Song Lili, Guo Yanping, Xu Kai, Zhang Liangcheng
Department of Horticulture, Anhui Agricultural University, Hefei 230036, China.
Ying Yong Sheng Tai Xue Bao. 2003 Jan;14(1):47-50.
By using a portable PAM-2000 fluorometer and a spectrophotometer (722 Model), the diurnal variation in main chlorophyll fluorescence parameters such as initial fluorescence (F0), maximal fluorescence (Fm), ratio of variable fluorescence to maximal fluorescence (Fv/Fm), non-photochemical quenching (qN), fast-phase (qNf) and slow-phase (qNs) of non-photochemical quenching, electron transport rate (ETR), and relative content of xeaxanthin in Citrus unshiu leaves were observed on fine days. The results showed that ETR, qN, qNf, qNs and relative content of xeaxanthin increased with increasing light intensity, but Fm, F0, photo-chemical efficiency of PS II (Fv/Fm) decreased. After treated by DTT, qNs was much lower, but F0 was much higher than control. These results indicated that xanthophyll cycle and delta pH existed, and played an important protective role against photo-damage to the photosynthetic apparatus in Citrus unshiu leaves during diurnal variation of photosynthetic efficiency.
利用便携式PAM - 2000荧光仪和分光光度计（722型），在晴天观测了温州蜜柑叶片初始荧光（F0）、最大荧光（Fm）、可变荧光与最大荧光比值（Fv/Fm）、非光化学猝灭（qN）、非光化学猝灭的快相（qNf）和慢相（qNs）、电子传递速率（ETR）以及玉米黄质相对含量等主要叶绿素荧光参数的日变化。结果表明，ETR、qN、qNf、qNs以及玉米黄质相对含量随光照强度增加而升高，而Fm、F0、PSⅡ光化学效率（Fv/Fm）降低。经二硫苏糖醇（DTT）处理后，qNs显著降低，而F0显著高于对照。这些结果表明，叶黄素循环和ΔpH存在，在光合效率日变化过程中对温州蜜柑叶片光合机构的光破坏起到重要保护作用。
