小麦光合特性、气孔导度和蒸腾速率对大气CO_2浓度升高的响应  

Responses of Photosynthetic Characteristics,Stomatal Conductanceand Transpiration of Wheat to the Increase of Atmospheric CO_2 Concentration

作　　者：蒋跃林[1] 张庆国[1] 张仕定[2] 王公明[1] 岳伟[1] 姚玉刚[1] 

机构地区：[1]安徽农业大学资源与环境学院,合肥230036 [2]中国科技大学理化测试中心,合肥230026

出　　处：《安徽农业大学学报》2005年第2期169-173,共5页Journal of Anhui Agricultural University

基　　金：国家自然科学基金项目(70271062)资助。

摘　　要：通过对不同大气CO2 浓度处理小麦的观测,研究大气CO2 浓度升高对小麦净光合速率、气孔导度、蒸腾速率、水分利用效率以及叶绿素含量等光合生理特性的影响,讨论了未来高CO2 条件下小麦水分利用效率的变化趋势。结果表明,与背景大气CO2 浓度350μmol·mol-1相比,当大气CO2 浓度为550和750μmol·mol-1时,小麦抽穗期日平均净光合速率分别提高20 8%和29 7%,并消除了光合午休现象。在不同生育期净光合速率提高幅度存在差异。气孔导度随CO2 浓度增加而下降,不同生育期平均降低15 3%和21 7%,小麦蒸腾速度则平均下降4 5%和9 4%。在2种高CO2 水平下,小麦水分利用效率显著提高,提高幅度分别为19 2%~25 7%和32 2% ~45 6%。同时使抽穗期小麦叶片叶绿素a、叶绿素b、叶绿素总量和类胡萝卜素含量分别提高11 0% ~14 8%、13 0% ~18 2%、11 5% ~15 7%和15 3% ~23 5%,但叶绿素a与叶绿素b的比值降低。The net photosynthesis (Pn),stomatal conductance(Cs),transpiration(Tr),water use efficiency(WUE) and chlorophyll content of wheat leaves under ambient and elevated CO_2 levels were measured, and their responses to the increase of CO_2 were discussed. The results showed that daily average Pn increased by 20.8% and 29.7% at earing stage under 550 and 750 μmol·mol^(-1),compared to the ambient air CO_2 concentration. At the same time, midday depression of photosynthesis disappeared. The average Cs decreased by 15.3% and 21.7% at different growth stages with air CO_2 enrichment. The average Tr reduced by 4.5% and 9.4%.WUE increased significantly by 19.2%~25.7% and 32.2%~45.6% in two elevated CO_2 levels. It was also found that chlorophyll a ,chlorophyll b, chlorophyll and carotenoid contents of wheat leaves increased by 11.0%~14.8%,13.0%~18.2%, 11.5%~15.7% and 15.3%~23.5% at earing stage. However, the ratio of chlorophyll a to chlorophyll b reduced under two elevated CO_2 conditions.

关 键 词：CO2增加 小麦 净光合速率 气孔导度 叶绿素 

分 类 号：S512.101[农业科学—作物学]