北固山湿地虉草光合日变化的研究  

The Photosynthetic Characteristics of Phalaris arundimacea in the Beigu Mountain Wetland

作　　者：付为国[1] 李萍萍[2] 陈歆[2] 卞新民[1] 陈冬梅[1] 

机构地区：[1]南京农业大学农学院,南京210095 [2]江苏大学农业装备学院,江苏镇江212013

出　　处：《武汉植物学研究》2005年第6期555-559,共5页Journal of Wuhan Botanical Research

基　　金：国家"十五"重大科技专项(2003AA60110-3)资助

摘　　要：采用便携式LI-6400光合测定仪,在晴朗的天气,对虉草成熟叶片净光合速率(Pn)以及光合有效辐射(Par)、气孔导度(Cond)、细胞间CO2浓度(Ci)、叶温(Tl)、叶周围气温(Ta)和蒸腾速率(Tr)等影响因子进行田间测定,研究虉草的光合日变化.结果表明:虉草净光合速率日变化呈双峰曲线,主峰出现在10∶00,次峰出现在15∶00,光合'午休'现象明显,非气孔限制是产生'午休'的主要原因.净光合速率变幅为5.86～20.64 μmol·m-2·s-1,蒸腾速率变幅为2.8～6.22 mmol·m-2·s-1,光补偿点为40 μmol·m-2·s-1,光饱和点为2 100 μmol·m-2·s-1(自然状态下达不到),表观光量子效率为0.056 5 mol·mol-1,暗呼吸速率为2.26 μmol·m-2·s-1,水分利用效率为2.31～3.65 μmol·mmol-1.数据显示,虉草是一种高光效植物,对于其资源的合理利用及其对湿地生态系统的稳定意义重大.Photosynthetic characteristics were studied in mature leaves of Phalaris arundirnacea using portable LI-6400 photosynthesis instrument （Licor, USA） in the field. The diurnal changes of net photosynthetic rate and its major affecting factors, including photosynthetically active radiation （Par）, stomatal conductance （Cond）, intercellar CO2 concentration （Ci）, leaves temperature （Tl）, air temperature （Ta）, transpiration rate （Tr）, were measured. The results showed that the diurnal process of photosynthetic rate exhibited a double peak curve in which the main peak appeared around 10：00, and the second around 15：00. This may reflected an obvious phenomena of midday depression of photosynthesis caused by Non-stomatal limition. Diurnal variation of net photosynthetic rate is 5.86-20. 64μmol·m^-2·s^-1 , and transpiration rate is 2.8-6.22 mmol·m^-2·s^-1. And the other parameters, light compensation point is 40 μmol·m^-2·s^-1, light saturation point 2 100μmol·m^-2·s^-1, apparent quantum yield 0. 056 5mol·mmol^-1, dark respiration rate 2.26μmol·m^-2·s^-1, and water use efficiency is 2.31-3.65μmol·mmol^-1. The data showed that P. arundirnacea was a kind of highly photosynthetic efficiency plant, illuminating for the exploitation of resources and maintaining the eco-stability of wetland ecosystem.

关 键 词：虉草 净光合速率 光合作用响应曲线 蒸腾速率 

分 类 号：Q945.11[生物学—植物学]