胁迫影响大于NO-3-N,在应用于水体氮污染修复时可通过改变水体无机氮的比例,削弱其对旱柳的影响,从而提高旱柳对水体氮污染的修复效果。In recent years, due to global climate change and unpredictable human activities, the problem of water resource shortage and environmental water pollution has become widespread. Particularly, nitrogen pollution of water in China is a problem, owing to atmospheric nitrogen deposition and excess of nitrate, which results in a significant increase in water soluble nitrogen and eutrophication. To address the issue, an important multipurpose tree species, willow （Salix sp. ） , which has large biomass production and high resistance to environmental stress, has been studied, and as proved effective in the uptake and accumulation of pollutants from contaminated waters and soils. Hence, it was employed in the present experiment. In the current study, the seeding of Salix matsudana was selected to probe the characteristics of growthnitrogen absorption/distribution, and physiological responses under different nitrogen treatments. These included poor nitrogen （1.4 mg/L）, medium nitrogen （2.8 mg/L）, high nitrogen （7.0 mg/L）, and excessive nitrogen （28.0 mg/L）, which are levels related to the water eutrophication classification standard. Nitrogen was added as ammonium nitrogen （NH4^＋-N） and nitrate nitrogen （NO^-N） through water culture experiments. The results showed that the biomass of Salix matsudana increased with increasing nitrogen to some extent, but the growth was inhibited under excessive nitrogen concentrations, and NH4^＋-N showed a higher inhibition than NO3^--N. Meanwhile, Salix matsudana had a preference for NH4^＋-N absorption over NO3^--N when provided with the same concentration of nitrogen. The order of AT% contents, 15^N absorption and Ndff% in different organs of Salix matsudana was, root 〉 stem 〉 leaf, and the content of NH4^＋-N was higher than that of NO3^--N. Furthermore, the difference showed an increasing trend with rising nitrogen concentration. Moreover, with increasing nitrogen concentration, the rate of ＇SN allocation was significantly different in different

关 键 词：15^N示踪 旱柳 铵态氮 硝态氮 吸收分配 生理响应 

分 类 号：S792.12[农业科学—林木遗传育种]