供氮水平对小麦生殖生长时期叶片光合速率、NR活性和核酸含量及产量的影响

在水培条件下，研究了氮素水平对小麦生殖生长时期一些生理特性及产量的影响。结果表明：生殖生长时期，外源供氮水平供应增加，叶面积、叶片光合速率及叶绿素含量均随之增加；叶片和根系硝酸还原酶活性（NRA）、叶片铵态氮含量和外源供氮水平间有显著正相关；根系DNA及RNA含量均随供氮水平升高而升高；孕穗期用不同氮素水平处理15 d，对小麦成熟后生物量及经济产量有明显影响。

Effect of Nitrogen Level on the Photosynthetic Rate, NR Activity and the Contents of Nucleic Acid of Wheat Leaf in the Stage of Reproduction

Water culture experiment was conducted using wheat (Triticum aestivum) as an indicating crop to study the influence of N level on photosynthesis rate , NR activity and content of RNA and DNA at the stage of reproductive growth. Four N levels were used as treatments: ① ников solution，② 1/5 N (16.8 mg N/L) Пряищников solution, ③ 1/2 N (42 mg N/L) Пряищников solution, ④ Пряищников solution (84 mg N/L) (CK). Each treatment had 5 replicates. During the experiment, the solution was aerated for 2-3 h everyday, the lost water of each pot was supplemented every day. The photosynthesis rate was measured in vivo with flag leaves. Take the flag leaf and the leaf next to it as material, the nitrate reductase activity (NRA), the content of nitrate, ammonium ions and chlorophyll, as well as RNA and DNA level were measured while the plants in other pots continued to grow until harvesting for measuring the biomass. The results showed as follows: with the increasing of exogenous N level, the leaf area, the photosynthetic rate and the content of chlorophyll were all enhanced; there were positive correlations between exogenous N level and activity of NR and the content of endogenous NH+4 nitrogen. It had the remarkable impact on the biomass and yield of wheat when supplying the different nitrogen level in the stage of reproduction.