中文摘要：

在水稻品种中，杂交籼稻因其杂种优势强、抗逆性好、穗型大、产量潜力高，在稻作生产中占有重要的、不可替代的作用。2005、2006年利用我国惟一的农田开放式空气CO2浓度增高（FACE）研究平台，设计施N量为125kg·hm^-2（LN）、250kg·hm^-2（NN）处理。研究大气CO2浓度比对照高200μmol·mol^-1的FACE处理对三系杂交籼稻汕优63不同生育时期N素含量、N素吸收、N素分配和N素效率的影响。结果表明：（1）FACE处理使汕优63各生育时期稻株含N率显著下降，使各生育时期N素吸收量显著增加．生育中期的增幅明显小于生育前、后期；（2）FACE处理对汕优63N素在不同器官中分配比例无明显影响；（3）FACE处理使汕优63不同生育期N素干物质生产效率极显著提高。使N素子粒效率显著提高，但对N素收获指数无显著影响；（4）增施N肥，使汕优63不同生育时期的植株N素含量和吸N量均得到显著或极显著的增加。使N素干物质生产效率和N素子粒效率下降；（5）CO2×Y、N×Y对植株含N率、吸N量的影响有互作效应。FACE处理使汕优63稻株含N率显著下降；使N素吸收量、N素干物质生产效率、N素子粒效率显著提高。

英文摘要：

Hybrid indiea rice （Oryza sativa L.） eultivars play an important and irreplaceable role in rice production system due to its heterosis, resistance to environmental stress, large panicle and high yield potential. In this study, the Chinese unique free air CO2 enrichment [FACE, 200 μmol·mol^-1 higher than ambient （AMB） ] research platform was used to investigate the effects of FACE on rice nitrogen （N） concentration, uptake, efficiency and allocation at different growth stages of three-line indiea hybrid rice eultivar Shanyou 63 under two levels of N： low （LN, 125kg·hm^-2） and normal N （NN, 250 kg·hm^-2） in 2005--2006. Main results showed that： （1） Compared with AMB, FACE significantly decreased N concentration in rice plant of Shanyou 63 over the season, FACE significantly increased nitrogen accumulation in rice plant, and the increasing rate at the middle growth stage was less than that at the early and late growth stage. （2） FACE had no obvious effect on nitrogen allocation pattern of Shanyou 63 over the season. （3） FACE treatment resulted in the significant increase in N use efficiency for biomass （NUEp） over the season and in N use efficiency for grain yield （NUEg） at grain maturity, but no CO2 effect was observed on nitrogen harvest index （NHI）. （4） Nitrogen concentration and accumulation at different growth stages of Shanyou 63 increased with increasing N supply （P〈0.05 or 0.01 ）, but NUEp and NUEg showed the opposite trends. （5） Significant interactions between [CO2]xyear and Nxyear were observed for N concentration and accumulation. FACE decreased N concentration, increased N uptake, NUEp and NUEg at different growth stages of Shanyou 63, but no CO2 effect was detected on N allocation.