【作者】 王强；

【导师】 彭少兵； 钟旭华； 崔克辉；

【作者基本信息】 华中农业大学 ， 作物栽培学与耕作学， 2006， 硕士

【摘要】 以两个杂交稻组合丰优998和培杂77为材料，在幼穗分化期于人工气候箱控光条件下，进行4种光照强度和3种氮水平的处理，研究了光照强度和施氮量对水稻干物质积累与分配、叶片特性和氮素的吸收与分配的影响。在结实期于盆栽条件下，通过遮光改变光照条件，设置3种光照条件和3种氮水平，研究了光照条件和氮水平对水稻产量与产量构成、干物质积累与分配、氮素的吸收与利用和叶色值的影响；同时，在结实期于田间条件下，以丰优998为材料，设置3种光照条件和4种氮水平，研究了光照条件和氮水平对水稻产量与产量构成、干物质积累与分配的影响。结果表明： 1．人工气候箱控光试验中，在一定光照强度下，干物质积累量与施氮量呈抛物线关系；在一定氮水平下，干物质积累量随着光照强度的增加而直线增加。水稻干物质积累量由施氮量（X₁，g／kg土）和光照强度(X₂，μmol·m^-2·s^-1)共同决定，其定量关系可用Y=b₀+b₁X₁+b₂X₂-b₃X₁²+b₄X₁X₂表示。根据这一定量关系，可求得最适施氮量(N_opt)与光强（X₂）的定量关系为：N_opt=c₀+c₁X₂，在本试验设置的条件下最适施氮量随光照强度的增加而直线增加。以处理期间的日均辐射量作为光照条件的指标，在盆栽和田间条件下，通过遮光改变光照条件，研究了施氮量和光照条件对水稻干物质积累量和稻谷产量的影响，得到了同样的结论。 2．遮光极显著地降低了水稻的产量，主要是极显著地影响了千粒重和结实率，特别是弱势粒重大幅度下降。抽穗后随着光照的减弱，干物质生产与积累的速率减慢，干物质积累量明显减少；茎鞘贮藏性光合产物的输出率及运转率高于自然光下的，干物质分配到穗中的比例低于自然光下的。3种光照条件下植株的物质生产和产量均随氮水平的增加先升后降，弱光下植株在较低的氮水平下具有较高的物质生产能力和产量，而强光下植株的最大物质生产能力和产量出现在较高的氮水平上。 3．幼穗分化期，在人工气候箱设定的光照强度范围内，水稻植株的吸氮量随着光照强度的增加而增加，随施氮量的增加而增加；单位干重的含氮量则随光照强度的升高而下降，随施氮量的增加而增加。结实期，遮光处理条件下水稻植株各器官的含氮量上升，低光照条件下植株对氮的吸收强度和积累量减少。叶片与茎鞘的氮输出率及茎鞘氮运转率均随施氮量的增加而呈下降的趋势，随光照的减弱而呈上升的趋势；穗部的氮输入量随施氮量的增加而增加，随光照的减弱而下降。粒肥的回更多还原

【Abstract】 Three experiments were conducted to investigate the interactive effects of light intensity and nitrogen supply on dry matter production, yield formation, and nitrogen use efficiency of rice. In experiment 1, two hybrid rice varieties, Fengyou 998 and Peiza77, were treated by three fertilizer-N rates （0, 0.085, and 0.185 gN/kg soil） at panicle initiation and then grown in growth chambers with four light intensities (100, 250, 350 and 750 μ mol · m^-2 · s^-1) for four weeks. Leaf characteristics, dry matter accumulation, nitrogen content of organs, leaf chlorophyll content and leaf color were measured. In experiment II, The two varieties were grown in pots until heading and then treated with three fertilizer-N rates and three light intensities by shading until harvest. Dry matter production, grain yield, yield components, nitrogen uptake were measured and nitrogen use efficiency was calculated. In experiment III, Fengyou 998 were grown in field until heading and then treated with four fertilizer-N rates and three light intensities during grain-filling stage. Dry matter production, grain yield and yield components were measured. The results were as follows:1. In the growth chamber experiment, the effects of nitrogen supply （X₁,g/kg-soil） and light intensity(X₂, μ mol · m^-2 · s^-1) on dry matter accumulation （Y, g/pot） were mathematically represented by the following equation: Y =b₀+b₁X₁+ b₂X₂-b₃X₁²+b₄X₁X₂. A quadratic equation Y=b₀+b₁X+b₂X² could be used to describe the relationship between N application and dry matter accumulation of rice. Also, a linear model could be used to describe the relationship between light intensity and dry matter accumulation. It was deduced that the optimum fertilizer-N rate increased linearly with light intensity. This could be expressed by the following equation: N_opt = c₀+c₁X. This indicated that the optimum fertilizer-N rate was influenced by light intensity. Similar results were obtained in pot and field experiments where light condition during grain-filling stage was changed by shading.2. Grains yield of rice was significantly affected by shading. The grain weight of low light treatments was significantly lower than the non-shading control. As the light intensity decreased, the filled grain percentage was reduced obviously and the dry matter accumulation decreased. The production, distribution and transformation of plant dry matter were significantly affected by shading during grain-filling. Under low-light condition the export and transformation percentage of dry matter in stems and sheaths increased, and the distribution percentage of dry matter to panicles decreased compared to the non-shading control. At a given light condition, the dry matter production and yield更多还原