中国沙漠 ›› 2017, Vol. 37 ›› Issue (3): 475-482.DOI: 10.7522/j.issn.1000-694X.2016.00021

• 生物与土壤 • 上一篇    下一篇

油蒿(Artemisia ordosica)光系统Ⅱ光化学效率对去除降雨的响应

张明艳, 贾昕, 查天山, 秦树高, 吴雅娟, 任才   

  1. 北京林业大学 水土保持学院/宁夏盐池毛乌素沙地生态系统国家定位观测研究站/水土保持国家林业局重点实验室, 北京 100083
  • 收稿日期:2015-12-03 修回日期:2016-03-01 出版日期:2017-05-20 发布日期:2017-05-20
  • 通讯作者: 贾昕(
  • 作者简介:张明艳(1990-),女,河北唐山人,硕士研究生,主要从事沙生植物生理生态过程研究。
  • 基金资助:

PSII Photochemical Efficiency of Artemisia ordosica in Response to Rainfall Exclusion

Zhang Mingyan, Jia Xin, Zha Tianshan, Qin Shugao, Wu Yajuan, Ren Cai   

  1. School of Soil and Water Conservation/Yanchi Research Station/Key Laboratory of Soil and Water Conservation of State Forestry Administration, Beijing Forestry University, Beijing 100083, China
  • Received:2015-12-03 Revised:2016-03-01 Online:2017-05-20 Published:2017-05-20

摘要: 认识植物生理特征对极端干旱的响应有助于理解和预测气候变化对生态系统过程的影响。通过对叶绿素荧光连续监测,研究了油蒿(Artemisia ordosica)光系统II(PSII)最大光化学效率(Fv/Fm)、实际光化学效率(ΦPSII)和非光化学淬灭(NPQ)对去除降雨的响应,旨在探讨干旱环境下PSII的光保护机制。结果表明:油蒿叶片ΦPSIINPQ受光合有效辐射影响呈现出明显的日变化。与对照相比,去除降雨条件下ΦPSII降低、NPQ升高。去除降雨降低了ΦPSII对环境因子的敏感性,提高了NPQ对环境因子的敏感性。去除降雨条件下Fv/Fm的降低是由于PSII反应中心的可逆性失活。这些结果表明极端干旱影响油蒿PSII光化学效率;油蒿通过增加非辐射热耗散来抵抗干旱胁迫。

关键词: 叶绿素荧光, 降雨, PSII光化学效率, 干旱半干旱区

Abstract: Understanding the adaptive strategy of psammophyte plants under drought stress has drawn much research attention. Artemisia ordosica is among the most important sand-fixing species in the Mu Us Sandland. We conducted continuous in situ measurements of chlorophyll fluorescence on A. ordosica under both rainfall exclusion and natural precipitation conditions to examine the response of PSII photochemical efficiency to water stress. Continuous measurements of the chlorophyll fluorescence parameters were made in August, 2013 at the Yanchi Research Station, Ningxia Hui Autonomous Region, northwest China. Chlorophyll fluorescence parameters were measured on Artemisia ordosica under both rainfall exclusion and natural precipitation conditions using a Monitoring-Pam fluorometer. Climatic variables were simultaneously measured with automated sensors. The maximum quantum yield of PSII photochemistry (Fv/Fm), photochemical efficiency (ΦPSII) and non-photochemical quenching (NPQ) were analyzed in relation to environmental factors at the hour and diel scales. Photosynthetically active radiation was the direct control over ΦPSII and NPQ at the diel scales. ΦPSII and NPQ were significantly different in different water cinditions. The sensitivity of ΦPSII to incident photosynthetically active radiation, air temperature and relative humidity was lower under rainfall exclusion than under natural rainfall, while the sensitivity of NPQ to these factors was increased by rainfall exclusion. The decrease of Fv/Fm was by the reversible inactivation of PSII reaction center. Our results indicated that drought stress strongly affects the dynamics of chlorophyll fluorescence parameters of Artemisia ordosica, which copes with harsh desert environments by adaptively increasing its thermal dissipation to avoid damages to the photosynthetic apparatus.

Key words: chlorophyll fluorescence, rainfall, PSII photochemical efficiency, arid and semiarid area