不同氮素形态比例对黄瓜幼苗生长和光合特性的影响

Effects of Different Ratios of Nitrogen Forms on Photosynthetic Characteristics and Growth of Cucumber Seedlings

采用砂培技术,以不同N素配比营养液处理黄瓜幼苗,研究不同N素形态养分供应与黄瓜幼苗生长、光合特性的关系。结果表明,黄瓜幼苗叶片的净光合速率、叶绿素含量、总生物量随硝态氮比例的增加而增加;胞间CO2浓度、气孔导度、蒸腾速率则随着硝态氮比例的增加而降低。异速生长分析表明,当硝态氮和铵态氮比例为75∶25和25∶75时,C分配偏向于根系,而其他处理C分配则偏向地上部分。

In this paper, cucumber seedlings were used as the experimental materials, and different ratios of nitrogen forms （ NO3-N 、NH4^＋- N ） were applied to the seedlings. The ratios were below： 100：0,75：25,50：50,25：75,0：100. Relationships between nutrient uptake and the results showed that net photosynthetical rates chlorophyll and total biomass increased as the ratios of nitrate to ammonium increased, but intracellular CO2 concentrations, stomatic conductance,transpiration rates were relatively decreased. The results of allometric analyses of seeding showed that when nitrate to ammonium were 75：25 and 25：75, biomass were allocated into roots, and others were allocated above-ground.