欢迎访问《应用生态学报》官方网站,今天是 分享到:

应用生态学报

• 研究报告 • 上一篇    下一篇

开放式空气二氧化碳浓度增高(FACE)条件下水稻的根系活力和氮同化能力

庞静1,2 朱建国1 谢祖彬1 刘钢1 陈改苹1 张雅丽1   

  1. 1中国科学院南京土壤研究所 土壤与农业可持续发展国家重点实验室,南京 210008;2湖北大学资源与环境学院,武汉 430062
  • 收稿日期:2004-10-02 修回日期:2005-02-21 出版日期:2005-08-18

Root activity and nitrogen assimilation of rice(Oryza sativa)under Free-Air CO2 Enrichment

PANG Jing 1,2,ZHU Jianguo 1,XIE Zubin 1,LIU Gang 1,CHEN Gaiping 1,ZHANG Yali 1   

  1. 1State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China;2Faculty of Resource and Environment,Hubei University,Wuhan 430062,China
  • Received:2004-10-02 Revised:2005-02-21 Online:2005-08-18

摘要: 利用FACE(Free Air Carbon-dioxide Enrichment)平台技术,用伤流量法研究了低氮(LN 150 kg·hm-2)和常氮(NN 250 kg·hm-2)水平下,大气CO2浓度升高对水稻分蘖、抽穗期和穗后35 d根系活力和根系N同化能力(氨基酸合成能力)的影响.结果表明,就整株水稻来看, CO2浓度升高和N处理对根系活力无显著影响;但由于FACE条件下水稻分蘖数增加14.5%(LN)和20.7%(NN),使每茎根系活力(伤流强度)降低1.4%~21.7%.在分蘖和抽穗期,虽然FACE处理促进了根系吸收的无机N向氨基酸转化,根系伤流液中氨基酸氮/无机氮提高11.1%~143.1%,但氨基酸浓度和合成总量和对照相比无明显差异.在穗后35 d,FACE处理减弱了水稻根系的N同化能力,表现为根系伤流液中氨基酸/无机氮降低38.1%(LN)和29.2%(NN);同时氨基酸浓度降低34.0%(LN)和44.7%(NN),氨基酸合成总量降低50.8%(LN)和40.0%(NN).提高施氮水平促进了抽穗期水稻根系对无机氮的吸收,伤流液中无机氮含量增加51.1%(对照)和155.2%(FACE),但并未增加氨基酸合成量,由此导致抽穗期氨基酸氮/无机氮显著降低19.5%(对照)和36.8%(FACE);同时,氮处理在这个时期与FACE处理表现出明显的交互作用.

关键词: 西伯利亚红松, 引种, 森林资源

Abstract: With Free-Air CO2 Enrichment(FACE)technique,this paper studied the root activity and amino acid(aa) synthesis of rice(Oryza sativa)at low N(LN,150 kgN·hm-2)and normal N(NN,250 kgN·hm-2)under ambient air and elevated atmospheric CO2(Ambient+200 μmol·mol-1).Under elevated CO2,the xylem exudates per hill changed little,while the xylem exudates per stem declined by 1.4%~21.7% as the result of greater tiller numbers.At tillering and heading stages,elevated CO2 increased aa N/inorganic N in xylem exudates by 11.1%~143.1%,but did not affect the aa concentration in xylem exudates and the total amount of aa in roots significantly.However,at 35 days after heading,the aa N/inorganic N ratio decreased by 38.1%(LN)and 29.2%(NN)under elevated CO2.FACE also declined the aa concentration in xylem exudates by 34.0%(LN)and 44.7%(NN),and the total amount of aa by 50.8%(LN) and 40.0%(NN),which meant the retarded capability of aa synthesis in roots.N amendment led to a decrease of aa N/inorganic N in xylem exudates by 19.5%(Ambient) and 36.8%(FACE) at heading stage,as the result of unaffected aa and increased inorganic N concentration.There existed a significantly antagonistical CO2×N interaction on aa N/inorganic N at heading stage.