大气CO_2浓度与温度升高对茶树光合系统及品质成分的影响

Effects of elevated atmospheric CO_2 concentration and temperature on photosynthesis system and quality components in tea plant

[目的]探究大气CO2浓度与温度升高对茶树光合系统及品质成分的影响,为未来气候变化条件下茶树栽培管理和茶叶加工提供科学依据。[方法]以‘龙井长叶’茶苗为材料,通过开顶式气室模拟高CO2浓度（648～658μmol·mol-1）和温度升高（＋0.57℃）,测定不同处理下茶树叶片光合参数、叶绿素荧光参数、叶绿素含量和品质成分含量,研究茶树光合系统及品质成分的变化情况。[结果]CO2浓度升高、温度升高、CO2浓度和温度共同升高,茶树叶片光合参数、叶绿素荧光参数与对照相比有显著变化。CO2浓度升高、温度升高能促进茶树叶片叶绿素a、叶绿素b合成,但与对照相比无显著变化,CO2浓度和温度共同升高能显著增加茶树叶片叶绿素a、叶绿素b含量。CO2浓度升高、温度升高、CO2浓度和温度共同升高均显著降低了茶树叶片中游离氨基酸和咖啡碱含量,而使茶多酚含量显著增加,酚氨比显著升高。[结论]CO2浓度升高、温度升高、CO2浓度和温度共同升高都能通过改善茶树叶片光系统结构促进光合作用,进而影响茶叶品质成分。在对茶树光合系统和品质成分的影响中,CO2浓度升高和温度升高表现出协同作用。

[Objectives] This study aimed at evaluating the effects of elevated atmospheric CO2 concentration and temperature on photosynthesis system and quality components in tea plant.[Methods] Elevated atmospheric CO2 concentrations（648-658 μmol·mol-1）and elevated temperature（＋0.57℃）were investigated in this study using cultivar‘Longjingchangye’as the material by open-top chambers. Photosynthetic parameters,chlorophyll fluorescence parameters,chlorophyll content and quality components of tea leaves under different treatments were measured.[Results] Elevated CO2 concentration,elevated temperature,and both elevated CO2 and temperature had significant effects on photosynthetic parameters and chlorophyll fluorescence parameters in tea leaves compared with the control. Elevated CO2 concentration and elevated temperature promoted the synthesis of chlorophyll a and chlorophyll b in tea leaves,but the increase was not significant. Both elevated CO2 and temperature significantly increased the chlorophyll a and chlorophyll b contents in tea leaves. Elevated CO2 concentration,elevated temperature,and both elevated CO2 and temperature significantly reduced the content of amino acids and caffeine in tea leaves,while increased the content of polyphenols and the ration of polyphenols and amino acids.[Conclusions] Elevated CO2 concentration,elevated temperature,and both elevated CO2 and temperature can promote the photosynthesis of tea leaves by improving the structure of photosynthetic system,there by affecting the quality components. Elevated CO2 concentration and elevated temperature showed a synergistic effect on photosynthesis system and quality components of tea plant.