scholarly journals Adaptive Mechanisms in Zilla spinosa and Leptadenia pyrotechnica Plants to Sever Aridity in the Egyptian Deserts

2016 ◽  
Vol 8 (4) ◽  
pp. 498-510 ◽  
Author(s):  
Fawzy Mahmoud SALAMA ◽  
Mohamed Abu El-Ela GADALLAH ◽  
Suzan Abd El-Monem SAYED ◽  
Ayat Abd El Monem ABD EL-GALIL
Keyword(s):  
Water Content ◽  
Chlorophyll A ◽  
Soluble Sugars ◽  
Winter Season ◽  
Stability Index ◽  
Severe Drought ◽  
Adaptive Mechanisms ◽  
Drought Conditions ◽  
Chlorophyll A And B ◽  
The Stability

In the present study two species were selected based on their highest presence values to study the response to the severe drought conditions in desert: these were Zilla spinosa and Leptadenia pyrotechnica. The results showed that soil water content and organic matter of Wadi El-Assiuty were very low over the study period. The estimated pH values in the soil solution at the different studied stands tended to be slight alkaline. Total soluble salts were generally higher during summer versus winter. The water content in the studied plants increased significantly during summer. The selected species increased their content of chlorophyll a and b in summer. The stability index of chlorophyll a and b was significantly higher in summer than that estimated in winter. Calcium and magnesium were accumulated in considerable amounts. Ca+2 was the main accumulated cation whereas its concentration were higher than magnesium. Z. spinosa accumulated more sulphates in summer than in winter. Phosphates appeared in low amounts in all the investigated plants. In L. pyrotechnica tissue, Na+ concentration correlated negatively with those found in soil during summer. In winter Na+ and SO4 correlated positively and K+ correlated negatively in Z. spinosa. The studied species showed slightly increase in soluble sugars accumulation. Soluble protein content in Z. spinosa and L. pyrotechnica decreased significantly during winter season. Amino acids content was low and varied between the two investigated species. It seemed that the Z. spinosa is better adapted than L. pyrotechnica to drought conditions, prevailing in the area under study. This judgement can be concluded by the average metabolic potentiality in the species, whereas soluble metabolites (soluble sugars and soluble proteins) were relatively much higher than in the case of L. pyrotechnica.

scholarly journals Dissecting Adaptation Mechanisms to Contrasting Solar Irradiance in the Mediterranean Shrub Cistus incanus

2019 ◽  
Vol 20 (14) ◽  
pp. 3599 ◽  
Author(s):  
Federico Sebastiani ◽  
Sara Torre ◽  
Antonella Gori ◽  
Cecilia Brunetti ◽  
Mauro Centritto ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
De Novo ◽  
Limited Attention ◽  
Severe Drought ◽  
Shade Avoidance ◽  
Environmental Pressures ◽  
Adaptive Mechanisms ◽  
Mediterranean Plants ◽  
Psii Photochemistry ◽  
The Stability

Molecular mechanisms that are the base of the strategies adopted by Mediterranean plants to cope with the challenges imposed by limited or excessive solar radiation during the summer season have received limited attention. In our study, conducted on C. incanus plants growing in the shade or in full sunlight, we performed measurements of relevant physiological traits, such as leaf water potential, gas exchange and PSII photochemistry, RNA-Seq with de-novo assembly, and the analysis of differentially expressed genes. We also identified and quantified photosynthetic pigments, abscisic acid, and flavonoids. Here, we show major mechanisms regulating light perception and signaling which, in turn, sustain the shade avoidance syndrome displayed by the ‘sun loving’ C. incanus. We offer clear evidence of the detrimental effects of excessive light on both the assembly and the stability of PSII, and the activation of a suite of both repair and effective antioxidant mechanisms in sun-adapted leaves. For instance, our study supports the view of major antioxidant functions of zeaxanthin in sunny plants concomitantly challenged by severe drought stress. Finally, our study confirms the multiple functions served by flavonoids, both flavonols and flavanols, in the adaptive mechanisms of plants to the environmental pressures associated to Mediterranean climate.

scholarly journals COMPARATIVE CHARACTERISTICS OF PHOTOSYNTHETIC ACTIVITY OF NECTARINE CULTIVARS AND FORMS WITH DIFFERENT COLORED LEAF PLATE

AGROFOR ◽  
2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Iuliia IVASHCHENKO ◽  
Yuriy IVASHCHENKO ◽  
Evgeny SHOFERISTOV ◽  
Sergei TSIUPKA
Keyword(s):  
Powdery Mildew ◽  
Chlorophyll A ◽  
Energy Supply ◽  
Photosynthetic Activity ◽  
Green Color ◽  
Primary Reactions ◽  
Chlorophyll A And B ◽  
Traditional Cultivars ◽  
The Stability ◽  
Kautsky Effect

Genotypes of nectarine with red leaves were created in Nikita botanical gardens.They have commercially valuable properties and biological characteristics (resistanceto powdery mildew, large-fruited, the ability of transmitting the trait of redleaves with constant result to progeny seed, etc. ). The aim of our researches was tostudy the main indicators of photoactivity of leaf apparatus of nectarine with greenand anthocyanin leaves coloration. Investigations have been carried out in 2010-2015 on intact leaf plates for three cultivars and forms of nectarine with greenleaves – Rubinoviy-8 (control), Chemus, Krymtsuht 53-85 and 2 forms withanthocyanin coloration of leaf plate (NektadianaKrasnolistnaya 996-88, Krasnola495-86). Photosynthetic activity was characterized by chlorophyll fluorescenceparameters (Kautsky effect). The content of chlorophyll a and b were determinedby spectrophotometry. The cultivar Rubinoviy-8 and the form - Krasnola 495-86were selected according to intensity indicators of the primary reactions ofphotosynthesis. Anthocyanin forms concede cultivar Rubinoviy-8 in efficiency ofthe primary reactions of photosynthesis an average of 48-50%; but they exceednectarines Chemus and Krymtsuht 53-85 with green color of leaves of 23-25%.The efficiency of energy supply in the "dark" reactions of photosynthesis in allvarieties and forms of nectarine maintained within 41-46%. But the further abilityto utilize received energy is most efficiently implemented at the nectarine cultivarRubinoviy-8 and form Krasnola 495-86. The forms of red-leaved nectarine incomparison with traditional cultivars are distinguished by a great potential forretaining the stability and productivity of the functioning of the photosyntheticapparatus.

scholarly journals Different Drought-Tolerant Mechanisms in Quinoa (Chenopodium quinoa Willd) and Djulis (Chenopodium formosanum Koidz.) Based on Physiological Analysis

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2279
Author(s):  
Pin-Hua Lin ◽  
Yun-Yang Chao
Keyword(s):  
Drought Stress ◽  
Water Content ◽  
Sugar Content ◽  
Soluble Sugar ◽  
Soluble Sugars ◽  
Chenopodium Quinoa ◽  
Proline Content ◽  
Severe Drought ◽  
Drought Treatment ◽  
Total Soluble Sugar

The purpose of this experiment is to study the effects of treatment with 90% (28.5% volumetric water content (VWC)), 75% (24% VWC), 50% (16% VWC), and 25% (8% VWC) of water requirements on the growth of two djulis (Chenopodium formosana Koidz) varieties (red: RP and yellow: OR) and one quinoa (Chenopodium quinoa Willd) varieties (PI). The results showed that drought stress (8% VWC) significantly reduced plant growth and relative water content, and increased H2O2 and MDA content in C. formosana and C. quinoa. The most significant increase in these parameters was detected in the OR variety. The antioxidant enzymes, such as SOD, APX, and GR activities of PI variety under drought treatment (8% VWC), are significantly increased, while GR activity of C. formosana also increased significantly. Additionally, C. formosana and PI variety remained at a stable AsA/DHA ratio, but the GSH/GSSG ratio decreased during drought treatment. Moreover, drought stress increased total soluble sugars and proline content in the PI variety. However, C. formosana proline content was extremely significantly enhanced, and only the OR variety increased the total soluble sugar content at the same time during the vegetative growth period. In summary, C. formosana and C. quinoa have different drought tolerance mechanisms to adapt to being cultivated and produced under severe drought conditions.

scholarly journals Study some of Morphological and Physiological Traits of Kurrajong Brachychiton populneus (Schott & Endl.) Seedlings Planted under Water Stress Conditions

2020 ◽  
Vol 33 (1) ◽  
pp. 213-220
Author(s):  
Shaima A. Karim ◽  
Sirwa A. Qadir ◽  
Halmat A. Sabr
Keyword(s):  
Drought Stress ◽  
Water Content ◽  
Chlorophyll A ◽  
Relative Water Content ◽  
Photosynthetic Pigment ◽  
Total Content ◽  
Dry Weight ◽  
Severe Drought ◽  
Shoot Height ◽  
Relative Water

In this study, Brachychiton populneus seedlings were subjected to drought stress for 90 Days and physiological and morphological characters analyzed to determine their response to water deficit. The growth characters including, height and diameter of shoots, the dry weight of shoots and roots as well as photosynthetic pigment and the leaves content of relative water content were measured to evaluate the effects of drought in the physiological growth of plant. The lowest means; 59 cm and 8 mm of shoot height and diameter respectively were recorded at 30% of water holding capacity of soil (WHC). Drought treated seedlings at both 60% and 30% WHC had lower dry weight of shoots; 9.54 and 8.24 g plant-1 respectively compared  to the control. Consequently, the increase of drought conditions led to enhancement the growth of roots and roots to shoots ratio. The highest increase in the dry weight of roots and roots to shoots ratio were25.96 g plant-1 and 3.19 recorded under severe drought stress condition. Lowest amount of chlorophyll a; 2.94 mg g-1 F W recorded under 30% SWHC. It is found also the total content of chlorophyll in the leaves decreased significantly; 5.86 and 7.88 mg g-1 F W under both levels. While the highest ratio of chlorophyll a: b was 1.59 recorded at 60% SWHC. However, the lowest leave relative water content LRWC%; 86% was recorded under 30% SWHC. These findings may explain the characters of the early growth and physiological responses of, Brachychiton populneus to dehydration and facilitate the selection of drought-resistant tree families.

A FORECAST OF PRODUCTIVE LONGEVITY OF HOLSTEIN COWS BY INDIRECT SIGNS

2020 ◽  
Author(s):  
З.С. САНОВА
Keyword(s):  
Correlation Coefficient ◽  
Aging Process ◽  
Direct Relationship ◽  
Stability Index ◽  
Age At First Calving ◽  
Group I ◽  
Predicted Values ◽  
The Stability ◽  
Relationship Of ◽  
The Relationship

В статье представлены материалы о взаимосвязи продолжительности продуктивного использования коров с характеристикой устойчивости к деградации, с возрастом отела и удоем. В исследованной, разнородной по происхождению, группе животных для прогноза продуктивного периода коров, обусловленного устойчивостью к деградации и возрастом первого отела, пригодно уравнение регрессии, аргументами в котором являются индекс устойчивости, возраст первого отела в первой и второй степенях. Коэффициент корреляции межу предсказанными значениями продуктивного периода и его фактическими величинами в I группе составляет 0,502, во II - 0,604. При этом крайние варианты прогнозируются со статистическими ошибками 5 мес при оценке индекса устойчивости по 2 лактациям и 4,1 мес по 3, а средние варианты, соответственно, 1,6 и 1,51 мес. Индекс устойчивости к процессу старения является важной характеристикой биологических особенностей коров, определяющий их продуктивное долголетие. Его оценка по первым 2 и 3 лактациям имеет прямолинейную связь с продуктивным периодом (r=0,4109 и r=0,5270), соответственно. Зависимость продуктивного периода от возраста первого отела криволинейная — с увеличением возраста первого отела сокращается срок продуктивного использования, при возрасте первого отела более 1400 дней срок продуктивного использования колеблется от 1,33 до 1,41 лактации. Коэффициент корреляции между этими характеристиками коров составляет - 0,2164 в I и - 0,2620 во II группах. The article presents materials about the relationship of the duration of productive use of cows with the characteristic of resistance to degradation, with the age of calving and milk yield. In the studied group of animals, which is heterogeneous in origin, the regression equation is suitable for predicting the productive period of cows due to resistance to degradation and the age of the first calving, the arguments of which are the stability index, the age of the first calving in the first and second degrees. The correlation coefficient between the predicted values of the productive period and its actual values in group I is 0.502, in group II - 0.604. At the same time, the extreme variants are predicted with statistical errors of 5 months when evaluating the stability index for 2 lactations and 4.1 months for 3, and the average variants, respectively, are 1.6 and 1.51 months. The index of resistance to the aging process is an important characteristic of the biological characteristics of cows, which determines their productive longevity. Its estimate for the first 2 and 3 lactations has a direct relationship with the productive period (r=0.4109 and r=0.5270), respectively. The dependence of the productive period age at first calving curvilinear with increasing age at first calving reduces the time to productive use, while age at first calving of more than 1400 days, the period of productive use ranges from 1.33 to 1.41 lactation. The correlation coefficient between these characteristics of cows is-0.2164 in I and-0.2620 in II groups.

scholarly journals The stability index of a cactus

1977 ◽  
Vol 24 (2) ◽  
pp. 170-183
Author(s):  
Douglas D. Grant ◽  
D. A. Holton
Keyword(s):  
Connected Graph ◽  
Stability Index ◽  
The Stability

AbstractWe show that ifGis a connected graph of ordernsuch that no line lies in more than one cycle (in other words,Gis a cactus of ordern), then the stability index ofGis one of the integers 0, 1,n−7,n−6,n−5,n−4 orn.

Mapping QTLs for yield components and chlorophyll a fluorescence parameters in wheat under three levels of water availability

2011 ◽  
Vol 9 (2) ◽  
pp. 291-295 ◽  
Author(s):  
Ilona Czyczyło-Mysza ◽  
Izabela Marcińska ◽  
Edyta Skrzypek ◽  
Małgorzata Chrupek ◽  
Stanisław Grzesiak ◽  
...  
Keyword(s):  
Drought Stress ◽  
Chlorophyll A ◽  
Chlorophyll A Fluorescence ◽  
Wheat Yield ◽  
Dry Weight ◽  
Interval Mapping ◽  
Main Stem ◽  
Severe Drought ◽  
Single Marker Analysis ◽  
Fluorescence Parameters

Drought is one of the major factors limiting wheat yield in many developing countries worldwide. Parameters of chlorophyll a fluorescence kinetics under drought stress conditions have been used to characterize dehydration tolerance in wheat. In the present study, a set of 94 doubled haploid lines obtained from Chinese Spring × SQ1 (CSDH), mapped with 450 markers, was evaluated for yield (grain dry weight/main stem ear), number of grains/main stem ear (NG) and chlorophyll a fluorescence parameters (FC) under moderate and severe drought stress, and compared with results for well-watered plants. quantitative trait loci (QTLs) were identified using Windows QTLCartographer version 2.5 software and the results were analysed using single-marker analysis (SMA) and composite interval mapping (CIM). Analysis using SMA and CIM showed mostly similar QTLs for all traits, though more QTLs were identified by SMA than by CIM. The genetic control of yield, NG and FC varied considerably between drought-stressed and non-stressed plants. Although no major QTL co-locations were found for yield and FC using CIM, the co-location of QTLs for NG, yield and Fv/Fm in drought-stressed plants was observed on chromosome 5A using SMA.

Features of pubertal patients with schizophrenia neurocognitive profile

2017 ◽  
Vol 41 (S1) ◽  
pp. S430-S431
Author(s):  
Y. Barylnik ◽  
S. Pakhomova ◽  
D. Samoylova ◽  
J. Abrosimova ◽  
E. Kolesnichenko ◽  
...  
Keyword(s):  
Stability Index ◽  
Neurocognitive Disorders ◽  
Motor Speed ◽  
Structuring Element ◽  
Test Part ◽  
Psychic Disorders ◽  
Competing Interest ◽  
Neurocognitive Profile ◽  
The Stability ◽  
High Level

Identifying the patterns of neurocognitive disorders in pubertal schizophrenia is actual.MethodsBenton Test of visual retention, methods of forward and reverse bills, Bourdon correction sample, Wechsler's subtests (subtest 11 – “Encryption”, subtest 12 – “Labyrinths” 1, 2, 3, 4, 5), Trail Creating a Test Part A.ResultsAll patients were divided into 3 groups. The first group (schizophrenia) and second group (other psychic disorders) showed the worst results than healthy subjects. Qualitative analysis of the “Benton Test” results showed similar variations of difficulty and types of errors in the subjects of the first and second groups – ignoring the number of the figure sides, as well as difficulties in the structuring element of the image corners. The “Methods of forward and reverse bills” demonstrated the fatigue and attention instability. “Bourdon test” showed a high level of the stability index (K = 0.09). Wechsler's subtest “Encryption B” obtained poor results, indicating a pathological decrease in visual-motor speed. During the subtest “Labyrinths 1, 2, 3, 4, 5” the subjects of first and second groups exceeded the allowable time limit, but the first group of schizophrenia patients allowed more blunders during pubertal study (ignored the walls of the maze, torn pencil despite the given instructions). The test groups 1 and 2 while passing “Trail Creating a Test Part A” have shown good results – job data did not cause difficulties and carried out in accordance with the specified instructions.ConclusionsNeurocognitive disorders allow to confirm the presence of morphological and functional brain changes when endogenous mental illness occurs.Disclosure of interestThe authors have not supplied their declaration of competing interest.

A new approach to the stability analysis of thawing slopes

1980 ◽  
Vol 17 (4) ◽  
pp. 607-612 ◽  
Author(s):  
Luis E. Vallejo
Keyword(s):  
Stability Analysis ◽  
Water Content ◽  
Pore Water ◽  
Active Layer ◽  
Necessary Conditions ◽  
Mass Movements ◽  
New Approach ◽  
Pore Water Pressures ◽  
The Stability ◽  
Excess Pore

A new approach to the stability analysis of thawing slopes at shallow depths, taking into consideration their structure (this being a mixture of hard crumbs of soil and a fluid matrix), is presented. The new approach explains shallow mass movements such as skin flows and tongues of bimodal flows, which usually take place on very low slope inclinations independently of excess pore water pressures or increased water content in the active layer, which are necessary conditions in the methods available to date to explain these movements.

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