Feng, Chaoyang

Lin, Dong

Lu, Shihai

Ma, Huiling

English

University of Kentucky

University of Kentucky UKnowledge International Grassland Congress Proceedings 21st International Grassland Congress / 8th International Rangeland Congress Characteristic of Gas Exchange and Chlorophyll Fluorescence Parameters in Leaves of Lespedeza davurica Dong Lin Gansu Agricultural University, China Huiling Ma Gansu Agricultural University, China Shihai Lu Chinese Research Academy of Environmental Sciences, China Chaoyang Feng Chinese Research Academy of Environmental Sciences, China Follow this and additional works at: https://uknowledge.uky.edu/igc  Part of the Plant Sciences Commons, and the Soil Science Commons This document is available at https://uknowledge.uky.edu/igc/21/1-5/17 The 21st International Grassland Congress / 8th International Rangeland Congress took place in Hohhot, China from June 29 through July 5, 2008. Proceedings edited by Organizing Committee of 2008 IGC/IRC Conference Published by Guangdong People's Publishing House This Event is brought to you for free and open access by the Plant and Soil Sciences at UKnowledge. It has been accepted for inclusion in International Grassland Congress Proceedings by an authorized administrator of UKnowledge. For more information, please contact UKnowledge@lsv.uky.edu. 瞯 ]216　 瞯 　 Multifunctional Grasslands in a Changing World 　 Volume Ⅰ 　Grasslands/Rangelands Resources and Ecology ——— Ecology of Grasslands/RangelandsCharacteristic of gas exchange and chlorophyll fluorescence parameters in leaves of LespedezadavuricaL IN Dong１ ,２ ,MA Hui‐ling１ ,LV Shi‐hai２ ,FENG Chao‐yang２１ .College o f Prataculture , Gansu A gricultural University , L anzou ７３００７０ ,China , E‐mail :lingrass＠ １６３ .com , ２ .Instituteo f Ecology , Chinese Research A cademy o f Env ironmental Sciences , Bei j ing １０００１２ ,ChinaKey words : gas exchange parameters , chlorophyll fluorescence , simulated photosynthetic , CO２ concentrations , Lespedez adavuricaIntroduction This paper tests and analyzes the net photosynthetic rate ( Pn) , transpiration rate ( T r) , stomatal conductance( Gs) , intracellular CO２ concentration ( Ci) , minimal fluorescence yield ( Fo ) , maximum fluorescence yield ( Fm ) , variablefluorescence yield ( Fv ) and electron transport rates ( ETR ) to reveal the physiological and ecological characteristics ofLespedez a davurica .Materials and methods Lespedez a davurica belongs to Lespedez a Michx of Leguminosae . It was measured with LI‐６４００portable photosynthesis system and comparative analysis was made . Light intensity was controlled by ２BLED of LI‐６４００ . In asimilar way , CO２ concentration was controlled by CO２ scrubber and the temperature of leaves was regulated by controller of LI‐６４００ . The leaf area of Lespedez e davurica was measured by an area meter ( LI‐３０００A ) . All of the digital information wasanalyzed by SPSS １３ .０ and Microsoft Excel for Windows .Results We can know from figure １ that Lespedez a davurica shows evident photosynthetic potentiality for the increase of CO２concentration . The figure ２ showed the relaxation rate of Lespedez a davurica . When the leaves of Lespedez a davuricachanged from dark to light , the qP and NPQ elevated gradually with the increase of illumination time . About ２４min later , theqP and NPQ tended to be stable and quenching . The trend of PhiPS２ change was influenced by ETR .Figure 1 Responses o f photosynthetic rate (Pn ) and transpitation rate(Tr ) to increasing CO2 concentrations .　Figure 2 Chlorophy ll f luorescence parameters o fleaves o f Lespedeza davurica in relaxation .Conclusions This experiment showed that water stress is one reason for inhibition in photosynthetic ability after the lightintensity over １６００μmolm‐２ s‐１ . So strong light should couple sufficient water condition and can promote the efficiency of lightenergy . The significantly positive correlation exists between T r and Gs of Lespedez a davurica ( P ＜ ０ .０１ ) . But there wassignificantly negative correlation between Pn and RH . High humidity air may be one reason for inhibition in photosyntheticability for experiment spot in closure area of Taihang Mountain . The qP and NPQ of Lespedez a davurica gradually increaseswith illumination time , showing the higher ability of heat dissipation and efficiently avoided the damage of photosyntheticapparatus from excess light energy . The NPQ was lower after ２７min because of the increase of photochemical quenching . Butit may be caused by the interior control of photosystem enzymes , which is a problem of great complexity . The exact mechanismremains to be studied further .ReferencesJIANG G M , LIN GH , Bruno DV Marino . Changes in stomata conductance , transpiration and water use efficiency of tenspecies experienced in high CO２ concentrations in biosphere ２ . A cta Botanicl Sinica . １９９７ , ３９(６ ) : ５４６‐５５３ .Rohacek K . Chlorophyll fluorescence parameters : the definitions , photosynthetic meaning and mutual relationships .Photosynthetica , ２００２ , ４０(１) :１３‐２９ .'" +-' :15 ro • ;._ 7 30 u CF, 25 +' N '" I • Pn E 20 "" +-' 15 C: N O Tr 0 ;,. C lfJ u 10 0 c +' E 5 0 "" ::t '1 0 +' C: -5 200 100 600 800 1000 1200 1100 160( (l) p_ z - 10 CO 2 concentrations ( µ mo l CO 2 mo 1 I) 9 8 '" +'ro 7 ,., 6 C: 0 5 •r, +' ro 4 ,., •C, 3 '1 C/j 2 C: ro 1 ,., r 0 7 lfJ N E rl 0 E E C, r ,I:. 330 ---¾- Fm ' '--._ j ~~~ --o-- Fo' " 180 -------------- - - - - - ---- ---Fs :l: 1 :rn , 0 6 121824303642485460 Time(min) 

Characteristic of Gas Exchange and Chlorophyll Fluorescence Parameters in Leaves of \u3cem\u3eLespedeza davurica\u3c/em\u3e

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Characteristic of Gas Exchange and Chlorophyll Fluorescence Parameters in Leaves of \u3cem\u3eLespedeza davurica\u3c/em\u3e

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