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高温胁迫下苋菜的叶绿素荧光特性

陈梅,唐运来**   

  1. (西南科技大学生命科学与工程学院, 四川绵阳 621010)
  • 出版日期:2013-07-10 发布日期:2013-07-10

Chlorophyll fluorescence characteristics of Amaranthus tricolor L. under high temperature stress.

CHEN Mei, TANG Yun-lai**   

  1. (School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, Sichuan, China)
  • Online:2013-07-10 Published:2013-07-10

摘要:

为了探明高温胁迫对苋菜(Amaranthus tricolor L.)光合过程的影响,用不同温度(25、30、35、40、45 ℃)处理苋菜植株1 h后,随即测定了其叶绿素荧光动力学参数和快速光响应曲线特征参数的变化。结果表明:40 ℃以上高温胁迫下,苋菜叶片的光系统Ⅱ(PSⅡ)潜在光化学效率(Fv/Fo)、最大光化学效率(Fv/Fm)下降;最大荧光(Fm)、光合电子传递速率(ETR)、PSⅡ实际光化学效率(Yield)、光化学淬灭系数(qP)也均有所下降;而初始荧光(Fo)和非光化学淬灭系数(NPQ)在40 ℃以上高温胁迫下显著上升。叶绿素荧光快速光响应曲线测定结果表明,初始斜率α、最大相对电子传递速率ETRmax和半饱和光强Ik在40 ℃以上高温胁迫下有所下降。研究表明,40 ℃以上高温胁迫对苋菜的光能的吸收、转换、光合电子传递和强光耐受能力等均有一定的影响。
 

关键词: 能量平衡方程, 时空尺度, 热岛效应

Abstract: Amaranth (Amaranthus tricolor L.) plants were exposed to several temperature levels (25, 30, 35, 40, and 45 ℃) for 1 h, and then, the characteristic parameters of chlorophyll fluorescence and the rapid light response curves of photosynthesis were measured, aimed to understand the effects of high temperature stress on the photosynthesis process of amaranth. High temperature stress (>40 ℃) decreased the maximum fluorescence (Fm), potential photochemical efficiency (Fv/Fo), and maximum photochemical efficiency of PSⅡ (Fv/Fm). Simultaneously, the electron transport rate (ETR), actual photochemical efficiency of PSⅡ (Yield), and photochemical quenching coefficient (qP) also had some decrease. In contrast, the initial fluorescence (Fo) and nonphotochemical quenching coefficient (NPQ) were increased significantly. The initial slope rate (α), maximum apparent electron transport rates (ETRmax), and halfsaturation light intensity (Ik) under high temperature stress also had some decline. These results indicated that the photosynthesis of A. tricolor plants was very sensitive to high temperature stress. High temperature (>40 ℃) disturbed the A. tricolor plant’s light energy absorption and conversion, photosynthetic electron transport efficiency, and endurance against strong light.

Key words: heat island effect, energy balance function, spatiotemporal scale.