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作 者 ：梁芳, 郑成淑, 孙宪芝, 王文莉

期 刊 ：应用生态学报 2010年 21卷 01期 页码：29-35

关键词：菊花；低温；弱光；光合作用；叶绿素荧光参数；

Keywords:chrysanthemum, low temperature, weak light, photosynthesis, chlorophyll fluorescence parameter,

摘 要 ：

以切花菊品种‘神马’为试材，在偏低温弱光（16 ℃/12 ℃，PFD 100 μmol·m^-2·s^-1）和临界低温弱光（12 ℃/8 ℃，PFD 60 μmol·m^-2·s^-1）下分别胁迫11 d，然后转入正常条件（22 ℃/18 ℃，PFD 450 μmol·m^-2·s^-1）恢复11 d，研究不同低温弱光强度及恢复对菊花光合作用和叶绿素荧光参数的影响.结果
表明：低温弱光导致菊花叶片的净光合速率（P_n）和气孔限制值（L_s）下降，而胞间CO₂浓度（C_i）上升.偏低温弱光胁迫下菊花叶片暗适应下最大光化学效率（F_v/F_m）和初始荧光（F_o）无明显变化，但光适应下最大光化学效率（F_v‘/F_m‘）在处理前期略有下降，后期则有所回升；而临界低温弱光处理的F_o明显升高，F_v/F_m和F_v‘/F_m‘显著降低.PSⅡ光合电子传递量子效率（Φ_PSⅡ）、光化学猝灭系数（q_P）和表观光合电子传递速率（ETR）均随着低温弱光胁迫程度的增加和时间的延长而降低；偏低温弱光处理植株在解除胁迫后能迅速恢复到对照水平，而临界低温弱光处理植株回升速度较慢；同时，低温弱光胁迫下吸收光强用于分配光化学反应部分（Prate）的比例减少，而天线热耗散（Drate）和反应中心的能量耗散（Ex）比例上升，但天线热耗散为过剩光能的主要分配途径.

Abstract:

The cut flower chrysanthemum ‘Jinba’ was respectively treated with lower temperature and weaker light (16 ℃/ 12 ℃, PFD 100  μmol·m^-2·s^-1) and critical low temperature and weak light (12 ℃/8 ℃, PFD 60 μmol·m^-2·s^-1 ) for 11 days, and then transferred to normal condition (22 ℃/18 ℃, PFD 450 μmol·m^-2·s^-1) for 11 days, aimed to study the low temperature and weak light stress and its recovery on the photosynthesis and chlorophyll fluorescence of chrysanthemum leaves. Under the stress of lower temperature and weaker light, the net photosynthetic rate (P_n) and stomatal limitation (L_s) of chrysanthemum leaves decreased while the intercellular CO₂ concentration (C_i) increased, the maximal photochemical efficiency of
PSⅡ(F_v/F_m) in dark and the initial fluorescence (F_o) had no obvious change, but the maximal photochemical efficiency of PSⅡ (F_v‘/F_m′) in light increased after an initial decrease. Contrarily, under the stress of critical low temperature and weak light, the F_o increased, and the F_v/F_m and F_v‘/F_m‘ decreased significantly. The quantum yield of PSⅡelectron transport (Φ_PSⅡ), photochemical quenching (q_P),and apparent photosynthetic electron transfer rate (ETR) of chrysanthemum leaves decreased with increasing stress and time, and recovered quickly after the release of lower temperature and weaker light stress but more slowly after the release of critical low temperature and weak light stress. At the same time,the photochemistry react rate (Prate) decreased, but the hot dissipation of antenna (Drate) and the energy dissipation of PSⅡ (Ex) increased under the stress conditions. Drate was the main pathway of superfluous light allocation.

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