植物生态学报 ›› 2013, Vol. 37 ›› Issue (2): 111-121.DOI: 10.3724/SP.J.1258.2013.00012

• 研究论文 • 上一篇    下一篇

贝壳砂生境干旱胁迫下杠柳叶片光合光响应模型比较

王荣荣1,2, 夏江宝2,*(), 杨吉华1, 赵艳云2,3, 刘京涛2, 孙景宽2,3   

  1. 1山东农业大学林学院, 山东泰安 271018
    2滨州学院山东省黄河三角洲生态环境重点实验室, 山东滨州 256603
    3中国矿业大学(北京)化学与环境工程学院, 北京 100083
  • 收稿日期:2012-11-13 接受日期:2012-12-19 出版日期:2013-11-13 发布日期:2013-01-31
  • 通讯作者: 夏江宝
  • 作者简介:* (E-mail: xiajb@163.com)
  • 基金资助:
    国家自然科学基金项目(31100468);国家自然科学基金项目(41201023);国家“十一五”科技支撑计划课题(2009BADB2B05);山东省自然科学基金项目(Y2006D01)

Comparison of light response models of photosynthesis in leaves of Periploca sepium under drought stress in sand habitat formed from seashells

WANG Rong-Rong1,2, XIA Jiang-Bao2,*(), YANG Ji-Hua1, ZHAO Yan-Yun2,3, LIU Jing-Tao2, SUN Jing-Kuan2,3   

  1. 1College of Forestry, Shandong Agricultural University, Taian, Shandong 271018, China
    2Shandong Provincial Key Laboratory of Eco-Environmental Science for Yellow River Delta, Binzhou University, Binzhou, Shandong 256603, China
    3College of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083, China
  • Received:2012-11-13 Accepted:2012-12-19 Online:2013-11-13 Published:2013-01-31
  • Contact: XIA Jiang-Bao

摘要:

以黄河三角洲贝壳堤岛3年生杠柳(Periploca sepium)苗木为试验材料, 模拟设置贝壳砂生境下的4种水分梯度, 利用CIRAS-2型光合作用系统测定杠柳叶片在不同干旱胁迫下的光合作用光响应过程, 采用4种光响应模型进行拟合分析, 以比较贝壳砂生境干旱胁迫下适宜的光响应模型, 探讨最佳光响应模型参数对干旱胁迫的适应规律。结果表明: 4种模型对杠柳叶片光合作用光响应过程拟合效果的优劣顺序为: 直角双曲线修正模型>非直角双曲线模型>指数模型>直角双曲线模型, 后3种模型均为没有极值的函数, 故不能很好地拟合光响应曲线光抑制过程, 并不能直接求解最大净光合速率(Pnmax)和光饱和点(LSP)。光响应参数拟合效果最佳表现为: 非直角双曲线模型的暗呼吸速率(Rd), 直角双曲线模型的光补偿点(LCP), 直角双曲线修正模型的PnmaxLSP。4种光响应模型对干旱胁迫具有不同的适应性, 直角双曲线修正模型适应各种水分条件, 直角双曲线模型和指数模型较适合轻度干旱胁迫条件, 非直角双曲线模型较适合重度干旱胁迫条件。随干旱胁迫的加剧, 光响应参数表观量子效率(AQY)、RdLCP先升高后下降, 净光合速率(Pn)、PnmaxLSP逐渐下降。轻度、中度和重度干旱胁迫下, LSP分别比对照下降5.2%、16.3%和34.5%, Pnmax分别比对照下降17.8%、39.0%和59.0%。水分充足条件下, 杠柳叶片光能利用最强, 光照生态幅最宽; 重度干旱胁迫下, 杠柳叶片表现出明显的光饱和、光抑制现象, 光能利用减弱, 光合能力受到较大限制。

关键词: 光响应模型, 净光合速率, 光合参数, 贝壳堤岛, 土壤水分

Abstract:

Aims Our objectives were to find the optimal models for different drought stresses by comparing four light response models of photosynthesis in leaves of Periploca sepium growing in sand formed from seashells, investigate the adaptability law of parameters of light response models to drought stresses, and define the adaptability of P. sepium to the shell sand moisture conditions.
Methods We used three-year-old P. sepium grown in shell ridge island of China’s Yellow River Delta as experimental material, set up four moisture conditions simulating those in shell sand, measured light responses of photosynthesis in leaves of P. sepium under different drought stresses using CIRAS-2 portable photosynthesis system, and fitted and analyzed the light response curves by four models: rectangular hyperbola, non-rectangular hyperbola, exponential and modified rectangular hyperbola.
Important findings The sequence of fitting effect of the four light response models was in descending order: modified rectangular hyperbola model > non-rectangular hyperbola model > exponential model > rectangular hyperbola model. This result was related to the latter three models not having extreme values, not fitting the process of light response curve declining after light saturation point (LSP), and not directly and accurately solving maximum net photosynthetic rate (Pnmax) and LSP. Among them, the non-rectangular hyperbola model best fit dark respiration rate (Rd), the rectangular hyperbola model best fit light compensation point (LCP) and modified rectangular hyperbola model best fit Pnmax and LSP. The adaptabilities of the four models to different drought stresses varied. The modified rectangular hyperbola model well fit the curves under all the drought stresses, the rectangular hyperbola model and exponential model suited mild drought stress and the non-rectangular hyperbola model suited severe drought stress. The light response parameters, including apparent quantum yield (AQY), Rd, LCP, Pnmax and LSP, responded to drought stresses differently. AQY, Rd and LCP first increased and then decreased with the aggravation of drought stress, while Pn, Pnmax and LSP decreased gradually. LSP decreased by 5.2%, 16.3% and 34.55% under light stress, moderate stress and severe stress, respectively, in comparison to the control (1556 μmol·m-2·s-1). Pnmax decreased by 17.8%, 39.0% and 59.0% compared to the control (22.58 μmol·m-2·s-1). Light use capability of P. sepium leaf was strongest and light ecological amplitude (1520 μmol·m-2·s-1) was widest under sufficient water condition; photo-saturation and photo-inhibition occurred significantly, light use capability weakened, and photosynthetic capacity was inhibited seriously under severe stress.

Key words: light response model, net photosynthetic rate, photosynthetic parameter, shell ridge island, soil water