【摘要】 利用FACE(FreeAirCarbon-DioxideEnrichment)平台技术,用水培试验研究了低氮(14mg/L)和高氮(28mg/L)水平下,大气CO2浓度升高条件下水稻蒸腾与N吸收速率的相关关系。结果表明,在CO2浓度升高条件下,水稻生物量增加了36%(低N)和29%(高N);总吸N量也增加达7%(低N)和5%(高N);而总蒸腾量减少28%(低N)和10%(高N)。由于促进更多分蘖的发生,高CO2浓度使分蘖期水稻平均N吸收速率提高了31%~156%(低N)和19%~87%(高N),在其他时期无明显影响;而高CO2浓度对水稻平均蒸腾速率的影响主要表现在抽穗到灌浆末期。在对照条件下,平均蒸腾速率和平均N吸收速率呈显著正相关;但在CO2浓度升高条件下,两者相关关系不显著。说明人们所推测的“蒸腾效应”———高CO2浓度条件下降低了的蒸腾作用并非影响水稻N吸收的关键因素。更多还原

【Abstract】 Correlation between transpiration and N uptake rate of rice at low N （LN, 14 mg/L） and high N （HN, 28 mg/L） in solution culture was studied under ambient air and elevated atmospheric p CO₂ （Ambient+200 μmol/mol） by the China FACE （Free-Air CO 2 Enrichment）. Elevated p CO₂ increased rice biomass and total N uptake significantly by 36% and 7% at LN, 29% and 5% at HN, respectively, while decreased total amount of transpiration by 28% at LN and 10% at HN. Elevated p CO₂ stimulated average N uptake rate at the tillering stage as the result of enhanced occurrence of tillers. However, the significant effect of elevated p CO₂ on average transpiration rate was only observed from the panicle initiation to late filling stage. The positive correlation between transpiration rate and N uptake rate was significant at Ambient but not elevated p CO₂, indicating that declined transpiration caused by CO 2 enrichment may not be the key factor affecting N uptake.更多还原