中文摘要：

【目的】研究不同氮效率夏玉米根系的时空分布、植株氮素吸收利用特性及其对氮素用量的响应,探讨玉米氮素高效利用的生理基础,以期探明通过采用氮高效品种、促进根土互作、提高根系与水肥时空耦合、提高玉米氮素利用效率,强化环境友好型生产的有效途径。【方法】试验于2011~2012年在山东农业大学黄淮海玉米技术创新中心(N36°18’,E117°12’)和作物生物学国家重点实验室进行,以氮高效玉米品种郑单958(ZD958)和氮低效品种玉米秀青73-1(XQ73-1)为试验材料,在大田条件下设置两个氮素水平(0和315 kg/hm2),采用土壤剖面取样法和系统取样法分别进行根系相关指标、干物质及氮素积累与分配的测定。【结果】ZD958整个生育期根系相关指标(根系干重、根长密度、根系TTC还原量、根系吸收面积及活跃吸收面积)及其在深层土壤(60—100 cm)中所占的比例、单株生物量、单株绿叶面积、植株氮素积累量、单株籽粒产量均显著高于XQ73-1(P【0.05),抽雄期和完熟期根系干重、根长密度、根系TTC还原量、根系吸收面积、根系活跃吸收面积、单株绿叶面积分别比XQ73-1高12.02%、8.39%、25.34%、34.48%、29.22%、7.76%和36.74%、24.21%、36.29%、29.94%、32.83%、13.73%,完熟期单株生物量、植株氮素积累量、籽粒产量分别比XQ73-1高11.65%、11.78%、15.16%。施氮后两品种各指标均显著提高,ZD958和XQ73-1根系干重、根长密度、根系TTC还原量、根系吸收面积、根系活跃吸收面积、单株绿叶面积抽雄期分别提高8.13%、6.12%、18.08%、15.10%、24.71%、12.06%和7.19%、4.59%、10.47%、10.82%、13.02%、7.15%,而完熟期分别提高16.48%、22.43%、19.26%、15.03%、27.45%、14.97%和15.02%、14.59%、13.01%、12.81%、21.95%、11.06%;单株生物量、植株氮素积累量、单株籽粒产量完熟期分别提高9.40%、10.08%、13.43%和5.20%、8.56%、9.69%。相关分析表明,植株?

英文摘要：

The ascertain of the physiological mechanism of nitrogen nutrition of a maize cultivar is the base of choosing nitrogen high efficient cultivar with reasonable and effective temporal and spatial coupling distribution. Therefore, the development and function of root, the relationship between temporal and spatial distribution characteristics of roots and the nitrogen uptake were studied. [Methods]Split plot experiments were conducted in 2011 2012 at the Technological Innovation Center of Maize in Huang-Huai-Hai Region ( N36 °18′, E117°12′) and the State Key Laboratory of Crop Biology, located at Shandong Agriculture University in Taian. One high efficiency cultivar ( ZD958 ) and one low efficiency cultivar ( XQ73-1 ) were used and two nitrogen levels:0 and 315 kg/ha, were designed. The temporal and spatial distribution characteristics of roots in the soil profile were investigated systematically and the nitrogen uptake of summer maize in different growth stages was analyzed and the accumulation amount of dry matter was calculated.[Results]All the terms investigated are significantly higher in ZD958 than in XQ73-1 throughout the whole growth stage ( P <0. 05 ) . The total root dry weight, root length density, root TTC reducing quantity, root absorbing area, root active absorbing area and leaf area of ZD958 are 12. 02%, 8. 39%, 25. 34%, 34. 48%, 29. 22%, 7. 76% and 36. 74%, 24. 21%, 36. 29%, 29. 94%, 32. 83%, 13. 73% higher than those of XQ73-1 at tasseling stage and fully ripening stage, respectively. The biomass, N accumulation amount, grain yield per plant of ZD958 are 11. 65%, 11. 78% and 15. 16% higher than those of XQ73-1 at fully ripening stage, respectively. The values of all the tested terms are increased significantly due to the application of nitrogen fertilizer. Compared with corresponding N0(no N application), the total root dry weight, root length density, root TTC reducing quantity, root absorbing area, root active absorbing area, leaf area increased by 8. 13%, 6. 12%, 18. 08%, 15. 10%, 24. 71%,