The greater seedling high-light tolerance of Quercus robur over Fagus sylvatica is linked to a greater physiological plasticity
The greater seedling high-light tolerance of Quercus robur over Fagus sylvatica is linked to a greater physiological plasticity
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DOI：
10.1007/s00468.002.0184.4
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发表时间：
2002-08-01
影响因子：
2.3
通讯作者：
Dreyer, E
中科院分区：
文献类型：
--
作者：
Valladares, F;Chico, JM;Dreyer, E
四种不同光环境对栎、山毛榉幼苗生长的影响在法国南西的一个森林苗圃中生长了2年后，在夏季期间探索了（全50%、40%和15%的阳光）和快速增加的辐照度。山毛榉的根冠比、叶大小、叶重量比高于橡木，而解剖结构比则相反。（气孔密度、表皮厚度、栅栏薄壁组织的交换表面积）和生理（最大光合速率气孔导度Rubisco活性）变量黎明前光化学效率（F-v/F-m）在除15%光照外的所有光环境中，栎的最大光合速率（A（max））均高于山毛榉，而在100%光照下，山毛榉的最大光合速率（A（max））显著低于其它光环境，而栎的最大光合速率（A（max））则不显著高于其它光环境两种植物的Rubisco活性均随光照强度的增加而增加，但始终以橡树高于山毛榉。在全光照条件下，橡树的Rubisco活性高于山毛榉。m，山毛榉比橡木大，移植的橡木而不是山毛榉植株逐渐恢复到对照的F-v/F-。m值在强光下观察到的叶绿素含量的降低和非光化学猝灭的增加不足以避免光抑制。对强光的耐受性与增强的生理可塑性（与光合作用相关的变量）有关，而耐荫性依赖于光捕获变量（树冠形态和叶绿素含量）的可塑性增强。
The responses of Quercus robur (oak) and Fagus sylvatica (beech) seedlings to four different light environments (full 50% 40% and 15% sunlight) and to a rapid increase in irradiance were explored during the summer after 2 years of growth in a forest nursery at Nancy (France) Significant differences between the two species were found for most variables Phenotypic plasticity for morphological variables (root shoot ratio leaf size leaf weight ratio) was higher in beech than in oak while the reverse was true for anatomical (stomatal density epidermis thickness exchange surface area of the palisade parenchyma) and physiological (maximum photo synthetic rate stomatal conductance Rubisco activity) variables Predawn photochemical efficiency (F-v/F-m) was higher in oak than in beech in all light environments except in 15% sunlight F-v/F-m was significantly lower in 100% sunlight than in the other light environments in beech but not in oak Maximum photosynthetic rates (A(max)) increased with increasing light availability in the two species but they were always higher in oak than in beech Oak exhibited higher Rubisco activity than beech in full sunlight The transfer of shade adapted seedlings to the open caused a decrease of F-v/F-m which was larger for beech than for oak Transferred oak but not beech plants recovered gradually to the control F-v/F-m values The decreased chlorophyll content and the increased non photochemical quenching observed in high light beech seedlings were not enough to avoid photoinhibition The results suggest that a greater tolerance of strong irradiance is linked to an enhanced physiological plasticity (variables related to photosynthesis) while shade tolerance relies on an enhanced plasticity in light harvesting variables (crown morphology and chlorophyll content).