^(13)C标记技术在土壤和植物营养研究中的应用

APLICATION OF ^(13)C LABELLING TECHNIQUE TO SOIL SCIENCE AND PLANT NUTRITION

过去研究有机物在土壤中的周转通常采用14 C标记技术 ,但由于人们对其放射性的关注 ,进入 80年代以来研究者趋于使用稳定性同位素13C标记技术。虽然13C标记技术相对来说还较年轻 ,但从已有有限的研究资料来看其优越性已经显示出来。一是在一定的条件下可以利用自然丰度分异较大的天然材料作为标记材料 ,既可以省去标记的时间和费用 ,又可以做到真正的“原位”研究 ;二是利用13C和15N加富标记技术 ,结合核磁共振测定 ,不仅可以研究有机物分解的动态变化 ,还可以追踪有机物在周转过程中C、N组分化学结构的变化 ,能为揭示土壤养分循环和腐殖质形成机理提供更多的信息。本文根据已收集到的部分资料 ,对13C标记技术在土壤和植物营养中的应用情况作一简要综述 ,并在此基础上讨论了13C加富标记技术在研究植物光合作用、光合产物的去向以及标记秸杆在土壤中的分解等方面的应用及其注意点 。

Owing to the concern of its radioactivity by human being, radioactive 14 C labelling technique used to study the turnover of organic materials added to soils has gradually been replaced by stable isotope 13 C labelling technique since 1980’s. The two advantages of stable isotope 13 C labelling technique have been recognized. Firstly, much time and cost spent on labelling can be saved while real in?situ study can be attained if we choose naturally labeling materials obtained with the help of discrimination of different plants between 13 C and 12 C . Secondly, enrichment of 13 C and 15 N and their combination with NMR (nuclear magnetic resonance) spectroscopy can help us study not only the dynamics of decomposition of organic materials but also the changes of their chemical structures during the turnover of the organic materials, which can provide more information in clarifying the C and N cycling and humification of the organic materials applied to soils. The paper gives a brief review on the application of 13 C labelling technique to soil science and plant nutrition, in which some key notes are devoted. Therefore, the paper will prove very useful in initiating the related research work in China.