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中国农学通报 ›› 2016, Vol. 32 ›› Issue (17): 115-121.doi: 10.11924/j.issn.1000-6850.casb16030126

• 资源 环境 生态 土壤 气象 • 上一篇    下一篇

干热河谷区土壤水分胁迫下扭黄茅光合作用光响应过程及其模拟

赵丽,贺玉晓,魏雅丽,金杰,刘刚才,熊东红,苏正安   

  1. 西南科技大学环境与资源学院,河南理工大学研究生处研招办,四川农业大学资环学院资源学院系,云南省农业科学院热区生态农业研究所草业中心,中国科学院水利部成都山地灾害与环境研究所泥石流室,中国科学院水利部成都山地灾害与环境研究所水土保持室,中国科学院水利部成都山地灾害与环境研究所水土保持室
  • 收稿日期:2016-03-16 修回日期:2016-04-07 接受日期:2016-04-21 出版日期:2016-06-20 发布日期:2016-06-20
  • 通讯作者: 贺玉晓
  • 基金资助:
    国家自然科学基金项目“干热河谷扭黄茅对土壤水分胁迫的生理生态响应机制”(41301287);国家自然科学基金项目“气候变化对紫色土容许土壤流失量的影响”(41471232);河南理工大学博士基金“干热河谷土壤水分胁迫对扭黄茅生理特性的影响机制”(B2014-070)。

Light response characteristics of photosynthesis of Paspalum notatum and its simulation under soil water stress in dry-hot valleyZhao Li1, He Yuxiao2, Wei Yali3, Jin Jie4, Liu Gangcai5,

  • Received:2016-03-16 Revised:2016-04-07 Accepted:2016-04-21 Online:2016-06-20 Published:2016-06-20

摘要: 采用3 种模型对光响应曲线进行拟合,比较不同拟合模型的优劣,旨在优选出水分胁迫下最优的光合作用光响应模型,为深入了解扭黄茅光合生理生态特征、合理使用水资源有效地进行植被恢复提供科学依据。利用Li-6400 光合仪测定了元谋干热河谷扭黄茅雨季在不同土壤水分胁迫程度下光合作用的光响应过程,并用直角双曲线模型、非直角双曲线模型和直角双曲线修正模型对光响应曲线进行拟合,通过决定系数(R2)、拟合的初始量子效率(α)、最大净光合速率(Pnmax)、光饱和点(LSP)、光补偿点(LCP)和暗呼吸速率(Rd) 6 个参数的对比,比较3 种模型的差异。研究结果表明:(1)随着土壤水分胁迫的加重,扭黄茅净光合速率、光补偿点、暗呼吸速率降低,强光下扭黄茅的光合作用发生光抑制现象,表现为光合速率随光合有效辐射强度的增加而呈现先升高后降低的趋势;(2)从决定系数比较来看,拟合效果优劣排序为直角双曲线修正模型>非直角双曲线模型>直角双曲线模型;(3)直角双曲线修正模型的Pnmax、LSP、LCP 和Rd 4 个光合参数均与实测值较为接近,而其他模型除个别参数较为接近外,多数参数差别较大。直角双曲线修正模型可以直接得出饱和光强和最大净光合速率,能够较好地拟合土壤水分胁迫下扭黄茅的光响应过程及其特征参数,拟合值较符合植物实际的生理情况,更接近实测值,该模型可以更好地拟合土壤水分胁迫下扭黄茅的光响应曲线。

关键词: 滴灌, 滴灌, 喷灌, 漫灌, 土壤含水率, 水分动态, 玉米

Abstract: In order to find out the optimum light response model of photosynthesis, compare the advantages and disadvantages of different models, understand physiological ecology characteristics of photosynthesis of Paspalum notatum and reasonably use water resource to conduct vegetation recovery, three light response models were used to simulate light response. Light response process of photosynthesis was studied by Li-6400 photosynthesis system under different soil water stresses in rainy season in Yuanmou dry-hot valley, light response curve was simulated by rectangular hyperbola model, non-rectangular hyperbola model and modified rectangular hyperbola model, respectively. The difference of the three models was analyzed by determination coefficient (R2), simulated initial quantum efficiency (α), the maximum net photosynthetic rate (Pnmax), light saturation point (LSP), light compensation point (LCP) and dark respiration rate (Rd). The results showed that (1) Pnmax, LCP and Rd of Heteropogon contortus decreased with the increase of water stress, light suppression phenomenon happened under strong light situation, photosynthetic (Pn) increased and then decreased with the increase of photosynthetically active radiation (PAR); (2) according to R2, the simulation results followed the order of modified rectangular hyperbola model > non-rectangular hyperbola model > rectangular hyperbola model; (3) the four parameters of Pnmax, LSP, LCP and Rd were close to the measured values in rectangular hyperbola model, while most of the parameters of other models had obvious differences from the measured values except individual parameters. Modified rectangular hyperbola model could get saturated light intensity and Pnmax directly, and well fit the light response process and characteristic parameters, the simulated values could meet the actual physiology condition and the measured values, thus this model could simulate the light response characteristics of photosynthesis of Paspalum notatum under water stress.

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