Effects of Osmotic Water Stress and Gibberellic Acid on Initial Growth of Oak Seedlings

1973 ◽  
Vol 3 (1) ◽  
pp. 75-82 ◽  
Author(s):  
M. M. Larson ◽  
I. Palashev
Keyword(s):  
Water Stress ◽  
Gibberellic Acid ◽  
Root Growth ◽  
Stress Condition ◽  
High Stress ◽  
Stress Conditions ◽  
Initial Growth ◽  
White Oak ◽  
High Stress Condition ◽  
Oak Seedlings

Red and white oak seeds were treated and untreated with gibberellic acid (GA) and then watered with graded polyethylene glycol 400 solutions to simulate various soil water stress conditions. Seedling growth decreased as the osmotic potential of the soil solution decreased from −1/3 bars to −4 bars to −8 bars (the low, moderate, and high osmotic stress conditions, respectively). Seedling dry weights at high stress condition averaged only 11% of seedling dry weights at low stress condition. At high stress condition, shoot growth was more suppressed than root growth. White oak roots grew somewhat better than red oak roots at high stress condition.Treatment of seed with GA prior to germination stimulated stem elongation and number of leaves per plant but inhibited formation of lateral roots and other aspects of shoot and root growth, especially among white oak seedlings. The GA-stimulated stem growth observed at the low stress condition was completely suppressed at moderate and high stress conditions. GA-white oak seedlings appeared to be less tolerant of soil stress than untreated seedlings.

Effects of Stress and Task Difficulty on Working Memory and Cortical Networking

2017 ◽  
Vol 124 (6) ◽  
pp. 1194-1210 ◽  
Author(s):  
Yujin Kim ◽  
Jihwan Woo ◽  
Minjung Woo
Keyword(s):  
Working Memory ◽  
Task Difficulty ◽  
Stress Condition ◽  
High Stress ◽  
Stress Conditions ◽  
Memory Encoding ◽  
Easy Task ◽  
Memory Accuracy ◽  
High Stress Condition ◽  
And Task

This study investigated interactive effects of stress and task difficulty on working memory and cortico-cortical communication during memory encoding. Thirty-eight adolescent participants (mean age of 15.7 ± 1.5 years) completed easy and hard working memory tasks under low- and high-stress conditions. We analyzed the accuracy and reaction time (RT) of working memory performance and inter- and intrahemispheric electroencephalogram coherences during memory encoding. Working memory accuracy was higher, and RT shorter, in the easy versus the hard task. RT was shorter under the high-stress (TENS) versus low-stress (no-TENS) condition, while there was no difference in memory accuracy between the two stress conditions. For electroencephalogram coherence, we found higher interhemispheric coherence in all bands but only at frontal electrode sites in the easy versus the hard task. On the other hand, intrahemispheric coherence was higher in the left hemisphere in the easy (versus hard task) and higher in the right hemisphere (with one exception) in the hard (versus easy task). Inter- and intracoherences were higher in the low- versus high-stress condition. Significant interactions between task difficulty and stress condition were observed in coherences of the beta frequency band. The difference in coherence between low- and high-stress conditions was greater in the hard compared with the easy task, with lower coherence under the high-stress condition relative to the low-stress condition. Stress seemed to cause a decrease in cortical network communications between memory-relevant cortical areas as task difficulty increased.

scholarly journals Does seed size affect the germination rate and seedling growth of peanut under salinity and water stress?

2019 ◽  
Vol 49 ◽  
Author(s):  
Fábio Steiner ◽  
Alan Mario Zuffo ◽  
Aécio Busch ◽  
Tiago de Oliveira Sousa ◽  
Tiago Zoz
Keyword(s):  
Water Stress ◽  
Seed Size ◽  
Seedling Growth ◽  
Germination Rate ◽  
Stress Conditions ◽  
Medium Size ◽  
Dry Matter Accumulation ◽  
Initial Growth ◽  
Sowing Time ◽  
Important Indicator

ABSTRACT Seed size is an important indicator of physiological quality, since it may affect seed germination and seedling growth, especially under stress conditions. This study aimed to investigate the effects of seed size on germination and initial seedling growth, under salinity and water stress conditions. The treatments were arranged in a completely randomized design, in a 3 × 3 factorial scheme: three seed size classes (small, medium and large) and three stress treatments (control, saline or water stress), with four replicates. Water and salt stresses do not reduce the germination rate of medium and large seeds; however, the germination rate of small seeds is reduced under salt stress conditions. Drought stress drastically reduces the shoot growth of seedlings regardless of seed size, whereas root growth is higher in seedlings from medium and large seeds under water stress conditions. Under non-stressful environments, the use of large seeds is preferable, resulting in more vigorous seedlings with a greater dry matter accumulation. Medium-size seeds are more adapted to adverse environmental conditions and, therefore, should be used under conditions of water shortage and salt excess in the soil at sowing time. Seedlings are more tolerant to salinity than to water stress during the germination stage and initial growth under laboratory conditions.

Coping with an ego‐threat: Monitoring and blunting during an intelligence test

1994 ◽  
Vol 8 (3) ◽  
pp. 213-221 ◽  
Author(s):  
Peter Muris ◽  
Florence J. van Zuuren ◽  
Harald Merckelbach ◽  
Evert‐Jan Stoffels ◽  
Merel Kindt
Keyword(s):  
Predictive Validity ◽  
Stress Condition ◽  
High Stress ◽  
Intelligence Test ◽  
Ego Threat ◽  
Behavioral Style ◽  
The Subject ◽  
High Stress Condition

This study investigated the predictive validity of the Miller Behavioral Style Scale (MBSS; Miller, 1987). Subjects had to work on an intelligence test. During this test, they could observe lights that informed them on how they were performing. There were two conditions: a low‐stress condition (n = 37) in which the lights always indicated that the subject was performing well, and a high‐stress condition (n.= 33) in which the lights signalled a deterioration of performance. In general, little support was found for the predictive validity of the MBSS.

Design and Application of Secondary High-Capacity Support to Large-Section Tunnel Excavated in High-Stress Condition with Fractured Surrounding Rock

2012 ◽  
Vol 170-173 ◽  
pp. 1777-1784
Author(s):  
Xin Ming Chen
Keyword(s):  
Bearing Capacity ◽  
Stress Condition ◽  
Lateral Pressure ◽  
High Stress ◽  
High Capacity ◽  
Field Testing ◽  
Surrounding Rock ◽  
Large Section ◽  
Different Characteristics ◽  
High Stress Condition

Aimed at the support problem of the deep large-section tunnel excavated in high-stress condition with fractured surrounding rock, the different characteristics of the stresses and displacements of the surrounding rock of the tunnel with different section supports and lateral pressure coefficients were analyzed using numerical simulation and theoretical calculation, so was the effect of the height of the double-layered I-section beam on the bearing capacity. Arched with bottom arch superimposed and fully-closed I-section beam suitable for large-section tunnel excavated in high-stress condition with fractured surrounding rock was developed. This support applies fully-closed and horse-shoe shaped structure with I-section beam overlapped and welded and its bearing capacity is 2.5 times higher than frequently-used I-section beam. Underground field testing showed that the deformation of the surrounding rock could be effectively controlled when the secondary arched with bottom arch superimposed and fully-closed I-section beam of high bearing capacity was used.

Experimental study on rock-like materials fragmentation by electric explosion method under high stress condition

2019 ◽  
Vol 356 ◽  
pp. 750-758 ◽  
Author(s):  
Jianyu Peng ◽  
Fengpeng Zhang ◽  
Guangliang Yan ◽  
Zhaoguo Qiu ◽  
Xinghang Dai
Keyword(s):  
Experimental Study ◽  
Stress Condition ◽  
High Stress ◽  
Electric Explosion ◽  
Explosion Method ◽  
High Stress Condition

scholarly journals Agronomic performance of sugarcane families in response to water stress

Bragantia ◽  
2008 ◽  
Vol 67 (3) ◽  
pp. 655-661 ◽  
Author(s):  
Marcelo de Almeida Silva ◽  
Rogério Augusto Bremm Soares ◽  
Marcos Guimarães de Andrade Landell ◽  
Mário Pércio Campana
Keyword(s):  
Water Stress ◽  
Water Deficit ◽  
Growth Phase ◽  
Stress Conditions ◽  
Initial Growth ◽  
Agronomic Performance ◽  
Water Deficiency ◽  
Ratoon Crop ◽  
Stalk Diameter ◽  
Major Factors

Water deficit is one of the major factors limiting the production of sugarcane, especially in areas where there is a prolonged period of water deficiency, such as the West Central Brazilian region. One way to overcome this problem is to cultivate resistant or tolerant varieties. An experiment was set up at the Jalles Machado Sugar Mill, located near Goianésia, Goiás State, Brazil, to evaluate agronomic performance of several sugarcane families. A comparative analysis was carried out among the families under two irrigation regimes, one under regular environmental conditions and another under monthly irrigations during the period of water deficiency. Evaluated families consisted of 25 progenies planted in a factorial design with three replications with 20 plants each. The first ratoon crop was evaluated for four yield components, stalk height, stalk diameter, stalk number and Brix. By analysis of variance, stalk number and stalk height were influenced by water stress conditions during the initial growth phase, and for stalk diameter and Brix, water regime had no effect on the average expression of the characters during the growth phase. The method of classification in four categories proved to be adequate. Some families had high values for stalk diameter, stalk number and stalk height under water stress conditions. This study showed that it is possible to select sugarcane families under water deficit conditions associated with higher stalk diameter, stalk number and stalk height.

Identification of QTLs for shoot and root growth under ionic–osmotic stress in Lotus, using a RIL population

2014 ◽  
Vol 65 (2) ◽  
pp. 139 ◽  
Author(s):  
Gastón Quero ◽  
Lucía Gutíerrez ◽  
Ramiro Lascano ◽  
Jorge Monza ◽  
Niels Sandal ◽  
...  
Keyword(s):  
Osmotic Stress ◽  
Root Growth ◽  
Stress Condition ◽  
Stress Conditions ◽  
Chromosome 1 ◽  
Chromosome 3 ◽  
Growth Responses ◽  
Parental Allele ◽  
Ionic Stress ◽  
Ril Population

The genus Lotus includes a group of forage legume species including genotypes of agronomic interest and model species. In this work, an experimental hydroponic growth system allowed the discrimination of growth responses to ionic–osmotic stress in a population of recombinant inbred lines (RILs) developed from L. japonicus × L. burttii and the identification of the associated quantitative trait loci (QTLs). The analyses led to the identification of eight QTLs: three for shoot growth localised on chromosome 3, 5 and 6; one for root growth on chromosome 1; three for total growth on chromosome 1, 4 and 5; and one associated with shoot/root ratio on chromosome 3. An interaction of QTL × stress condition was established and the effect of the environment quantified. In summary, it was established that the allele from L. burttii explained most responses to osmotic stress, while the alleles of L. japonicus explained the responses related to ionic stress conditions. Of 49 markers linked to all QTLs identified, 41 expressed superiority of the L. burttii parental allele in the osmotic stress condition, but when an iso-osmotic concentration of NaCl was applied, L. burttii lost superiority in 21 of these markers. This shows the superiority of the L. japonicus parental allele in ionic stress conditions. This study is the first report in which a RIL population of lotus is analysed with the aim of providing molecular markers associated with plant responses to ionic or osmotic stress.

scholarly journals Full Field Strain Analysis of Blasting Under High Stress Condition Based on Digital Image Correlation Method

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Liyun Yang ◽  
Chenxi Ding ◽  
Renshu Yang ◽  
Zhen Lei ◽  
Jing Wang
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Stress Condition ◽  
High Stress ◽  
Correlation Method ◽  
Image Correlation ◽  
High Speed Photography ◽  
Digital Image Correlation Method ◽  
Propagation Law ◽  
High Stress Condition

The depth of mineral resources like coal continuously increases due to the exhaustion of shallow resources, and the characteristic of high ground stress in deep ground inevitably affects fracture of rock blasting. Combining with high-speed photography technology, the digital image correlation method (DIC) is introduced into experimental study on explosive mechanics. And strain evolution process of blasting under high stress condition is obtained by using the model experiment method. The preliminary results show that high stress condition has no obvious effects on the propagation law of blasting stress wave or its stress peak in the medium. In addition, it is found that medium in the “elastic vibration area” by conventional blast zoning is not always “elastic,” and on this basis, the concepts of “plastic area” and “quasielastic area” are put forward. The high stress condition does not influence partition range of above “plastic area” or “quasielastic area,” but in the “plastic area,” the high stress condition decreases both plastic strain value and its decay rate of relevant gauging points.

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