氮素处理对2种丁香的生长和光合特性的影响1）

摘要

We studied on the effect of growth and photosynthetic response curve characteristics of Syringa oblata and Sytinga mi-crophylla with different nitrogen levels and nitrogen form ratios .When the NH+4 N/O -3 ratio was 2∶2, the optimal amount of nitrogen nutrition for Syringaoblata and Syit ngamicrophylla were 30 and 40 mmol·L -1, respectively.The plant height in-crement, diameter increment , the maximum photosynthetic efficiency , apparent quantum efficiency and dark respiration reached the maximum , significantly different from the control groups .When the nitrogen level was at 20 mmol· L-1 , the optimal proportion of NH+4/NO-3 ratios for these two plants were 1∶3 and 2∶2, respectively.But for the growth increment , N form had little effect on Syringaoblata, but, Sytingamicrophylla preferred to NO-3 .%研究了不同氮素水平和氮素形态比例对紫丁香（ Syringa oblata）和小叶丁香（ Sytinga microphylla）的生长和光合响应曲线特性的影响。结果表明：当m（铵态氮）∶m（硝态氮）＝2∶2时，紫丁香和小叶丁香的最佳氮素营养用量分别为30、40 mmol· L－1，此时2种丁香的株高增量、地径增量、最大光合速率、表观量子效率，暗呼吸均达到最大值，与对照组差异显著（P＜0．05）；当氮素水平为20 mmol· L－1时，紫丁香和小叶丁香的最适铵态氮硝态氮质量比分别为1∶3和2∶2。从2种丁香的生长量看，氮素形态对紫丁香的影响不大，但小叶丁香更偏好于硝态氮。