中文摘要：

以两优培九和武香粳14号水稻品种为材料，在不同栽插密度和施氮水平下进行2年田间试验，研究水稻冠层光合有效辐射（PAR）截获率、光能利用率与水稻产量的关系．结果表明：分蘖期至成熟期，各处理水稻冠层平均PAR反射率为3．45％，其中，分蘖期至抽穗期的冠层反射PAR占冠层总PAR损失的10．90％，显著小于抽穗期至成熟期的22．06％．分蘖期至成熟期的冠层PAR转化率随栽插密度的增加而减少，随施氮量的增加而增大；分蘖期至抽穗期的冠层PAR转化率高于抽穗期至成熟期．在分蘖期至成熟期，冠层PAR利用率随栽插密度和施氮量的增加而增大，各处理中两优培九的平均PAR利用率（1．83g·MJ^1）显著高于武香粳14（1．42g·MJ^1）；武香粳14因生育期较长，分蘖期至成熟期的入射PAR及中、高栽插密度处理的PAR截获量均高于两优培九．水稻不同生长阶段冠层PAR截获率和利用率与产量呈显著正相关，PAR转化率与产量也呈正相关，但相关性不显著．因此，在保持较高PAR截获率的基础上提高冠层PAR转化率，进而提高冠层PAR利用率，有利于水稻高产．曹卫星

英文摘要：

Taking two rice cuhivars （ Liangyoupeijiu and Wuxiangjing 14） with different plant types as test materials, a 2-year field experiment was conducted to study the relationships of rice canopy photosynthetically active radiation （PAR） interception and light use efficiency to grain yield under three planting densities and five nitrogen （N） application rates. From tillering to maturing stage, the average PAR reflectance in all treatments was 3.45 %. The ratio of reflected PAR to the total loss of PAR from tillering to heading stage was 10.90% , which was significanlty lower than that （22.06%） from heading to maturiting stage. The PAR conversion efficiency from tillering to matu- ring stage decreased with increasing planting density but increased with increasing nitrogen rate, and the conversion efficiency was significantly higher from tillering to heading than from heading to maturing stage. The PAR use efficiency from tiHering to maturing stage increased with the increase of planting density and nitrogen application rate, and the average PAR use efficiency of Liangyou- peijiu （ 1.83 g ~ MJ^1 ） was significantly higher than that of Wuxiangjing 14 （ 1.42 g ~ MJ^1）. Due to the longer growth period of Wuxiangjing 14, its incident PAR and intercepted PAR under midium and high planting densities were higher, as compared with Liangyoupeijiu. The grain yield was sig- nificantly positively correlated with the canopy PAR interceptance and use efficiency at different growth stages, but less correlated with the PAR conversion efficiency. To increase the canopy PAR use efficiency and conversion efficiency on the basis of maintaining higher PAR interception rate could be an effective way to increase rice yield.