高产夏玉米密植效应与耐密机理研究及其氮素调控

发布时间：2018-05-25 15:36

本文选题：夏玉米 + 密度　；参考：《山东农业大学》2016年博士论文

【摘要】：增加种植密度是当代玉米产量进一步提高的主要途径之一。然而,高密度下获得高产的同时,往往伴随着单株产量降低、倒伏率升高等一系列问题,选用耐密型品种可有效降低高密度种植带来的负面效应。本试验于2014-2015年在山东农业大学黄淮海玉米科技创新中心及作物生物学国家重点实验室进行,选用紧凑耐密型品种郑单958(ZD958)及稀植大穗型品种鲁单981(LD981)为试验材料,设置52 500株/ha(D1)及82 500株/ha(D2)两个种植密度,研究不同耐密型夏玉米品种形态学、生理学及差异蛋白质组学特性对增密的差异响应,确定耐密植品种的耐密机理;在此基础上设置0,180及360kg/ha三个施氮量,研究施氮量对高密度下各指标的调控效应。主要研究结果如下:1.种植密度及施氮量对夏玉米产量及构成因素的影响增密可以提高两品种子粒产量,但增产幅度不同。2014年及2015年ZD958分别增产33.7%及33.1,而LD981仅增产3.2%及4.9%。增加种植密度两品种穗粒数、千粒重均降低,但千粒重降低幅度较低,说明密度主要通过影响穗粒数影响籽粒库容;高密度下两品种籽粒库容差异不显著。因此,倒伏率较高,收获穗数是较低是LD981增产不显著的主要原因。高密度条件下,施用氮肥可以通过提高夏玉米穗粒数、千粒重及公顷穗数,增加子粒产量。增密及施氮均显著提高两品种收获期及花后干物质积累量,高密度下两品种干物重差异不显著,LD981收获指数较低也是其子粒产量较低的一个重要原因。2.种植密度及施氮对夏玉米抗倒伏性能的影响增加种植密度可提高夏玉米株高、穗位高、基部第三茎节长度,并显著降低夏玉米茎粗、茎秆穿刺强度、弯曲性能、硬皮组织厚度、维管束鞘细胞厚度、维管束数目。这些指标的变化导致高密度下倒伏率的升高,以2014年为例,高密度下LD981及ZD958倒伏率分别为42.8%及14.6。与LD981比较发现,ZD958株高、穗位高较低、茎秆穿刺强度及弯曲性能高、维管束细胞数目多,且受密度影响较小是其在高密度下倒伏率较低的主要原因;施用氮肥可以显著改善夏玉米茎秆质量,减少倒伏率。另外,经过逐步回归分析,穗位高及硬皮组织厚度是制约玉米茎秆倒伏的关键因素。3.种植密度及施氮对夏玉米光合特性的影响高密度条件下,两品种叶面积指数显著升高、冠层透光率降低,可以显著提高群体光能利用率,但叶绿素含量、净光合速率、光合酶活性显著降低,说明高密度下容易造成群体内光分布不合理,单株光合性能降低;高密度条件下,适当施用氮肥可以提高夏玉米叶绿素含量、净光合速率、光合酶活性,改善植株光合性能。LD981底层透光率过低,株间郁闭,叶片衰老速度快,并且叶绿素含量、净光合速率及光合酶活性较低是其在高密度下光合性能较低、增产不显著的重要原因之一。4.种植密度及施氮对夏玉米不同器官~（13)C同化物分配的影响增加种植密度显著影响~（13)C同化物分配在不同器官分配。吐丝期~（13)C同化物主要分配在茎鞘中,但高密度条件下,~（13)C同化物向茎鞘转运比例减少,且LD981降低幅度较大;适当施氮显著提高~（13)C同化物向各器官转运。随灌浆期的推进,~（13)C同化物逐渐向子粒中转运,增密降低收获期子粒中~（13)C同化物分配比例。5.种植密度及施氮对夏玉米碳氮比及氮素吸收、转运及利用效率的影响增密显著降低叶片碳氮代谢酶活性,高密度下,施氮显著降低两品种碳氮比。高密度条件下,两品种氮素转运量及转运率显著升高,较高的转运率是LD981高密度下衰老速度较快的的重要原因;适当施用氮肥尽管氮素转运量显著增加,但转运率减低;增密显著提高两品种氮肥利用率、氮素农学利用效率及氮肥偏生产力,施氮显著降低了氮素利用效率。6.种植密度对根系生长的影响ZD958根系受密度影响较小,高密度下,能够维持相对较高的根量、根长、根系吸收面积及根系活力,且高值持续期长,生育后期衰老缓慢,保证了植株对氮素吸收;根系大小不是影响氮素吸收的限制因素,植株吸氮量同时受地上部生长需求所调控;高密度下ZD958籽粒库容较高、库调节能力较强,使其氮利用效率及氮肥偏生产力显著高于LD981的主要原因。7.种植密度对穗位叶差异蛋白质表达的影响高密度下,夏玉米穗位叶差异蛋白质表达按主要功能可分为光合作用,代谢,胁迫与防御及蛋白合成、组装、降解相关蛋白,LD981受密度影响差异表达的蛋白点显著高于ZD958;两品种均受密度影响显著差异表达的蛋白点有12个,功能涉及光合磷酸化、卡尔文循环、C4途径、糖酵解、氮同化及逆境胁迫响应等生理过程;高密度下两品种光合磷酸化、卡尔文循环、C4途径、糖酵解、氮同化相关蛋白表达丰度均显著下调,与高密度下光合性能、碳氮代谢均显著降低结果一致;逆境胁迫响应相关蛋白在高密度下表达丰度上调,减少增密对玉米植株造成的损害;同时高密度下,ZD958各类蛋白表达丰度均显著高于LD981,可能是其耐密植的分子学基础。
[Abstract]:Increasing the planting density is one of the main ways to further improve the yield of contemporary maize. However, high yield under high density is often accompanied by a series of problems, such as the yield of single plant and the rise of lodging rate, and the negative effect of high density planting can be effectively reduced. The experiment was conducted in Shandong agriculture in the past 2014-2015 years. At the University of Huang Huai Hai corn science and technology innovation center and the State Key Laboratory for Crop Biology, the compact and tight tolerant variety Zhengdan 958 (ZD958) and Ru Dan 981 (LD981) were used as experimental materials, and 52500 plant /ha (D1) and 82500 /ha (D2) plant density were set up to study the morphology and physiology of different dense summer maize varieties. And the differential proteomic characteristics of the difference response to the density of the density, determine the tolerance mechanism of the dense plant variety; based on this basis, set 0180 and 360kg/ha three nitrogen application levels, and study the effects of Nitrogen Application on the high density of each index. The main results are as follows: 1. density and the effect of Nitrogen Application on the yield and factors of summer maize yield and factors The seed yield of two products could be increased, but the yield increased by 33.7% and 33.1 in.2014 year and ZD958 in 2015, while LD981 increased by 3.2% and 4.9%. only by 3.2% and 4.9%., and the 1000 grain weight decreased, but the 1000 grain weight was lower, indicating that the density was mainly influenced by the number of spike grains and the two varieties under high density. There was no significant difference in grain storage capacity. Therefore, the rate of lodging was higher and the number of harvested ears was lower than that of LD981. Under high density, the application of nitrogen fertilizer could increase the grain yield by increasing the number of spike grains, 1000 grain weight and the number of hectare spikes, and increasing the harvest time of two varieties and the accumulation of dry matter after the application of nitrogen. There was no significant difference in dry matter weight between the two varieties in high density, low LD981 harvest index and low grain yield, and the effect of.2. planting density and nitrogen application on the lodging resistance of summer maize increased the height of the summer maize, the height of the spike, the length of the base third stem nodes, and the decrease of the stem diameter and stem puncture of summer corn. Strength, flexural performance, thickness of hard skin tissue, vascular bundle sheath thickness, vascular bundle number. These changes lead to the increase of lodging rate at high density. In 2014, the LD981 and ZD958 lodging rates at high density were 42.8% and 14.6. were compared with LD981 respectively. The height of ZD958 was higher, the height of ear was lower, and the puncture strength and bending property of stem were high. The main reason for the number of vascular bundle cells and low density is the lower lodging rate at high density. The application of nitrogen fertilizer can significantly improve the quality of summer corn stalk and reduce the lodging rate. In addition, the height of the ear and the thickness of the hard skin tissue are the key factors to restrict the planting density and nitrogen application of.3.. Under the high density condition of Summer Maize Photosynthetic characteristics, the leaf area index of two varieties increased significantly, the light transmittance of canopy decreased, but the chlorophyll content, net photosynthetic rate and photosynthetic enzyme activity decreased significantly, indicating that the light distribution in the group was unreasonable and the photosynthetic performance of single plant decreased. Under high density, proper application of nitrogen fertilizer could increase the content of chlorophyll, net photosynthetic rate, and photosynthetic enzyme activity, improve the light transmittance of.LD981, lower the light transmittance at the bottom of the plant, the canopy closure and the speed of leaf senescence, and the chlorophyll content, the net photosynthetic rate and the low photosynthetic enzyme activity were low, and the photosynthetic performance was lower at high density and increased. The effect of.4. planting density and nitrogen application on the distribution of ~ (13) C assimilates in different organs of summer maize increased significantly. The planting density significantly affected the distribution of ~ (13) C assimilates in different organs. ~ (13) C assimilates were mainly distributed in the stem sheath, but the transfer ratio of ~ (13) C assimilates to the stem sheath was reduced under high density. And LD981 decreased significantly; proper nitrogen application significantly enhanced the transfer of ~ (13) C assimilates to various organs. With the advance of the grain filling period, ~ (13) C assimilates were gradually transported to the grain, and the density of ~ (13) C assimilates in the grain of harvest and the effect of nitrogen application on the ratio of Xia Yu's carbon and nitrogen and nitrogen absorption, transport and utilization efficiency were increased. Density significantly reduced the activity of carbon and nitrogen metabolizing enzymes in leaves. Under high density, nitrogen application was significantly reduced by two varieties. Under high density, nitrogen transport and transport rate of two varieties increased significantly. The higher transport rate was an important reason for fast aging at LD981 high density. Increasing density significantly increased nitrogen use efficiency of two varieties, nitrogen use efficiency and nitrogen partial productivity, nitrogen application efficiency significantly reduced the effect of nitrogen use efficiency.6. planting density on root growth, ZD958 root density was less affected, high density, can maintain a relatively high root, root length, root absorption area and root activity, With the long duration of high value and slow aging in the late stage of fertility, the plant's absorption of nitrogen is guaranteed. The size of the root is not a limiting factor of nitrogen absorption, and the amount of nitrogen uptake is regulated by the demand for the growth of the upper part of the plant. The grain storage capacity of ZD958 is higher and the storage capacity is stronger, which makes the nitrogen use efficiency and partial productivity of nitrogen fertilizer are significantly higher than that of LD. The main reason for 981 is the effect of.7. planting density on the expression of protein expression in ear and leaf. The protein expression of spike leaf difference in summer maize can be divided into photosynthesis, metabolism, stress and defense and protein synthesis, assembly, degradation of related proteins, and the protein points of LD981 are significantly higher than that of ZD958; two varieties are significantly higher than those of ZD958; There were 12 protein points that were significantly affected by density. The functions involved photophosphorylation, Calvin cycle, C4 pathway, glycolysis, nitrogen assimilation and stress response. The expression of two varieties under high density photosynthetic phosphorylation, Calvin cycle, C4 pathway, glycolysis, nitrogen assimilation related protein expression abundances were significantly down, and high density Under the high density, the expression abundances of the response related proteins up up and reduced the damage to the maize plants. At the same time, the expression abundances of all kinds of ZD958 proteins were significantly higher than that of LD981.
【学位授予单位】：山东农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S513

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