胡杨净光合速率日变化及主要影响因子研究  

Diurnal Variation of Net Photosynthetic Rate of Populus euphratica and Its Main Influencing Factors

作　　者：李雪娇 李伟[1] 高冠龙[1,2,3,4] LI Xuejiao;LI Wei;GAO Guanlong(School of Environmental and Resource Sciences,Shanxi University,Taiyuan 030006,China;Shaanxi Provincial Key Laboratory of Land Remediation,Xi'an 710064,China;Northwest Institute of Eco-Environmental Resources,Chinese Academy of Sciences,Lanzhou 730000.China;Qilian Mountain Water Resources Conservation Forest Research Institute,Gansu Province,Zhangye 734000,China)

机构地区：[1]山西大学环境与资源学院,山西太原030006 [2]陕西省土地整治重点实验室,陕西西安710064 [3]中国科学院西北生态环境资源研究院,甘肃兰州730000 [4]甘肃省祁连山水源涵养林研究院,甘肃张掖734000

出　　处：《山西大学学报（自然科学版）》2021年第6期1241-1249,共9页Journal of Shanxi University(Natural Science Edition)

基　　金：山西省高等学校科技创新项目(2020L0028);中国博士后科学基金资助项目(2018M643769);山西省应用基础研究面上青年基金项目(201801D221286);中央高校基本科研业务费(自然科学类)资助项目(300102279505)。

摘　　要：基于Li-COR 6400便携式光合作用测定系统,于2016年7-9月测定了内蒙古额济纳胡杨叶片净光合速率(P_(n))及其他主要生理因子,结合气象站实测环境数据,分析各生理及环境因子日变化曲线,并对胡杨叶片P_(n)与生理和环境因子进行相关性、多元逐步回归和通径分析。结果显示:(1)极端干旱区胡杨P_(n)日变化主要呈先上升后下降的趋势。在气温高、相对湿度小而辐射强烈天气条件下的正午时分,胡杨叶片出现明显的"光合午休"现象(P_(n)在7月25日12:00出现极小值22.37 mmol·m^(-2)·s^(-1),在8月26日15:00出现极小值22.63 mmol·m^(-2)·s^(-1);(2)P_(n)与蒸腾速率(T_(r))以及环境因子:包括入射光合有效辐射(PAR)、气温(T_(a))、叶片水汽压差(VPD)之间呈现极显著正相关(相关系数分别为:0.658^(**)、0.820^(**)、0.489^(**)和0.463^(**)),与大气中CO_(2)浓度(Ca)呈现极显著负相关(P=-0.503^(**));(3)多元逐步回归和通径分析结果表明,PAR是主要决定因子(R_(path)^(2)=0.614),其次是T_(r)(R_(path)^(2)=0.392),主要限定因子是Ta_(Rpath)^(2)=-2.764),说明PAR和T_(r)对胡杨叶片P_(n)的促进作用最大,T_(a)对P_(n)表现为抑制作用。Based on the Li-COR 6400 portable photosynthesis measurement system,the net photosynthetic rate(P_(n))and other major physiological factors of Populus euphratica leaves in Ejina,Inner Mongolia were studied from July to September in 2016.Combined with the environmental data of meteorological stations,the daily variation curves of various physiological and environmental factors were analyzed,and the relationship between P_(n) and physiological as well as environmental factors in P.euphratica leaves were analyzed by correlation analysis,stepwise regression and path analysis,respectively.The results showed that:(1)The daily variation of P_(n) in P.euphratica in the extreme arid area mainly increased first and then decreased.With the high temperature,the low relative humidity and strong noon weather,P_(n) showed obvious"photosynthetic lunch break"phenomenon(P_(n) appeared at a minimum value of 22.37 mmol·m^(-2)·s^(-1) at 12:00 on July 25 and 22.63 mmol·m^(-2)·s^(-1) at 15:00 on August 26);(2)P_(n) and transpiration rate(T_(r))and the environmental factor,including incident photosynthetically active radiation(PAR),temperature(T_(a)),leaf water vapor pressure difference(VPD)showed higher significant positive correlation(r=0.658^(**),r=0.820^(**),r=0.489^(**),r=0.463^(**),respectively),which showed a significant negative correlation with atmospheric CO_(2) concentration(Ca)(r=-0.503**);(3)Stepwise regression and path analysis showed that PAR was the main determinant(R_(path)^(2)=0.614),followed by physiological factor T_(r)(R_(path)^(2)=0.392),and the main limiting factor was T_(a)(R_(path)^(2)=-2.764).This shows that PAR and T_(r) have the largest promotion effect on P_(n) in P.euphratica leaves,and T_(a) shows inhibition on P_(n).

关 键 词：净光合速率 多元逐步回归分析 通径分析 胡杨 

分 类 号：O436[机械工程—光学工程]