Photoinhibition in seedlings of Fraxinus and Fagus under natural light conditions: implications for forest regeneration?
Photoinhibition in seedlings of Fraxinus and Fagus under natural light conditions: implications for forest regeneration?
复制标题
自然光条件下白蜡树和水青冈幼苗的光抑制：对森林再生的影响？
DOI：
10.1007/s00442-004-1591-6
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发表时间：
2004
期刊：
影响因子：
2.7
通讯作者：
J. Leverenz
中科院分区：
文献类型：
--
作者：
K. Einhorn;E. Rosenqvist;J. Leverenz
以白蜡树（Fraxinus excelsior L.）和山毛榉（Fagus sylvatica L.）幼苗为试验材料，在(1)露天、(2)缝隙和(3)遮荫三个自然光水平下进行田间生长。利用完整叶片的叶绿素a荧光调节来表征光合作用的光驯化，并在生长季节结束时测量生长参数。白天对适应黑暗的叶片的最大光化学效率（Fv/Fm）的测量表明，白蜡在空地和林隙中比山毛榉有更高的Fv/Fm，而在遮荫地则没有。这表明在间隙和开放条件下，山毛榉的光抑制作用更大。稳态光响应曲线中PSII的工作效率（F 'q /F 'm）、电子传递速率（ETR）和光化学效率因子（F 'q /F 'v）在不同光处理下的变化大于山毛榉。两种植物对光的非光化学猝灭（NPQ）反应相似。当数据归一化为生长环境中平均最大辐照度时，所有光化学参数在处理期间的变化都有所减少，这表明两个物种的光驯化主要是通过光化学速率的调整来实现的。两个物种的热耗散调节都很小。这种模式在灰树中更强，表明在这个早期演替物种中光合能力的表型可塑性更大。与我们的预期相反，山毛榉中光抑制的积累似乎对相对于灰的总生物量积累没有负面影响。
Ash (Fraxinus excelsior L.) and beech (Fagus sylvatica L.) seedlings were grown in the field under three levels of natural light: (1) open, (2) gap and (3) shade. Light acclimation of photosynthesis was characterized by means of modulated chlorophyll a fluorescence of intact leaves and growth parameters were measured at the end of the growing season. Measurements of maximum photochemical efficiency (Fv/Fm) of dark-adapted leaves at intervals through the day showed that ash had a higher Fv/Fm than beech in open and gap plots but not in shade plots. This indicated a larger build-up of photoinhibition in beech under gap and open conditions. Steady-state light response curves of the operating efficiency of PSII (F′q/F′m), the electron transport rate (ETR) and the photochemical efficiency factor (F′q/F′v) showed greater variability across light treatments in ash than in beech. Both species exhibited similar responses of non-photochemical quenching (NPQ) to light. When the data were normalized to the mean maximum irradiance in the growth environment, all photochemical parameters showed a reduction in variation across treatments, indicating that light acclimation in the two species occurred primarily through adjustments in rates of photochemistry. Adjustments in thermal heat dissipation were small in both species. This pattern was stronger in ash, suggesting a greater degree of phenotypic plasticity in photosynthetic capacity in this earlier successional species. Contrary to our expectations, the build-up of photoinhibition in beech did not appear to have a negative effect on total biomass accumulation relative to ash.
影响因子：
4.3
作者：
BJORKMAN, O;DEMMIG, B
通讯作者：
DEMMIG, B