Impacts of elevated atmospheric CO2 on growth and yield of rice and wheat：a Meta-analysis | 大气二氧化碳含量升高对稻麦产量影响的整合分析

Chinese. 收集整理国内外130篇原始论文的试验数据资料，应用整合分析（metaanalysis）方法定量评估大气CO2含量升高对水稻和小麦产量形成及相关生理学指标的影响。结果表明：与本底大气CO2含量相比，大气CO2含量升高导致水稻和小麦产量平均分别增加了19．31％（95％置信区间CI：16．87％～21．76％）和17．27％（CI：14．94％-19．60％），主要通过增加穗数和每穗粒数实现，其中水稻单位面积穗数和每穗粒数分别增加11．9％和13．4％，小麦单位面积穗数和每穗粒数分别增加12．8％和10．5％，而对稻麦千粒质量的影响不显著。水稻和小麦总生物量分别增加22．11％和15．86％，其中地下部分生物量的增加高于地上部分。当大气CO2含量为600―680μmol・mol. 1时，稻麦产量及生物量的增加量最大。作物叶片生理学指标对大气CO2含量升高的响应敏感，如水稻光饱和光合速率、叶面积指数分别增加8．15％和19．39％，小麦光饱和光合速率和叶面积指数分别增加10．49％和9．40％。大气CO2含量升高对稻麦的施肥效应在气室模拟研究中最为明显，高于开顶气室（OTC）和自由大气CO2富集（FACE）平台研究。大气O3升高、高温、干旱、低N等胁迫因子可削弱大气CO2含量升高对稻麦的施肥效应。

English. A Meta-analysis was conducted to quantitatively evaluate the effects of elevated atmospheric CO2 on growth and grain yield of rice and wheat. We established a field experimental database by compiling 130 peer-reviewed studies in Chinese and English books and journals between 1985 and 2010. The results suggested that the elevated CO2 relative to ambient atmospheric CO2,on average, increased rice and wheat grain yields by 19.31% and 17.27% ,primarily due to increased ear number per plant（ ENP, 11.9% for rice and 12. 8% for wheat） and grain number per ear（ GNE, 13.4% for rice and 10.5% for wheat） ,while the contribution of grain weight was not pronounced. Similarly, the elevated CO2 increased the total biomass of rice and wheat by 22.11% and 15.86% , re- spectively, of which the increased biomass was more allocated to the belowground than aboveground components. Compared with ambient CO2 ,the highest yield and biomass of the two crops would be attained at the atmospheric CO2 of 600- 680 μmol・ mol. 1 Leaf physiological variables such as photosynthetic rates and leaf area index of rice, increased by 8.15% and 19.39% due to the elevated CO2 , while those 10.49% and 9.40% for wheat, respeetively. The fertilization effect of CO2 was much higher in the Glass House（GH） than in the other equipments, such as open top chamber（OTC） and free air CO2 enrichment （FACE）. The interactions of CO2 with other stress factors, such as high temperature, low nitrogen input and elevated atmospheric O3 would depress the fertilization effects of CO2 on growth and yield of rice and wheat crops.