闽楠不同季节光合特性日进程变化研究

A Study of the Changes of Photosynthetic Characteristics of Phoebe bournei in Different Seasons

以珍贵用材树种闽楠(Phoebe bournei)为研究材料,采用便携式Li-6400光合测定仪和OS5p调制叶绿素荧光仪,测定和分析其在不同季节的光合和叶绿素荧光参数值,探究其日进程变化趋势。分析结果表明,闽楠不同季节光合特性日进程变化有所差异。其中,Pn、Tr、Gs等均呈春秋"单峰型"、夏冬"双峰型"变化曲线,Ci为四季"U"型,WUE呈四季"双峰型"曲线,而Ls呈春秋冬"单峰型"、夏季"W"型曲线。不同季节Fv/Fo呈春秋"V"型、夏冬"双峰型"曲线,Fv/Fm四季均呈"V型"曲线,NPQ四季日进程变化无明显规律。Yield、q P和ETR日进程均呈春秋"单峰型"、夏冬"双峰型"变化曲线。闽楠光合和叶绿素荧光参数值整体呈秋季较大,冬季较小,即秋季为闽楠生长期,而冬季存在生长休眠期。

Taking the precious timber tree of Phoebe bournei as experimental materials,the changes of photosynthesis and chlorophyll fluorescence parameters of Phoebe bournei during different stages were studied by means of the Li-6400 photosynthesis analyzer and OS5 p chlorophyll fluorescence analyzer modulation. The results showed that there were big differences in photosynthesis characteristics and the diurnal variation in chlorophyll fluorescence parameters of Phoebe bournei in different seasons. The photosynthesis paramenters of Pn,Tr,Gs were on a ＂single-peak＂curve in spring and autumn and a ＂double-peak＂curve in summer and winter.Ci was in ＂U＂type while WUE was on a ＂double-peak＂curve in all seasons.Ls was on a ＂single-peak＂curve in spring,summer and autumn and in a ＂W＂type in summer. The diurnal variation of Fv/Fo was in a＂V＂type in spring and autumn and on a＂single-peak＂or a＂double-peak＂curve in summer and winter.Fv/Fm was in a ＂V＂type,and NPO had no obvious diurnal variation. The diurnal vatistion of yield,q P and ETR diurnal variation were on a ＂single-peak＂curve in spring and autumn and a ＂double-peak＂curve in summer and winter.Photosynthesis and chlorophyll fluorescence parameters were generally larager in autumn,and smaller in winter,which indicates a relatively strong growth in autumn,while growth dormancy in winter.