摘要
用便携式L I-6400光合测定仪,在晴朗的天气,对芦苇成熟叶片净光合速率(Pn)以及光合有效辐射(Par)、气孔导度(G s)、细胞间CO2浓度(C i)、叶温(T l)、叶周围气温(T a)和蒸腾速率(T r)等影响因子进行田间测定,研究芦苇的光合日变化。结果表明:芦苇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,且气孔限制是产生“午休”的主要原因。净光合速率日均为20.01μm o l.m-2.s-1,蒸腾速率日均为6.15 mm o l.m-2.-s 1,光补偿点为98μm o l.m-2.-s 1,光饱和点为2 125μm o l.m-2.-s 1(自然状态下达不到),表观光量子效率为0.060 4 m o l.m o-l 1,暗呼吸速率为2.91μm o l.m-2.-s 1,CO2补偿点为53μm o l.m o-l 1,饱和点为1 368μm o l.m o-l 1,羧化效率为0.064 7。数据显示,芦苇是一种高光效阳性植物,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。
Portable photosynthetic system was employed to measure the net photosynthetic rate, photosynthetically active radiation, stomatal conductance,intercellular carbon dioxide concentration leaf temperature,atmospheric temperature around the leaves and transpiration rate of Phragmites communis on clear days to study the diurnal photosynthetic changes of Phragmites communis. The results showed that the net photosynthetic rate of Phragmites communis changed in a double-peak curve with its peaks occurring separately at 10：00 and 15：00,which indicated a remarkable photosynthetic ＂noon depression＂ that mainly resulted from stomatal constraint, on average ,the net photosynthetic rate ,transpiration rate ,light compensation point ,light saturation point （impossible to arrive at under natural circumstances）, apparent quantum yield ,dark respiration rate ,carbon dioxide compensation point and carboxylation point ,on daily basis ,were 20.0μmol·m^-2·S^-1,6.15mmol·m^-2·S^-1,98μmol·m^-2·S^-1,2 125μmol·m^-2·S^-1,0.0604mol· mol^-1,2. 91μmol·m^-2·S^-1,53 mol · mol^-1,1 368 μmol·mol-1,and 0.064 7,respectively. The data showed that Phragrnites cornrnunis is a plant with high light use efficiency so its reasonable exploitation can play a great role in stabilizing wetland ecosystems.
出处
《西北植物学报》
CAS
CSCD
北大核心
2006年第3期496-501,共6页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家"十五"重大科技专项(2003AA60110-3)
