摘要
利用LI-6400光合仪测定苜蓿叶片净光合速率,研究其日变化及与环境因子的关系。结果表明:苜蓿叶片净光合速率、蒸腾速率日变化均呈现"双峰"曲线,有明显的光合"午休"现象;净光合速率峰值出现在10:00和13:00,分别为33.55和27.88μmol CO2.m-2.s-1,第1峰值大于第2峰值;蒸腾速率的峰值出现在11:00和14:00,比光合速率滞后1小时;相关分析表明,苜蓿净光合速率与光合有效辐射、气孔导度呈极显著正相关(r=0.8433**、0.8223**),与田间CO2浓度呈极显著负相关(r=-0.8125**);在光照强度、CO2浓度、气温和空气湿度4个环境因子中,影响净光合速率日变化的主要因子是田间CO2浓度。
In order to identify the relationship between diurnal changes of photosynthetic rate and environmental factors of Alfalfa(Medicago sativa L.cv.Zhenyuan),photosynthetic characteristics were monitored using portable LI-6400 photosynthesis system.The results show that the curves of diurnal variation in Pn(net photosynthetic rate) and Tr(transpiration rate) had two peaks and an obvious midday depression at 12:00 O′clock.The Pn peaks were detected at 10:00 am and 13:00 pm and reached to 33.55 μmol CO2·m-2·s-1 and 27.88 μmol CO2·m-2·s-1,respectively;the first peak was higher than the second.The Tr peaks were detected at 11:00 am and 14:00 pm and 1 hour behind those of Pn.Pn was significantly positively correlated with PAR(photosynthetically available radiation;r=0.8433**) and Gs(stomatal conductance;r=0.8223**) and significantly negatively correlated with Ci(intercellular CO2 concentration;r=-0.8125**).Ci was the major environmental factor influencing diurnal changes of the Pn of alfalfa.
出处
《草地学报》
CAS
CSCD
北大核心
2009年第1期27-31,共5页
Acta Agrestia Sinica
基金
国家"十一五"科技支撑计划(2006BAD29B03)
农业部农业结构调整重大技术研究专项项目(2002-09-02A)
关键词
苜蓿
光合速率
日变化
环境因子
气孔导度
Alfalfa
Photosynthetic rate
Diurnal change
Environmental factor
Stomatal conductance