scholarly journals GAS EXCHANGES, QUANTUM YIELD AND PHOTOSYNTHETIC PIGMENTS OF WEST INDIAN CHERRY UNDER SALT STRESS AND POTASSIUM FERTILIZATION

2019 ◽  
Vol 32 (2) ◽  
pp. 429-439 ◽  
Author(s):  
ADAAN SUDARIO DIAS ◽  
GEOVANI SOARES DE LIMA ◽  
FRANCISCO WESLEY ALVES PINHEIRO ◽  
HANS RAJ GHEYI ◽  
LAURIANE ALMEIDA DOS ANJOS SOARES
Keyword(s):  
Electrical Conductivity ◽  
Salt Stress ◽  
Quantum Yield ◽  
Chlorophyll A ◽  
Photosynthetic Pigments ◽  
Photochemical Efficiency ◽  
Photosynthetic Apparatus ◽  
West Indian ◽  
Gas Exchanges ◽  
Potassium Fertilization

ABSTRACT Water resources in the semi-arid region of Northeast Brazil commonly contain high salt concentrations, compromising the quality of water for agriculture. Thus, adopting techniques that make the use of these resources feasible in agriculture is fundamental. The present study aimed to evaluate the gas exchanges, quantum yield and photosynthetic pigments of grafted West Indian cherry subjected to salt stress and potassium fertilization under greenhouse conditions in the municipality of Campina Grande, PB, Brazil. Treatments were distributed in randomized blocks, composed of two levels of electrical conductivity - ECw (0.8 and 3.8 dS m-1) of water and four doses of potassium (50, 75, 100 and 125% of the dose recommended for the crop), with three replicates. The dose relative to 100% corresponded to 19.8 g of K2O per plant. Gas exchanges, chlorophyll a fluorescence and photosynthetic pigments of West Indian cherry are negatively affected by irrigation using water with electrical conductivity of 3.8 dS m-1, which compromises the photosynthetic apparatus of the plant, a situation evidenced by the reduction in photosystem II quantum efficiency. Increasing potassium doses led to increments in transpiration, chlorophyll a maximum fluorescence and chlorophyll b content in West Indian cherry grown under salt stress, but do not attenuate the negative effects of irrigation with 3.8 dS m-1 water on its potential photochemical efficiency.

scholarly journals Gas exchanges and photochemical efficiency of hydroponic bell pepper under salinity and plant density

2019 ◽  
Vol 23 (1) ◽  
pp. 3-8
Author(s):  
Antônio R. Cavalcante ◽  
José A. Santos Júnior ◽  
Guilherme de F. Furtado ◽  
Lúcia H. G. Chaves
Keyword(s):  
Electrical Conductivity ◽  
Salt Stress ◽  
Plant Density ◽  
Photochemical Efficiency ◽  
Photosynthetic Apparatus ◽  
Bell Pepper ◽  
Gas Exchanges ◽  
Hydroponic System ◽  
Salinity Levels ◽  
Pepper Plants

ABSTRACT Gas exchanges and chlorophyll a fluorescence are ways to physiologically analyze the response of plants to salt stress. In this context, the present work was conducted between August and November 2016 in a greenhouse at the Federal University of Campina Grande (7°12’52” S, 35°54’24” W, mean altitude of 550 m), using bell pepper plants cv. All Big, exposed to levels of nutrient solution electrical conductivity (1.7, 3.7, 5.7, 7.7, 9.7 and 11.7 dS m-1) and cultivated in hydroponic system, spaced by 0.2 and 0.3 m, focusing on the analysis of gas exchanges and photochemical efficiency. The experimental design was completely randomized, in a 6 x 2 factorial scheme, with five replicates. Plant density influenced the sensitivity of the gas exchanges to salinity and, when reduced, mitigated its effects at higher salinity levels. Increasing plant density at high levels of electrical conductivity caused damage to the photosynthetic apparatus and even reduced the levels of efficiency of the photosystem II from 3.98 dS m-1.

scholarly journals Gas exchanges and photochemical efficiency of West Indian cherry cultivated with saline water and potassium fertilization

2018 ◽  
Vol 22 (9) ◽  
pp. 628-633 ◽  
Author(s):  
Adaan S. Dias ◽  
Geovani S. de Lima ◽  
Francisco V. da S. Sá ◽  
Hans R. Gheyi ◽  
Lauriane A. dos A. Soares ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Sandy Loam ◽  
Saline Water ◽  
Photochemical Efficiency ◽  
West Indian ◽  
High Concentration ◽  
Gas Exchanges ◽  
Potassium Fertilization ◽  
Loam Soil ◽  
K Fertilization

ABSTRACT The problem of the lack of adequate water resources for agriculture has intensified in recent years, making it necessary to use waters with relatively high concentration of salts for the irrigation of crops all over the world. The objective of this study was to evaluate the influence of potassium (K) fertilization as a salt stress attenuator on gas exchanges and photochemical efficiency of West Indian cherry. The crop was cultivated under greenhouse conditions in the municipality of Campina Grande, PB, in lysimeters filled with 250 kg of sandy loam soil. Treatments were distributed in randomized blocks, in a 2 x 4 factorial scheme, with two levels of electrical conductivity of irrigation water - ECw (0.8 and 3.8 dS m-1) and four K doses (50, 75, 100 and 125% of recommendation), in which the dose corresponding to 100% was equal to 19.8 g of K2O, with three replicates and one plant per repetition. Seedlings of the West Indian cherry cultivar BRS 366-Jaburu, grafted onto a locally developed rootstock from the clonal garden of the EMBRAPA Tropical Agroindustry, Pacajus, CE, were used. Irrigation with salinized water (electrical conductivity of 3.8 dS m-1) compromised the gas exchange and the photochemical efficiency of West Indian cherry plants. Potassium fertilization was not efficient at reducing the stress caused by water salinity on West Indian cherry plants.

scholarly journals Water Relations and Gas Exchanges of West Indian Cherry under Salt Stress and Nitrogen and Phosphorus Doses

2017 ◽  
Vol 9 (10) ◽  
pp. 168 ◽  
Author(s):  
Francisco V. da S. Sá ◽  
Hans R. Gheyi ◽  
Geovani S. de Lima ◽  
Emanoela P. de Paiva ◽  
Pedro D. Fernandes ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Water Relations ◽  
Irrigation Water ◽  
Chlorophyll A Fluorescence ◽  
Saline Water ◽  
Block Design ◽  
West Indian ◽  
N Fertilization ◽  
Nitrogen And Phosphorus ◽  
Gas Exchanges

This study aimed to evaluate the interaction between the fertilization with nitrogen (N) and phosphorus (P) and irrigation with saline water on the water relations, gas exchanges and chlorophyll a fluorescence in West Indian cherry in the vegetative stage. The study was carried out in protected environment, using lysimeters filled with clay loam Regolithic Neosol, with low P content, installed in a randomized block design, arranged in a factorial scheme with five levels of electrical conductivity of irrigation water (ECw), and four managements of P and N fertilization, with three replicates and one plant per plot. Along the experiment, water relations, gas exchanges and chlorophyll a fluorescence were evaluated in West Indian cherry plants. The increase in irrigation water salinity reduces the gas exchanges of the plants, but the increment of 40% in N supply increases the photosynthetic activity of West Indian cherry at recommendation levels higher than 100:100% of the P/N ratio, when irrigated with ECw of up to 3.0 dS m-1. The combined action of N and P, at doses of 140:140% N/P recommendation, increases leaf turgor in the plants, regardless of the ECw level. The increment of 40% in N dose reduces the effects of salinity on the initial fluorescence of chlorophyll a in West Indian cherry irrigated with up to 2.2 dS m-1.

Photobiology of the zoanthid Zoanthus sociatus in intertidal and subtidal habitats

2016 ◽  
Vol 67 (12) ◽  
pp. 1991 ◽  
Author(s):  
Miguel C. Leal ◽  
Igor C. S. Cruz ◽  
Carlos R. Mendes ◽  
Ricardo Calado ◽  
Ruy K. P. Kikuchi ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Photosynthetic Pigments ◽  
Photochemical Efficiency ◽  
Terrestrial Ecosystems ◽  
Aerial Exposure ◽  
Future Studies ◽  
Tidal Cycles ◽  
First Time ◽  
Intertidal Pools ◽  
Intertidal Environments

Intertidal environments are boundaries between marine and terrestrial ecosystems that are subject to rapid fluctuations across tidal cycles. This study investigates, for the first time, the photobiology of symbiotic zoanthids inhabiting different tidal environments: subtidal, intertidal pools and intertidal areas exposed to air during low tide. More specifically, we assessed the photochemical efficiency, Symbiodinium density and photosynthetic pigments profile of Zoanthus sociatus during low tide. Photochemical efficiency was lower and cell density higher in air exposed zoanthids. The profile of photosynthetic pigments also varied significantly among tidal habitats, particularly photoprotective pigments such as dinoxanthin and diadinoxanthin. Differences were also observed for the pigment content per cell, but the proportion of particular pigments (peridinin/chlorophyll-a and diatoxanthin+diadinoxanthin/chlorophyll-a) remained stable. Results suggest that aerial exposure conditions induce reversible downregulation of photochemical processes but no photophysiological impairment or bleaching. These findings provide a baseline for future studies addressing the prevalence of these overlooked cnidarians in environmentally dynamic reef flats.

scholarly journals QUANTUM YIELD, PHOTOSYNTHETIC PIGMENTS AND BIOMASS OF MINIWATERMELON UNDER IRRIGATION STRATEGIES AND POTASSIUM1

2021 ◽  
Vol 34 (3) ◽  
pp. 659-669
Author(s):  
SAULO SOARES DA SILVA ◽  
GEOVANI SOARES DE LIMA ◽  
VERA LÚCIA ANTUNES DE LIMA ◽  
LAURIANE ALMEIDA DOS ANJOS SOARES ◽  
HANS RAJ GHEYI ◽  
...  
Keyword(s):  
Salt Stress ◽  
Quantum Yield ◽  
Photosynthetic Pigments ◽  
Saline Water ◽  
Block Design ◽  
Irrigation Management ◽  
Biomass Accumulation ◽  
Maturation Stage ◽  
Fruit Maturation ◽  
Maturation Stages

ABSTRACT This study was conducted with the objective of evaluating the quantum yield, photosynthetic pigments and biomass accumulation of mini watermelon cv. Sugar Baby, under strategies of irrigation with saline water and potassium fertilization. The experiment was conducted in a randomized block design, in a 8 × 3 factorial scheme, with three replicates, corresponding to eight strategies of irrigation with saline water applied at different phenological stages of the crop (control - irrigation with low-salinity water throughout the crop cycle, and salt stress in the vegetative, vegetative/flowering, flowering, flowering/fruiting, fruiting, fruiting/ fruit maturation and fruit maturation stage) and three potassium doses (50, 100 and 150% of the recommendation). The dose of 100% corresponded to 150 mg of K2O kg-1 of soil. Two levels of electrical conductivity of water were used: 0.8 and 4.0 dS m-1. Irrigation with water of 4.0 dS m-1 continuously in the vegetative and flowering stages increased the initial fluorescence and decreased the quantum efficiency of photosystem II of mini watermelon fertilized with 100 and 150% of K recommendation. Fertilization with 50% recommendation did not interfere in the fluorescence parameters of the mini watermelon, regardless of the irrigation management strategy. Chlorophyll a synthesis is inhibited by salt stress in the vegetative/flowering, flowering, flowering/fruiting, fruiting/maturation stages, as well as for total chlorophyll, except for the flowering stage. Application of 4.0 dS m-1 water in the flowering, fruiting/maturation and maturation stages promoted greater biomass accumulation in mini watermelon.

scholarly journals Growth, photosynthetic pigments, and photochemical efficiency of sour passion fruit as a function of the cationic nature of water

2021 ◽  
Vol 42 (2) ◽  
pp. 583-598
Author(s):  
Francisco Jean da Silva Paiva ◽  
◽  
Geovani Soares de Lima ◽  
Vera Lúcia Antunes de Lima ◽  
Jailton Garcia Ramos ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Photosynthetic Pigments ◽  
Irrigation Water ◽  
Photochemical Efficiency ◽  
Passion Fruit ◽  
Control Treatment ◽  
Chlorophyll B ◽  
Academic Unit ◽  
Agricultural Engineering ◽  
Sour Passion Fruit

The objective of this study was to evaluate the growth, photosynthetic pigments, and photochemical efficiency of sour passion fruit cv. BRS Rubi do Cerrado irrigated with waters of different cationic natures. The experiment was carried out from March 2019 to January 2020 in a protected environment belonging to the Academic Unit of Agricultural Engineering of the Federal University of Campina Grande (UFCG), Campina Grande, PB, Brazil. The treatments consisted of eight combinations of irrigation water with different cationic natures: S1 - Control; S2 - Na+; S3 - Ca2+; S4 - Mg2+; S5 - Na+ + Ca2+; S6 - Na+ + Mg2+; S7 - Ca2+ + Mg2+, and S8 - Na+ + Ca2+ + Mg2+. Plants in the control treatment (S1) were irrigated using water with an electrical conductivity (ECw) of 0.4 dS m-1, while the other treatments (S2; S3; S4; S5; S6; S7; and S8) were subjected to an ECw of 3.5 dS m-1. Sour passion fruit growth was affected by variations in the level of electrical conductivity, regardless of the cationic nature of irrigation water. The use of salinized water with sodium favored the synthesis of chlorophyll a, chlorophyll b, and carotenoids of passion fruit plants at 180 days after transplanting. The distinct cationic natures of irrigation water did not influence the fluorescence variables of sour passion fruit.

scholarly journals DAYTIME VARIATIONS OF CHLOROPHYLL A FLUORESCENCE IN PAU D'ALHO SEEDLINGS

2016 ◽  
Vol 40 (6) ◽  
pp. 1023-1030 ◽  
Author(s):  
Marcos Antonio Bacarin ◽  
Emanuela Garbin Martinazzo ◽  
Daniela Cassol ◽  
Antelmo Ralph Falqueto ◽  
Diolina Moura Silva
Keyword(s):  
Chlorophyll A ◽  
Chlorophyll A Fluorescence ◽  
Photochemical Efficiency ◽  
Photosynthetic Apparatus ◽  
Photosynthetic Active Radiation ◽  
High Radiation ◽  
Active Radiation ◽  
Fluorescence Measurements ◽  
Subsequent Decrease ◽  
Modulated Fluorescence

ABSTRACT Analysis of transient and modulated fluorescence of chlorophyll a were made at one-hour intervals during an eight-hour period starting at 07:30h aiming to study mechanisms of photoprotection against high radiation and temperature in Gallesia integrifolia plants. Seeds were germinated inside plastic pots containing soil as substrate. At 120 days after emergence, chlorophyll fluorescence measurements were performed using Handy-PEA and FMS2 fluorometers. During the course of a day, an increase and a subsequent decrease in temperature and in photosynthetic active radiation were observed until 12:30h. Changes in transient kinetic curves of chlorophyll a fluorescence were identified. This resulted in changes in JIP test parameters. An increase during the period of high radiation and temperature may be stressed in relation to variables related to dissipation flux and appearance of positive -K and -L bands. Considering the modulated fluorescence, high values of non-photochemical quenching coefficients associated with lower values of effective photochemical efficiency of the photosystem II (FV'/ FM') and current photochemical efficiency of PSII (φPSII) could be observed during early morning. This was probably the result of an inhibition of the biochemical phase of photosynthesis. It can be concluded that Gallesia integrifolia decrease its photochemical activity with the increase in the photosynthetic active radiation, demonstrating a photoinhibitory effect under high irradiance conditions, but without irreversible damages to the photosynthetic apparatus.

scholarly journals Salt stress change chlorophyll fluorescence in mango

2012 ◽  
Vol 34 (4) ◽  
pp. 1245-1255 ◽  
Author(s):  
Cicero Cartaxo de Lucena ◽  
Dalmo Lopes de Siqueira ◽  
Hermínia Emilia Prieto Martinez ◽  
Paulo Roberto Cecon
Keyword(s):  
Salt Stress ◽  
Chlorophyll Fluorescence ◽  
Quantum Yield ◽  
Photosystem Ii ◽  
Early Detection ◽  
Leaf Area ◽  
Photochemical Efficiency ◽  
Leaf Abscission ◽  
Hoagland Solution ◽  
Mango Tree

This study evaluated the tolerance of mango cultivars 'Haden', 'Palmer', 'Tommy Atkins' and 'Uba' grafted on rootstock 'Imbú' to salt stress using chlorophyll fluorescence. Plants were grown in modified Hoagland solution containing 0, 15, 30, and 45 mmol L-1 NaCl. At 97 days the parameters of the chlorophyll fluorescence (F0, Fm, Fv, F0/Fm, Fv/Fm, Fv'/Fm', ΦPSII = [(Fm'-Fs)/(Fm')], D = (1- Fv'/Fm') and ETR = (ΦPSII×PPF×0,84×0,5) were determined. At 100 days, the leaf emission and leaf area, toxicity and leaf abscission indexes were determined. In all cultivars evaluated, in different degree, there were decreases in photochemical efficiency of photosystem II, enhanced concentrations from 15 mmol L-1 NaCl. The decreases in the potential quantum yield of photosystem II (Fv/Fm) were 27.9, 18.7, 20.5, and 27.4%, for cultivars 'Haden', 'Palmer', 'Tommy Atkins', and 'Uba', respectively, when grown in 45 mmol L-1 NaCl. It was found decreases in leaf emission and mean leaf area in all cultivars from 15 mmol L-1 NaCl. There were increases in leaf toxicity of 33.0, 67.5, 41.6 and 80.8% and in leaf abscission of 71.8, 29.2, 32.5, and 67.9% for the cultivars 'Haden', 'Palmer', 'Tommy Atkins', and 'Uba' respectively, when grown in 45 mmol L-1 NaCl. Leaf toxicity and leaf abscission were not observed in 15 mmol L-1 NaCl. The decrease in Fv/Fm ratio were accompanied by decreasing in leaf emission and increased leaf toxicity index, showing, therefore, the potential of chlorophyll fluorescence in the early detection of salt stress in mango tree.

Content of Photosynthetic Pigments and Leaf Gas Exchanges of Young Coffee Plants under Light Restriction and Treated with Paclobutrazol

2019 ◽  
pp. 1-13
Author(s):  
André Felipe Fialho Ribeiro ◽  
Sylvana Naomi Matsumoto ◽  
Luanna Fernandes Pereira ◽  
Ueliton Soares De Oliveira ◽  
Ednilson Carvalho Teixeira ◽  
...  
Keyword(s):  
Photosynthetic Pigments ◽  
Photosynthetic Pigment ◽  
Photosynthetic Apparatus ◽  
Atmospheric Temperature ◽  
Joint Analysis ◽  
Negative Effects ◽  
Gas Exchanges ◽  
High Solar Radiation ◽  
Leaf Gas Exchanges ◽  
Coffee Plants

The use of shading and paclobutrazol in coffee plants can be an important cultivation strategy to mitigate the negative effects of high solar radiation and atmospheric temperature. Therefore, the levels of photosynthetic pigments and foliar gas exchanges of young coffee plants submitted to doses of paclobutrazol were evaluated, in environments with artificial light restriction. Five experiments were performed: one in full sunlight and four in artificially shaded environments with black polyethylene meshes at 20%, 40%, 60% and 80% levels of light restriction. In each of these environments, an experiment was carried out, consisting of five treatments, defined by the application of paclobutrazol via substrate, at doses of 0, 10, 20, 30 and 40 mg of active ingredient per plant. Joint analysis of experiments and analysis of variance of the regression were made, for the study of levels of shading and doses of paclobutrazol. The light restriction optimized the photosynthetic apparatus of the plants, mainly at levels close to 60%, and considerably favored leaf gas exchanges of arabica coffee. The application of paclobutrazol in the studied dosages resulted in little or no effect on photosynthetic pigment contents and did not influence leaf gas exchanges of coffee plants.

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