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人工设置长日照和短日照2种光周期(以自然条件为对照),测定6年生春捷桃树叶片光合参数和叶绿素荧光快速诱导动力学参数,研究诱导休眠期间光周期对北方落叶果树光合性能的影响.结果表明:短日照条件下树体可提前进入休眠诱导期,长日照条件下则延后进入.休眠诱导期间,桃树叶片净光合速率(Pn)、气孔导度(gs)降低,胞间CO2浓度(Ci)升高,表明Pn降低的原因是非气孔限制;PSⅡ的最大光化学效率φPo(或Fv/Fm)、潜在活性(Fv/Fo)、PSⅡ反应中心捕获的光能用于QA-下游的电子传递的能量比例(ψo)和光合性能指数(PIABS)均降低,表明光合电子传递链的电子传递能力受到抑制,其原因可能是PSⅡ反应中心受体侧QA-下游的电子传递链受到了伤害.长日照有利于提高休眠诱导期的光合速率,减小PIABS下降幅度,减轻光系统的受害程度,短日照则明显加深、加速光合机构的损坏.光周期的诱导效应与休眠进程相关.
The photosynthetic parameters and chlorophyll fluorescence rapid induction kinetic parameters of 6-year-old Peach tree peach were determined by manually setting two photoperiods of long-day and short-day sunshine. The photosynthetic characteristics The results showed that: under short-day conditions, the tree could enter dormancy-inducing stage in advance and the long-day illumination could delay in. During the dormancy induction, the net photosynthetic rate (Pn) and stomatal conductance (Gs) The increase of intercellular CO2 concentration (Ci) indicated that the reason for the decrease of Pn was non-stomatal limitation. The maximum photochemical efficiency of PSⅡ, φPo (or Fv / Fm), potential activity (Fv / Fo) (Ψo) and photosynthetic performance index (PIABS) of the downstream electron transfer decreased, indicating that the electron transfer ability of the photosynthetic electron transport chain was inhibited, which may be due to the QA-downstream electron transport chain on the acceptor side of the PSⅡ reaction center Was harmed.Pattern sunshine is conducive to improve the photosynthetic rate during dormancy induction, reduce the decline of PIABS and reduce the damage degree of light system, the short day is significantly deepened to accelerate the damage of photosynthetic apparatus. Lead effect and sleep process related.