【摘要】 用叶绿素荧光技术研究了低夜温后光照对榕树与海桐叶片光合电子传递和吸收光能分配的影响.结果表明:低夜温胁迫及随后的光照导致榕树叶片质子醌(PQ)还原程度增加,光合电子传递速率受阻,引起光化学速率的降低,虽然榕树叶片能通过增强热耗散消耗部分过量光能,但其光化学能力的下降导致了光系统Ⅱ(PSⅡ)反应中心过剩激发能的增加;而低夜温后光照并未导致海桐叶片PQ还原程度增加与光合电子传递速率受阻,叶片吸收光能主要分配于光化学反应和热耗散,未引起PSⅡ反应中心的过剩激发能增加.更多还原

【Abstract】 In this study,the effects of full sunlight after low night temperature on photosynthetic electron transport and absorbed light allocation in leaves of and Pittosporum tobira were examined by using chlorophyll fluorescence measurements.For Ficus microcarpa,low night temperature and light energy resulted larger extent of PQ reduction,and blocked photosynthetic electron transport,so decreased the rate of photochemistry.Although the rate of heat dissipation increased,the excess energy of PSⅡ reaction centers was increased by decrease of PSⅡ photochemistry.However for Pittosporum tobira,low night temperature and light energy did not increase the extent of PQ reduction and block photosynthetic electron transport,the absorbed light energy of leaf was dissipated by photochemistry and heat,so the excess energy of PSⅡ reaction centers was slight.更多还原