【作者】 刘建福； 范燕萍； 王奇志； 欧阳昌东；

【Author】 LIU Jian-fu~1 FAN Yan-ping~2 WANG Qi-zhi~1 OUYANG Chang-dong~1 (1 Department of Bioengineering,Huaqiao University,Xiamen 361021; 2 College of Horticulture,South China Agricultural University,Guangzhou 510642)

【机构】 华侨大学生物工程系； 华南农业大学园艺学院；

【摘要】 以多年生非洲茉莉为材料,研究光合作用日变化及其与环境因子之间的关系。结果表明:非洲茉莉净光合速率（Pn）、气孔导度（C）和蒸腾速率（E）的日变化趋势均呈不对称的双峰曲线,有明显的"午休"现象;净光合速率最大值为8.73μmol·m^-2·s^-1,光补偿点为17.50μmol·m^-2·s^-1,光饱和点为707.50μmol·m^-2·s^-1,主峰值出现在10:00,次峰值出现在15:00。净光合速率最大值时的最适温度为18.14℃。各因子对净光合速率直接作用大小为C>E>RH>Tair>Ci>Ca>PAR,建立净光合速率的多元线性回归方程Y=-4.282+0.122 C+0.002 PAR+0.055 RH。净光合速率在10:00至15:00出现下降取决于气孔限制和非气孔限制的共同作用。PSⅡ原初光能转换效率（Fv/Fm）和PSⅡ潜在活性（Fv/Fo）的日变化趋势均呈"V"型。上午随着光照强度增加而逐渐降低,12:00降为最低值,然后逐渐上升;说明叶绿体在中午光照强度和温度较高下光合活性受到暂时抑制,光合器官并没有受到损伤。更多还原

【Abstract】 By studying on the relationship between diurnal variation of net photosynthetic rate and environmental factors of Fagraea ceilanica Thunb leaves,the diurnal change of net photosynthetic rate and transpiration rate and stomatal conductance of Fagraea ceilanica Thunb have been showed by a double-peak curve with two separate peaks at 10:00 and 15:00.These results indicated a remarkable photosynthetic"noon depression"and the main reason for that was stomatal constraint The net photosynthetic rate maximum value was 8.73μmol·m^-2·s^-1and the light compensation point was 17.50μmol·m^-2·s^-1and light saturation point was 707.50μmol·m^-2·s^-1.The optimum temperature of Maximum net photosynthetic rate was 18.14℃.The direct effects of environment factors on net photosynthetic rate of Fagraea ceilanica Thunb were ordered from larger to small as C>E>RH>Tair>Ci>Ca>PAR.The multiple linear regression equation of net photosynthetic rate was Y= -4.282+0.122 C+0.002 PAR+0.055 RH.The reasons of diurnal variation of net photosynthetic rate of Fagraea ceilanica Thunb decrease from 10:00 to 15:00 can be attributed to the effects of the stomatal limitation as well as the nonstomatal limitation.The primary light energy conversion of PSII（Fv/Fm）and potential activities of PSD（Fv/Fo）decreased with the increase of PAR,the values of Fv/Fm and Fv/Fo decreased first and then increase,it showed that photosynthetic activities and photosynthetic primary reaction inhibited and photosynthetic organ didn’ t damaged.These results showed that under high temperature and high radiation,as a drought-tolerant plant,Fagraea ceilanica Thunb could limit transpiration level by effectively reducing the rate of stomatal conductance.更多还原