scholarly journals Photosynthesis of Physalis peruviana under different densities of photons and saline stress

2021 ◽  
Vol 37 ◽  
pp. e37082
Author(s):  
Francisco Romário Andrade Figueiredo ◽  
João Everthon da Silva Ribeiro ◽  
Jackson Silva Nóbrega ◽  
Wilma Freitas Celedônio ◽  
Reynaldo Teodoro de Fátima ◽  
...  

Physalis peruviana L. is a solanacea that has been gaining prominence due to its fruits presenting good acceptance in the national and international market. However, several abiotic factors, such as salinity, can cause physiological disturbances in plants, and these changes may be of greater or lesser intent according to species. Therefore, the objective of the present work was to evaluate the physiological behavior of P. peruviana submitted to different fluxes of photosynthetically active photons (PPFD) and saline stress. The experimental design was a randomized block design with three saline levels (ECw) (0.5, 2.75 and 5.00 dS m-1) with four replications. Gas exchange measurements were performed with a portable infrared gas analyzer. Liquid CO2 assimilation, stomatal conductance, internal CO2 concentration, water use efficiency and instantaneous carboxylation efficiency were measured. Data were subjected to analysis of variance by F test and in cases of significance applied to regression analysis. The increase in PPFD provided reductions in stomatal conductance up to the density of approximately 400 μmol m-2s-1, being more pronounced in ECw of 2.75 and 5.0 dS m-1. The maximum CO2 assimilation rates in the three salinities are different according to the PPFD. The salinity of irrigation water reduced the quantum efficiency of photosynthesis in P. peruviana plants.

Author(s):  
Lucas Aparecido Manzani Lisboa ◽  
Fernando Takayuki Nakayama ◽  
Edivaldo Cia ◽  
Paulo Alexandre Monteiro de Figueiredo ◽  
Sérgio Bispo Ramos ◽  
...  

The luminosity and the temperature are factors that act directly in the photosynthetic process, where an elevation of the luminous intensity can cause a reduction of the assimilation of carbon, which consequently lowers the development of the cotton. The objective of this work was to assess the response of physiological parameters of cotton when subjected to different artificial light intensities. Two varieties of cotton IMA5801B2RF and IACRDN, were interacting with five artificial light intensities: 0 (control); 500; 1000; 1500 and 2000 μmol m−2 s−1 of photosynthetically active radiation provided by LED bulbs. The experiment was set in a randomized complete block design using a 2x5 factorial scheme. The variables measured were the rate of CO2 assimilation, transpiration, stomatal conductance, inner CO2 concentration in the substomatic chamber, and efficient use of water (for which a portable device of gas exchange was used). The cotton varieties responded positively to different luminous intensities until reaching the point of maximum saturation between 1400 and 1600 µmol m-1 s-1 of light, which provided a better rate of CO2 assimilation, concentration of CO2 in the substomatic chamber, and efficient use of water. Leaf transpiration and stomatal conductance showed a positive linear response with increasing light intensity. The ideal luminous intensity for the use of Infra-Red Gas Analyzer - IRGA was 1500 µmol m-1 s-1 for the tested cotton varieties.


Author(s):  
Idelfonso Leandro Bezerra ◽  
Hans Raj Gheyi ◽  
Reginaldo Gomes Nobre ◽  
Geovani Soares de Lima ◽  
João Batista dos Santos ◽  
...  

This study evaluated the growth and gas exchanges of guava, cv. ‘Paluma’ cultivated in salinized soil and subjected to different nitrogen (N) doses in a protected environment in the municipality of Campina Grande-PB. The experimental design was randomized blocks, in a 5 x 4 factorial arrangement with three replicates, and the treatments resulted from the combination of five salinity levels in the soil saturation extract - ECse (2.15, 3.15,4.15, 5.15 and 6.15 dS m-1) and four N doses (70, 100, 130 and 160% of the recommended N dose). The dose referring to 100% of N corresponded to 541.1 mg of N dm-3 of soil. At 120 and 180 days after (DAT), plant growth was evaluated based on stem diameter (SD), leaf area (LA) and number of leaves (NL). At 210 DAT, the following variables of leaf gas exchanges were evaluated: stomatal conductance (gs), internal CO2 concentration (Ci), transpiration (E) and CO2 assimilation rate (A). ECse above 2.15 dS m-1 reduced stem diameter, leaf area, number of leaves, stomatal conductance, internal CO2 concentration, transpiration and CO2 assimilation rate, in both evaluation periods. N dose above 70% of the recommendation (378.7 mg N dm-3 of soil) did not mitigate the deleterious effects caused by the salt stress on the growth and gas exchanges of guava plants.


2020 ◽  
Vol 41 (6supl2) ◽  
pp. 3039-3052
Author(s):  
Geovani Soares de Lima ◽  
◽  
Charles Macedo Félix ◽  
Saulo Soares da Silva ◽  
Lauriane Almeida dos Anjos Soares ◽  
...  

In the semi-arid region of Northeastern Brazil, due to the occurrence of excess salts, both in the water and soil, plants are constantly exposed to various conditions of abiotic stress. Thus, it is extremely important to identify methods capable of minimizing the effects of salt stress on plants as a way to ensure the expansion of irrigated areas. In this context, the objective of this study was to evaluate the gas exchange, growth, and production of mini-watermelon irrigated with saline waters and fertilized with phosphorus. The experiment was conducted in pots under greenhouse conditions in Pombal, PB, Brazil, using a randomized block design in a 5 x 4 factorial scheme, corresponding to five levels of electrical conductivity of irrigation water—ECw (0.3, 1.3, 2.3, 3.3, and 4.3 dS m-1), four phosphorus doses— PD (60, 80, 100, and 120% of the recommendation), and with three replicates. Watermelon plants cv. Sugar Baby were sensitive to water salinity greater than 0.3 dS m-1, with more pronounced inhibition of gas exchange, growth, and production. Reduction in the CO2 assimilation rate of watermelon plants cv. Sugar Baby was associated with factors of stomatal and non-stomatal origin. Phosphorous doses corresponding to 73 and 88% of the recommended values promoted an increase in the intercellular CO2 concentration and stem diameter of mini-watermelon plants. P2O5 doses ranging from 60 to 120% of the recommendation did not mitigate the effects of salt stress on the cultivation of watermelon cv. Sugar Baby.


2004 ◽  
Vol 26 (2) ◽  
pp. 206-208 ◽  
Author(s):  
José Moacir Pinheiro Lima Filho

A study was carried out at Embrapa Semi-Árido, Petrolina-PE, Brazil, aiming to understand the gas exchange process of the umbu tree (Spondias tuberosa Arr. Cam.) in the dry and rainy seasons. Stomatal conductance, transpiration, photosynthesis and internal CO2 concentration were obtained with a portable infrared gas analyzer (IRGA). During the dry season the umbu tree showed a much lower stomatal conductance early in the morning, as soon as the vapor pressure deficit increased, apparently affecting CO2 assimilation more than transpiration. The highest values were detected around 6:00 am but decreased to the lowest points between 10:00 am and 2:00 pm. During the rainy season, however, stomatal conductance, transpiration and photosynthesis were significantly higher, reaching the highest values between 8:00 and 10:00 am and the lowest around 2:00 pm. It was also observed at 4:00 pm, mainly during the rainy season, an increase on these variables indicating that the umbu tree exhibits a two-picked daily course of gas exchange.


2018 ◽  
Vol 31 (4) ◽  
pp. 808-816
Author(s):  
Idelfonso Leandro Bezerra ◽  
Reginaldo Gomes Nobre ◽  
Hans Raj Gheyi ◽  
Geovani Soares De Lima ◽  
Joicy Lima Barbosa

ABSTRACT The cultivation of irrigated guava in semi-arid areas highlights the need for information regarding its responses to irrigation water quality and the fertilization management that enables its exploitation. Thus, this study aimed to evaluate the effect of water salinity and nitrogen (N) doses on the growth and physiology of the guava cv. ‘Paluma’. The experiments was conducted in drainage lysimeters under field conditions in an experimental area at the Center of Sciences and Agri-Food Technology of the Federal University of Campina Grande (CCTA/UFCG), Campus II, in Pombal, PB, Brazil. The experiment had a randomized block design, and treatments consisted of a 5 x 4 factorial arrangement corresponding to five levels of irrigation water electrical conductivity, ECw (0.3, 1.1, 1.9, 2.7, and 3.5 dS m-1), and four N doses (70, 100, 130, and 160% of the recommended N dose). The 100% dose corresponded to 541.1 mg of N dm-3 of soil. Increments in irrigation water salinity from 0.3 dS m-1 led to a reduction in stomatal conductance, internal CO2 concentration, CO2 assimilation rate, transpiration, instantaneous water use efficiency, the number of leaves and branches, stem diameter, and absolute and relative growth rates. Nitrogen doses ranging from 378.7 to 865.7 mg of N dm-3 of soil did not affect gas exchange and plant growth. Although ‘Paluma’ guava growth was affected by increases in water salinity, these plants can be irrigated using water of up to 1.42 dS m-1 with an acceptable reduction of 10% in growth variables. The interaction between irrigation water salinity and N fertilization had no significant effect on any of the variables studied.


Author(s):  
Allan R. F. Campos ◽  
Rosiane L. S. de Lima ◽  
Carlos A. V. de Azevedo ◽  
Ronaldo do Nascimento ◽  
Sonivagno S. Silva

ABSTRACT Nitrogen (N) fertilization associated with planting density is a practice that can improve the physiological aspects and consequently increase the yield of a crop. Thus, this study aimed to evaluate the effects of planting density and N levels on the physiological aspects of jatropha in the ‘Agreste’ region of Paraíba. Treatments consisted of four planting densities (833, 1,111, 1,666 and 2,500 plants ha-1) representing the plots and five N doses (0, 40, 80, 120 and 180 kg ha-1) corresponding the subplots. The effects of treatments on CO2 assimilation rate, internal CO2 concentration, transpiration, stomatal conductance, water use efficiency, instantaneous carboxylation efficiency and SPAD index were analysed. Except for stomatal conductance, the other variables were influenced by the interaction between planting densities and N levels. The association of the dose of 80 kg ha-1 with a planting density of 2,200 plants ha-1 provided adequate conditions for the production of plants with increased photosynthetic activity and efficient use of water.


2021 ◽  
Vol 45 ◽  
Author(s):  
André Alisson Rodrigues da Silva ◽  
Geovani Soares de Lima ◽  
Carlos Alberto Vieira de Azevedo ◽  
Hans Raj Gheyi ◽  
Allesson Ramos de Souza ◽  
...  

ABSTRACT The cultivation of soursop has increased in recent years due to the advance of agribusiness and due to its use by the pharmaceutical industry. As a source of vitamin C, calcium, carbohydrates and antioxidant substances, soursop helps to protect the human body against oxidative stress, acting in the prevention of a series of chronic degenerative disorders. In this context, the objective of present study was to evaluate the effects of foliar sprays with salicylic acid to mitigate the effects of salt stress on the morphophysiology of soursop. The study was conducted in a greenhouse, in a randomized block design and a 5 × 4 factorial arrangement, with five levels of electrical conductivity of irrigation water - ECw (0.8-control; 1.6; 2.4; 3.2 and 4.0 dS m-1) and four concentrations of salicylic acid - SA (0; 1.2; 2.4 and 3.6 mM), with three replicates. Foliar application of SA at concentrations between 1.2 and 1.6 mM mitigated the effects of salt stress on stomatal conductance, CO2 assimilation rate, transpiration and instantaneous carboxylation efficiency of soursop at 480 days after transplanting. Spraying with SA at concentrations between 1.3 and 1.6 mM induced acclimatization to salt stress in soursop plants, since the percentage of intercellular electrolyte leakage was reduced and the growth was favored by the application of SA, even when exposed to salinity. Irrigation with ECw above 0.8 dS m-1 reduced the relative water content in the leaves of soursop cv. Morada Nova.


2017 ◽  
Vol 39 (4) ◽  
Author(s):  
NICOLE TREVISANI ◽  
RITA CAROLINA DE MELO ◽  
MAURO PORTO COLLI ◽  
JEFFERSON LUÍS MEIRELLES COIMBRA ◽  
ALTAMIR FREDERICO GUIDOLIN

ABSTRACT Knowledge about associations between traits is fundamental for plant breeding, since indirect selection can accelerate the development of promising genotypes. This study assessed the magnitude of associations between agronomically important traits in fisális (Physalis peruviana L). The experiment was conducted in Lages, Santa Catarina, and the treatments consisted of six fisális populations. The experiment was arranged in a randomized block design, with two replications and seven plants per plot. The correlations between traits were estimated based on the Pearson correlation coefficients and partitioned into direct and indirect effects through path analysis. Fruit weight was positively correlated with number of seeds (0.874), equatorial fruit diameter (0.738) and polar fruit diameter (0.672). By path analysis, number of seeds was identified as the trait with the highest direct contribution to fruit weight. The high phenotypic correlations between the equatorial and polar fruit diameters with fruit weight were mainly due to the indirect effect via number of seeds (0.505 and 0.459). The selection for heavier fisális fruits was strongly influenced by number of seeds, i.e., this trait should be taken into account for selection.


2019 ◽  
Vol 11 (9) ◽  
pp. 272
Author(s):  
Milena Barretta Franceschetti ◽  
Leandro Galon ◽  
Maico André Michelon Bagnara ◽  
Renan Pawelkiewicz ◽  
Leonardo Brunetto ◽  
...  

Among the factors which affect crop productivity, there are weeds which compete for environment resources. The objective of this work was to determine the periods of interference of alexandergrass on the morphophysiology and productivity components of black beans. The experiment was conducted in a complete randomized block design with four replications. The bean cultivar of the black type used was IPR Uirapuru, being the treatments separated in two models of interference: in the coexistence group, the crop of the bean lived with the alexandergrass by growing periods of 0, 7, 14, 21, 28, 35, 42 and throughout the cycledays after emergence and throughout the cycle; in the control group the crop was kept free of the infestation for the same periods described previously. At 42 DAE were evaluated the variables related to plant morphology and physiology (height of bean plants, number of trifoliate leaves, dry mass plant, number of grains pods, number od pods plants, stomatal conductance, internal CO2 concentration, photosynthetic activity, efficiency of carboxylation, efficient use of water, transpiration rate). Considering the results, it is possible to conclude that the critical period of interference prevention (CPIP) comprises 24 to 50 DAE, the period before the interference (PBI) was 24 DAE and the total period of interference prevention (TPIP) was 50 days and that the morphological and physiological variables of the plants were negatively affected in the coexistence with the alexandergrass when compared to the treatments kept free of weeds throughout the crop cycle.


2020 ◽  
Vol 11 ◽  
pp. E3113
Author(s):  
José Sebastião de Melo Filho ◽  
Toshik Iarley da Silva ◽  
Anderson Carlos de Melo Gonçalves ◽  
Leonardo Vieira de Sousa ◽  
Mario Leno Martins Véras ◽  
...  

Although not considered an essential element, silicon can be used to increase crop productivity, especially under stress conditions. In this sense, the objective was to evaluate the gas exchange of beet plants irrigated with saline water depending on the application of silicon. The experiment was conducted in a randomized block design, in a 5 x 5 factorial, referring to five levels of electrical conductivity of irrigation water (ECw): (0.5; 1.3; 3.25; 5.2 and 6.0 dS m-1) and five doses of silicon (0.00; 2.64; 9.08; 15.52 and 18.16 mL L-1), with six beet plants as an experimental unit. The effect of treatments on beet culture was evaluated at 30 and 60 days after irrigation with saline water from measurements of internal carbon concentration, stomatal conductance, net photosynthesis rate, instantaneous water use efficiency and instantaneous carboxylation efficiency using the LCpro+Sistem infrared gas analyzer (IRGA). Irrigation with saline water reduced the gas exchange of beet plants at 60 days after irrigation, but at 30 days after irrigation, the use of saline water increased stomatal conductance, transpiration rate and internal carbon concentration. The application of silicon decreased stomatal conductance, internal carbon concentration and efficiency in the use of water, but increased the rate of net photosynthesis, the rate of transpiration and instantaneous efficiency of carboxylation at 30 and 60 days after irrigation.


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