Zhao Liying, Deng Xiping, Shan Lun
Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Northwestern Sci Tech University of Agriculture and Forestry, Yangling, China.
Ying Yong Sheng Tai Xue Bao. 2005 Jul;16(7):1261-4.
By using chlorophyll fluorescence kinetics technology, this paper determined the chlorophyll fluorescence parameters Fv/Fm, phiPSII, qP, qNP, ETR of winter wheat seedling under simulated osmotic stress. The results showed that with the increase of osmotic stress, Fv/Fm and Fv/Fo had the trend of decrease-increase-decrease, indicating that photoinhibition did not happen at the first stage of osmotic stress, but the followed increase of Fv/Fm resulted in the photoinhibition and the decrease of phiPSII and ETR. During the course of osmotic stress, qP and qNP decreased firstly and then increased, which was helpful to enhance the open ratio of PSII reaction center, and made more photosynthetic energy use the photosynthetic electron transport to enhance the electron transport capacity. Meanwhile, the increase of non-photochemical quenching coefficient could be helpful to dissipate excess light energy, which protected the photosynthetic tissue, and mitigated the effect of environment on photosynthesis. All the results indicated that wheat seedling had its protection mechanism. Between the two test winter wheat varieties, Changwu 134 had a higher drought-resistance capacity than Shan 253.
利用叶绿素荧光动力学技术，测定了模拟渗透胁迫下冬小麦幼苗的叶绿素荧光参数Fv/Fm、phiPSII、qP、qNP、ETR。结果表明，随着渗透胁迫的增加，Fv/Fm和Fv/Fo呈先降低后升高再降低的趋势，表明在渗透胁迫初期未发生光抑制，但随后Fv/Fm的升高导致了光抑制以及phiPSII和ETR的降低。在渗透胁迫过程中，qP和qNP先降低后升高，这有助于提高PSII反应中心的开放比例，使更多的光合能量用于光合电子传递以增强电子传递能力。同时，非光化学猝灭系数的增加有助于耗散过剩光能，保护光合组织，减轻环境对光合作用的影响。所有结果表明，小麦幼苗具有自身的保护机制。在两个供试冬小麦品种中，长武134的抗旱能力高于陕253。
