摘要
以盆栽3年生观光木为试材,利用便携式光合作用测量系统、叶绿素荧光仪及叶圆片氧电极等在夏季对其气体交换特性、叶绿素荧光参数及离体叶片的光合放氧等进行了测定.结果表明,3年生观光木幼树叶片的光补偿点为10.1μmo L/(m^2·s),光饱和点约为为800μmol/(m^2·s),CO_2补偿点为50.72μmol/mol,CO_2饱和点为1 200μmol/mol.夏季晴好天气下,观光木净光合速率(Pn)的日变化曲线呈双峰型,第1个峰出现在08:00,Pn为9.0μmol/(m^2·s),第2个峰出现在16:00,Pn为4.6μmol/(m^2·s),12:00有明显的光合午休现象.在光合有效辐射较高的时段(10:00至14:00),观光木的F_v/F——m(PSⅡphotochemical efficiency)和PSⅡ实际光化学效率(ΦPSⅡ)均处于低水平,表明PSⅡ活性明显下降.
The gas exchange characteristics,chlorophyll fluorescence and photosynthetic oxygen release of 3-yearold Tsoongiodendron odorum( pot-cultured) were measured in summer using a portable photosynthesis system,a PAM chlorophyll fluorometer and a leaf discs oxygen electrode,respectively. The results showed that the carbondioxide compensation point was 10.1 μmol/( m^2·s),the light saturation point was 800 μmol/( m^2·s),the carbon dioxide compensation point was 50.72 μmol/mol,and the carbon dioxide saturation point was 1 200 μmol/mol. The diurnal variations of net photosynthetic rate( Pn) presented as a bimodal shape. The first peak was 9.0 μmol/( m^2·s) which appeared at 08: 00. The second peak was 4.6 μmol/(m^2·s) appearing at 16: 00. There was a distinct"noon break"phenomenon at 12: 00. Both PSⅡphotochemical efficiency( F_v/F_m) and actual photochemical efficiency( ΦPSⅡ)were low during 10: 00 to 14: 00 when photosynthetic active radiation were high,which indicated that the activity of PSⅡ decreased.
出处
《华南师范大学学报（自然科学版）》
CAS
北大核心
2017年第6期65-70,共6页
Journal of South China Normal University(Natural Science Edition)
基金
国家自然科学基金项目(3157020131)
关键词
观光木
光合特性
FV/FM
光合作用
Tsoongiodendron odorum
photosynthetic characteristics
chlorophyll fluorescence
photosynthesis
