植物对开放式CO2 浓度增高(FACE)的响应与适应研究进展

开放式CO2浓度增高(FACE)系统是近年研究植物对高CO2浓度响应和适应的新手段,它比以往密闭和半密闭系统对实验植物生长环境的干扰少.利用FACE系统进行研究更有助于正确地预测未来大气CO2浓度增高对植物的影响.该文结合作者的研究工作简要评介了FACE系统与以往密闭和半密闭式CO2浓度增高实验系统的不同之处以及近年来利用FACE系统所作的最新研究进展.

Advances in the Study on Response and Acclimation of Plants to Free-Air CO2 Enrichment(FACE)

Free-air CO 2 enrichment (FACE) technique is a new method to study the effects of elevated CO 2 on plants developed in the mid 1980s for overcoming the limitation of chamber-based methods using plants grown in greenhouses, controlled-environment chambers, open-top chambers (OTC). The plants grown under FACE are more like a natural system compared with other methods. The plants grown in FACE system can be free from considerable influences induced by limited pot size and the effects of enclosures on environment factors, such as solar radiation, temperature, wind speed and humidity. The much larger plot area used in FACE system means that larger plant material can be collected for analysis. However, the relatively high cost of FACE systems, both building and running, is the major disadvantage for its wide application. Compared with chamber-based CO 2 enrichment systems, there were many different results in FACE experiments, such as the stomatal conductance (Gs) of leaves is decreased to a lesser extent, the biomass and the root/shoot-ratio is stimulated much more, but the amplitude of crop yield increase is smaller. These differences can be explained with the temperature changes, limitation of root growth and other enclosure effects on environment in chamber-based methods. And the acclimation of photosynthesis has been explained by the limitation of root growth in other chamber-based experiments. The study of FACE begins to probe into the physiological, biochemical and molecular mechanisms for some phenomenon of acclimation to high CO 2. How does the photosynthetic acclimation occur?How does the elevated CO 2 concentration lead to the prematurity of crop? How does the activity of root effect on the crop prematurity? And how can keep with the quality of crop grain? These interesting questions need more experiments under FACE conditions to explore.