scholarly journals Characteristics of Gas Exchange and Chlorophyll Fluorescence during Senescence of Flag Leaf in Different Rice (Oryza sativaL.) Cultivars Grown under Nitrogen-Deficient Condition

2009 ◽  
Vol 12 (3) ◽  
pp. 285-292 ◽  
Author(s):  
Etsushi Kumagai ◽  
Takuya Araki ◽  
Fumitake Kubota
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Flag Leaf

The Effect of Water Shortage on Potted Peach Trees in Relation to Ecophysiological Parameters and Infra-red Thermometry

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 541b-541
Author(s):  
Rita Giuliani ◽  
James A. Flore
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Early Detection ◽  
Water Potential ◽  
Canopy Temperature ◽  
Water Shortage ◽  
Development Rate ◽  
Plant Water ◽  
Infra Red ◽  
Peach Trees

Potted peach trees grown outdoors during the 1997 season were subjected to drought and subsequent rewatering to evaluate their dynamic response to soil water content. The investigation was primarily focused on the early detection of plant water stress to prevent negative effects on the growth. Leaf chlorophyll fluorescence and canopy temperature estimates (by infra-red thermometry) were conducted. Drought effect on physiological processes were detected through by estimates of canopy development rate, leaf gas-exchange measurements; while leaf water potential was measured to characterize plant water status. A decrease in the canopy's development rate was found 1 week after irrigation was stopped, which also coincided with a more-negative leaf water potential, whereas a decrease of the gas-exchange activities occurred several days later. No significant differences between the stressed and control plants were recorded by the chlorophyll fluorescence parameters (Fo, Fm, Fv and the ratio Fv/Fm), whereas the infra-red estimates of canopy temperature detected a slight increase of the canopy surface temperature (connected to the change of leaf energy balance and in relation to partial stomatal closure) on the non-irrigated plants 1 week after the beginning of the trial. The use of infra-red thermometry for early detection of water shortage is discussed.

Effects of Autotoxicity on Seed Germination, Gas Exchange Attributes and Chlorophyll Fluorescence in Melon Seedlings

2021 ◽  
Author(s):  
Zhizhong Zhang ◽  
Jinghua Wu ◽  
Yupei Xi ◽  
Lizhen Zhang ◽  
Qiang Gao ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Seed Germination ◽  
Gas Exchange

Nitrogen application improves gas exchange characteristics and chlorophyll fluorescence in maize hybrids under salinity conditions

2011 ◽  
Vol 58 (3) ◽  
pp. 394-401 ◽  
Author(s):  
M. Akram ◽  
M. Y. Ashraf ◽  
M. Jamil ◽  
R. M. Iqbal ◽  
M. Nafees ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Nitrogen Application ◽  
Maize Hybrids ◽  
Gas Exchange Characteristics

scholarly journals Variations in leaf gas exchange, chlorophyll fluorescence and membrane potential of Medicago sativa root cortex cells exposed to increased salinity: The role of the antioxidant potential in salt tolerance

2018 ◽  
Vol 70 (3) ◽  
pp. 413-423 ◽  
Author(s):  
Mohamed Farissi ◽  
Mohammed Mouradi ◽  
Omar Farssi ◽  
Abdelaziz Bouizgaren ◽  
Cherki Ghoulam
Keyword(s):  
Antioxidant Enzymes ◽  
Salt Stress ◽  
Chlorophyll Fluorescence ◽  
Membrane Potential ◽  
Salt Tolerance ◽  
Gas Exchange ◽  
Medicago Sativa ◽  
Leaf Gas Exchange ◽  
Root Cortex ◽  
Root Cortex Cells

Salinity is one of the most serious agricultural problems that adversely affects growth and productivity of pasture crops such as alfalfa. In this study, the effects of salinity on some ecophysiological and biochemical criteria associated with salt tolerance were assessed in two Moroccan alfalfa (Medicago sativa L.) populations, Taf 1 and Tata. The experiment was conducted in a hydro-aeroponic system containing nutrient solutions, with the addition of NaCl at concentrations of 100 and 200 mM. The salt stress was applied for a month. Several traits in relation to salt tolerance, such as plant dry biomass, relative water content, leaf gas exchange, chlorophyll fluorescence, nutrient uptake, lipid peroxidation and antioxidant enzymes, were analyzed at the end of the experiment. The membrane potential was measured in root cortex cells of plants grown with or without NaCl treatment during a week. The results indicated that under salt stress, plant growth and all of the studied physiological and biochemical traits were significantly decreased, except for malondialdehyde and H2O2 contents, which were found to be increased under salt stress. Depolarization of membrane root cortex cells with the increase in external NaCl concentration was noted, irrespective of the growth conditions. The Tata population was more tolerant to high salinity (200 mM NaCl) and its tolerance was associated with the ability of plants to maintain adequate levels of the studied parameters and their ability to overcome oxidative stress by the induction of antioxidant enzymes, such as guaiacol peroxidase, catalase and superoxide dismutase.

Zinc and potassium fertilizer recommendation for cotton seedlings under salinity stress based on gas exchange and chlorophyll fluorescence responses

2020 ◽  
Vol 130 ◽  
pp. 155-164 ◽  
Author(s):  
Zahra Hatam ◽  
Mohammad Sadegh Sabet ◽  
Mohammad Jafar Malakouti ◽  
Ali Mokhtassi-Bidgoli ◽  
Mehdi Homaee
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Salinity Stress ◽  
Potassium Fertilizer ◽  
Fertilizer Recommendation

scholarly journals Modification of a gas exchange system to measure active and passive chlorophyll fluorescence simultaneously under field conditions

AoB Plants ◽  
2020 ◽  
Author(s):  
Eliot W Meeker ◽  
Troy S Magney ◽  
Nicolas Bambach ◽  
Mina Momayyezi ◽  
Andrew J McElrone
Keyword(s):  
Chlorophyll Fluorescence ◽  
Steady State ◽  
Gas Exchange ◽  
Near Infrared ◽  
Pulse Amplitude ◽  
Bottom Plate ◽  
Pam Fluorometer ◽  
Promising Tool ◽  
Leaf Level ◽  
Gas Exchange System

Abstract Solar-induced fluorescence (SIF) is a promising tool to estimate photosynthesis across scales; however, there has been limited research done at the leaf-level to investigate the relationship between SIF and photosynthesis. To help bridge this gap, a LI-COR LI-6800 gas exchange instrument was modified with a visible-near-infrared (VIS-NIR) spectrometer to measure active and passive fluorescence simultaneously. The system was adapted by drilling a hole into the bottom plate of the leaf chamber and inserting a fiber-optic to measure passive steady-state fluorescence (Ft,λ, analogous to SIF) from the abaxial surface of a leaf. This new modification can concurrently measure gas exchange, passive fluorescence, and active fluorescence over the same leaf area and will allow researchers to measure leaf-level Ft,λ in the field to validate tower-based and satellite measurements. To test the modified instrument, measurements were performed on leaves of well-watered and water stressed walnut plants at three light-levels and a constant air temperature. Measurements on these same plants were also conducted using a similarly modified Walz GFS-3000 gas exchange instrument to compare results. We found a positive linear correlation between Ft,λ measurements from the modified LI-6800 and GFS-3000 instruments. We also report a positive linear relationship between Ft,λ and normalized steady-state chlorophyll fluorescence (Ft/Fo) from the pulse-amplitude modulation (PAM) fluorometer of the LI-6800 system. Accordingly, this modification will inform the link between spectrally resolved Ft,λ and gas-exchange – leading to improved interpretation of how remotely sensed SIF tracks changes in the light reactions of photosynthesis.

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