scholarly journals Effects of Interval Flooding Stress on Physiological Characteristics of Apple Leaves

Horticulturae ◽  
2021 ◽  
Vol 7 (10) ◽  
pp. 331
Author(s):  
Pengyu Zhou ◽  
Ji Qian ◽  
Weidong Yuan ◽  
Xin Yang ◽  
Bao Di ◽  
...  
Keyword(s):  
Water Stress ◽  
Photochemical Efficiency ◽  
Principal Component ◽  
Annual Number ◽  
Apple Rootstocks ◽  
Apple Leaves ◽  
Maximum Photochemical Efficiency ◽  
Growth Of Seedlings ◽  
Average Annual Number ◽  
Relative Chlorophyll Content

As a result of the continuous global warming in recent years, the average annual number of rain days in China has been on the decline, while the number of rainstorm days has gradually increased. These conditions make it extremely easy to form a waterlogging environment, which has an adverse impact on plant growth and development. In many apple-producing areas in China, apples are subject to severe flooding during planting. In this study, two-year-old apple rootstock M9T337 was used to explore the effects of interval water stress on the morphological and physiological parameters of apple leaves. The purpose was to determine the plant’s adaptability to waterlogged environments and provide theoretical reference for management and maintenance after waterlogging. The results showed that the effect on flooded (T2) on apple stock was greater than that of waterlogged (T1), Short-term (7 d) waterlogging (T1) did not affect the growth of seedlings but was conducive to the accumulation of dry matter. Furthermore, the initial stress was be imprinted on the plants, which could directly affect their response to later stress. The results of principal component analysis (PCA) revealed that PC1, PC2, and PC3 explained 26.92%, 17.46%, and 13.03% of the physiological changes under water stress, respectively. By calculating the weight of each indicator, we concluded that high-frequency resistance r, relative chlorophyll content (SPAD) and maximum photochemical efficiency Fv/Fm are important parameters for apple rootstocks affected by water stress.

scholarly journals Knockout of Auxin Response Factor SlARF4 Improves Tomato Resistance to Water Deficit

2021 ◽  
Vol 22 (7) ◽  
pp. 3347
Author(s):  
Mengyi Chen ◽  
Xiaoyang Zhu ◽  
Xiaojuan Liu ◽  
Caiyu Wu ◽  
Canye Yu ◽  
...  
Keyword(s):  
Water Stress ◽  
Water Deficit ◽  
Vascular Bundle ◽  
Plant Resistance ◽  
Quantitative Polymerase Chain Reaction ◽  
Photochemical Efficiency ◽  
Differentially Expressed ◽  
Vascular Bundles ◽  
Aba Signaling ◽  
Auxin Response

Auxin response factors (ARFs) play important roles in various plant physiological processes; however, knowledge of the exact role of ARFs in plant responses to water deficit is limited. In this study, SlARF4, a member of the ARF family, was functionally characterized under water deficit. Real-time fluorescence quantitative polymerase chain reaction (PCR) and β-glucuronidase (GUS) staining showed that water deficit and abscisic acid (ABA) treatment reduced the expression of SlARF4. SlARF4 was expressed in the vascular bundles and guard cells of tomato stomata. Loss of function of SlARF4 (arf4) by using Clustered Regularly Interspaced Short Palindromic Repeats/Cas 9 (CRISPR/Cas 9) technology enhanced plant resistance to water stress and rehydration ability. The arf4 mutant plants exhibited curly leaves and a thick stem. Malondialdehyde content was significantly lower in arf4 mutants than in wildtype plants under water stress; furthermore, arf4 mutants showed higher content of antioxidant substances, superoxide dismutase, actual photochemical efficiency of photosystem II (PSII), and catalase activities. Stomatal and vascular bundle morphology was changed in arf4 mutants. We identified 628 differentially expressed genes specifically expressed under water deficit in arf4 mutants; six of these genes, including ABA signaling pathway-related genes, were differentially expressed between the wildtype and arf4 mutants under water deficit and unlimited water supply. Auxin responsive element (AuxRE) elements were found in these genes’ promoters indicating that SlARF4 participates in ABA signaling pathways by regulating the expression of SlABI5/ABF and SCL3, thereby influencing stomatal morphology and vascular bundle development and ultimately improving plant resistance to water deficit.

Relation of geographic variation in the skull of Microtus pennsylvanicus to climate

1983 ◽  
Vol 61 (6) ◽  
pp. 1232-1241 ◽  
Author(s):  
Richard R. Snell ◽  
Kimberly M. Cunnison
Keyword(s):  
Low Temperature ◽  
Geographic Variation ◽  
Multiple Regression ◽  
Minimum Spanning Tree ◽  
Climatic Factors ◽  
Principal Component ◽  
Microtus Pennsylvanicus ◽  
Annual Number ◽  
Simple Correlation ◽  
Morphometric Variation

Analyses of geographic variation in the skull of meadow voles (Microtus pennsylvanicus) indicate that phenetic distances among samples are not related to geographic distance: a minimum spanning tree based on average taxonomic distance superimposed on a map of 38 localities provides no particular phenetic clustering of those samples geographically proximate. A multiple regression of phenetic component one (skull size) onto orthogonally rotated climatic factors explains much less morphometric variation (25.6%) than a simple correlation with recorded extreme low temperature (38.9%). Multiple regression of phenetic principal component two (interorbital width) onto the same climatic factors explains minimally more morphological variation (42.1%) than a simple correlation with mean annual number of days with frost (41.7%). Microtus pennsylvanicus shows a pattern of size variation that is the reverse of Bergmann's rule: these voles are large where it is warm and small where it is cold. Since small size reduces total energy expenditure, we predict that during times of extreme low temperature (i) smaller voles will be less energetically stressed than larger voles and (ii) large size will be actively selected against.

The prevention of tetanus - the use of Human Antitetanus Immunoglobulin

1975 ◽  
Vol 13 (20) ◽  
pp. 77-79
Keyword(s):  
Rare Disease ◽  
Annual Number ◽  
True Incidence ◽  
Average Annual Number

Tetanus is a preventable though rare disease. In Britain, its incidence is steadily diminishing.1 The average annual number of deaths from tetanus over the period 1960–70 was 17 compared with 45 in the period 1950–60. The disease has been notifiable since October 1968 but the number of notifications returned annually does not represent the true incidence.

scholarly journals Alterations in Gas Exchange and Oxidative Metabolism in Rice Leaves Infected by Pyricularia oryzae are Attenuated by Silicon

2015 ◽  
Vol 105 (6) ◽  
pp. 738-747 ◽  
Author(s):  
Gisele Pereira Domiciano ◽  
Isaías Severino Cacique ◽  
Cecília Chagas Freitas ◽  
Marta Cristina Corsi Filippi ◽  
Fábio Murilo DaMatta ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Photochemical Efficiency ◽  
Pyricularia Oryzae ◽  
Gas Exchange Parameters ◽  
Photosynthetic Gas Exchange ◽  
Exchange Performance ◽  
Rice Leaves ◽  
Maximum Photochemical Efficiency ◽  
Important Disease ◽  
Exchange Parameters

Rice blast, caused by Pyricularia oryzae, is the most important disease in rice worldwide. This study investigated the effects of silicon (Si) on the photosynthetic gas exchange parameters (net CO2 assimilation rate [A], stomatal conductance to water vapor [gs], internal-to-ambient CO2 concentration ratio [Ci/Ca], and transpiration rate [E]); chlorophyll fluorescence a (Chla) parameters (maximum photochemical efficiency of photosystem II [Fv/Fm], photochemical [qP] and nonphotochemical [NPQ] quenching coefficients, and electron transport rate [ETR]); concentrations of pigments, malondialdehyde (MDA), and hydrogen peroxide (H2O2); and activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), and lypoxigenase (LOX) in rice leaves. Rice plants were grown in a nutrient solution containing 0 or 2 mM Si (−Si or +Si, respectively) with and without P. oryzae inoculation. Blast severity decreased with higher foliar Si concentration. The values of A, gs and E were generally higher for the +Si plants in comparison with the −Si plants upon P. oryzae infection. The Fv/Fm, qp, NPQ, and ETR were greater for the +Si plants relative to the −Si plants at 108 and 132 h after inoculation (hai). The values for qp and ETR were significantly higher for the –Si plants in comparison with the +Si plants at 36 hai, and the NPQ was significantly higher for the –Si plants in comparison with the +Si plants at 0 and 36 hai. The concentrations of Chla, Chlb, Chla+b, and carotenoids were significantly greater in the +Si plants relative to the –Si plants. For the –Si plants, the MDA and H2O2 concentrations were significantly higher than those in the +Si plants. The LOX activity was significantly higher in the +Si plants than in the –Si plants. The SOD and GR activities were significantly higher for the –Si plants than in the +Si plants. The CAT and APX activities were significantly higher in the +Si plants than in the –Si plants. The supply of Si contributed to a decrease in blast severity, improved the gas exchange performance, and caused less dysfunction at the photochemical level.

scholarly journals Transcriptional and Physiological Analyses to Assess the Effects of a Novel Biostimulant in Tomato

2022 ◽  
Vol 12 ◽  
Author(s):  
Maria Cristina Della Lucia ◽  
Ali Baghdadi ◽  
Francesca Mangione ◽  
Matteo Borella ◽  
Walter Zegada-Lizarazu ◽  
...  
Keyword(s):  
Water Stress ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Gene Expression Profiles ◽  
Principal Component ◽  
Negative Effects ◽  
Nutrient Metabolism ◽  
Tomato Plants ◽  
Reverse Transcription Pcr ◽  
Osmotic Stress Tolerance

This work aimed to study the effects in tomato (Solanum lycopersicum L.) of foliar applications of a novel calcium-based biostimulant (SOB01) using an omics approach involving transcriptomics and physiological profiling. A calcium-chloride fertilizer (SOB02) was used as a product reference standard. Plants were grown under well-watered (WW) and water stress (WS) conditions in a growth chamber. We firstly compared the transcriptome profile of treated and untreated tomato plants using the software RStudio. Totally, 968 and 1,657 differentially expressed genes (DEGs) (adj-p-value < 0.1 and |log2(fold change)| ≥ 1) were identified after SOB01 and SOB02 leaf treatments, respectively. Expression patterns of 9 DEGs involved in nutrient metabolism and osmotic stress tolerance were validated by real-time quantitative reverse transcription PCR (RT-qPCR) analysis. Principal component analysis (PCA) on RT-qPCR results highlighted that the gene expression profiles after SOB01 treatment in different water regimes were clustering together, suggesting that the expression pattern of the analyzed genes in well water and water stress plants was similar in the presence of SOB01 treatment. Physiological analyses demonstrated that the biostimulant application increased the photosynthetic rate and the chlorophyll content under water deficiency compared to the standard fertilizer and led to a higher yield in terms of fruit dry matter and a reduction in the number of cracked fruits. In conclusion, transcriptome and physiological profiling provided comprehensive information on the biostimulant effects highlighting that SOB01 applications improved the ability of the tomato plants to mitigate the negative effects of water stress.

scholarly journals THE INFLUENCE OF BIO-ALGEEN S90 ON THE GROWTHOF MULTIFLORA ROSE SEEDLINGS (Rosa multiflora Thunb.)

2019 ◽  
Vol 18 (3) ◽  
pp. 35-43
Author(s):  
Mariusz Szmagara ◽  
Krystyna Pudelska ◽  
Wojciech Durlak ◽  
Barbara Marcinek ◽  
Kamila Rojek
Keyword(s):  
Chlorophyll Fluorescence ◽  
Photochemical Efficiency ◽  
Morphological Characteristics ◽  
Rosa Multiflora ◽  
Plant Growth And Development ◽  
Agent Based ◽  
Photochemical Efficiency Of Psii ◽  
Stimulate Plant Growth ◽  
Maximum Photochemical Efficiency ◽  
Natural Agent

Striving to intensify horticultural production, new and more effective bio-preparations are being sought to stimulate plant growth and development. Bio-algeen S90 is a natural agent based on sea algae, the high bi- ological activity of which results from the high content of natural growth regulators. The aim of the study was to verify the influence of Bio-algeen S90 on the growth, morphological characteristics and chlorophyll fluorescence of Rosa multiflora seedlings. The bio-preparation was applied one, two and three times at con- centrations: 0.1, 0.2, 0.4 and 0.6 mg.dm−3. Following parameters were measured to evaluate the response of plants to the bio-preparation: F0 – initial fluorescence, Fm – maximal fluorescence in the dark-adapted state, Fv/Fm – maximum photochemical efficiency of PSII. All concentrations of the bio-preparation and frequency of its application stimulated the number of shoots in a bush, the length of shoots and the diameter of the root crown of plants intended for budding. The most beneficial was the two-fold bio-preparation application at a concentration of 0.4 mg.dm–3. Bio-algeen also positively influenced the chlorophyll fluorescence parame- ters. The highest mean F0 and Fm values were recorded with the two-fold preparation treatment. There was no significant effect of the bio-preparation on the Fv/Fm index, which was within the range of 0.75–0.66.

Evaluation of the effectiveness of mechanisms for eliminating flooding of urbanized areas with surface runoff

2021 ◽  
pp. 32-39
Author(s):  
С.Н. Волков ◽  
А.И. Житенев ◽  
О.Н. Рублевская ◽  
Ю.А. Курганов ◽  
И.Г. Костенко ◽  
...  
Keyword(s):  
Standard Method ◽  
Surface Runoff ◽  
Hydraulic Calculation ◽  
Annual Number ◽  
Runoff Coefficient ◽  
The World ◽  
The Russian Federation ◽  
Urbanized Areas ◽  
Average Annual Number ◽  
Heavy Rains

Подтопления урбанизированных территорий, когда вода в периоды ливневых дождей поднимается на поверхность, затапливая улицы и подвалы, наблюдаются достаточно часто. Происходят они по разным причинам или их совокупности. Перечень мероприятий для сокращения количества таких подтоплений в мировой практике отработан. К ним можно отнести мероприятия, направленные на уменьшение коэффициента стока водосборных площадей, а также на увеличение свободных регулирующих объемов сетей и коллекторов и т. п. Однако оценка их эффективности в Российской Федерации затруднена в связи с тем, что нормативный метод гидравлического расчета предусматривает учет значений периодов однократного превышения расчетных интенсивностей дождей p, который указывает, с какой периодичностью переполняются сети. Но этот метод не отвечает на вопрос, с какой периодичностью pp происходят затопления территорий в результате выхода воды на поверхность. На примере Санкт-Петербурга приведен расчетный метод для определения среднегодового числа затоплений, а также результаты оценки эффективности мероприятий, направленных на их сокращение. Flooding of urbanized areas happens quite often, while, during periods of heavy rains, water rises to the surface flooding streets and basements. Flooding occurs for different reasons or due to their combination. The list of measures to reduce the flooding rate has been worked out in the world practice. These include measures aimed at reducing the runoff coefficient of drainage areas, as well as increasing the spare regulating capacities of the networks and sewers, etc. However, evaluating their effectiveness in the Russian Federation is complicated by the fact that the standard method of hydraulic calculation provides for taking into account the values ​​of the periods of one-time excess of the calculated rainfall rates p that indicates the overflow rate in the networks. However, this method does not determine the rate pp of area flooding that results from the water spills. Through the example of St. Petersburg, a calculation method is presented for determining the average annual number of floods, as well as the results of evaluating the effectiveness of measures aimed at reducing them.

On the assessment of production costs and profitability of agricultural organizations of the Orel region

2020 ◽  
pp. 67-73
Author(s):  
L. Golovina ◽  
O. Logacheva
Keyword(s):  
Agricultural Production ◽  
Agricultural Sector ◽  
Production Costs ◽  
Annual Number ◽  
Business Activity ◽  
Main Production ◽  
Systematic Development ◽  
Agricultural Organizations ◽  
The Cost ◽  
Average Annual Number

The trends of changes in the structure of production costs and profitability of agricultural organizations of the Orel region are studied. The ratio of income and expenses that develops in the course of business activity is analyzed. The share of the cost of purchased products in the composition of material costs in connection with its growth is highlighted. The emphasis is placed on ensuring the systematic development of agricultural production in the region. The fact of a decrease in the share of wages in the structure of costs for the main production and a reduction in the average annual number of employees is revealed. The study is supplemented by an analysis of vacancies in agriculture in Russia, highlighting the most popular and highly paid professions in the agricultural sector of the country.

scholarly journals Maize hybrids contrasting for drought tolerance differ during the vegetative stage

2020 ◽  
Vol 41 (4) ◽  
pp. 1093
Author(s):  
Suerlani Aparecida Ferreira Moreira ◽  
Pablo Fernando Santos Alves ◽  
Carlos Eduardo Corsato ◽  
Alcinei Mistico Azevedo
Keyword(s):  
Water Stress ◽  
Drought Tolerance ◽  
Chlorophyll Content ◽  
Water Deficit ◽  
Leaf Temperature ◽  
Vegetative Stage ◽  
Maize Hybrids ◽  
Water Regimes ◽  
Dry Biomass ◽  
Relative Chlorophyll Content

Maize hybrids contrasting for drought tolerance differ during the vegetative stage. Drought is the main constraint on maize production in developing nations. Differences during development between genetic materials of maize grown under water restriction suggest that the plant can be improved with a view to its adaptation. In maize, sensitivity to water stress can occur at any stage of its phenological development. However, few studies report its effects on the vegetative phase of the cycle. On this basis, this study was conducted to examine how shoot and root-system indices are expressed in cultivation under water deficit as well as determine which indicators best explain the difference between hybrids in the evaluated water regimes. Commercial seeds of hybrids BR1055 and DKB-390 (drought-tolerant) and BRS1010 (drought-sensitive) were germinated in PVC tubes (1.0 m × 0.1 m) in a randomized complete block design, in a 3 × 2 factorial arrangement. The experiment was developed in a greenhouse where two water regimes were tested: no water stress and with water stress from the VE stage. The soil consisted of quartz sand mixed with a commercial fertilizer. Stem and root traits were evaluated up to the V5 growth stage. Relative chlorophyll content, leaf temperature, stem length, phenology, shoot dry biomass, root length, root dry biomass, root surface area, root volume and D95 were responsive to water deficit. The parameters that allowed the distinction between the hybrids in water the regimes were relative chlorophyll content, leaf temperature, phenology and average root diameter.

Analysis of the effects of the spotted tentiform leafminer (Phyllonorycter blancardella) on the photosynthetic characteristics of apple leaves

1982 ◽  
Vol 60 (12) ◽  
pp. 2734-2740 ◽  
Author(s):  
J. T. A. Proctor ◽  
J. M. Bodnar ◽  
W. J. Blackburn ◽  
R. L. Watson
Keyword(s):  
Photosynthetic Rate ◽  
Dark Respiration ◽  
Photochemical Efficiency ◽  
Photosynthetic Apparatus ◽  
Light Response ◽  
Apple Leaves ◽  
Economic Thresholds ◽  
Fluorescence Reading ◽  
Use Efficiency ◽  
High Fluorescence

Infestation of apple leaves with the spotted tentiform leafminer (STLM) reduced their net photosynthetic rate (Pn) over a range of light intensities. At a saturating irradiance level of 1240 μE∙m−2∙s−1 and 20 mines per leaf, 32.9% of the leaf area was injured but Pn was decreased by only 23.2%. Examination of parameters in a model for leaf photosynthesis showed a reduction in maximum photosynthetic rate (asymptotic value of the light-response curve) and mesophyll conductance but not in photochemical efficiency or dark respiration. The STLM injury had no effect on transpiration, stomatal conductance, and a slight effect on internal CO2 concentration and water-use efficiency. Mining reduced chlorophyll content of the leaves and this reduced the chlorophyll fluorescence of the mined areas. Tissue around the mines had a relatively high fluorescence reading confirming the Pn measurements and suggesting that this technique was suitable for these and similar studies. Mining by the STLM disrupts the photosynthetic apparatus of the leaf and affects a number of mechanisms in the photosynthetic process. Correlating these effects with field observations will help in determining economic thresholds for this insect.

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