scholarly journals Photosynthetic parameters and stomatal conductance in attached and detached balsam fir foliage

2021 ◽  
Author(s):  
Matthew E. Akalusi ◽  
Fan‐Rui Meng ◽  
Charles P.‐A. Bourque
Keyword(s):  
Stomatal Conductance ◽  
Balsam Fir ◽  
Photosynthetic Parameters

Changes of Photosynthetic Parameters in Jatropha curcas L. Leaves under Cobalt Stress

2019 ◽  
Vol 5 (04) ◽  
pp. 278-283
Author(s):  
Kamal Kant Patra ◽  
Deepti Oberoi ◽  
Rajat Kumar Joshi ◽  
Raghunath Prasad ◽  
Dharam Deo Pandey
Keyword(s):  
Stomatal Conductance ◽  
Chlorophyll A ◽  
Photosynthetic Pigments ◽  
Transpiration Rate ◽  
Jatropha Curcas ◽  
Photosynthetic Parameters ◽  
Cobalt Toxicity ◽  
Use Efficiency ◽  
Survival Potential ◽  
Increasing Trends

In the present investigation, changes of photosynthetic parameters including net photosynthetic rate (PN); stomatal conductance (gs), transpiration rate (E), and water-use efficiency (WUE) were studied in Jatropha (Jatropha curcas cv. DARL-2) under different concentrations of cobalt (Co) (0, 100, 200, 400, 600, 800, and 1000 mg kg-1) toxicity. The PN, gs, and E trends were shown in increasing trends up to 200 mg kg-1 Co in comparison to controlled plants. However, trends of WUE and photosynthetic pigments [chlorophyll a, b, (a+b), and carotenoids] were found in decreasing order in all concentrations of cobalt stress as compared to controlled plants. The PN value was ~1.33, and ~2.44 fold higher in 100 and 200 mg kg-1 but decreased ~2.61, ~6.86, and ~15.40 fold in 400, 600, and 800 mg kg-1 cobalt treatment, respectively. Similarly, the gs rate was ~1.33, and ~1.69 fold higher in 100 and 200 mg kg-1 but decreased ~1.89, ~3.38, and ~8.71 fold in 400, 600, and 800 mg kg-1 cobalt treatment. The E was significantly ~1.44, ~2.74, and ~1.35 fold higher in 100, 200, and 400 mg kg-1 decreased ~1.03 and ~1.43 fold in 600 and 800 mg kg-1. The WUE was ~0.93, ~0.89, ~3.50, ~6.51, and ~10.76 fold decreased in all Co treated plants. In addition, the content of photosynthetic pigments [chlorophyll a, b, (a+b), and carotenoids] was varying in all Co treated plants. All studied plants were survived morphologically up to 800 mg kg-1 but seedlings were not survived due to severe cobalt toxicity stress in 1000 mg kg-1. Among studied plants, Jatropha seedlings showed the best survival potential under 200 mg kg-1 Co stress.

scholarly journals Phenotyping of rice in salt stress environment using high-throughput infrared imaging

2014 ◽  
Vol 73 (1) ◽  
pp. 312-321 ◽  
Author(s):  
Zamin S. Siddiqui ◽  
Jung-Il Cho ◽  
Sung-Han Park ◽  
Taek-Ryoun Kwon ◽  
Gang-Seob Lee ◽  
...  
Keyword(s):  
Salt Stress ◽  
Stomatal Conductance ◽  
Water Content ◽  
Relative Water Content ◽  
Infrared Imaging ◽  
Oryza Sativa L ◽  
Photosynthetic Parameters ◽  
Relative Water ◽  
Stress Environment ◽  
And Performance

Abstract Phenotyping of rice (Oryza sativa L. cv. Donggin) in salt stress environment using infrared imaging was conducted. Results were correlated with the most frequently used physiological parameters such as stomatal conductance, relative water content and photosynthetic parameters. It was observed that stomatal conductance (R2 = -0.618) and relative water content (R2 = -0.852) were significantly negatively correlated with average plant temperature (thermal images), while dark-adapted quantum yield (Fv/Fm, R2 = -0.325) and performance index (R2 = -0.315) were not consistent with plant temperature. Advantages of infrared thermography and utilization of this technology for the selection of stress tolerance physiotypes are discussed in detail.

scholarly journals PHOTOSYNTHETIC PARAMETERS AS PHYSIOLOGICAL INDICATORS OF TOLERANCE TO CADMIUM STRESS IN SUNFLOWER GENOTYPES

2018 ◽  
Vol 31 (4) ◽  
pp. 907-916 ◽  
Author(s):  
Bárbara Lima do Sacramento ◽  
André Dias de Azevedo Neto ◽  
Andréia Teixeira Alves ◽  
Silvany Cardim Moura ◽  
Rogério Ferreira Ribas
Keyword(s):  
Stomatal Conductance ◽  
Quantum Yield ◽  
Nutrient Solution ◽  
Photosynthetic Pigment ◽  
Photosynthetic Parameters ◽  
Effective Quantum Yield ◽  
Cd Stress ◽  
Physiological Indicators ◽  
Net Assimilation ◽  
Tolerance To Cadmium

ABSTRACT The objective of the present study was to evaluate the tolerance to cadmium (Cd) of sunflower genotypes grown in greenhouse conditions, and the effectiveness of using photosynthetic parameters as physiological indicators of this tolerance. Seeds of two sunflower genotypes previously identified as tolerant (H358) and Cd-sensitive (AG960) to Cd were used. The seeds were germinated in plastic cups containing plant substrate; after 9 days, the seedlings were transplanted to plastic basins containing a nutrient solution with 0 or 10 µM of Cd, where they remained for 16 days. Samples of the plants were harvested every 5 days. The experiment was carried out in a randomized complete design, using a 4×2×2 factorial arrangement (4 days of grown in a nutrient solution with Cd, 2 sunflower genotypes, and 2 Cd levels) with four replications. Cd stress decreased CO2 net assimilation, stomatal conductance, carboxylation efficiency, photosynthetic pigment contents, potential quantum yield (Fv/Fm), and effective quantum yield of plants of the two evaluated genotypes. The decrease in photosynthetic rates of these plants was caused by both stomatal and non-stomatal limitations. Plants of the AG960 genotype showed more pronounced deleterious effects due to Cd stress than those of the H358 genotype. Thus, CO2 net assimilation rate, stomatal conductance, and chloroplast pigment content are good physiological indicators of sunflower tolerance to Cd and can at least in part, explain the greater tolerance of the H358 genotype to Cd stress when compared to the AG960 genotype.

Effect of Water Stress on Photosynthetic Parameters of Soybean (Glycine max) and Velvetleaf (Abutilon theophrasti)

Weed Science ◽  
1987 ◽  
Vol 35 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Philip H. Munger ◽  
James M. Chandler ◽  
J. Tom Cothren
Keyword(s):  
Glycine Max ◽  
Water Stress ◽  
Stomatal Conductance ◽  
Water Potential ◽  
Net Photosynthetic Rate ◽  
Photosynthetic Rate ◽  
Transpiration Rate ◽  
Abutilon Theophrasti ◽  
Leaf Water ◽  
Photosynthetic Parameters

Greenhouse experiments were conducted to elucidate the effects of water stress on photosynthetic parameters of soybean [Glycine max(L.) Merr. ‘Hutton′] and velvetleaf (Abutilon theophrastiMedik. # ABUTH). Stomatal conductance of both species responded curvilinearly to reductions in leaf water potential. At leaf water potentials less negative than −2.5 MPa, stomatal conductance, net photosynthetic rate, and transpiration rate were greater in velvetleaf than in soybean. Soybean photosynthetic rate was linearly related to stomatal conductance. Velvetleaf photosynthetic rate increased linearly with stomatal conductances up to 1.5 cm s–1; however, no increase in photosynthetic rate was observed at stomatal conductances greater than 1.5 cm s–1, indicating nonstomatal limitations to photosynthesis. As water stress intensified, stomatal conductance, photosynthetic rate, and transpiration of velvetleaf declined more rapidly than in soybean.

scholarly journals Impact of Drought and Salinity on Sweetgum Tree (Liquidambar styraciflua L.): Understanding Tree Ecophysiological Responses in the Urban Context

Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 1032
Author(s):  
Rita Baraldi ◽  
Arkadiusz Przybysz ◽  
Osvaldo Facini ◽  
Lorenzo Pierdonà ◽  
Giulia Carriero ◽  
...  
Keyword(s):  
Salt Stress ◽  
Stomatal Conductance ◽  
Xanthophyll Cycle ◽  
Photochemical Efficiency ◽  
Photosynthetic Apparatus ◽  
Liquidambar Styraciflua ◽  
Photosynthetic Parameters ◽  
Urban Tree ◽  
Isoprene Emission ◽  
The Impact

Understanding urban tree responses to drought, salt stress, and co-occurring stresses, as well as the capability to recover afterward, is important to prevent the cited stresses’ negative effects on tree performance and ecological functionality. We investigated the impact of drought and salinity, alone and in combination, on leaf water potential, gas exchange, chlorophyll a fluorescence, xanthophyll cycle pigments, and isoprene emission of the urban tree species Liquidambar styraciflua L. Generally, drought had a rapid negative impact, while the effect of salt stress was more long lasting. Both stressors significantly decreased photosynthesis, transpiration, and stomatal conductance, as well as the maximum quantum efficiency of photosystem II (Fv/Fm) and the photochemical efficiency of PSII (ΦPSII), but increased nonphotochemical quenching (NPQ). Under stress conditions, a strong negative correlation between the PSII efficiency and the xanthophyll cycle pigment composition indicated a nocturnal retention of zeaxanthin and antheraxanthin in a state primed for energy dissipation. Drought and salt stress inhibited isoprene emission from leaves, although its emission was less responsive to stresses than stomatal conductance and photosynthesis. Full recovery of photosynthetic parameters took place after rewatering and washing off of excess salt, indicating that no permanent damage occurred, and suggesting downregulation rather than permanent impairment of the photosynthetic apparatus. Sweetgum trees were capable of withstanding and surviving moderate drought and salt events by activating defense mechanisms conferring tolerance to environmental stresses, without increasing the emission in the atmosphere of the highly reactive isoprene.

scholarly journals Modelling basin-wide variations in Amazon forest productivity – Part 1: Model calibration, evaluation and upscaling functions for canopy photosynthesis

2009 ◽  
Vol 6 (2) ◽  
pp. 2965-3030 ◽  
Author(s):  
L. M. Mercado ◽  
J. Lloyd ◽  
A. J. Dolman ◽  
S. Sitch ◽  
S. Patiño
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Ecosystem Respiration ◽  
Eddy Correlation ◽  
Critical Parameters ◽  
Photosynthetic Parameters ◽  
Amazon Forest ◽  
Model Data ◽  
Vegetation Models ◽  
Sun And Shade

Abstract. Given the importance of Amazon rainforest in the global carbon and hydrological cycles, there is a need to parameterize and validate ecosystem gas exchange and vegetation models for this region in order to adequately simulate present and future carbon and water balances. In this study, a sun and shade canopy gas exchange model is calibrated and evaluated at five rainforest sites using eddy correlation measurements of carbon and energy fluxes. Results from the model-data evaluation suggest that with adequate parameterisation, photosynthesis models taking into account the separation of diffuse and direct irradiance and the dynamics of sunlit and shaded leaves can accurately represent photosynthesis in these forests. Also, stomatal conductance formulations that only take into account atmospheric demand fail to correctly simulate moisture and CO2 fluxes in forests with a pronounced dry season, particularly during afternoon conditions. Nevertheless, it is also the case that large uncertainties are associated not only with the eddy correlation data, but also with the estimates of ecosystem respiration required for model validation. To accurately simulate Gross Primary Productivity (GPP) and energy partitioning the most critical parameters and model processes are the quantum yield of photosynthetic uptake, the maximum carboxylation capacity of Rubisco, and simulation of stomatal conductance. Using this model-data synergy, we developed scaling functions to provide estimates of canopy photosynthetic parameters for a~range of diverse forests across the Amazon region, utilising the best fitted parameter for maximum carboxylation capacity of Rubisco, and foliar nutrients (N and P) for all sites.

Effect of Elevated CO2 Concentration on Leaf Photosynthesis in Sanjiang-Deyeuxia angustifolia

2013 ◽  
Vol 726-731 ◽  
pp. 305-309
Author(s):  
Ming Yi Xu ◽  
Ao Xue Wang ◽  
Hong Wei Ni
Keyword(s):  
Stomatal Conductance ◽  
Chlorophyll Content ◽  
Photosynthetic Parameters ◽  
Leaf Photosynthesis ◽  
Short Term ◽  
Deyeuxia Angustifolia ◽  
Different Levels ◽  
Concentration Condition ◽  
Photosynthetic Ability

Deyeuxia angustifolia were grown under three different levels of CO2concentration conditions, 370μmol mol-1(ambient CO2), 550μmol mol-1(elevated CO2) and 700μmol mol-1(elevated CO2) respectively. We investigated the responses of photosynthesis and growth ofD.angustifoliaunder different CO2concentration conditions. Leaf photosynthesis and chlorophyll content were checked. The results showed that the values of net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2concentration (Ci), transpiration (E), chlorophyll content were influenced by the elevated CO2concentrations. The photosynthetic parameters changed in parallel with CO2enrichment. CO2enrichment in short term improved the photosynthetic ability of leaves, whereas the capacity was weakened under long-term elevated CO2concentration condition. The leaves ofD.angustifoliagrown under elevated CO2concentrations at the end of growth, had lower Pn, Gs, Ci, E and chlorophyll content than those grown and measuered under ambient CO2concentration. The results indicated thatD.angustifoliaappeared photosynthetic acclimation.

scholarly journals PREDICTION OF PHOTOSYNTHETIC RESPONSES BY MATHEMATICAL MODEL

2020 ◽  
Vol 8 (6) ◽  
pp. 102-120
Author(s):  
Krishan Verma ◽  
Chedilal Verma ◽  
Munna Singh ◽  
Yash Pal Singh ◽  
Damodaran T. ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Stomatal Conductance ◽  
Diurnal Variations ◽  
Photosynthetic Parameters ◽  
Plant Responses ◽  
Average Deviation ◽  
Proposed Model ◽  
Photosynthetic Responses ◽  
The Comparative Study

English: Plant photosynthetic responses such as photosynthesis, transpiration rate and stomatal conductance are interrelated. There is a definite tendency for variability between photosynthetic responses and leaf positions at different branches. The variability is in the form of diurnal variations relative to the leaf positions of photosynthesis, transpiration and stomatal conductance on the same branch of Jatropha curcas plants. This research paper presented shows that the correlation between plant photosynthetic responses through mathematical modeling. Through the proposed model, the characteristic of plant responses constants for jatropha plants were calculated and the different deviation from their observed value was calculated by calculating the different plant photosynthetic parameters. In the comparative study, the average deviation of the photosynthetic responses ranged from 1.69 - 13.21. This model can be easily used in calculating plant photosynthetic responses according to their leaf positions on the branches of other plants.   Hindi: पादप कार्यिकी अनुक्रियायें यथा प्रकाश संश्लेषण, उत्स्वेदन एवं रंघ्रीय चालकता परस्पर सह संबंधित हैं।  शाखाओं पर विभिन्न स्थितियों पर अवस्थित पर्णों के पादप कार्यिकी अनुक्रियाओं एवं पर्ण स्थिति के बीच परिवर्तनीयता की एक निश्चित प्रवृत्ति होती है।  जट्रोफा की सरल शाखा पर स्थित विभिन्न पत्तियों के प्रकाश संश्लेषण, उत्स्वेदन दर एवं रंघ्री चालकता की पर्ण स्थिति के सापेक्ष परिवर्तनीयता एक घण्टाकृति के रूप में होती हैं।  प्रस्तुत शोध पत्र में पादप कार्यिकी अनुक्रियाओं के परस्पर सह संबंध को गणितीय सूत्र के माध्यम से दर्शाया गया है।  प्रस्तावित प्रतिदर्श के द्वारा जट्रोफा के लिये अभिलाक्षणिक पादप कार्यिकी युगल अनुक्रिया स्थिरांकों की गणना की गयी एवं उनसे विभिन्न पादप कार्यिकी अनुक्रियाओं की गणना करके उनके प्रेक्षित मान से प्रतिशत विचलन की गणना की गयी।  तुलनात्मक अध्ययन में कलित पादप कार्यिकी अनुक्रियाओं का औसत विचलन 1.69 से 13.21% के बीच रहा।  इस प्रतिदर्श का प्रयोग अन्यान्य पौधों के शाखाओं पर अवस्थित पत्तियों की उनकी स्थिति के अनुरूप पादप कार्यिकी अनुक्रियाओं की गणना में सहजता पूर्वक किया जा सकता है।

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