不同供磷水平对温州蜜柑叶片光合作用的影响

用营养液培养的方法 ,研究了不同供磷水平对温州蜜柑叶片光合作用的影响。结果表明 ,在缺磷培养条件下 ,叶片中无机磷含量 (Pi)、Rubisco活性、RuBP再生速率、表观量子效率 (AQY)、光化学效率 (Fv/Fm)及电子传递速率 (ETR)下降 ,光呼吸速率 (Pr)与净光合速率 (Pn)之比升高 ,光系统Ⅱ反应中心可逆失活 ,但对叶片叶绿素含量影响不显著。给缺磷培养的植株叶片喂KH2PO4,Pn、Rubisco活性、RuBP再生速率、光化学效率、光系统Ⅱ反应中心的活性及Pr/Pn比值可得到迅速恢复。在营养液磷浓度过高条件下 ,叶片中的Pi升高 ,Pn、Rubisco活性及RuBP再生速率下降 ,对叶绿素含量、Pr、AQY、叶绿素荧光参数及ETR影响不大

Effects of different phosphorus nutrition levels on photosynthesis in satsuma mandarin (Citrus unshiu Marc.) leaves

The effects of different phosphate levels on the photosynthesis of satsuma mandarin(Citrus unshiu Marc ) leaves were studied in the culture solution It shows that under the lack of phosphate, phosphate content, Rubisco activity, rate of RuBP regeneration, apparent quantum yield (AQY), photochemical efficiency of PSⅡ(Fv/Fm)and electron transport rate (ETR) decrease, in addition, the ratio of photorespiratory rate (Pr) to net photosynthetic rate (Pn) go up; PSⅡ reaction centers is reversible inactivation; chlorophyll content change unsignally After supplying leaves being lack of phosphate with 20 mmol/L KH₂PO₄ for 12 hours, the Pn, rubisco activity, rate of RuBP regeneration, AQY, photochemical efficiency of PSⅡ, PSⅡ reaction centers activity and ETR come back rapidly, and the Pr/Pn decrease The Pn, rubisco activity and rate of RuBP regeneration declined, while phosphorus content increased in the surplus phosphate, but the chlorophyll content, Pr, AQY, chlorophyll fluorescence parameters Fo, Fv/Fm, and the ETR keep the stabilization basically