The effects of different nitrogen levels on dry matter production of two-line hybrid rice combination Guanglianguyou 676 were studied. The results indicated that the SPAD value kept higher level under more nitrogen fertilizers and leaf area index (LAI)increased with the increase of nitrogen levels. Crop growth rate (CGR)showed a positive linear correlation with nitrogen levels from transplanting to 30d after transplanting,but then a parabolic correlation. The nitrogen level of 20 g·m-2 has kept the highest CGR since 30d after transplanting. The total dry matter production exhibited a positive linear correlation with nitrogen levels at 30d after transplanting or at elongation stage,but a parabolic correlation at full heading stage or at mature stage. Grain yield was not significant correlation with dry matter accumulation in early stage,but had a significant and very closely significant positive correlation in middle and late stages respectively. About 20% - 30% of the carbohydrates stored in stem and leaf transferred to the spike after full heading stage,which formed rice yield of 21.9%-31.3%.%以两系杂交稻品种广两优676为材料,研究不同施氮量对杂交水稻干物质生产的影响。结果表明,增施氮肥,叶片的 SPAD 值维持较高的水平；叶面积指数(LAI)随施氮水平的增加而提高；在移栽至栽后30 d,群体生长率(CGR)与施氮量呈线性正相关,此后则与施氮量呈抛物线型相关,且均以施氮量为20 g·m-2的处理为最高。总干物质生产量与施氮量的关系,在栽后30 d、拔节期呈直线型正相关,而在齐穗期、成熟期则呈先增后减的抛物线型关系；稻谷产量与前期的干物质积累量的关系不密切,而与中、后期干物质积累量呈显著、极显著的正相关。茎叶中贮积的碳水化合物约20%~30%在齐穗后输出到稻穗,构成稻谷产量的21.9%~31.3%。
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