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    不同NH+4/NO-3配比作用下红松幼苗的氮吸收和同化特征

    Nitrogen absorption and assimilation characteristics of Pinus koraiensis seedings in different NH+4/NO-3 ratios

    • 摘要: 采用营养液培养法,研究不同NH+4/NO-3配比供氮模式下红松幼苗的氮素吸收水平、主要氮同化酶活性及苗木生长水平。结果表明:红松幼苗在NH+4占优势的营养条件下吸收氮素能力较强、总生物量较大。苗木根系中硝酸还原酶(NR)活性较强,营养液中的NO-3对NR活性有明显的促进作用,且随其中供NO-3比例的增加而增强。谷氨酰胺合成酶(GS)活性和谷氨酸脱氢酶(GDH)活性则可能因外源NH+4的诱导作用而增加;与根系相比,针叶中GS活性较强,且NH+4优势处理苗木的酶活性较强。GDH活性在苗木根系和针叶中均较强,且在供NH+4优势时酶活性较强。

       

      Abstract: A solution cultivation experiment with Pinus koraiensis seedlings was conducted to study the effect of different NH+4/NO-3 ratio on nitrogen absorption,nitrogen assimilation enzyme and growth. The results showed that more nitrogen was absorbed by the seedlings in high NH+4/NO-3 ratio solution, whose total biomass was more than the others. Nitrate reductase (NR) activity was higher in the roots than the leaves, NO-3 promoted NR activity, which responsed to increased NO-3 availability of the solution. Glutamine synthetase (GS) activity and glutamate dehydrogenase (GDH) activity was improved by the induction of exogenous NH+4. GS activity was higher in the leaves than the roots, and which was higher in the seedlings of high NH+4/NO-3 ratio solution. GDH activity of the roots and the leaves was high, and which was higher in the seedlings of high NH+4/NO-3 ratio solution.

       

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