南京夏季不同叶位凤眼莲叶片光合作用的日变化及其生态因子分析  

The Diurnal Variation of Photosynthesis of Water Hyacinth Leaves in Different Positions in Summer of Nanjing and Its Ecological Factors

作　　者：丛伟[1,2] 李霞[1] 盛婧[1] 郑建初[1] 严少华[1] 

机构地区：[1]江苏省农业科学院,江苏南京210014 [2]南京农业大学生命科学学院,江苏南京210097

出　　处：《江西农业大学学报》2011年第3期445-451,共7页Acta Agriculturae Universitatis Jiangxiensis

基　　金：国家科技支撑计划项目(2009BAC63B01)

摘　　要：利用Li-6400便携式光合作用系统,在南京夏季(2010年6—8月)晴天,分别选取人工种养凤眼莲的倒1叶、倒3叶和倒6叶,测定不同叶位叶片一天中不同时间净光合速率(Pn)等光合参数的变化,并将外界光强和气温与叶片的光合参数进行相关性分析。结果表明:凤眼莲不同叶位叶片Pn的日变化6月呈典型的单峰曲线,但是7月,8月呈现典型的双峰曲线,整个夏季凤眼莲叶片都出现了明显的中午光合作用的抑制现象——光合"午睡"现象,显示了凤眼莲为C3植物的光合特征。其中气孔导度(Gs)的日变化与Pn的日变化相似;蒸腾速率(Tr)的日变化在6月与Pn基本相似,但是7月,8月的Tr与Pn不同,呈现出单峰曲线,在15:00出现峰值;胞间CO2浓度(Ci)的日变化则与Pn的相反;而其不同叶位的Pn也存在一定差异,相对而言,倒6叶的Pn均明显低于倒1叶和倒3叶,而倒3叶的光合能力最强。相关性分析表明,不同月份影响光合的生态因子有差异。In order to provide effective measures for farming and cultivation of water hyacinth in Jiangsu region,using Li-6400 portable photosynthesis system,the net photosynthetic rate（Pn） and other photosynthetic parameters of 1th,3rd and 6th leaf from artificial planting water hyacinth were selected,and then measured respectively at different times of the sunny day.Then the correlation analysis was made between the environment conditions such as air temperature and light intensity and all the photosynthetic parameters,The results were as follows： Pn of different leaf positions showed a single peak curve in a day in June,but those were a bimodal curve in July and August.Pn of all the leaves of water hyacinth were suffering a remarkable inhibition at noon during the whole summer,showing that the photosynthetic characteristics of water hyacinth is pertain to C 3 plant.At the same time,the diurnal variations of stomatal conductance（Gs） were similar to those of Pn at the similar period.The diurnal variation of Pn and Transpiration rate（Tr） were very similar in June.However, the diurnal variation between Pn and Tr was different in July and August,which showed a single peak,and the peak appeared at 15：00.The diurnal variation between Pn and Intercellular CO 2 concentration（Ci） was converse;while the Pn of leaves at different positions were of some differences,the Pn of the 6th leaf was significantly lower than that of the 1th and the 3rd leaf,while photosynthetic capacity of the 3rd leaf was the highest of the leaves,due to their different developmental stages of leaves.Correlation analysis showed that the photosynthetic performance of the plants during different months of summer was closely related to their environmental factors.

关 键 词：凤眼莲 光合作用 日变化 

分 类 号：Q945.11[生物学—植物学]