scholarly journals Silicon-induced increase in chlorophyll is modulated by the leaf water potential in two water-deficient tomato cultivars

2012 ◽  
Vol 58 (No. 11) ◽  
pp. 481-486 ◽  
Author(s):  
O.N. Silva ◽  
A.K.S. Lobato ◽  
F.W. Ávila ◽  
R.C.L. Costa ◽  
C.F. Oliveira Neto ◽  
...  
Keyword(s):  
Water Potential ◽  
Water Deficit ◽  
Leaf Water Potential ◽  
Leaf Water ◽  
Soluble Carbohydrates ◽  
Total Chlorophyll ◽  
Water Restriction ◽  
Positive Interaction ◽  
Total Carbohydrates ◽  
Carbohydrate Levels

This study aims to explain the effects of silicon on chlorophyll and to measure gas exchange and carbohydrate levels in two Lycopersicon esculentum cultivars that are exposed to drought. The experimental design used in this study was a randomised combination of five different water and silicon conditions (control, water deficit + 0.00 μmol Si, water deficit + 0.25 μmol Si, water deficit + 1.00 μmol Si, and water deficit + 1.75 μmol Si) applied to the two cultivars (Super Marmante and Santa Cruz). Parameters measured were gas exchanges, chlorophylls, and total soluble carbohydrates. Silicon at concentrations of 0.25, 1.00, and 1.75 μmol induced a gradual increase in the total chlorophyll levels. A correlation analysis revealed a linear, positive interaction between the leaf water potential and the total chlorophyll (r = 0.71; P < 0.05). This study confirmed the hypothesis that silicon has a beneficial effect with regard to chlorophyll. Under water-deficient conditions, both cultivars showed an increase in chlorophyll a when treated with silicon in addition to changes in the total chlorophyll levels. These results were supported by the change in leaf water potential. In addition, a reduction of the effects of water restriction was also observed in the transpiration rate, the stomatal conductance and in the levels of total carbohydrates.

scholarly journals Optimizing irrigation and determining the most sensitive development stage to drought in barley (Hordeum vulgare L.) in a semi-arid environment

2020 ◽  
Vol 79 (1) ◽  
pp. 87-94
Author(s):  
Leila Romdhane ◽  
Nicola Dal Ferro ◽  
Amor Slama ◽  
Leila Radhouane
Keyword(s):  
Water Potential ◽  
Water Deficit ◽  
Leaf Water Potential ◽  
Yield Components ◽  
Stem Elongation ◽  
Leaf Water ◽  
Water Deficit Stress ◽  
Growth Stages ◽  
Development Stages ◽  
Three Stages

Rising temperatures and increasing water scarcity, which are already important issues, are expected to intensify in the near future due to global warming. Optimizing irrigation in agriculture is a challenge. Understanding the response of crop development stages to water deficit stress provides an opportunity for optimizing irrigation. Here we studied the response of two barley varieties (Rihane, Martin), to water deficit stress at three development stages (tillering, stem elongation, and heading) by measuring water status and grain yield components in a field experiment in Tunisia. The three stages were selected due to their importance in crop growth and grain development. Water deficit stress was initiated by withholding water for 21 days at the three stages with subsequent re-watering. Water deficit led to a progressive decrease in leaf water potential. In both varieties, heading was the stage most sensitive to water deficit. Leaf water potential measurements indicated that water deficit stress was more severe during heading, which to some extent may have influenced the comparison between growth stages. During heading, the number of ears per plant and weight of a thousand grains were reduced by more than 70% and 50%, respectively compared with stress at tillering. Comparison of yield components showed differences between the two barley varieties only when the water deficit was produced during the tillering stage.

Genotypic variation in osmotic adjustment in grain sorghum. I. Development of variation in osmotic adjustment under water-limited conditions

1991 ◽  
Vol 42 (5) ◽  
pp. 747 ◽  
Author(s):  
T Tangpremsri ◽  
S Fukai ◽  
KS Fischer ◽  
RG Henzell
Keyword(s):  
Water Potential ◽  
Water Deficit ◽  
Leaf Water Potential ◽  
Osmotic Adjustment ◽  
Osmotic Potential ◽  
Genotypic Variation ◽  
Genetic Material ◽  
Covariance Analysis ◽  
Leaf Water ◽  
The Other

Development of genotypic variation in osmotic adjustment was examined in two glasshouse experiments using two sets of sorghum material. In the first experiment, 47 S2 lines extracted from a randomly mated population were used, whereas in the other, inbred parents and their 15 hybrids were compared. In both experiments, water deficit was induced in two periods, one before anthesis and the other after anthesis for most genotypes. In both experiments osmotic potential at the beginning of the first drying period was similar among genotypes and therefore osmotic potential obtained under water deficit was used for the comparison of osmotic adjustment among genotypes. In the first drying period of both experiments, when stress was milder, about 40% of the variation in osmotic adjustment was accounted for by difference in leaf water potential. When the effect of water potential was removed by covariance analysis, there was significant genotypic variation in osmotic adjustment in the second experiment, but not in the first experiment. On the other hand, in the second drying period, when stress was more severe, the effect of leaf water potential on osmotic adjustment was small. There was significant genotypic variation in osmotic adjustment in both experiments after the water potential effect was removed by covariance analysis. Osmotic adjustment in the second drying period was also negatively correlated with grain sink/source ratio (number of grains/leaf area) in the first set of materials. The comparison of osmotic adjustment among hybrids and their parents showed that, in this particular set of genotypes, the female parents were more important than the male in determining osmotic adjustment of the hybrids. The genotypic variation was associated with performance under water deficit in the field. It is concluded that there is considerable genotypic variation in osmotic adjustment in the genetic material examined. Osmotic adjustment is, however, correlated with water potential and grain sink/source balance, and hence the selection for osmotic adjustment needs to ensure that high value is not due simply to low water potential or small head size.

scholarly journals Vine water deficit : among the 3 applications of pressure chamber, stem water potential is the most sensitive indicator

OENO One ◽  
2000 ◽  
Vol 34 (4) ◽  
pp. 169
Author(s):  
Xavier Choné ◽  
Olivier Trégoat ◽  
Cornelis Van Leeuwen ◽  
Denis Dubourdieu
Keyword(s):  
Water Potential ◽  
Water Deficit ◽  
Leaf Water Potential ◽  
Water Status ◽  
Pressure Chamber ◽  
Leaf Water ◽  
Sensitive Indicator ◽  
Stem Water Potential ◽  
Water Deficits ◽  
Stem Water

<p style="text-align: justify;">Vine water status is an important factor in grape quality. High tannin and anthocyanin content in red grape berries are related to moderate vine water deficits. Hence, a simple and sensitive indicator is required to determine vine water status and especially water constraint. Pressure chamber allows a quick and easy to practice determination of water status in the vineyard. Three applications of pressure chamber are known: predawn leaf water potential (ΨB), leaf water potential (ΨF) and stem water potential (ΨT). Only ΨB and ΨF are widely used on vines. In this survey ΨB, ΨF, ΨT and transpiration flow were measured on mature leaves to determine non-irrigated vine water status in field grown vines during the growing season. In California as well as in France, stem Ψ was the most discriminating indicator for both moderate and severe water deficits. In every plot surveyed ΨT was much better correlated to leaf transpiration than ΨF. Moreover, ΨT revealed nascent water deficit earlier than ΨB did. Among the three application of pressure chamber, ΨT was the only one to indicate short term water deficit after a rainfall. Hence, ΨT appears to be a useful indicator for grapevine management in both non-irrigated and irrigated vineyards.</p>

scholarly journals Penggulungan daun pada tanaman monokotil saat kekurangan air (Leaf rolling in monocotyledon plants under water deficit)

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
Song Ai Nio ◽  
Audry Agatha Lenak
Keyword(s):  
Water Potential ◽  
Water Deficit ◽  
Leaf Water Potential ◽  
Drought Resistance ◽  
Leaf Water ◽  
Leaf Rolling ◽  
Bulliform Cells ◽  
Drought Avoidance ◽  
Evapotranspiration Rate ◽  
Dry Soil

Abstrak Penggulungan daun merupakan salah satu bentuk resistensi terhadap kekeringan atau lebih tepatnya mekanisme menghindari kekeringan pada tumbuhan monokotil. Mekanisme ini terjadi dengan cara menurunkan laju evapotranspirasi atau dengan meningkatkan absorpsi air pada tanah kering untuk mempertahankan potensial air daun tetap tinggi. Proses penggulungan daun ini berkaitan erat dengan peranan sel kipas. Pada saat kekurangan air, jumlah dan ukuran sel kipas meningkat, sehingga daun akan menggulung. Tingkat penggulungan daun dapat ditentukan secara visual berdasarkan sistem standar evaluasi untuk tanaman padi dengan memberi skor 1-9. Rendahnya tingkat penggulungan daun berkorelasi positif dengan meningkatnya potensial air daun. Kata kunci: menghindari kekeringan, penggulungan daun Abstract Leaf rolling is one mechanism of drought resistance, i.e. drought avoidance. This mechanism was resulted from decreasing evapotranspiration rate or increasing water absorption in the dry soil to maintain high leaf water potential. The process of leaf rolling in monocotyledon was closely related to the activity of bulliform cells. The number and size of bulliform cells were increased under water deficit, so that leaf rolling occurred. Leaf rolling score (1-9) could be visually determined based on the system of standard evaluation in rice. The low leaf rolling score was positively correlated with high leaf water potential. Keywords: drought avoidance, leaf rolling

scholarly journals POTENCIAL HÍDRICO FOLIAR EM MILHO SUBMETIDO AO DÉFICIT HÍDRICO

Irriga ◽  
2010 ◽  
Vol 15 (3) ◽  
pp. 324-334
Author(s):  
Juliano Dalcin Martins ◽  
Reimar Carlesso ◽  
Alberto Eduardo Knies ◽  
Zanandra Boff de Oliveira ◽  
Tiago Broetto ◽  
...  
Keyword(s):  
Water Potential ◽  
Water Deficit ◽  
Leaf Water Potential ◽  
Irrigation Management ◽  
Leaf Water ◽  
Maize Leaf ◽  
Randomized Design ◽  
Development Cycle ◽  
Rainout Shelter ◽  
Completely Randomized Design

O potencial hídrico foliar pode ser considerado como um parâmetro de indicação da condição hídrica das culturas. Este trabalho teve como objetivo estudar o potencial hídrico foliar das plantas de milho sobre déficit hídrico no estágio inicial de desenvolvimento reprodutivo. O experimento foi conduzido no interior de uma cobertura móvel “Rainout shelter”, utilizando o delineamento experimental inteiramente casualizado, com dois tratamentos e quinze repetições. Os tratamentos foram constituídos de dois manejos da água de irrigação: (i) irrigado (as plantas de milho receberam irrigação conforme suas necessidades durante todo o ciclo de desenvolvimento); (ii) déficit hídrico aplicado antes do pendoamento.   O déficit hídrico teve uma duração de aproximadamente 50 mm de ETo acumulada. A cobertura móvel foi acionada quando da ocorrência de chuvas, impedindo que esta ocorresse sobre a área experimental. Determinou-se o conteúdo de água disponível nas camadas de 0-10, 10-25, 25-55 e 55-85 cm de profundidade e variação diária do potencial hídrico das folhas de milho. Não foram observadas diferenças entre os tratamentos para o potencial de água na folha. O potencial hídrico foliar em plantas de milho não apresenta variação para déficit hídrico de 50 mm de evapotranspiração de referência acumulada.   UNITERMOS: déficit hídrico, potencial hídrico foliar, milho, irrigação.     MARTINS, J. D.; CARLESSO. R.; KNIES, A. E.; OLIVEIRA, Z. B.; BROETTO, T.; RODRIGUES, G. J. LEAF WATER POTENTIAL IN MAIZE EXPOSED TO WATER DEFICIT 2 ABSTRACT   The leaf water potential can be considered as a parameter for indicating the crops water condition. This work aimed to study the maize leaf water potential on water deficit in the reproductive developmentinitial stage. The experiment was conducted within a mobile coverage "rainout shelter" using a completely randomized design with two treatments and fifteen repetitions. The treatments consisted of two water irrigation management: (i) irrigated (maize was irrigated as needed throughout the development cycle), (ii) water stress applied before tasseling. The drought lasted approximately 50 mm of accumulated reference evapotranspiration (ETo). The mobile coverage was triggered when rainfall occurred, preventing water from falling into the experimental area. Available water was determined  in layers of 0-10, 10-25, 25-55 and 55-85 cm depth and daily variation of water potential in maize leaves were also  evaluated. There were no differences between treatments for leaf water potential. The maize leaf water potential presented no change to water deficit equivalent to 50 mm of accumulated ETo.  KEYWORDS: water deficit, leaf water potential, maize, irrigation.

Partitioning of [14C]Glucose Into Sorbitol and Other Carbohydrates in Apple Under Water Stress

1996 ◽  
Vol 23 (3) ◽  
pp. 245 ◽  
Author(s):  
Z Wang ◽  
B Quebedeaux ◽  
GW Stutte
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Malus Domestica ◽  
Osmotic Adjustment ◽  
Leaf Water ◽  
Soluble Carbohydrates ◽  
Malus Domestica Borkh ◽  
Apple Leaves ◽  
Mature Apple

Sorbitol plays an important role in osmotic adjustment in mature apple leaves under water stress. This study was conducted to determine whether water stress increases the conversion of glucose to sorbitol in mature apple leaves. A solution of [14C]glucose or [14C]sorbitol was introduced into the cut end of detached apple (Malus domestica Borkh. 'Red Jonathan') shoots which had previously experienced either water stress or no stress. The cut shoots were then placed in sterile deionised water to maintain well-watered conditions or in no water to continue water-stressed conditions. When shoots were labelled with [14C]glucose, 38% of [14C]glucose was recovered as glucose in the leaves at a leaf water potential (Ψw) of -1.0 MPa following a 30-min labelling. The remaining [14C]glucose was converted to sucrose (24%), fructose (21%), and sorbitol (17%). Water stress altered the partitioning of [14C]glucose between sorbitol and sucrose, increasing the ratio from 0.8 at Ψw = -1.0 to 1.7 at Ψw = -3.0 MPa. When shoots were supplied with [14C]sorbitol, <10% of [14C]sorbitol was converted to other soluble carbohydrates. Water stress inhibited the conversion of both [14C]glucose and [14C]sorbitol into starch. The results suggest that sorbitol accumulation may result from the preferential conversion of glucose to sorbitol rather than to sucrose and starch.

The effect of root hairs under drought in open field conditions

2021 ◽  
Author(s):  
Maria Marin ◽  
Deborah S Feeney ◽  
Lawrie K Brown ◽  
Muhammad Naveed ◽  
Siul Ruiz ◽  
...  
Keyword(s):  
Water Potential ◽  
Water Deficit ◽  
Open Field ◽  
Leaf Water Potential ◽  
Root Hair ◽  
Root Hairs ◽  
Leaf Water ◽  
Plant Water ◽  
Clay Loam ◽  
Wild Type

&lt;p&gt;Root hairs represent an attractive target for future crop breeding, to improve resource use efficiency and stress tolerance. Most studies investigating root hairs have focused on plant tolerance to phosphorus deficiency and rhizosheath formation under controlled conditions. However, data on the interplay between root hairs and open-field systems, under contrasting soils and climate conditions, are limited. Although root hairs and rhizosphere are assumed to play a key role in regulating plant water relations, their effect on plant water uptake has been rarely investigated. As such, this study aimed to experimentally elucidate some of the impacts that root hairs have on plant performance under field conditions and water deficit. A field experiment was set up in Scotland for two consecutive years, in 2017 (a typical year) and 2018 (the driest growing season ever recorded at this site), under different soil textures (i.e., clay loam vs. sandy loam). Five barley (Hordeum vulgare) genotypes exhibiting variation in root hair length and density were used in the study. Measurements of root hair density, length and its correlation with rhizosheath weight highlighted trait robustness in the field under variable environmental conditions. Root hairs did not confer a notable advantage to barley under optimal conditions, but under soil water deficit root hairs enhanced plant water status and stress tolerance. This resulted in less negative leaf water potential and lower leaf abscisic acid concentration, while promoting shoot phosphorus accumulation. Specifically, minimum leaf water potential differed significantly (P = 0.021) between the wild type (-1.43 MPa) and its hairless mutant (-1.76 MPa) grown in clay loam, with the mutant exhibiting greater water stress. In agreement with leaf water potential measurements, at the peak of water stress, leaf abscisic acid concentration was significantly (P = 0.023) greater for the hairless mutant (394 ng g&lt;sup&gt;-1&lt;/sup&gt;) than the wild type (250 ng g&lt;sup&gt;-1&lt;/sup&gt;) grown in clay loam soil. Under water deficit conditions, in clay loam soil, shoot phosphorus accumulation in the wild type (2.49 mg P shoot&lt;sup&gt;-1&lt;/sup&gt;) was over twice that in the hairless mutant (1.10 mg P shoot&lt;sup&gt;-1&lt;/sup&gt;). Furthermore, the presence of root hairs did not decrease yield under optimal conditions, while root hairs enhanced yield stability under drought. While yield of the hairless mutant significantly (P = 0.012) decreased from 2017 to 2018 in both clay (-26%) and sandy (-33%) loam soils, no significant differences were found between years in the yield of the wild type. Therefore, selecting for beneficial root hair traits can enhance yield stability without diminishing yield potential, overcoming the breeder&amp;#8217;s dilemma of trying to simultaneously enhance both productivity and resilience. To our knowledge, the present findings provide the first evidence of the effect of root hairs under drought in open field conditions (i.e., real agricultural system). Therefore, along with the well-recognized role for P uptake, maintenance or enhancement of root hairs can represent a key trait for breeding the next generation of crops for improved drought tolerance in relation to climate change.&lt;/p&gt;

A basis for improved soil and water management for irrigated pastures in northern Victoria

1988 ◽  
Vol 28 (3) ◽  
pp. 315 ◽  
Author(s):  
SJ Blaikie ◽  
FM Martin ◽  
WK Mason ◽  
DJ Connor
Keyword(s):  
Water Potential ◽  
Soil Water ◽  
Water Deficit ◽  
Leaf Water Potential ◽  
White Clover ◽  
Soil Profile ◽  
Leaf Water ◽  
Individual Species ◽  
Soil Water Deficit ◽  
Leaf Elongation

The water relations of white clover and paspalum as monocultures and components of a mixed pasture were studied on a normal and a modified soil profile during the interval between 2 successive irrigations. Responses of individual species were similar in monocultures and mixed pastures. On the normal profile white clover was the first species to react to soil water deficit when the rate of leaf elongation fell by 33% to about 10 mm/day after 30 mm of cumulative evaporation minus rainfall (E - R). This was followed by a reduction in dawn and midday leaf water potential at around 50 mm E - R. After 65 mm E - R, leaf elongation had ceased. In contrast, paspalum showed no signs of water shortage until 70-80 mm E - R. At this stage both the rate of leaf elongation and midday leaf water potential fell. After 90 mm E - R the dawn leaf water potential fell and by 120 mm E - R leaf elongation was negligible. Modification of the profile increased soil water availability by allowing more extraction of water at depth in the profile. This delayed the onset of water stress by about 40 mm E - R in both species. These observations show that the common irrigation interval of 60-90 mm E - R in northern Victoria is likely to restrict pasture yields because it causes a period of soil water deficit stress, especially for white clover, and the development of leaf area is impeded, increasing the time taken for canopies to recover maximum productivity after grazing. To overcome these limitations farmers will have to water more frequently or modify the soil profile to provide pastures with a better water supply.

Sign in / Sign up

Export Citation Format

Share Document