Winter Klaus, Lesch Maria
Lehrstuhl für Botanik II, Mittlerer Dallenbergweg 64, W-8700, Würzburg, Federal Republic of Germany.
Oecologia. 1992 Oct;91(4):505-510. doi: 10.1007/BF00650323.
Diurnal changes in chlorophylla fluorescence were determined in four species, differing in life form, in Portugal during the summer of 1989. These includedOpuntia ficus-indica, a CAM plant, andHelianthus annuus, Ficus carica andArbutus unedo, three C species. Steady state fluorescence yield,F , and maximum fluorescence yield,F ', were determined at different times of the day. Using the model of Genty et al. (1989), the photon use efficiency of photosystem II electron transport,φ , was calculated from (F '-F )/F '. Diurnal changes in relative rate of non-cyclic electron transport through photosystem II,J , were derived by multiplyingφ by the incident photon flux density (PFD). WhenJ , determined for each species for various points in time throughout the day, was plotted against corresponding values of PFD, the light response curves obtained showed thatJ was linearly dependent on PFD in low light and approached saturation in high light. The highest values ofJ were observed inHelianthus annuus, followed byOpuntia ficus-indica, Ficus carica andArbutus unedo. The proportion of the xanthophyll zeaxanthin to total carotenoids, determined around noon, was inversely related to maximum rates ofJ .
1989年夏季，在葡萄牙对四种生活型不同的植物的叶绿素a荧光日变化进行了测定。这些植物包括仙人掌科的肉质植物印度榕仙人掌，以及三种C3植物，分别是向日葵、无花果和草莓树。在一天中的不同时间测定了稳态荧光产量（F）和最大荧光产量（F'）。根据Genty等人（1989年）的模型，通过（F'-F）/F'计算光系统II电子传递的光子利用效率（φ）。通过将φ乘以入射光量子通量密度（PFD）得出光系统II非循环电子传递相对速率（J）的日变化。当将一天中不同时间为每个物种测定的J值与相应的PFD值作图时，得到的光响应曲线表明，在低光条件下J与PFD呈线性相关，在高光条件下接近饱和。向日葵的J值最高，其次是印度榕仙人掌、无花果和草莓树。中午左右测定的叶黄素与总类胡萝卜素的比例与J的最大速率呈负相关。
