【作者】 薛盈文；

【导师】 王志敏；

【作者基本信息】 中国农业大学 ， 作物生理学， 2014， 博士

【摘要】 针对冬小麦现实生产中农田间产量差距大、个体不均衡导致区域产量水平低、资源利用效率不高等问题,基于通过提高农田内群体均匀度来提高产量和资源利用效率,进而实现农田间均衡增产增效的设想,通过考察不同品种、不同播种方式、不同产量水平群体内个体性状的变异性,分析群体均匀度与产量的关系,在此基础上通过设置行距和行内种子分布方式,塑造不同均匀度类型群体,研究了不同类型群体的冠层结构与微气候环境特征、物质生产积累与转运分配特性、产量品质形成、’水氮利用特点,探讨提高群体均匀度实现增产增效的机制。主要结果如下：1.不同生产群体内个体生产性能存在较大差异,单株穗粒重与单株干重变异系数密切相关,缩小穗粒重变异程度可显著提高穗粒重,进而提高产量。不同品种群体内个体穗粒重变化范围为0.2～2.2g,穗粒重的变异系数达24%～34%。单株重量和穗粒数的变异系数与穗粒重呈负相关；单株重量对穗粒重的直接作用系数最大,可以作为衡量品种单株生产力的指标。同一品种不同栽培条件(行距、播种方式、水分管理)下穗粒重的变异程度不同,穗粒重变异系数较大的群体其平均穗粒重较低。高产群体的平均穗粒重高于低产群体,而穗粒重及其它农艺性状的变异系数明显小于低产群体。播期、行距及行内种子分布方式对群体内个体性状及其变异系数有很大影响,个体株高、穗粒数、单株干重的变异系数与单株穗粒重呈显著负相关。晚播小麦缩小行距和增加行内种子分布均匀度,显著降低了成熟期个体农艺性状的变异程度,并提高了个体平均穗粒重和群体产量。2.窄行匀播形成的较均匀群体,其冠层结构和群体内微环境得到明显改善。晚播小麦的行距从20cm缩小到10cm,群体LAI显著提高、平均叶倾角(MLA)显著降低,消光系数(K)随天顶角、行内植株分布均匀度的增加而增大。行内种子不同分布类型处理对群体MLA的影响不显著。窄行匀播增加了群体内植株个体分布的均匀度,增加了冠层中上部的光截获量、减少了冠层下部的漏光损失,降低了群体下层的温度值及其变幅,增加了群体内的相对湿度。3.窄行匀播改善了群体均匀性,增加了群体库容量,并提高了群体光合速率,增加了花后物质积累及其对产量的贡献。无论早播和晚播,在10-30cm行距范围内,随行距减小、群体均匀度提高,库容(穗数×穗粒数)增加,且花后同化物积累量(AA)和花后同化物对籽粒的贡献率(CAA)显著提高。在相同行距内,随着落种均匀度增加,灌浆期群体光合速率明显提高,花后同化物积累量及其对籽粒的贡献率增加。晚播小麦10cm行距配合均匀播种,可获得群体源库性能的高水平协调。4.窄行匀播形成的均匀群体改善了产量和品质性状、提高了水氮利用效率。10cm行距相对于20cm行距、均匀播种相对于随机播种,籽粒产量增加。10cm行距配合均匀播种处理(10A)与20cm行距内随机非均匀播种处理(20R)相比,籽粒产量增加22.7%～33.1%,且湿面筋含量、干面筋含量、面团稳定时间显著增加。窄行匀播增加了总耗水量和吸氮量,但主要增加了生育后期的水氮吸收量。10A的最终群体水分利用效率和氮肥生产效率明显高于20R。综合研究表明,提高群体内个体分布均匀度可协调提高群体的生产性能和水氮资源利用效率。在华北地区小麦晚播大群体栽培条件下,缩小行距和均匀播种的结合是改善群体均匀性、实现高产高效的有效措施。更多还原

【Abstract】 Aimed at the larger yield gap among different cultivated land, the lower yield level caused by the imbalance single plant in farm in special district, and lower resource usage efficiency, in order to realize the assumption of the balanced raise of farm yield and resource usage efficiency through enhancing population uniformity in farm, the single plant variation was systematically investigated for the population of different varieties, sowing modes, and different yield level, and the relation between population uniformity and yield. On the basis of above results, the canopy structure and micro-climate factors, the traits of material accumulation and transporting distribution, the yield and quality formation, and the trait of water and nitrogen usage were investigated, and the mechanism of attaining high yield and efficiency were discussed on the basis of modulating rowing space and inner distribution patterns and creating different uniformity population. The main results were as follows:1. The larger difference was existed for the single plant productivity in different population. The spike grains weight was closely correlated with single plant weight coefficient variance. The spike grains weight was raised by reducing the coefficient variance of spike grains weight, and then the yield was increased.The range of spike grains weight in different varieties was0.2-2.2g, and the coefficient variance (CV) of it was24%-34%. The grains weight was negatively related with the single plant weight and grains amount. The direct effect coefficient on the grains weight of the single plant weight was greater than other characters, and it could be used as the index to measure the single plant productivity.The coefficient variance of grains weight of the same variety was different on the distinct cultivating condition (rowing space, sowing mode, water condition), the mean grains weight was lower for the population that the CV of grains weight was higher. The mean grains weight of high-yield population was higher than low-yield population, but the CV of grains weight and other characters was apparently less than the low-yield population.There was great influence of sowing date, rowing space and seed distributing patterns on the single plant character and its CV. The single plant grain weight was a evidently negativly related with the CV plant height, grains and single plant.The CV of single plant character in maturity was apparently decreased, the mean grains weight and population yield were increased through reducing row pitch and raising the seed distribution uniformity.2. The more uniform population was formed by reducing row width and increasing seed distribution uniformity, its canopy structure and micro-environment were evidently improved.The row with was reduced from20cm to10cm, the LAI was apparently increased, and the mean leaf angle (MLA) was evidently decreased. The K was magnified with the increasing for the zenith angle and distributing uniformity. MLA was not evidently influenced by the inner distribution patterns (R and A). The single plant distributing uniformity was increased by narrow rowing space and uniformly planting, and the light interception of the middle-upper situation in canopy was increased, and the light loss in the bottom of population was decreased, the temperature and its variance degree wer decreased, the relative humidity was raised. 3. The population uniformity was improved, and the grains capacity of population, population photosynthesis rate, the amount of material accumulation and its contribution rate to yield were increased after anthesis stage by narrow rowing space and uniformly planting.In the range of10-30cm regardless of early or late sowing date, the sink capacity (spikes x grains) was increased with the reduce of rowing space and the increase of population uniformity, the assimilation amount after anthesis (AA) and its contribution ratio to seed (CAA) were apparently raised. In the same rowing space, the population photosynthesis rate in filling stage was apparently increased with the increase of seed distributing uniformity, the AA and CAA was increased. The high level source-sink capability can be gained by10cm with seed uniform distribution of late-sowing wheat.4. The yield and quality character was improved by uniform population created from the narrow space and uniformly sowing, and the water-nitrogen usage efficiency was increased.The yield of10cm was evidently than20cm, the yield of uniform pattern (A) in15cm and20cm was apparently than the random pattern in the corresponding row. The yield of narrow row with uniformly distributing pattern (10A) was evidently than the random pattern in20cm (20R), the yield was increased22.7-33.1%, and the wet gluten content, dry gluten content, flour stability time were apparently increased. The water consumption, nitrogen assimilation amount were heightened for the treatment of narrow row with uniformly distributing pattern (10A), and above characters were increased apparently in the late growth stage. The water and nitrogen usage efficiency of10A were evidently increased than the20R.The results of integrated study indicated that the production capacity and water-nitrogen usage efficiency of wheat population were improved cooperatively through raising the single plant distributing uniformity. It was an effective measure to improve population’s uniformity, to attain the aim of high yield and efficiency through reducing row width and uniformly sowing under the condition of late-sowing and high-density population in North China district.更多还原