【摘要】 冬、春柑桔光合作用的最适温度不同,春季光合作用的最适温度高于冬季,而且冬季柑桔光合作用的最适温度远远高于环境温度,冬季柑桔的净光合速率(Pn)、Rubisco活性、RuBP再生速率、表观量子效率(AQY)、PSⅡ最大光化学效率(Fv/Fm)、光下的光化学效率(Fv′/Fm′)、光化学猝灭系数(qP)及电子传递速率(ETR)较低,PSⅡ反应中心失活或破坏,细胞间隙CO2浓度与环境CO2浓度比值(Ci/Ca)、非光化学猝灭系数(qN)较高.这些结果表明,柑桔光合作用的最适温度与环境温度变化相适应,冬季低温是限制柑桔光合作用的主要因子;光合碳代谢和光化学反应受低温限制是冬季光合作用较低的重要原因.更多还原

【Abstract】 Optimum temperature for photosynthesis of citrus leaves planted in field was lower in winter than in spring,and it was higher than environmental temperature in winter.In the winter,the net photosynthetic rate（Pn）,Rubisco activity,rate of RuBP regeneration,apparent quanturn yield（AQY）,photochemical efficiency of PSⅡ（Fv/Fm）,photochemical efficiency under light（Fv′/Fm′）,photochemical quenching coefficient（qP）,and electron transport rate（ETR）were lower,but the ratio of internal CO₂ concentration（Ci）to air CO₂ concentration（Ca）,and non-photochemica1 quenching coefficient（qN）were higher,PSⅡ reaction centers were reversibly inactivated or damaged.These results indicated that the optimum temperature for photosynthesis of citrus leaves was adaptable to the changing natural environmental temperature.Low temperature in winter limited photosynthetic carbohydrate metabolism and photochemical reaction caused low photosynthesis.更多还原