Dynamics of leaf gas exchange, chlorophyll fluorescence and stem diameter changes during freezing and thawing of Scots pine seedlings

2015 ◽  
Vol 35 (12) ◽  
pp. 1314-1324 ◽  
Author(s):  
Lauri Lindfors ◽  
Teemu Hölttä ◽  
Anna Lintunen ◽  
Albert Porcar-Castell ◽  
Eero Nikinmaa ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Scots Pine ◽  
Leaf Gas Exchange ◽  
Stem Diameter ◽  
Freezing And Thawing ◽  
Pine Seedlings

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.

scholarly journals Changes in Leaf Structural and Functional Characteristics when Changing Planting Density at Different Growth Stages Alters Cotton Lint Yield under a New Planting Model

Agronomy ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 859 ◽  
Author(s):  
Aziz Khan ◽  
Jie Zheng ◽  
Daniel Kean Yuen Tan ◽  
Ahmad Khan ◽  
Kashif Akhtar ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Quantum Yield ◽  
Gas Exchange ◽  
Stomatal Density ◽  
Leaf Gas Exchange ◽  
High Density ◽  
Lint Yield ◽  
Planting Density ◽  
Cotton Lint ◽  
Cotton Lint Yield

Manipulation of planting density and choice of variety are effective management components in any cropping system that aims to enhance the balance between environmental resource availability and crop requirements. One-time fertilization at first flower with a medium plant stand under late sowing has not yet been attempted. To fill this knowledge gap, changes in leaf structural (stomatal density, stomatal length, stomata width, stomatal pore perimeter, and leaf thickness), leaf gas exchange, and chlorophyll fluorescence attributes of different cotton varieties were made in order to change the planting densities to improve lint yield under a new planting model. A two-year field evaluation was carried out on cotton varieties—V1 (Zhongmian-16) and V2 (J-4B)—to examine the effect of changing the planting density (D1, low, 3 × 104; D2, moderate, 6 × 104; and D3, dense, 9 × 104) on cotton lint yield, leaf structure, chlorophyll fluorescence, and leaf gas exchange attribute responses. Across these varieties, J-4B had higher lint yield compared with Zhongmian-16 in both years. Plants at high density had depressed leaf structural traits, net photosynthetic rate, stomatal conductance, intercellular CO2 uptake, quenching (qP), actual quantum yield of photosystem II (ΦPSII), and maximum quantum yield of PSII (Fv/Fm) in both years. Crops at moderate density had improved leaf gas exchange traits, stomatal density, number of stomata, pore perimeter, length, and width, as well as increased qP, ΦPSII, and Fv/Fm compared with low- and high-density plants. Improvement in leaf structural and functional traits contributed to 15.9%–10.7% and 12.3%–10.5% more boll m−2, with 20.6%–13.4% and 28.9%–24.1% higher lint yield averaged across both years, respectively, under moderate planting density compared with low and high density. In conclusion, the data underscore the importance of proper agronomic methods for cotton production, and that J-4B and Zhongmian-16 varieties, grown under moderate and lower densities, could be a promising option based on improved lint yield in subtropical regions.

scholarly journals Effect of fungal infection on leaf gas-exchange and chlorophyll fluorescence in Quercus ilex

2001 ◽  
Vol 58 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Bouchra El Omari ◽  
Isabel Fleck ◽  
Xavier Aranda ◽  
Asumpci� Moret ◽  
Mart� Nadal
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Fungal Infection ◽  
Quercus Ilex ◽  
Leaf Gas Exchange

Discussion on simultaneous measurements of leaf gas exchange and chlorophyll fluorescence for estimating photosynthetic electron allocation

2015 ◽  
Vol 35 (4) ◽  
Author(s):  
康华靖 KANG Huajing ◽  
李红 LI Hong ◽  
陶月良 TAO Yueliang ◽  
张海利 ZHANG Haili ◽  
权伟 QUAN Wei ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Simultaneous Measurements

scholarly journals Waterlogging tolerance evaluation of fifteen poplar clones cultivated in the Jianghan Plain of China

2021 ◽  
Vol 49 (3) ◽  
pp. 12421
Author(s):  
Ruonan GENG ◽  
Xinye ZHANG ◽  
Xiaoping FAN ◽  
Qian HU ◽  
Tianhong NI ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Survival Rates ◽  
Biomass Accumulation ◽  
Co2 Concentration ◽  
Jianghan Plain ◽  
Waterlogging Tolerance ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters

To provide references for poplar cultivation in waterlogged prone area of Jianghan Plain of China, the waterlogging tolerance of 15 poplar clones widely cultivated in these areas were evaluated based on their responses to 45-day waterlogging stress followed by 15-day drainage recovery in morphology, growth, biomass accumulation, leaf gas exchange and chlorophyll fluorescence parameters. The results showed that the normal watered seedlings (CK) of the 15 clones grew vigorously during the experiment, and no defoliation and death occurred. For the seedlings under waterlogging treatment (water 10 cm above the soil surface), its morphology changed markedly, including slowing growth, chlorosis and abscission of leaves, development of hypertrophied lenticels and adventitious roots etc. Waterlogging stress significantly inhibited the seedling growth of height and ground diameter, biomass accumulation, as well as leaf gas exchange and chlorophyll fluorescence parameters of the 15 clones with varying degrees. The net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), intercellular CO2 concentration/ environmental CO2 concentration (Ci/Ca), variable fluorescence (Fv), variable fluorescence/ initial fluorescence (Fv/Fo) and PS Ⅱ primary light energy conversion efficiency (Fv/Fm) decreased gradually with the prolonged waterlogging, and reached their bottom on day 45. During the terminal recovery stage, the leaf gas exchange and chlorophyll fluorescence parameters of the most clones increased, but their recovery abilities were significantly different. At the end of the experiment, the highest survival rates (100%) were observed in DHY, HS-1, HS-2, I-72, I-69, I-63 and NL-895, and the lowest (zero) occurred in XYY. Survival rates of the other clones ranged from 33.33% to 83.33%. Both results of cluster analysis and membership function analysis showed that HS-1, I-69, DHY, NL-895 and HS-2 had the strongest waterlogging tolerance, XYY and HBY were the worst, and the other clones were moderate. These results would provide guidance not only for the selection of cultivated varieties in Jianghan Plain, but also for the selection of hybrid parents for waterlogging resistance breeding.

Responses of Chlorophyll Fluorescence, Stomatal Conductance, and Net Photosynthesis Rates of Four Rubber (Hevea brasiliensis) Genotypes to Drought

2013 ◽  
Vol 844 ◽  
pp. 11-14
Author(s):  
Aidil Azhar ◽  
Jate Sathornkich ◽  
Ratchanee Rattanawong ◽  
Poonpipope Kasemsap
Keyword(s):  
Chlorophyll Fluorescence ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Net Photosynthesis ◽  
Partial Recovery ◽  
Gas Exchange Parameters ◽  
Leaf Chlorophyll ◽  
Drought Conditions ◽  
Leaf Chlorophyll Fluorescence

This experiment aimed to evaluate the leaf chlorophyll fluorescence and gas exchange response to drought conditions of young rubber plants with different scions. Buds from four genotypes of a progeny derived from crossed clones of RRIM600 x RRII105 from Nongkhai Rubber Research Center, T187, T186, T149 and T172, were grafted to RRIM 600 rootstocks. Eight-month old plants with two flushes were used in this study. Two levels of water treatment were used, drought condition (W1) and well-watered as control (W0). Leaf chlorophyll fluorescence, stomatal conductance (gs) and net photosynthesis rate (Pn) were investigated in three phases: before drought, during drought and after re-watering. Leaf gas exchange parameters were measured using Li-6400 (LiCor Inc.). Leaf chlorophyll fluorescence was measured using FluorPen FP 100 (Photon Systems Instruments). Before drought, genotype T186 had the greatest net photosynthesis rates followed by T172, T187 and T149; there was no difference in maximum quantum yield of photosystem II (Fv/Fm) and performance index on absorption basis (PIABS). Drought conditions caused reduction in stomatal conductance, net photosynthesis rates, and leaf chlorophyll fluorescence in all genotypes. In re-watering conditions, genotype T186 and T172 experienced quick recovery while the others showed partial recovery but the values of all parameters did not reach previous levels before treatment.

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