为明确产量差异显著的2个夏玉米品种植株氮素利用和叶绿素荧光特性对水氮互作的响应，以德单5号和郑单958为材料，设3个灌溉（W2充分灌溉、减半灌溉W1和不灌溉W0）和4个氮肥水平（N1不施氮、N2 158 kg/hm2、N3 180 kg/hm2、N4 225 kg/hm2）开展大田试验，分析水氮互作对玉米产量、植株转运量和转运效率、氮素吸收和氮肥利用效率、吐丝期叶绿素含量以及叶绿素荧光参数最大光化学效率（Fv/Fm）和潜在活性（Fv/Fo）的影响研究。结果表明，2个品种氮素利用和叶绿素荧光特性对水氮响应一致，且郑单958仅在氮肥利用效率上较德单5号显著提高了0.08kg/kg。在不同灌溉处理下，增施氮肥显著提高了营养器官氮素转运量，降低了氮素转运效率；且N3和N4处理间无显著差异；而大喇叭口阶段（7月中旬）较大的降雨量（303.30mm）导致各灌溉处理间差异未达显著水平。同样，增施氮肥也显著提高了各灌溉条件下2个品种吐丝期穗位叶Fv/Fm和Fv/F0，但当氮肥施用量增加到180 kg/hm2后增肥效果不显著。综合考虑，大喇叭口期和吐丝散粉期减半灌溉37.5mm配合180 kg/hm2的施氮量有利于提高叶绿素荧光参数Fv/Fm和Fv/F0，促进夏玉米植株氮素转运，提高氮肥利用效率。此外，叶绿素荧光参数Fv/Fm和Fv/F0均与植株氮素转运量和氮肥利用效率呈极显著正相关，可作为衡量植株氮素转运和利用的有效手段。

In order to identify the response of nitrogen utilization and chlorophyll fluorescence characteristics to irrigation and nitrogen, two summer cultivars of Dedan5 and Zhengdan958, with significant yield differences were used. The experiment was caried out with three irrigations (W2 sufficient irrigation, W1 halve irrigation and W0 non-irrigation) and four nitrogen fertilizer applications (N1 0 kg/hm2, N2 158 kg/hm2, N3 180 kg/hm2, N4 225 kg/hm2). The effects of nitrogen and irrigation to nitrogen translocation amount, nitrogen transport and absorption efficiency, nitrogen use efficiency, SPAD value and Chlorophyll Fluorescence (Fv/Fm and Fv/Fo) of summer maize were analysed. The results showed that the response of nitrogen utilization and chlorophyll fluorescence characteristics of two cultivars to nitrogen and irrigation were consistent, and Zhengdan958 only had significant higher nitrogen utilization efficiency of 0.08 kg/kg than that of Dedan5. In all irrigation treatments, nitrogen fertilization application significantly improved the translocation amount of nitrogen in vegetative organs, while reduced the nitrogen transport efficiency. And the differences for them between N3 and N4 were non-significant. No significant differences among irrigation treatments were observed, due to the higher rainfall (303.30 mm) during the flare opening period (mid-July). Similarly, the nitrogen fertilizer application also significantly improved the two parameters of Fv/Fm and Fv/F0 in ear leaf, under the three irrigation conditions. While no significant benefits were observed when the nitrogen fertilizer application increased more than 180 kg/hm2. In this study, the treatment of halve irrigation of 37.5mm with nitrogen fertilizer application of 180 kg/hm2 was conductive to improve the chlorophyll fluorescent parameters of Fv/Fm and Fv/F0, and accelerate the nitrogen transport of plant, and increase the nitrogen use efficiency. Furthermore, the Fv/Fm and Fv/F0 were significantly positive correlation with nitrogen translocation amount of plant, and nitrogen use efficiency, indicating that they could be used as an effective measure to evaluate the plant nitrogen accumulation, transport and utilization.

河南省重点研发与推广专项；河南省农业科学院优秀青年科技基金(2022YQ21)