Seasonal response of net photosynthesis to environmental factors in Osmanthus fragrans
0
Citation
0
Reference
20
Related Paper
Abstract:
As an important species of plant used in urban landscape construction in China,Osmanthus fragrans is deployed in up to 98.88% in the greening of Shanghai residential areas.Present studies of Osmanthus fragrans are focused on its planting,cultivation and conservation,but that on photosynthesis and transpiration is sparse.Diurnal Variation of Net photosynthetic rate of Osmanthus fragrans under natural condition was measured by using LICOR-6400XT portable photosynthesis system in winter and in summer.And transpiration,intercellular CO2 concentration,stomatal conductance,air temperature,relative humidity,and photosynthetically active radiation were also measured at the same time.The paper analyzed the relation among net photosynthetic rate,physiological factors and environmental factors,and discussed the difference of net photosynthetic rate between in winter and in summer and the adaptive strategies to air temperature.The results were as follows.With the increased of T and GS,Pn increased gradually.And when it got the limitation of stomata regulation,Pn got the maximum and then deduced slightly.Efficiency of photosynthesis was lower in winter than in summer.By enlarging the adaptation range of light and fully using the optimum temperature and light at noon,Pn and fixed carbon content maintained at a high level.The hurt of High temperature and high light was avoided by Midday depression of photosynthesis and high transpiration in summer.The ability of carbon fixation had few differences between that in winter and in summer,and the water use efficiency in summer was much lower than that in winter.Keywords:
Osmanthus fragrans
Photosynthetically active radiation
Stomatal Conductance
Diurnal temperature variation
Water Use Efficiency
Shading
Noon
Cite
The characteristics of photosynthetic rate in response to light intensity and the rules of diurnal variations in photosynthesis, light use efficiency and water use efficiency of the representative soybean leaves during the filling period in the Northeastern China were determined and investigated under the artificial and field conditions by using the portable photosynthesis system(LI-6400).The results showed that photosynthetic rate in response to the photosynthetically active radiation flow followed a typical nonlinear curve,which could be expressed by Michalis-Menten equation.Under natural light conditions,apparent maximum photosynthetic rate and initial quantum efficiency were 37.25μmol CO2m-2s-1 and 0.0376μmol CO2m-2s-1 respectively.Changes in photosynthetic rate,transpiration rate,stomatal conductance,photosynthetically active radiation,air temperature,light use efficiency and water use efficiency along with the time elapsed could be simulated by sine curves,but the peaks came forth differently in time.The peak of the photosynthesis and stomatal conductance appeared at the forenoon,while the peak of the photosynthetically active radiation appeared at noon and for transpiration and air temperature in the afternoon,which indicated that fall in photosynthesis because of stomatal limit caused by higher air temperature,rather than the light stress.Light use efficiency of soybean decreased with the time elapsed and stabilized between 0.015 and 0.02μmol CO2m-2s-1 at about 10:30.Water use efficiency of soybean differed significantly.It was higher in the forenoon than that in the afternoon,which could also be caused by temperature.
Photosynthetically active radiation
Light intensity
Stomatal Conductance
Noon
Diurnal temperature variation
Water Use Efficiency
Cite
Citations (0)
In order to improve cultivation techniques of chestnut and enhance photosynthetic efficiency,diurnal variations of photosynthesis and some related factors were researched,taken Yanlong chestnut with 2 years as materials.The results showed that the curve of diurnal variations of net photosynthetic rate had 2 peaks,which were at 10:00 and 15:00 respectively,and midday depression was significant at 13:00-14:00;net photosynthetic rate was decreased after removing stamens;the trend of diurnal variations of stomata conductance was consistent with that of photosynthetic rate,but that of transpiration rate had only a peak which appeared at 13:00;intercellular CO2 concentration was high during midday depression.Air temperature,leave temperature and transpiration rate were increased with increasing of light intensity at noon,while stomata conductance and photosynthetic rate were decreased.
Noon
Diurnal temperature variation
Stomatal Conductance
Light intensity
Water Use Efficiency
Cite
Citations (0)
Photosynthetic characteristics were studied in mature leaves of Phalaris arundimacea using portable LI-6400 photosynthesis instrument(Licor,USA) in the field.The diurnal changes of net photosynthetic rate and its major affecting factors,including photosynthetically active radiation(Par),stomatal conductance(Cond),intercellar CO_2 concentration(Ci),leaves temperature(Tl),air temperature(Ta),transpiration rate(Tr),were measured.The results showed that the diurnal process of photosynthetic rate exhibited a double peak curve in which the main peak appeared around(10∶00),and the second around(15∶00).This may reflected an obvious phenomena of midday depression of photosynthesis caused by Non-stomatal limition.Diurnal variation of net photosynthetic rate is 5.86-20.64 μmol·m~(-2)·s~(-1),and transpiration rate is 2.8-6.22 mmol·m~(-2)·s~(-1).And the other parameters,light compensation point is 40 μmol·m~(-2)·s~(-1),light saturation point 2100 μmol·m~(-2)·s~(-1),apparent quantum yield 0.0565 mol·mol~(-1),dark(respiration) rate 2.26 μmol·m~(-2)·s~(-1),and water use efficiency is 2.31-3.65 μmol·mmol~(-1).The data showed that P.arundimacea was a kind of highly photosynthetic efficiency plant,(illumina-)ting for the exploitation of resources and maintaining the eco-stability of wetland ecosystem.
Photosynthetically active radiation
Compensation point
Stomatal Conductance
Water Use Efficiency
Diurnal temperature variation
Respiration rate
Cite
Citations (0)
The physiological factors of Camellia japonica such as net photosynthetic rate and transpiration rate,and environmental factors such as light intensity,air temperature,relative humidity were measured in spring and autumn.The results are as follows: With the appropriate environmental conditions,Pn increased gradually,but when it got the limitation of stomata regulation,Pn presented middy depression.The transpiration rate of Camellia japonica was significantly associated with temperature.As the temperature increased,transpiration was strengthened.After the comparison of spring and autumn,photosynthetic efficiency and transpiration were better in autumn,and carbon fixation and humidification content were significantly higher than in spring.In different light environments the photoperiodic induction in the morning made photosynthesis and transpiration maintained at a higher level,but strong light inducing middy depression got the photosynthesis deducing.So Camellia japonica planted with upper trees should be given the suitable photoperiodic induction and also shade environment at noon.
Light intensity
Water Use Efficiency
Cite
Citations (0)
CID-340Portable photosynthetic system was employed to measure the net photosynthetic rate,intercellular carbon dioxide concentration,photosynthetically active radiation,stomatal conductance,atmospheric temperature around the leaves,leaf temperature,and transpiration rate of Hydrocotylev ulgaris to study the photosynthetic characteristics in ecological ditch.The objective was to provide theoretic bases for ditch wetland restoration.The results were as follows:(1) The net photosynthetic rate of Hydrocotylev ulgaris changed in a double-peak curve with its peaks occurring separately at 11:00(16.21 μ mol.m-2.s-1) and 15:00(19.32 μ mol.m-2.s-1),which indicated a photosynthetic midday depressions at noon.(2) The regression equation of the diurnal variation of Pnand its major physi-ecological factors attained by the method of stepwise multiple-regression was as follows:Pn=-5.45613+0.006797PAR+0.050099Gs(multiple correlated coefficient 0.868).The results indicated that stomatal conductance(Gs) and transpiration rate(Tr) were the important factors that affected Pn.The analysis of partial correlation and path on Pnand factors showed that the diurnal variation of Pnhad significan impact with photosynthetically active radiation(PAR) and stomatal conductance(Gs),were the important factors which affected Pnand he order of effecting ability was GsPAR.
Photosynthetically active radiation
Stomatal Conductance
Diurnal temperature variation
Water Use Efficiency
Cite
Citations (0)
[Objective] The study was to provide the physiological ecology basis for the control of Spartina alterniflora.[Method] The diurnal variation of photosynthetic physiological characteristics of S.alterniflora and its relationship with environmental impact factors in mature stage of S.alterniflora was determined by LI-6400 portable photosynthesis system.[Result] The diurnal variation of net photosynthetic rate(Pn) of S.alterniflora was bimodal curve.The Pn was increased rapidly at 7:00-9:00 am,it reached the highest at 9:00 am and decreased continuously at 9:00-13:00,so obvious midday depression of photosynthesis appeared.The diurnal variations of stomatal conductance(Cd) and transpiration rate(Tr) were single peak curve.The intercellular CO2 concn had highly significant negative correlation with Pn.The peak values of light,temperature,stomatal conductance and transpiration rate were all appeared at 12:00.[Conclusion] The midday depression of photosynthesis of S.alterniflora was common affected by non stomatal factors and stomatal factors.
Spartina alterniflora
Stomatal Conductance
Diurnal temperature variation
Spartina
Cite
Citations (0)
In order to discuss the photosynthesis characters of mulberry in Yunnan laterite plateau,Nongsang 12 in Heqing Yunnan were used as experimental materials to analyze the diurnal variation of net photosynthetic rate,transpiration rate,other photosynthetic characteristic parameters and corresponding environmental factors.The results showed that the curves of daily variation of net photosynthetic rate displayed a bimodal curve and an obviously midday depression.The lower net photosynthetic rate at noon was mainly affected by non-stomatal limitation factors.The curves of daily variation of transpiration rate and stomatal conductance displayed bimodal curves,and showed significantly positive correlation.Diurnal variation of intercellular CO2 was reverse of that of net photosynthesis rate basically.The environmental factors affected the photosynthetic characteristic parameters of mulberry,and photosynthetic effective radiation played a decisive role on net photosynthetic rate.
Diurnal temperature variation
Stomatal Conductance
Noon
Photosynthetically active radiation
Cite
Citations (0)
Diurnal changes of leaf net photosynthetic rates of two cultivars of Pueraria lobata were measured using the CIRAS-Ⅰ portable photosynthesis system(PP-Systems Co.,British),and the relationship among diurnal changes of net photosynthetic rates and those of environmental factors were analyzed.The results showed that diurnal changes in the net photosynthetic rates of both two cultivars could be interpreted as double-peak curves,i.e.they possessed obvious so-called midday depression phenomenon.Further analyses showed that the correlation between net photosynthetic rate and stomatal conductance was positive and extremely significant(P 0.01),the correlations between net photosynthetic rate and intercellular CO2 concentration as well as the transpiration rate were positive and significant(P 0.05),and the correlations between net photosynthetic rate and air temperature as well as leaf temperature were negative and significant(P 0.05).The results indicate that among the factors affecting photosynthetic characteristics,some of them could be grouped as stomatal restrictions,while the others could be grouped as non-stomatal restrictions.
Lobata
Stomatal Conductance
Diurnal temperature variation
Cite
Citations (0)
Under different cultivation density,net photosynthetic rate,transpiration rate and related physiological factors(leaf temperature,stomatec conductance,intercellular CO2 concentration) and ecological factors(PAR radiation,atmospheric CO2 concentrations,temperature and relative humidity of the atmosphere) of Ranunculus ternatus Thunb.during the fruiting stage were mea-sured and analyzed by using CI-340 portale photosynthesis system.The results showed that with the increase of the cultivation density,the net photosynthesis and stomatic conductance were increased slowly firstly,and then decreased significantly.While the transpiration rate showed a trend of high-low-high,internal CO2 concentration significantly increased with the increase of density.Coefficient analysis showed that the atmosphere relative humidity(RH),CO2 concentration in the field,stomatic conductance(Gs) and leaf temperature(Tl)were the main factors influencing the characteristics of photosynthesis and transpiration.Non-stoma-related factors affected net photosynthetic rate(Pn) changes under high-density conditions,while under low-density conditions stomatic factors affected net photosynthetic rate(Pn) changes.
Stoma (medicine)
Cite
Citations (0)
The Photosynthetic changes of trifolium L.were studied at the full light and light shaded conditions.The results showed that the net photosynthetic rates of the trifolium L under full light were higher than those under light shaded conditions.The daily patterns of net photosynthetic rate and transpiration rate appeared as double-peak curves.The stomatal limitation was the main factor of midday photosynthetic break.The trends of diurnal stomatal Conductance was similitudear to the diurnal net photosynthetic rates,and the intercellular CO2 concentration has a negative relationship to the net photosynthetic rate.The diurnal curves of Pn,Tr,Gs,Ci under light shaded conditions were different to full light conditions.
Stomatal Conductance
Diurnal temperature variation
Light intensity
Cite
Citations (0)