scholarly journals A Physiological behavior and tolerance of Lactuca sativa to lead nitrate and silver nitrate heavy metals

2022 ◽  
Vol 82 ◽  
Author(s):  
J. D. O. Santos ◽  
E.S. Silva ◽  
P. Silva ◽  
M. A. C. Silva ◽  
L. A. Santos ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Silver Nitrate ◽  
Lactuca Sativa ◽  
Lead Nitrate ◽  
Photosynthetic Apparatus ◽  
Seed Vigor ◽  
National Council ◽  
Initial Growth ◽  
Arable Soils ◽  
Experimental Conditions

Abstract This study goal to evaluate the effects of different concentrations of lead (Pb) and silver (Ag) on germination, initial growth and anatomical alterations of Lactuca sativa L. Plants use various mechanisms to reduce the impacts caused by anthropic action, such as xenobiotic elements of soils and water contaminated by heavy metals. These metals were supplied as lead nitrate and silver nitrate and the following treatments were established: control for both metals, maximum dose of heavy metals, for arable soils, allowed by the National Council of the Environment (Ag = 25 mg. Kg-1, Pb = 180 mg. Kg-1), double (Ag = 50 mg. Kg-1, Pb = 360 mg. Kg-1) and triple (Ag = 75 mg. Kg-1, Pb = 540 mg. Kg -1) of this dosage. Vigor and germination tests of the seeds and possible anatomical changes in the leaves and roots of lettuce plants were performed. The species showed a high capacity to germinate under Pb and Ag stress, and the germination was never completely inhibited; however, the germination decreased with increasing Pb concentrations, but not under Ag stress. The use of increasing doses of metals reduced seed vigor and increased chlorophyll content. An increase in biomass was also observed in plants from treatments submitted to Pb. The phytotoxic effects of metals were more pronounced at 15 days after sowing. Anatomically, L. sativa was influenced by metal concentrations, and had a reduction of up to 79.9% in root epidermis thickness at the highest Pb concentration, although some structures did not suffer significant changes. The results suggest that L. sativa presents tolerance to high concentrations of heavy metals, showing possible mechanisms to overcome the stress caused by these metals. In this research lettuce possibly used the mechanism of exclusion of metals retaining Pb and Ag in the roots preserving the photosynthetic apparatus in the aerial part of the plants. In general, the chemical element Pb was more toxic than Ag, in these experimental conditions.

Germination and initial growth of triticale seeds under stationary magnetic fields

2014 ◽  
Vol 2 (2) ◽  
pp. 72-79 ◽  
Author(s):  
Mercedes Florez ◽  
Elvira Martinez ◽  
Victoria Carbonell
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Seed Vigor ◽  
Initial Growth ◽  
Practical Application ◽  
Biochemical Processes ◽  
Mean Germination Time ◽  
Nutrition Value ◽  
The Mean ◽  
Growth Of Seedlings

The main objective of this study is to determine the effects of 125 mT and 250mT magnetic treatment on the germination and initial growth of triticale seeds. This objective has a practical application in agriculture science: early growth of triticale. An increase in the percentage and rate of germination of seeds and a stimulation of growth of seedlings as positive response to magnetic field treatment in rice, wheat, maize and barley seeds have been found in previous studies. Germination tests were carried out under laboratory conditions by exposing triticale seeds to magnetic field for different times. The effect was studied by exposure of seeds prior sowing. The mean germination time were reduced for all the magnetic treatments applied. Most significant differences were obtained for time of exposure of 1 and 24 hours and maximum reductions was 12%. Furthermore, seedlings from magnetically treated seeds grew taller than control. The longest mean total length was obtained from seedlings exposed to 125 and 250 mT for 24 hours. External magnetic fields are assumed to enhance seed vigor by influencing the biochemical processes by stimulating activity of proteins and enzymes. Numerous studies suggested that magnetic field increases ions uptake and consequently improves nutrition value.

scholarly journals Edaphic factors and plants influence denitrification in soils from a long-term arable experiment

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ian M. Clark ◽  
Qingling Fu ◽  
Maïder Abadie ◽  
Elizabeth R. Dixon ◽  
Aimeric Blaud ◽  
...  
Keyword(s):  
Gas Production ◽  
Soil Treatment ◽  
Soil Microbiome ◽  
Arable Soils ◽  
Experimental Conditions ◽  
Mineral N ◽  
Nitrate Availability ◽  
Denitrification Gene ◽  
Denitrification Genes

Abstract Factors influencing production of greenhouse gases nitrous oxide (N2O) and nitrogen (N2) in arable soils include high nitrate, moisture and plants; we investigate how differences in the soil microbiome due to antecedent soil treatment additionally influence denitrification. Microbial communities, denitrification gene abundance and gas production in soils from tilled arable plots with contrasting fertilizer inputs (no N, mineral N, FYM) and regenerated woodland in the long-term Broadbalk field experiment were investigated. Soil was transferred to pots, kept bare or planted with wheat and after 6 weeks, transferred to sealed chambers with or without K15NO3 fertilizer for 4 days; N2O and N2 were measured daily. Concentrations of N2O were higher when fertilizer was added, lower in the presence of plants, whilst N2 increased over time and with plants. Prior soil treatment but not exposure to N-fertiliser or plants during the experiment influenced denitrification gene (nirK, nirS, nosZI, nosZII) relative abundance. Under our experimental conditions, denitrification generated mostly N2; N2O was around 2% of total gaseous N2 + N2O. Prior long-term soil management influenced the soil microbiome and abundance of denitrification genes. The production of N2O was driven by nitrate availability and N2 generation increased in the presence of plants.

Atomic Layer Deposition of Ruthenium Films on Hydrogen terminated Silicon

2009 ◽  
Vol 1156 ◽  
Author(s):  
Sun Kyung Park ◽  
K. Roodenko ◽  
Yves J. Chabal ◽  
L. Wielunski ◽  
R. Kanjolia ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Initial Growth ◽  
Experimental Conditions ◽  
Metallic Component ◽  
Broadband Absorption ◽  
Lorentz Oscillator ◽  
Layer Deposition ◽  
Drude Term ◽  
Number Of Cycles

AbstractAtomic Layer deposition of thin Ruthenium films has been studied using a newly synthesized precursor (Cyclopentadienyl ethylruthenium dicarbonyl) and O2 as reactant gases. Under our experimental conditions, the film comprises both Ru and RuO2. The initial growth is dominated by Ru metal. As the number of cycles is increased, RuO2 appears. From infrared broadband absorption measurements, the transition from isolated, nucleated film to a continuous, conducting film (characterized by Drude absorption) can be determined. Optical simulations based on an effective-medium approach are implemented to simulate the in-situ broadband infrared absorption. A Lorentz oscillator model is developed, together with a Drude term for the metallic component, to describe optical properties of Ru/RuO2 growth.

scholarly journals Responses of quinoa (Chenopodium quinoa Willd.) seeds stored under different germination temperatures

2017 ◽  
Vol 39 (1) ◽  
pp. 83 ◽  
Author(s):  
Andressa Strenske ◽  
Edmar Soares de Vasconcelos ◽  
Vanessa Aline Egewarth ◽  
Neusa Francisca Michelon Herzog ◽  
Marlene De Matos Malavasi
Keyword(s):  
Room Temperature ◽  
Storage Time ◽  
Chenopodium Quinoa ◽  
Seed Vigor ◽  
Continuous Darkness ◽  
Experimental Conditions ◽  
Growing Seasons ◽  
Germinating Seeds ◽  
Germinated Seeds ◽  
Plot Design

In this experiment, we assessed the germination and vigor of quinoa seeds packed in paper bags and stored at room temperature for 36, 85, 119, 146, 177 and 270 days. The seeds were harvested under experimental conditions in Marechal Candido Rondon, Paraná, during the 2012/13 growing seasons. Four replicates of 100 seeds each were established for each storage time, and the seeds were evaluated, on paper, based on the BOD under the following experimental temperature conditions: alternating temperatures of 20 and 30°C and a constant temperature of 25°C. The seeds from both treatments were subject to seven-hour photoperiods and 25°C under continuous darkness. The germinated seeds were counted daily for eight days after sowing, and we evaluated the percentages of normal and abnormal seedlings and the germination index. The experimental design was completely randomized using a split-plot design. Increasing the storage time decreased the percentage of germinated seeds and seed vigor due to the increased number of abnormal seedlings. Over the 430-day study period, quinoa seed germination completely declined under the experimental conditions. The final number of germinating seeds should be evaluated 7 days after the beginning of the germination test. 

scholarly journals Impact of sludge and wastewater on Lactuca sativa L. growth and on soil pollution

2015 ◽  
Vol 17 (1) ◽  
pp. 148-161
Keyword(s):  
Heavy Metals ◽  
Soil Pollution ◽  
Plant Height ◽  
Lactuca Sativa ◽  
Dry Matter ◽  
Municipal Wastewater ◽  
Pollution Load Index ◽  
Dry Matter Yield ◽  
Pollution Load ◽  
Treated Municipal Wastewater

<div> <p>Two greenhouse pot experiments were conducted in Agrinion, Greece. The impact of treated municipal wastewater (TMWW) and sludge (i) on the growth of <em>Lactuca sativa</em> L. var Longifolia (lettuce) and (ii) on the extent of soil pollution with heavy metals was studied. Soil pollution was assessed by calculating the Pollution Load Index (PLI). Both of these experiments were conducted, using a randomized block design in four replications and seven treatments, respectively, as follows: (a) Experiment A: study of the effect of treated municipal wastewater (TMWW): [Control, 20%, 40%, 60%, 80%, 100%, (100%+30 t/ha Sludge)] and (b) Experiment B: Study of the effect of sludge (t/ha): 0, &nbsp;6, 12,&nbsp; 18, 24 , 30, (30+100%TMWW). The sludge affected significantly plant height and fresh and dry matter yield, as well as the dry matter N content of plants, while the TMWW affected significantly the dry matter yield and non-significantly the plant height. The pollution load index (PLI) was non-significant for both treatments (sludge and TMWW). According to PLI calibration scale, the soil was found to be slightly polluted with heavy metals under both treatments.</p> </div> <p>&nbsp;</p>

scholarly journals Sanitary landfill leachate as a source of nutrients on the initial growth of sunflower plants

2016 ◽  
Vol 20 (8) ◽  
pp. 746-750 ◽  
Author(s):  
Francisco H. Nunes Júnior ◽  
Franklin A. Gondim ◽  
Magnum de S. Pereira ◽  
Brennda B. Braga ◽  
Roberto A. Pontes Filho ◽  
...  
Keyword(s):  
Landfill Leachate ◽  
Polynomial Regression ◽  
Inhibitory Effect ◽  
Sanitary Landfill ◽  
Initial Growth ◽  
Experimental Conditions ◽  
Shoot Height ◽  
Number Of Leaves ◽  
Collar Diameter ◽  
Sanitary Landfill Leachate

ABSTRACT The aim of this study was to evaluate the initial growth of sunflower seedlings under different concentrations of sanitary landfill leachate, considering the feasibility of its use as source of nutrients for agricultural production. Biometric and vigor variables were analyzed through the measurements of collar diameter, shoot height, number of leaves and shoot and root fresh and dry matters, from January to February 2015. The experimental design was completely randomized in a 5 x 4 factorial scheme: five leachate concentrations (0, 40, 60, 80 and 100 kg N ha-1) x four harvest periods (14, 21, 25 and 29 days after sowing), with five replicates each containing two plants. The data were subjected to analysis of variance and polynomial regression, and the results of the last harvest (29 DAS) were compared by Tukey test (p ≤ 0.05). The use of sanitary landfill leachate increased all analyzed variables in sunflower plants when compared to the control plants (without leachate), especially in the treatment of 100 kg N ha-1. There was no inhibitory effect of the leachate on the initial growth of sunflower seedlings under adopted experimental conditions.

The photosynthetic apparatus ofConocarpus lancifoliusEngl. (Combretaceae) suffers damage in soil contaminated with heavy metals

Botany ◽  
2019 ◽  
Vol 97 (3) ◽  
pp. 179-189
Author(s):  
Amina Redha ◽  
Redah Al-Hasan ◽  
Jacquilion Jose ◽  
Divya Saju ◽  
Mohammad Afzal
Keyword(s):  
Heavy Metals ◽  
Electron Transport Rate ◽  
Photosynthetic Apparatus ◽  
Growth Conditions ◽  
Photosynthetic Parameters ◽  
Physiological Changes ◽  
Transmission Electron ◽  
Content Index ◽  
Slow Adaptation ◽  
Chloroplast Morphology

Conocarpus lancifolius Engl. (Combretaceae), a heat tolerant plant, has potential for use in the phytoremediation of polluted soil. We analyzed the physiological changes in C. lancifolius exposed to single and mixed heavy metals (HMs; cadmium, nickel, and lead). For 30 days under controlled growth conditions, we exposed some groups of plants to a single HM at concentrations of 25 or 50 μmol·L–1and other groups were exposed to 25 μmol·L–1of a mixture of HMs. Photosynthetic parameters such as electron transport rate, photosynthetic rate, chlorophyll fluorescence, chlorophyll content index, and photosynthetic pigments were measured. Chloroplast morphology was studied by transmission electron microscopy (TEM). In plants exposed to 25 μmol·L–1of HMs, the photosynthetic parameters were unaffected, whereas at 50 μmol·L–1of HMs, all parameters significantly decreased up to 20 days of exposure, followed by an increase up to 30 days, indicating a slow adaptation of plants to HM under stress. Compared with the single HMs, mixtures of HMs were more toxic at the same concentration. All parameters indicated damage to the photosynthetic apparatus due to stress from 25 μmol·L–1of the HM mixtures and 50 μmol·L–1of the single HMs. TEM analyses showed a dispersion of grana in the chloroplast of the affected C. lancifolius plants.

scholarly journals Toxicity Effects of Selected Heavy Metals on Lactuca sativa and Hydra viridissima used for Sustainable Crop Production

2018 ◽  
Vol 7 (3) ◽  
pp. 82
Author(s):  
Lina Maria Caceres Diaz ◽  
Claudia Campos ◽  
Gideon Oron
Keyword(s):  
Heavy Metals ◽  
Acute Toxicity ◽  
Lactuca Sativa ◽  
Toxicity Test ◽  
Crop Production ◽  
Arid Regions ◽  
Toxicity Assessment ◽  
Agricultural Irrigation ◽  
Lactuca Sativa L ◽  
Toxicity Effects

This study examines the prospects for using Hydra viridissima toxicity test 96-h LC50, served as a model invertebrate, Lactuca sativa L. was applied for seeds toxicity test (120-h IC50) and a model plant for an acute toxicity assessment of heavy metals content in water. The heavy metals used to assess the acute toxicity of the water utilized for agricultural irrigation in arid regions includes cadmium (CdCl2.2H2O), chromium (K2Cr2O7), zinc (ZnSO4. 7H2O), and boron (H3BO3). A grading of the substances was conducted, and it was found that the toxicity levels for H. viridissima and L. sativa were, with the least harmful first: B < Cr < Zn < Cd and Zn < B < Cr < Cd, respectively. Results indicate that H. viridissima was a more sensitive indicator of toxicity for all of the evaluated substances. However, L. sativa could also be used successfully to rank toxicants in order of their potential hazards.

scholarly journals Phytotoxic effects of Morus nigra aqueous extract on germination and seedling growth of Lactuca sativa

Rodriguésia ◽  
2018 ◽  
Vol 69 (4) ◽  
pp. 2153-2161
Author(s):  
Letícia Rodrigues Vieira ◽  
Eliane Regina da Silva ◽  
Geraldo Luiz Gonçalves Soares ◽  
Claudimar Sidnei Fior ◽  
Eduardo Miranda Ethur ◽  
...  
Keyword(s):  
Seedling Growth ◽  
Lactuca Sativa ◽  
Membrane Integrity ◽  
Initial Growth ◽  
Aqueous Extracts ◽  
Allelopathic Potential ◽  
Morus Nigra ◽  
Phytotoxic Effects ◽  
Root And Shoot Length ◽  
Morphological Deformities

Abstract Some exotic species threat the integrity of natural environments due to their invasive potential. They can affect other species by releasing secondary compounds in the soil. Morus nigra (Moraceae) is an invasive species of riparian forests in southern Brazil. The objective of this study was to verify if the aqueous extracts of fruit, fresh and dry leaves of M. nigra show phytotoxic effects on germination, seedling growth and membrane integrity of seedlings of Lactuca sativa. Extract concentrations of 0.1, 0.25, 0.5, 0.75, 1, 2.5, 5, 7.5 and 10% were tested. Germination rate and speed of germination were determined. Effects on initial growth were evaluated by measuring seedling root and shoot length, and membrane integrity was assessed by conductivity tests. Results showed the phytotoxicity of M. nigra aqueous extracts, causing significant inhibition on germination and seedling growth. The fruit extract was generally less phytotoxic than extracts from fresh and dry leaves. Moreover, the extracts induced changes in membrane integrity and caused morphological deformities in seedlings, such as necrotic roots and chlorotic plants. The high phytotoxicity of fruit, dry and fresh leaf extracts of M. nigra was evidenced, indicating the allelopathic potential of the species.

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