CHLOROPHYLL FLUORESCENCE IN Brachiaria decumbens AND Brachiaria ruziziensis SUBMITTED TO HERBICIDES

ABSTRACT Different doses of herbicides can promote a differentiated physiological response in grasses of the same genus. This study has been proposed in order to evaluate physiological responses of B. ruziziensis and B. decumbens submitted to glyphosate and fluazifop-p-butyl. Treatments were distributed in a 2 x 6 factorial design with five repetitions, being two grasses: B. decumbens cv. Basilisk and B. ruziziensis with six doses of herbicides: 0.00; 0.25; 0.50; 1.00; 1.5 and 2.00 times the commercial dose recommended by manufacturers. At 7, 15, 21, and 30 days after herbicide application (DAA) chlorophyll luminous energy uptake efficiency was evaluated. Plants subjected to glyphosate at 7 days after application (DAA) showed minimum fluorescence of 270 and 245 quantum-1 electrons to B. ruziziensis and B. decumbens, respectively, levels increased by 350% when compared to the control, and at 15 DAA the treated plants have completely dried up. At 15 DAA, both forage species submitted to the fluazifop-p-butyl showed a 25% reduction in Fv/Fm ratio compared with the control and there was no significant difference between the lowest and highest doses applied. B. ruziziensis and B. decumbens are more sensitive to glyphosate than fluazifop-p-butyl. Regarding fluazifop-p-butyl, B. ruziziensis was more sensitive than B. decumbens and at 45 days after cutting B. decumbens plants submitted to doses up to 100 g ha-1 were able to regenerate their photosynthetic apparatus.

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Chemical control of signalgrass in alfalfa crops

Semina Ciências Agrárias ◽

10.5433/1679-0359.2017v38n6p3695 ◽

2017 ◽

Vol 38 (6) ◽

pp. 3695 ◽

Cited By ~ 1

Author(s):

Renan Coelho Dias ◽

Márcia Vitória Santos ◽

Fabiana Lopes Ramos de Oliveira ◽

Evander Alves Ferreira ◽

José Barbosa dos Santos ◽

...

Keyword(s):

Dry Matter ◽

Physiological Stress ◽

Block Design ◽

Photosynthetic Apparatus ◽

Herbicide Application ◽

Brachiaria Decumbens ◽

Physiological Variables ◽

Randomized Block Design ◽

Forage Species ◽

Tiller Density

The use of herbicides to control grass in Medicago sativa (alfalfa) pastures is still incipient. Therefore, the objective of this study was to evaluate the efficiency of fluazifop-p-butyl in the control of Brachiaria decumbens (signalgrass) in alfalfa. Thus, randomized block design was used, with seven doses of fluazifop-p-butyl (0, 25, 50, 100, 200, 300, 400 g ha-1), and four replications. Herbicide application was performed when the plants had about 20 cm height. Chlorophyll fluorescence, control of signalgrass and alfalfa toxicity were evaluated at 7, 15 e 30 days after application (DAA) and, at 45 DAA and 45 days after cut (DAC), both species were cut and tiller density, as well as branches and dry matter of forage species, were determined. Fluazifop-p-butyl does not affect the integrity of the photosynthetic apparatus of alfalfa plants, due to high tolerance to this mechanism of action presented by dicotyledonous species. However, signalgrass had physiological variables negatively affected by the herbicide, indicating the presence of physiological stress, even at the lowest doses of the product. The dose of 50 g ha-1 of fluazifop-p-butyl is effective in controlling signalgrass, without causing physiological and growth damage in alfalfa plants.

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HERBICIDE SELECTIVITY TO SIGNAL GRASS AND CONGO GRASS

Planta Daninha ◽

10.1590/s0100-83582017350100062 ◽

2017 ◽

Vol 35 (0) ◽

Author(s):

A.H.C. ANÉSIO ◽

M.V. SANTOS ◽

R.R. SILVEIRA ◽

E.A. FERREIRA ◽

T.G.S. BRAZ ◽

...

Keyword(s):

Electron Transport Chain ◽

Block Design ◽

Herbicide Application ◽

Brachiaria Decumbens ◽

Brachiaria Ruziziensis ◽

Randomized Block Design ◽

Transport Chain ◽

Minas Gerais State ◽

Signal Grass ◽

Control Samples

ABSTRACT This study was conducted in order to evaluate the selectivity of signal grass and congo grass, submitted to post-emergence herbicide application. The experiment was conducted under greenhouse conditions, in Diamantina, Minas Gerais state, and it was arranged in a randomized block design, with five replications. Treatments were set in factor scheme (8 x 2) + 2. Eight herbicides (nicosulfuron; clomazone; glyphosate; fluazifop-p-butyl + fomesafen; lactofen; fomesafen; fluazifop-p-butyl and mesotrione) were applied in doses recommended by the manufacturer on two fodder species: Brachiaria decumbens cv. Basilisk (signal grass) and Brachiaria ruziziensis (congo grass); in addition, there were two control samples without herbicide application, for a total of 18 treatments. The evaluated herbicides showed less intoxication on signal grass when compared to congo grass. Nicosulfuron and glyphosate promoted higher intoxication on both species when compared to the other herbicides. Glyphosate, fluazifop-p-butyl + fomesafen, fluazifop-p-butyl, mesotrione and nicosulfuron affected the ratio variable / maximum fluorescence (Fv/Fm) in both species, indicating an effect provided by these herbicides on the electron transport chain. Results demonstrated that signal grass and congo grass have higher susceptibility to glyphosate, fluazifop-p-butyl + fomesafen, fluazifop-p-butyl, mesotrione and nicosulfuron. congo grass shows higher susceptibility to the studied herbicides when compared to signal grass.

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Physiological Response of Brachiaria sp on Acid Soil

Indonesian Bulletin of Animal and Veterinary Sciences ◽

10.14334/wartazoa.v26i3.1396 ◽

2017 ◽

Vol 26 (3) ◽

pp. 143

Author(s):

Achmad Fanindi

Keyword(s):

Soil Fertility ◽

Physiological Response ◽

Acid Soil ◽

Marginal Land ◽

Brachiaria Decumbens ◽

Brachiaria Ruziziensis ◽

Marginal Areas ◽

Morphological Responses ◽

Selection Of

The utilization of marginal land, especially the acid soil, for cultivation of forages is promising. Forage as a source of feed for ruminants, can also be used to improve soil fertility. Brachiaria sp is found widely grow in marginal areas, especially on acid soil showing its high adaptability. The diverse of genotypes have become interesting because the mechanism of its adaption can be studied by observing the physiological response of Brachiaria on acid soil. Brachiaria decumbens has high tolerant, while Brachiaria ruziziensis is sensitive to acid soil. Variance of physiological and morphological responses to acid soil are the foundation for determining the traits of selection in breeding activities of Brachiaria sp. This paper aims to provide the knowledge of physiological response of Brachiaria sp and this information is useful for selection of Brachiaria sp tolerant on acid soil.

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Chemical control of signalgrass for establishing Tanzania-grass

Acta Scientiarum Animal Sciences ◽

10.4025/actascianimsci.v42i1.48408 ◽

2020 ◽

Vol 42 ◽

pp. e48408

Author(s):

Barbara Martins Rodrigues ◽

Marcia Vitoria Santos ◽

Josimari Regina Paschoaloto ◽

Thiago Gomes dos Santos Braz ◽

José Barbosa Santos ◽

...

Keyword(s):

Chemical Control ◽

Panicum Maximum ◽

Herbicide Application ◽

Brachiaria Decumbens ◽

Forage Species ◽

Efficient Control ◽

Guinea Grass

Herbicides have been used to control Brachiaria grass in pastures established or in formation given their practicality, however their efficiency is questionable due to the lack of specific graminicides for different forage species. Therefore, the goal of this study was to evaluate the efficiency of glyphosate and fluazifop-p-butyl in the control of Brachiaria decumbens (signalgrass) and the intoxication levels of Panicum maximum cv. Tanzania (Tanzania quinea grass) in pasture establishment. The experiments were designed in randomized blocks, in a 2 × 5 × 4 factorial arrangement of two herbicides (fluazifop-p-butyl and glyphosate), five doses equivalent to the commercial dosage of each herbicide (0.25; 0.50; 1.00; 1.50; 200), and four evaluation times after herbicide application (15, 21, 30 and 45 days). There was interaction between doses and evaluation times. The dose 1.5 L ha-1 fluazifop-p-butyl provides efficient control of signalgrass, however, leads to high intoxication in Tanzania guinea grass. Glyphosate is efficient in the control of signalgrass even at the lowest dose (90 g ha-1), however, it causes high intoxication in Tanzania guinea grass, preventing its use in developing pastures. It can be concluded that fluazifop-p-butyl and glyphosate herbicides are not recommended for the control of B. decumbens, cv. Basilisk in developing pastures of Tanzania guinea grass.

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Variations in Soil Urease and Dehydrogenase Activities as Determined by Diuron, Pyrithiobac Sodium and Quizalofop Ethyl Applied to Cotton Cultivated in Red and Black Soils

Current Journal of Applied Science and Technology ◽

10.9734/cjast/2020/v39i1630742 ◽

2020 ◽

pp. 103-111

Author(s):

Md. Mifta Faizullah ◽

T. Ramprakash ◽

T. Anjaiah ◽

M. Madhavi

Keyword(s):

Urease Activity ◽

Field Experiments ◽

Herbicide Application ◽

Flowering Stage ◽

Significant Difference ◽

Soil Urease ◽

Increasing Trend ◽

Postemergence Herbicides ◽

Quizalofop Ethyl ◽

Different Doses

Activities of soil enzymes viz., urease and dehydrogenase were studied in two field experiments conducted in red and black soils at Professor Jayashankar Telangana State Agricultural University, Rajendranagar during kharif, 2018. Different doses of diuron in combination with postemergence tank-mix application of pyrithiobac sodium + quizalofop ethyl were tested. Soil urease activity showed an increasing trend and it increased from the day of PE herbicide application to flowering. Highest urease activity was noticed at flowering stage and then after the activity decreased upto harvest. In diuron treatments, the urease activity decreased substantially upto 5 DAHS, which later increased at flowering. Significant differences were observed in urease activity among all the treatments from the day of PE application to the day of postemergence spray in both red and black soils. No significant difference was observed in urease activity due to application of postemergence herbicide in both red and black soils. No significant difference was observed due to the application of pre and postemergence herbicides on the activity of dehydrogenase in both red and black soils but the activity of dehydrogenase increased from the day of PE herbicide application to flowering, exhibited highest activity at flowering stage and there after the activity decreased at harvest in both red and black soils.

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Transcriptional analysis of the response of C. elegans to ethanol exposure

Scientific Reports ◽

10.1038/s41598-021-90282-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Mark G. Sterken ◽

Marijke H. van Wijk ◽

Elizabeth C. Quamme ◽

Joost A. G. Riksen ◽

Lucinda Carnell ◽

...

Keyword(s):

Gene Expression ◽

Physiological Response ◽

Physiological Responses ◽

Ethanol Exposure ◽

Transcriptional Analysis ◽

Transcriptional Responses ◽

Genetic Pathways ◽

C Elegans ◽

Chronic Ethanol Consumption ◽

Transcriptional Changes

AbstractEthanol-induced transcriptional changes underlie important physiological responses to ethanol that are likely to contribute to the addictive properties of the drug. We examined the transcriptional responses of Caenorhabditis elegans across a timecourse of ethanol exposure, between 30 min and 8 h, to determine what genes and genetic pathways are regulated in response to ethanol in this model. We found that short exposures to ethanol (up to 2 h) induced expression of metabolic enzymes involved in metabolizing ethanol and retinol, while longer exposure (8 h) had much more profound effects on the transcriptome. Several genes that are known to be involved in the physiological response to ethanol, including direct ethanol targets, were regulated at 8 h of exposure. This longer exposure to ethanol also resulted in the regulation of genes involved in cilia function, which is consistent with an important role for the effects of ethanol on cilia in the deleterious effects of chronic ethanol consumption in humans. Finally, we found that food deprivation for an 8-h period induced gene expression changes that were somewhat ameliorated by the presence of ethanol, supporting previous observations that worms can use ethanol as a calorie source.

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Survival of Xanthoria parietina in simulated space conditions: spectroscopic analysis and vitality assessment

10.5194/epsc2021-207 ◽

2021 ◽

Author(s):

Christian Lorenz ◽

Renato Benesperi ◽

Elisabetta Bianchi ◽

Stefano Loppi ◽

Alessio Papini ◽

...

Keyword(s):

Uv Radiation ◽

Spectral Band ◽

High Vacuum ◽

Photosynthetic Apparatus ◽

Space Radiation ◽

Adaptive Plasticity ◽

Cotton Cloth ◽

Extreme Conditions ◽

Significant Difference ◽

Xanthoria Parietina

One of the main topics of astrobiology is the study of life limits in stressful environments. This field of research has the aim to understand the physiological and biochemical effects on unprotected biological samples in extreme conditions, such as space. Moreover, these studies provide indications about organisms&#8217; adaptive plasticity under a climate change perspective, the terrestrial geological past and future scenarios, as well as extra-terrestrial habitats as Mars surface. The biological specimen chosen for this study was Xanthoria parietina (L.) Th. Fr. It is a widespread foliose lichen growing on bark and rocks which has a broad spectrum of tolerance to air pollutants such as NOX and heavy metals, and resistance to UV-radiation because of the screening properties provided by the secondary metabolism product parietin. In this study we evaluated the ability of this lichen specie to survive under simulated UV space radiation in two different extreme environments i.e., in N2 atmosphere (N2) and in vacuum (100~10-2 Pa) (VAC). Thalli of X. parietina were randomly collected in a remote area of Tuscany, Italy in June and July 2020. Thalli were dehydrated for 24 h at room temperature (25&#176;C) and stored at -18&#176;C until treatment. Three days before the treatment, thalli were allowed to recover their normal metabolic conditions in a growth chamber at 25 &#176;C and 70 &#956;mol m-2 s-1 PAR photons. Overnight, thalli were covered with a black cotton cloth and kept moistened by spraying with distilled water. The simulated UV space radiation was produced using a Xe-enhanced UV lamp with a sun-like emission spectrum (wavelength range 185-2000 nm). The aforementioned atmospheric conditions (N2 and VAC) were chosen to set up an extreme and dehydrating environment for the lichen. The total absorbed UV radiation dose was 1.34 MJ m-2 for each exposed sample. During the irradiation, the IR reflectance spectrum of the lichen was monitored in situ with infrared spectroscopy to assess changes in spectral bands. The efficiency of the photosynthetic apparatus was assessed as indicator of vitality, and was expressed in terms of chlorophyll a fluorescence (FV/FM) and Normalized Difference Vegetation Index (NDVI). The examination of X. parietina recovery through eco-physiological analysis revealed the capacity of this lichen species to survive in extreme conditions such as those simulated in this investigation. It has been highlighted the significant difference between treatments about the photosynthetic efficiency parameters recovery trends, finding that UV-radiation in vacuum produces more intense effects on FV/FM values. After 72h, UV N2 fluorescence mean values recovered up to 93% of the starting ones, while UV VAC fluorescence recovered up to 45% of the pre-exposure values. The IR analysis revealed several spectral band changes in the fingerprint region. The most visible variation was the 5200 cm-1 water band, disappearing in the overtone region. This analysis suggests that the disappearance of H2O band after treatment is strictly linked to the thalli dehydration due to the atmospheric simulated conditions represented by N2 insufflation and high vacuum application. Nevertheless, X. parietina was able to survive to UV-radiation in N2 atmosphere and in vacuum, and for this reason it may be considered a candidate for further evaluations on its survival capacity in extreme conditions.

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The effect of water deficit on some physiological indices of Indian lettuce (Lactuca indica L.)

Journal of Science Natural Science ◽

10.18173/2354-1059.2021-0010 ◽

2021 ◽

Vol 66 (1) ◽

pp. 80-86

Author(s):

Thin Pham Thi Thanh ◽

Bang Cao Phi ◽

Hai Nguyen Thi Thanh ◽

Khuynh Bui The ◽

Mai Nguyen Phuong ◽

...

Keyword(s):

Chlorophyll Fluorescence ◽

Water Stress ◽

Water Content ◽

Flowering Time ◽

Water Deficit ◽

Physiological Responses ◽

Water Deficit Stress ◽

Flower Formation ◽

Lactuca Indica ◽

Wilting Rate

Indian Lettuce (Lactuca indica L.) is a valuable medicinal herb but there are still no many researches about this plant. In this work, the physiological responses of Indian lettuce plants under water deficit conditions (5, 8, and 11 days of water stress) were investigated. The Indian lettuce wilted after 5 days of water stress (66.66%), the wilting rate increased after 8 (93.33%) and 11 days (100%) of water stress. The longer duration of water deficit stress caused the slower recovery of plants after rewatering. The water deficit stress caused a decrease in chlorophyll fluorescence, non-associated water content as well as flower formation of Indian lettuce. But the water deficit stress increases the associated water content and the flowering time of this plant.

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THE EFFECT OF THE POP-UP BOOK AKU DAN GIGIKU ON PULSE RATE IN CHILDREN AGED 4–6 YEARS

International Journal of Applied Pharmaceutics ◽

10.22159/ijap.2017.v9s2.36 ◽

2018 ◽

Vol 9 ◽

pp. 135

Author(s):

Meutia D Citrawuni ◽

Margaretha Suharsini ◽

Eva Fauziah ◽

Kusuma P Adriani

Keyword(s):

Health Education ◽

Clinical Research ◽

Pulse Rate ◽

Dental Treatment ◽

Psychological Intervention ◽

Dental Health ◽

Physiological Responses ◽

Intervention Group ◽

Control Group ◽

Significant Difference

Objective: Anxiety is regarded as a major problem in children undergoing dental treatment. One of the physiological responses to anxiety is an increased pulse rate. Young children respond aggressively to anxiety and are in need of psychological intervention. Pop-up books can be used as an instrument to improve their interest and to help them understand the substance of dental health education.The objective of this study was to utilize pulse rate measurements to investigate the intervention of a pop-up book in reducing anxiety. A total of 78 children aged 4–6 years were divided into two groups: An intervention group with the pop-up book Aku dan Gigiku and a control group without intervention. The pulse rates of both groups were measured. This study comprised an experimental clinical research design. The independent t-test was used to measure comparisons of decreased pulse rate between the two groups.Result: The result showed that there was a statistically significant difference in decreased pulse rate with and without the intervention of the pop-up book Aku dan Gigiku. Pop-up books are often used as an educational medium for children because they present interesting illustrations and are easy to understand.Conclusion: As a medium of dental health education, pop-up books can contribute significantly to reducing anxiety in children.

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Physiological and biophysical limits to work in the heat for clothed men and women

Journal of Applied Physiology ◽

10.1152/jappl.1978.44.6.918 ◽

1978 ◽

Vol 44 (6) ◽

pp. 918-925 ◽

Cited By ~ 17

Author(s):

E. Kamon ◽

B. Avellini ◽

J. Krajewski

Keyword(s):

Steady State ◽

Vapor Pressure ◽

Physiological Responses ◽

Men And Women ◽

Mean Values ◽

Air Temperatures ◽

Significant Difference ◽

The Mean ◽

Evaporative Heat Transfer ◽

The One

Heat-acclimated, lightly clothed men and women (four of each) walked on a treadmill at 25% and 43% VO2 max, respectively, (M =194 W.m-2), under seven air temperatures (Ta) ranging from 36 to 52 degrees C. Each experiment involved 1 h of fixed and a 2nd h of progressively increasing ambient vapor pressure (Pa). The relative steady state of rectal temperature (Tre), mean skin temperature (Tsk), and heart rate (HR) reached in the 1st h were forced upward during the 2nd h by the rising Pa. The critical air vapor pressure (Pcrit) was identified by the Tre point of inflection for each Ta. One man did not fully reach steady state, but inflection could be determined for his physiological responses. The mean values of all points of inflection were calculated for Tre, Tsk, and HR. Significant sex difference in HR was found only by excluding the results of the one man. Tre and Tsk showed no significant difference between men and women. The coefficient for evaporative heat transfer (he), which could be derived using the Pcrit for the low Ta range, was 14.5 +/- 2.2 W.m-1 Torr-1.

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