大气CO_2升高对大豆生理指标及产量影响的研究进展

Research Advances on Physiological Parameters and Yield of Soybean in Response to Elevated CO_2

在全球气候变化过程中,大气CO2浓度不断升高,已从工业革命前的270μmol·L-1升高到2013年的390μmol·L-1,预计到本世纪末将达到700μmol·L-1,CO2浓度的快速升高将对大豆生产产生重要影响。本文从光合速率、叶面积、叶绿素含量、共生固氮、内源激素、以及干物质积累和大豆产量等方面综述了大气CO2浓度升高产生的影响。大多数研究发现,随着大气CO2浓度升高,大豆光合速率随之升高,但少数研究发现,随大气CO2浓度升高,光合速率反而降低,这可能与植物对CO2浓度升高的光合适应反应有关;叶绿素含量随CO2浓度升高呈现增加趋势,但对一些夏大豆研究发现,叶绿素含量无明显变化;叶面积、共生固氮、干物质积累和产量也都对CO2升高产生不同程度的响应,但响应程度因CO2升高幅度、大豆品种、生育时期和其他试验条件而有所差异;有关于CO2升高对内源激素影响的研究报导较少。针对未来所需要开展的研究,我们提出与光合作用相关酶学生理、内源激素以及碳氮代谢角度对CO2影响大豆产量机制进行深入解析,而且在不同品种之间对CO2浓度升高的响应进行分析,明确品种之间是否存在差异。这将对未来大豆高产育种,提高大豆生长的环境适应性有重要的理论价值;并提出了今后的研究方向。

During global climate change,the concentration of CO2 in the atmosphere has increased from 270 μmol·L- 1prior to the Industrial Revolution to 390 μmol·L- 1in 2013. It is expected that CO2 will increase to 700 μmol·L- 1by the end of the century. The increase of atmospheric CO2 concentration is likely to affect soybean production. The impacts of elevated CO2 on photosynthetic rate,leaf area,chlorophyll content,phytohormones,nitrogen fixation,biomass accumulation and yield are reviewed. Many studies stated that photosynthetic rate of soybean had positive response to elevated CO2,while a decrease trend was observed in other studies. This is likely due to photosynthetic acclimation in response to elevated CO2. Elevated CO2 generally facilitates the accumulation of the chlorophyll content,but there was no response in some summer-sowing cultivars of soybean. The magnitude of leaf area,nitrogen fixation,biomass and yield in response to elevated CO2 varied depending on the extent of CO2 rise,cultivars,growth stages and other experimental conditions. The information on the effect of elevated CO2 on phytohormones is very rare to our knowledge. It is worth further investigating on the mechanisms of yield in response to elevated CO2,including enzyme activities in relevant photosynthetic physiology,and metabolisms of carbon and nitrogen etc. Such work is fundamental to the high-yield breeding and the improvement of environmental adaptability in soybean in the future.