植物生态学报 ›› 2014, Vol. 38 ›› Issue (4): 375-386.DOI: 10.3724/SP.J.1258.2014.00034

所属专题: 青藏高原植物生态学:生理生态学

• 研究论文 • 上一篇    下一篇

青藏高原春小麦叶片光合作用的光抑制及PSII反应中心光化学效率的恢复分析

师生波1(), 张怀刚1, 师瑞2, 李妙1,3, 陈文杰1, 孙亚男1,3   

  1. 1中国科学院西北高原生物研究所, 高原生物适应与进化重点实验室, 西宁 810001
    2中山大学生命科学学院, 广州 510275
  • 收稿日期:2013-11-28 接受日期:2014-02-11 出版日期:2014-11-28 发布日期:2014-04-08
  • 作者简介:*E-mail:sbshi@nwipb.cas.cn
  • 基金资助:
    国家自然科学基金(30670307);中国科学院重要方向性项目(KSCX3-EW-N-02-3);青海省自然科学基金(2013-Z-915)

Assessment of photosynthetic photo-inhibition and recovery of PSII photochemical efficiency in leaves of wheat varieties in Qinghai-Xizang Plateau

SHI Sheng-Bo1(), ZHANG Huai-Gang1, SHI Rui2, LI Miao1,3, CHEN Wen-Jie1, SUN Ya-Nan1,3   

  1. 1Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810001, China
    2College of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China; and 3University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2013-11-28 Accepted:2014-02-11 Online:2014-11-28 Published:2014-04-08

摘要:

在青海省都兰县香日德镇东盛村, 以中国科学院西北高原生物研究所培育的春小麦(Triticum aestivum)品种为材料, 主要采用调制叶绿素荧光分析手段, 研究了抽穗期旗叶光合作用的光抑制现象, 并分析了非光化学猝灭组分的光诱导和非光诱导耗散的量子产量变化。结果表明, 高原春小麦各品种间旗叶光合色素含量和比叶重存在差异; 全晴天3个典型时段准确暗适应20 min后的PSII最大光化学效率(Fv/Fm)的比较分析证实, 高原春小麦存在着光合作用的光抑制现象, Fv/Fm的降低是由于PSII反应中心的可逆失活; 稳态作用光下PSII有效光化学效率(Fv′/Fm′)易受持续强光胁迫的影响, 而PSII实际光化学效率(ΦPSII)在各春小麦品种间的差异略为明显; 上下午间4个春小麦品种的光化学猝灭系数(qP)和非光化学猝灭系数(NPQ)呈较一致的变化趋势, 显然qPNPQ既属品种的内禀特性, 又与强太阳光胁迫的累积密切相关; 非光化学猝灭组分中光诱导的PSII调节性能量耗散的量子产量(ΦNPQ)所占比例较大, 下午时分ΦNPQ的上调反映了高原春小麦对青藏高原持续强光胁迫的驯化适应。

关键词: 叶绿素荧光, 强光胁迫, 光抑制, PSII光化学效率, 青藏高原, 春小麦

Abstract:

Aims Several local varieties of wheat (Triticum aestivum) developed by Northwest Institute of Plateau Biology, Chinese Academy of Sciences, are widely cultivated in the agricultural regions in Qinghai-Xizang Plateau. These varieties are well adapted to multiple environmental stresses such as low temperature, strong solar radiation, and drought. The objective of this study was to determine the responses of PSII photochemical efficiency to high solar irradiance in leaves of four wheat varieties. We examined whether photo-inhibition was appeared in wheat varieties and analysed variations of quantum yield of quenching due to light-induced and non-light-induced.
Methods Field experiments were conducted on the farmland of Xiangride, which is located in the eastern side of Caidamu Basin, Qinghai Province. Four local wheat varieties were used during the heading stage in 2013. Measurements of photochemical efficiency and quantum yield were made on the abaxial surface of flag leaves facing the Sun by using a FMS-2 fluorometer, and the content of photosynthetic pigments and specific leaf weight (SLW) were concurrently determined. Pulse-modulated in-vivo chlorophyll fluorescence technique was used to obtain rapid information on photosynthetic processes. The maximum quantum efficiency of PSII photochemistry (Fv/Fm) was determined at 8:30, 12:00 and 16:30 on clear days after allowing for 20 min dark adaptation with leaf clips. The PSII maximal and actual photochemical efficiency (Fv′/Fm′ and ΦPSII), the PSII photochemical and non-photochemical quenching coefficient (qP and NPQ) were analyzed between morning and afternoon using inner actinic light with photosynthetically active photon flux density at 1120 μmol photons∙m-2∙s-1. Furthermore, along with analysis of the fraction of PSII reaction centers that are opened (qL), the quantum yield of quenching due to light-induced processes (ΦNPQ) and non-light-induced processes (ΦNO) were explored.
Important findings There were significant differences in the content of photosynthetic pigments and SLW among the four wheat varieties. Under conditions of clear days, the flag leaves exhibited marked depressions in Fv/Fm at three typical times when determined after 20 min dark adaptation. At a given light intensity, the values of Fv′/Fm′ were significantly reduced in the afternoon due to influences by long-lasting high-light irradiation, and ΦPSII showed little differences among the four wheat varieties and no difference between morning and afternoon. There were almost similar variations in qP and NPQ among the four wheat varieties, suggesting that qP and NPQ belong to instinct property and are influenced by the accumulative stresses of high-light intensity. The fractions of ΦNPQ were higher than that of ΦNO in the four wheat varieties and the up-regulatory of ΦNPQ in the afternoon indicated that the photosynthetic apparatus in these wheat varieties had already acclimated to strong solar irradiation in agricultural regions of Qinghai-Xizang Plateau.

Key words: chlorophyll fluorescence, high-light stress, photosynthetic photo-inhibition, PSII photochemical efficiency, Qinghai- Xizang Plateau, spring wheat