CO_2阶跃变化对茄子动态光合特征参数的影响  

Effect of CO_2 Step Changes on Characteristic Parameters of Dynamic Photosynthesis in Eggplant

作　　者：薛占军[1] 高志奎[1] 王梅[1] 吕桂云[1] 杜爽[1] 高荣孚[2] 

机构地区：[1]河北农业大学园艺学院,保定071001 [2]北京林业大学生物科学与技术学院,北京100083

出　　处：《生物物理学报》2011年第2期135-144,共10页Acta Biophysica Sinica

基　　金：国家自然科学基金项目(30571267);国家科技攻关计划项目(2004BA525B14)~~

摘　　要：针对CO2阶跃变化下茄子光合的振荡动态现象,采用CO2阶跃起点(Ca1)和阶点(Ca2)处理,以及不同光照水平(PAR)下的CO2阶跃处理,结合光合系统反馈控制动态生化模型中传递函数的振荡单元,分析了茄子动态光合的振荡特征参数。通过稳态光合参数,将茄子光合速率(Pn)转化为羧化速率(Vc)的动态进程,发现在较低的CO2阶跃起点(Ca1≤180μmol/L)下,光合系统的时间常数T较大,光合系统的阻尼系数ζ、无阻尼自然振荡频率ωn和阻尼振荡频率ωd则较小,因而Pn和Vc振荡剧烈;较高的CO2阶跃阶点(Ca2≥900μmol/L)下,ζ急剧减小,Pn和Vc振荡愈加剧烈;光强PAR增至900μmol.quata/m2.s以上时,ζ急剧减小,Pn和Vc振荡也愈加剧烈。综合分析可见,发生光合振荡的条件是较低的ζ和较大的T;相反,不发生光合振荡的条件是较高的ζ和较小的T;但是,发生光合振荡的临界条件需要在中高的ζ下配合较大(甚至更大)的T。本试验中,能够引起茄子光合振荡的CO2阶跃起点、阶点和光强临界量分别选定为300μmol/L、900μmol/L、500μmol.quata/m2.s。据此计算的CO2阶跃扰动强度Dc与茄子光合振荡系统的阻尼系数ζ之间呈指数极显著负相关关系(r=-0.858**)。With the constitution of dynamic biochemistry model containing a key of feedback controlled system,which was on the basis of oscillation unit in the transfer function,the characteristic parameters of oscillation in dynamic photosynthesis by CO2 step-transformation were analyzed in solar greenhouse eggplant treated by combination of CO2 step starting point（Ca1） and order point（Ca2） with different photosynthetically active radiation（PAR）.The results showed that dynamic course of oscillation of photosynthetic rate（Pn） and carboxylation velocity（Vc） which was translated from Pn through stable photosynthesis parameters was significantly violent due to the increase of time constant（T） and decrease of damp coefficient（）,natural oscillation frequency for undamped present（ωn） and damped oscillation frequency（ωd） of photosynthetic system.Analogously,under the condition of Ca2≥900 μmol/L and PAR≥900 μmol·quata/m2·s,the phenomena of oscillation was more marked accompanied the lower ζ.Consequently,the photosynthetic oscillation could occur in combination of lower ζ and upper T.Conversely,it could not display in combination of upper ζ and lower T.However,the moderate ζ and high（or higher） T were the critical conditions needed for occurring of photosynthetic oscillation.In our experiment,the critical quantity of photosynthetic oscillation for Ca1,Ca2 and PAR was 300 μmol/L,900 μmol/L and 500 μmol·quata/m2·s,respectively.Meanwhile,the negative relationship（r=-0.858＊＊） between disturbed intensity（Dc） by CO2 step-transformation and damp coefficient （ζ） of photosynthetic oscillation system can be described by exponential equation.

关 键 词：动态光合 振颤 CO2阶跃变化 阻尼系数 振荡频率 时间常数 

分 类 号：Q945.11[生物学—植物学] S641.1[农业科学—蔬菜学]