scholarly journals The impact of humic acid fractions on swelling and germination of ‘Progres’ and ‘Nawiko’ soybean seeds under salt and water deficit stresses

2016 ◽  
Vol 69 (3) ◽  
Author(s):  
Andrzej Gawlik ◽  
Dorota Gołębiowska ◽  
Danuta Kulpa ◽  
Romualda Bejger ◽  
Renata Matuszak-Slamani ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Salt Stress ◽  
Polyethylene Glycol ◽  
Water Deficit ◽  
Negative Impact ◽  
Laboratory Research ◽  
Water Deficit Stress ◽  
Soybean Seeds ◽  
The Impact ◽  
Millipore Filters

A laboratory research was carried out to examine the impact of humic acids (HA) on swelling and germination of ‘Nawiko’ and ‘Progres’ soybean seeds under salt stress (50 mM dm<sup>−3</sup> NaCl) and water deficit stress (−0.5 MPa) induced by polyethylene glycol (PEG) 6000. HA in the form of a dry preparation was obtained from peat using the IHSS method. Tests on swelling and germination used non-fractionate preparation (NFHA) and two of its molecular fractions obtained using Millipore filters with a 30 kDa cut-off point. This enabled us to obtain two fractions: with a higher molecular weight, above 30 kDa (HMHA), and a lower molecular weight, below 30 kDa (LMHA). The carbon concentration in HA solutions, used in all tests, was 0.005 g C<span><sub>HA</sub></span> dm<sup>−3</sup>. The results showed that HA mitigate the negative impact of salinity and water deficit on swelling and germination of soybean seeds.

Seasonal differences in the relative importance of specific phenolics and twig morphology result in contrasting patterns of foraging by a generalist herbivore

2013 ◽  
Vol 91 (5) ◽  
pp. 338-347 ◽  
Author(s):  
C. Stolter ◽  
John P. Ball ◽  
R. Julkunen-Tiitto
Keyword(s):  
Molecular Weight ◽  
Negative Impact ◽  
Plant Morphology ◽  
Diet Selection ◽  
Low Molecular Weight ◽  
Relative Importance ◽  
Secondary Chemistry ◽  
Generalist Herbivore ◽  
Chemical Composition Of Plants ◽  
The Impact

The co-evolved relationship between the chemical composition of plants and herbivory is fundamental in understanding diet selection of herbivores and their impacts on plants and ecosystems. However, the impact of plant secondary chemistry on mammalian herbivory is not fully understood. We investigated seasonal influences of phenolics with low molecular weight (e.g., flavonoids, salicylates) and plant morphology of the tea-leaved willow (Salix phylicifolia L.) on moose (Alces alces (L., 1758)) foraging. We analysed the relationship of different phenolic compounds in twigs and browsing in winter, and in leaves and the degree of leaf stripping in summer, and the role of plant morphology. In winter, higher concentrations of phenolics, e.g., myricetin-related compounds (belonging to the flavonoids), had a negative impact on herbivory by moose. This impact was not associated with a single compound but instead seemed to be more a result of synergistic or additive effects of different compounds. In contrast, the models for summer browsing showed a pronounced effect of plant morphology. Our analyses reveal differences in the relative importance of phenolics of low molecular weight and plant morphology on diet selection between seasons. These findings are relevant for understanding feeding decisions and mechanisms deterring mammalian herbivores known for shaping the vegetation on the ecosystem level.

Blend membranes based on polyurethane and polyethylene glycol: exploring the impact of molecular weight and concentration of the second phase on gas permeation enhancement

2016 ◽  
Vol 36 (5) ◽  
pp. 513-519 ◽  
Author(s):  
Milad Abdolmaleki ◽  
Touraj Tavakoli ◽  
Omid Moini Jazani ◽  
Mohammad Reza Saeb
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Gas Permeation ◽  
Point Of View ◽  
Second Phase ◽  
X Ray Diffraction ◽  
Blend Films ◽  
Blend Membranes ◽  
Solution Casting Method ◽  
The Impact

Abstract This work seeks to explore the permeability dependence of polyurethane (PU)/polyethylene glycol (PEG) blend membranes on the molecular weight and composition of PEG constituent polymer. In this regard, gases with different polar nature were mixed (CO2/N2, CO2/CH4, and O2/N2) and subjected to a series of PU/PEG blends prepared via solution casting method. With the alteration of the molecular weight (1000, 2000, and 6000 g/mol) and composition (0, 10, 15, and 20 wt.%) of PEG in the blend films, the potentials of membranes in controlling the permeation of gas molecules within the films were quantified, compared, and discussed. It is known that the introduction of PEG into PU-based membranes causes the films to become more flexible, which brings advantages from an application point of view. Fourier transform infrared spectroscopy, wide-angle X-ray diffraction, and scanning electron microscopy analyses were used to study the microstructural changes in the prepared PU/PEG blend membranes. The selectivity of the films was obviously displaced by the introduction of PEG, particularly when higher-molecular-weight PEGs were used and the resulting hybrid membranes were subjected to a mixture of CO2/CH4 or CO2/N2 gases.

scholarly journals Review of water deficit mediated changes in vine and berry physiology; Consequences for the optimization of irrigation strategies

OENO One ◽  
2019 ◽  
Vol 53 (3) ◽  
Author(s):  
Thibaut Scholasch ◽  
Markus Rienth
Keyword(s):  
Water Deficit ◽  
Water Use ◽  
Water Status ◽  
Abiotic Factors ◽  
Mitigation Strategies ◽  
Water Deficit Stress ◽  
Current Debate ◽  
Status Assessment ◽  
The Impact ◽  
Scientific Advances

The increasing risk of water deficit stress due to global warming subjects winegrowers of traditional rain fed viticulture regions to new challenges regarding vine water status assessment and possible drought mitigation strategies, such as irrigation.This review summarizes the most recent studies on the impact of water deficit stress on vine and berry physiology; it discusses the latest scientific advances regarding hormonal and hydraulic regulation and segmentation and addresses the current debate on iso/an-isohydricity within vine cultivars. Latest literature on irrigation frequency, water stress memory and the impact of abiotic factors such as VPD (Vapor Pressure Deficit), radiation, temperature and canopy architecture on vine physiology and water use, raise important questions on water status assessment and the implementation of irrigation strategies. Practical consequences regarding the effects of vine water regime on vine water regulatory mechanisms are discussed. Recent technical and scientific advances shed new light on how site specific irrigation strategies matching production objectives could improve vineyard water use.

scholarly journals Effect of Polyethylene Glycol Induced Water Stress on Germination and Seedling Growth of Wheat (Triticum aestivum)

2017 ◽  
Vol 15 (1) ◽  
pp. 81-91 ◽  
Author(s):  
MS Rana ◽  
MA Hasan ◽  
MM Bahadur ◽  
MR Islam
Keyword(s):  
Polyethylene Glycol ◽  
Water Stress ◽  
Stress Tolerance ◽  
Water Deficit ◽  
Seedling Growth ◽  
Dry Weight ◽  
Stress Sensitivity ◽  
Water Deficit Stress ◽  
Growth Stages ◽  
Wheat Genotypes

The performance of twenty wheat genotypes under Polyethylene Glycol (PEG) induced water stress during germination and early seedling growth stages were tested under three levels of water potential i) Control (Tap water), ii) -2 bars and iii) -4 bar at the Crop Physiology and Ecology Laboratory of Hajee Mohammad Danesh Science and Technology University, Dinajpur during September 2014 to October 2014. Rate of germination and vigor index of all wheat genotypes were delayed with the increment of water stress induced by PEG. Shoot and root lengths and seedling dry weight of 10 days old seedlings were found to be reduced due to the increment of water stress. However, the degree of reduction of these parameters with the increment of water stress was not similar for all wheat genotypes. Stress tolerance index (STI) based on seedling dry weight indicated a wide difference in stress tolerance among the wheat genotypes. At moderate water deficit stress, BARI Gom 25, E 34, E 28 and BAW 1170 showed more stress tolerance and the wheat genotypes- Sourav, E 23 and BAW 1140 showed greater stress sensitivity than the other wheat genotypes. At higher water deficit stress, BARI Gom 25, BARI Gom 28, E 28 and BAW 1170 showed more stress tolerance and the wheat genotypes- Satabdi, Sourav, BARI Gom 26, E 23, E 38, E 24, BAW 1163, BAW 1140 and BAW 1151 showed greater stress sensitivity than the others. Considering both moderate and high water deficit stress, BARI Gom 25, E 28 and BAW 1170 were found as tolerant and Sourav, E 23 and BAW 1140 were found as water deficit stress sensitive wheat genotypes. The Agriculturists 2017; 15(1) 81-91

scholarly journals Toward Coalescing Gene Expression and Function with QTLs of Water-Deficit Stress in Cotton

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Hirut Kebede ◽  
Paxton Payton ◽  
Hanh Thi My Pham ◽  
Randy D. Allen ◽  
Robert J. Wright
Keyword(s):  
Abiotic Stress ◽  
Water Deficit ◽  
Fiber Quality ◽  
Water Deficit Stress ◽  
Abiotic Stress Response ◽  
Consensus Sequences ◽  
Stress Genes ◽  
Sequence Tagged Sites ◽  
And Function ◽  
The Impact

Cotton exhibits moderately high vegetative tolerance to water-deficit stress but lint production is restricted by the available rainfed and irrigation capacity. We have described the impact of water-deficit stress on the genetic and metabolic control of fiber quality and production. Here we examine the association of tentative consensus sequences (TCs) derived from various cotton tissues under irrigated and water-limited conditions with stress-responsive QTLs. Three thousand sixteen mapped sequence-tagged-sites were used as anchored targets to examine sequence homology with 15,784 TCs to test the hypothesis that putative stress-responsive genes will map within QTLs associated with stress-related phenotypic variation more frequently than with other genomic regions not associated with these QTLs. Approximately 1,906 of 15,784 TCs were mapped to the consensus map. About 35% of the annotated TCs that mapped within QTL regions were genes involved in an abiotic stress response. By comparison, only 14.5% of the annotated TCs mapped outside these QTLs were classified as abiotic stress genes. A simple binomial probability calculation of this degree of bias being observed if QTL and non-QTL regions are equally likely to contain stress genes was P(x ≥ 85)=7.99  × 10−15. These results suggest that the QTL regions have a higher propensity to contain stress genes.

scholarly journals The effect of interspecies interactions and water deficit on spring barley and red clover biomass accumulation at successive growth stages

2016 ◽  
Vol 69 (4) ◽  
Author(s):  
Magdalena Jastrzębska ◽  
Marta K. Kostrzewska ◽  
Maria Wanic ◽  
Kinga Treder ◽  
Przemysław Makowski
Keyword(s):  
Growth Rate ◽  
Water Deficit ◽  
Spring Barley ◽  
Red Clover ◽  
Biomass Accumulation ◽  
Growing Season ◽  
Water Deficit Stress ◽  
Leaf Biomass ◽  
Growth Stages ◽  
The Impact

<p>A pot experiment was conducted in a greenhouse in Olsztyn, Poland, in the period 2010–2012. The aim of the study was to examine whether soil water deficit would change biomass volume and distribution of pure sown spring barley and red clover as well as growth rate during their joint vegetation and mutual interactions. The interactions between spring barley and red clover were of a competitive character, and the cereal was the stronger crop. The strength of this competition increased in time with the growing season. Through most of the growing season, the competition was poorer in water deficit conditions.</p><p>The impact of clover on barley before the heading stage showed facilitation symptoms. Interspecific competition reduced the rate of barley biomass accumulation and decreased stem and leaf biomass towards the end of the growing season. Intensified translocation of assimilates from the vegetative parts to grain minimized the decrease in spike biomass.</p><p>Water deficit stress had a more inhibitory effect on the biomass and growth rate of barley than competition, and competition did not exacerbate the adverse influence of water deficit stress on barley. Competition from barley significantly reduced the biomass and biomass accumulation rate of clover. Water deficit stress did not exacerbate barley’s competitive effect on clover, but it strongly inhibited the growth of aboveground biomass in pure-sown clover.</p>

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