Susceptibility to low-temperature photoinhibition in three conifers differing in successional status.
Susceptibility to low-temperature photoinhibition in three conifers differing in successional status.
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DOI：
10.1093/treephys/25.9.1151
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发表时间：
2005-09
期刊：
影响因子：
4
通讯作者：
P. Robakowski
中科院分区：
文献类型：
--
作者：
P. Robakowski
常绿针叶树冷杉对光抑制的敏感性。云杉（Picea abies）岩溶。2003年冬、春季在不加热温室中对松进行了研究。通过叶绿素a荧光和针叶中叶绿素和总类胡萝卜素浓度分析来评价幼苗的光合性能。在冬季，白桦的PSII光化学最大量子产率（可变荧光与最大荧光之比，Fv/Fm）显著高于白桦和白桦。白冷杉的最大表观电子传递率（ETRmax）也高于冷杉和毛冷杉。白桦针叶中叶绿素和类胡萝卜素的总浓度在冬季呈下降趋势，而白桦针叶中叶绿素和类胡萝卜素的总浓度保持稳定。所有物种的Fv/Fm在12月至2月间呈下降趋势，4月达到最大值。在平均气温最低的2月份，所有幼苗的光抑制作用最大（Fv/Fm < 0.80）。饱和光合光子通量（PPFsat）和ETRmax与气温呈正相关。冬季各树种的ETRmax和PPFsat值均低于春季。叶绿素荧光非光化学猝灭（NPQ）在低温下最高。不同物种对冬季光抑制的敏感性差异源于它们对光的特定偏好，并导致了不同的光抑制机制。耐荫性较强的白杨在冬季的光合能力高于冷杉和白杨树。冷杉、白杨和白杨的冬季光抑制可能反映了光合机构在冬季的适应性光保护。
Susceptibility to photoinhibition of the evergreen conifers Abies alba Mill., Picea abies (L.) Karst. and Pinus mugo Turra was investigated in an unheated greenhouse during winter and spring 2003. Photosynthetic performance of the seedlings was assessed by chlorophyll a fluorescence and analyses of chlorophyll and total carotenoid concentrations in needles. During winter months, maximum quantum yield of PSII photochemistry (ratio of variable to maximum fluorescence, Fv/Fm) was significantly greater in A. alba than in P. abies and P. mugo. Abies alba also sustained higher maximum apparent electron transport rate (ETRmax) than P. abies and P. mugo. Total concentrations of chlorophyll and carotenoids in needles decreased during the winter in P. mugo and P. abies, but remained stable in A. alba. For all species, Fv/Fm decreased from December until February and then increased to a maximum in April. Photoinhibition was greatest (Fv/Fm < 0.80) in all seedlings in February, the month with the lowest mean temperature. Saturating photosynthetic photon flux (PPFsat) and ETRmax were positively related to air temperature. All species had lower values of ETRmax and PPFsat in winter than in spring. Non-photochemical quenching of chlorophyll fluorescence (NPQ) was highest at low air temperatures. Differences among species in susceptibility to winter photoinhibition resulted from their specific light preferences and led to different mechanisms to cope with photoinhibitory stress. The more shade-tolerant A. alba sustained a higher photosynthetic capacity in winter than P. abies and P. mugo. Winter photoinhibition in P. abies, P. mugo and, to a lesser extent, in A. alba may reflect adaptive photoprotection of the photosynthetic apparatus in winter.