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【目的】研究玉米根系特性与氮素吸收利用及其与地上部生物量和产量形成的关系,探明根系形态特征与氮素吸收能力对玉米高产性能的影响,为玉米高产高效生产提供理论依据。【方法】试验于2014—2015年在山东农业大学黄淮海区域玉米技术创新中心(36°18′N,117°12′E)和作物生物学国家重点实验室进行,以京科968(JK968)、郑单958(ZD958)和先玉335(XY335)为试验材料,采用土柱栽培,设置两个氮素水平,施氮量分别为1.5 g/plant(LN)和4.5 g/plant(HN),在抽雄期(VT)和完熟期(R6)进行根系及植株取样,测定根系相关指标(根系干重、根系长度、根系表面积、根系体积),干物质及氮素积累与分配规律,探究品种和氮素供应对玉米根系特征及氮素吸收利用的影响。【结果】两个氮素水平下JK968单株籽粒产量、生物量、根系各指标和植株氮素积累量、氮转运率、氮素收获指数、氮素利用效率均显著高于XY335和ZD958(P<0.05)。JK968单株生物量、籽粒产量、植株氮素积累量较XY335和ZD958在低氮水平下分别增加15.2%、17.7%、9.0%和31.6%、44.1%、31.4%,在高氮水平下分别增加5.4%、12.9%、8.9%和13.5%、26.8%、23.5%;高氮水平下JK968、XY335、ZD958的单株生物量、单株籽粒产量和植株氮素积累量较低氮水平下分别增加15.7%、10.2%、33.9%,26.5%、14.8%、34.0%和34.3%、25.1%、42.5%。抽雄期JK968根系干重、根系长度、根系表面积、根系体积较XY335和ZD958在低氮水平下分别增加41.8%、9.0%、47.1%、24.0%和63.2%、41.6%、60.4%、105.1%,在高氮水平下分别增加24.3%、6.0%、35.2%、19.7%和40.3%、30.0%、49.3%、78.7%;高氮水平下JK968、XY335、ZD958的根系干重、根系长度、根系表面积、根系体积较低氮水平下分别增加48.3%、37.3%、36.4%、12.7%,69.1%、41.3%、48.4%、16.7%和72.5%、49.7%、46.5%、29.3%。相关分析表明,吸氮量与根系干重、根系长度、根系表面积、根系体积呈显著线性正相关,但品种的响应程度不同。在抽雄前,JK968植株吸氮量对根系干重、根系长度、根系表面积、根系体积增长的响应度要高于XY335和ZD958;而抽雄后的响应度则低于XY335和ZD958。【结论】JK968整个生育期的根系各项指标均显著高于XY335和ZD958,且氮素吸收能力强,生物量大,低氮条件下优势更加明显。JK968较发达的根系,保证了植株对氮素的吸收,具有较高的氮素转运效率、贡献率和氮素利用效率,有利于进行物质生产,因而获得更高的籽粒产量。
【Objective】 The objective of this study was to investigate the relationship between root system characteristics, nitrogen uptake and utilization, and aboveground biomass and yield formation in maize to determine the effects of root morphological characteristics and nitrogen absorption capacity on high yield performance of maize, providing a theoretical basis for high yield and high efficiency maize production . 【Method】 The experiment was conducted at National Key Laboratory of Crop Biology at 36 ° 18’N, 117 ° 12’E and Huanghuaihai Regional Maize Technology Innovation Center of Shandong Agricultural University from 2014 to 2015. The experiment was conducted with Beijing Branch 968 (JK968) , Zhengdan 958 (ZD958) and Xiangyu 335 (XY335) were used as experimental materials. Two soil nitrogen levels were set by soil column cultivation. The nitrogen rates were 1.5 g / plant (LN) and 4.5 g / plant (HN) (Root dry weight, root length, root surface area, root volume), dry matter and nitrogen accumulation and distribution were measured at the tasseling stage (VT) and maturity stage (R6) And nitrogen supply on root characteristics and nitrogen uptake and utilization of maize. 【Result】 The results showed that grain yield, biomass, root system index and plant N accumulation, nitrogen transport rate, nitrogen harvest index and nitrogen use efficiency of JK968 were significantly higher than those of XY335 and ZD958 (P <0.05). Compared with XY335 and ZD958, the biomass, grain yield and plant nitrogen accumulation of JK968 increased by 15.2%, 17.7%, 9.0% and 31.6%, 44.1% and 31.4% at low nitrogen level respectively and increased at high nitrogen level 5.4%, 12.9%, 8.9% and 13.5%, 26.8% and 23.5% respectively. Under high nitrogen level, the biomass per plant, the grain yield per plant and the plant nitrogen accumulation increased under nitrogen level 15.7%, 10.2%, 33.9%, 26.5%, 14.8%, 34.0% and 34.3%, 25.1% and 42.5% respectively. Compared with XY335 and ZD958, the root dry weight, root length, root surface area and root volume of JK968 increased 41.8%, 9.0%, 47.1%, 24.0% and 63.2%, 41.6%, 60.4% and 105.1% The root dry weight, root length, root surface area and root surface area of JK968, XY335 and ZD958 under high nitrogen level increased by 24.3%, 6.0%, 35.2%, 19.7% and 40.3%, 30.0%, 49.3% and 78.7% , Respectively, increased by 48.3%, 37.3%, 36.4%, 12.7%, 69.1%, 41.3%, 48.4%, 16.7% and 72.5%, 49.7%, 46.5% and 29.3% under the lower nitrogen level. Correlation analysis showed that there was a significant linear positive correlation between nitrogen uptake and root dry weight, root length, root surface area and root volume, but the response of varieties was different. Before tasseling, the responsiveness of nitrogen uptake of JK968 to root dry weight, root length, root surface area and root volume growth was higher than that of XY335 and ZD958, while that of JK968 was lower than that of XY335 and ZD958. 【Conclusion】 All indexes of root system of JK968 were significantly higher than that of XY335 and ZD958 during the whole growing period, and the nitrogen absorption ability, biomass and low nitrogen were more obvious. JK968 more developed roots, to ensure that plants absorb nitrogen, nitrogen transport efficiency with high, the contribution rate and efficiency of nitrogen use, conducive to material production, resulting in higher grain yield.