酸橙夏季光合作用特性研究  

Study on the Photosynthetic Characteristics of Citrus aurantium in Summer

作　　者：孙年喜[1] 莫让瑜[1] 谭均[1] 彭锐[1] SUN Nian-xi;MO Rang-yu;TAN Jun(Chongqing Academy of Chinese Materia Medica,Chongqing 400065)

机构地区：[1]重庆市中药研究院,重庆400065

出　　处：《安徽农业科学》2024年第16期145-148,224,共5页Journal of Anhui Agricultural Sciences

基　　金：重庆市技术创新与应用发展专项(cstc2019jscx-gksbX0078);四川省科技计划项目(2022YFS0587)。

摘　　要：[目的]研究酸橙夏季光合作用特性。[方法]采用Li-6400便携式光合作用测定系统测定酸橙不同位置叶片净光合速率、酸橙光合日变化、光响应曲线和CO_(2)响应曲线。[结果]酸橙不同方位和不同部位叶片净光合速率存在一定差异;酸橙夏季净光合速率日变化呈双峰型,存在“午睡”现象,其光合峰值分别出现在10:00和14:30;气孔导度的日变化与净光合速率日变化相似。从光响应曲线看,酸橙光饱和点高,光强为0~2000μmol/(m^(2)·s),净光合速率不断上升,最大为13.44μmol/(m^(2)·s),光补偿点为28.33μmol/(m^(2)·s),表观光量子效率为0.036。从CO_(2)响应曲线看,酸橙CO_(2)饱和点在1500μmol/mol,CO_(2)补偿点为60.65μmol/mol,羧化效率为0.079。相关及回归分析结果表明,夏季酸橙净光合速率与气孔导度、空气相对湿度、胞间CO_(2)浓度、蒸腾速率、水汽压亏缺等生理生态因子关系密切。[结论]酸橙是一种喜阳的C_(3)型植物,且对弱光有较强的适应及利用能力,对CO_(2)具有较强的同化能力,同时在夏季高温低湿环境下,酸橙光合作用受各种生理生态因子影响,此期光合有效辐射不是影响净光合速率的关键因子,空气相对湿度与净光合速率呈显著正相关,因此通过环境选择或增加相对湿度的措施,可缓解酸橙夏季“午睡”现象,提高净光合效率。[Objective]To study the photosynthetic characteristics of Citrus aurantium in summer.[Method]By using Li-6400 portable photo⁃synthesis system,the net photosynthetic rate(Pn)of leaves in different positions,diurnal variation of photosynthesis,light response curve and CO2 response curve of Citrus aurantium were measured.[Result]There were certain differences in Pn of leaves in different directions and parts.The diurnal variation of Pn of Citrus aurantium in summer showed a double⁃peak curve with a“nap”phenomenon,and the photosynthetic peaks appeared at 10:00 and 14:30,respectively.The diurnal variation of stomatal conductance was similar to that of Pn.From the light re⁃sponse curve,it could be seen that Citrus aurantium had a high saturation point and a light intensity of 0-2000μmol/(m^(2)·s),the Pn contin⁃ued to increase,reaching a maximum of 13.44μmol/(m^(2)·s),with a light compensation point of 28.33μmol/(m^(2)·s),the apparent quantum efficiency was 0.036.From CO_(2)response curve,the CO_(2)saturation point and CO_(2)compensation point were about 1500μmol/mol and 60.65μmol/mol,respectively,and the carboxylation efficiency was 0.079.The results of correlation and regression analysis showed that in sum⁃mer Pn of Citrus aurantium was closely associated with physiological and ecological factors,such as stomatal conductance,relative humidity,in⁃tercelluar CO_(2)concentration,transpiration rate,vapor pressure deficienc.[Conclusion]Citrus aurantium was a heliophile C_(3)plant and it had a strong ability to adapt and utilize low light and strong assimilation ability to CO_(2).And under the high temperature and low air relative humidity in summer,the photosynthesis of Citrus aurantium was affected by various physiological and ecological factors.In this period,the photosynthet⁃ic active radiation was not the key factor affecting Pn,and the air relative humidity was significantly positively correlated with Pn.Therefore,environmental selection or cultivation measures to increase the air relative hu

关 键 词：酸橙 光合作用特性 净光合速率 响应曲线 

分 类 号：S666[农业科学—果树学]