Proline, Soluble Sugar, Leaf Starch and Relative Water Contents of Four Maize Varieties in Response to Different Watering Regimes

Abstract The purpose of this study was to evaluate the response of four maize varieties to different simulated watering regimes in term of proline, starch and soluble sugar contents as well as relative water content. Maize seeds were planted in 64 plastic pots of 20 litre capacity, arranged in a factorial fitted in completely randomized design (CRD), with four replications in the screen house of the Institute of Agricultural Research and Training (I.A.R&T), Moor Plantation Ibadan. The watering was done based on the designated field capacities (FC) of 25, 50, 75 and 100%. Fresh leaf samples were collected five weeks after planting and at the end of each stress period. The proline, soluble sugar, leaf starch and the relative water contents in the leaves were estimated. The results obtained showed that watering regime significantly influenced the leaf starch, soluble sugar, proline and relative water contents. The varieties also differ significantly in the proline, soluble sugar content, leaf starch and the relative water contents. Watering regime and variety interaction was significant for soluble sugar, starch, proline and the relative water content. Highest soluble sugar of 1.28 mg/g and proline of 35.70 μmol/g FW were obtained when FC was 25% and lowest when watering level was optimum. The starch and relative water contents were optimum under full watering (100% FC) and lowest when field capacity was 25%. Variations were observed with regards to different maize varieties. ART98SW6-OB accumulated the highest quantity of soluble sugar and proline under 25 and 50% field capacities alongside DTESYN, which is a drought tolerant maize variety. It could be concluded that water stress increased production of soluble sugar and proline, while water availability increases relative water content and favors starch accumulation. The consideration of these metabolites alongside other physiological features is a very fast and reliable method for drought tolerant plant selection even at the plant seedling growth stage.

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Evaluation of diverse cowpea [Vigna unguiculata (L.) Walp.] germplasm accessions for drought tolerance

Legume Research - An International Journal ◽

10.18805/lr-428 ◽

2019 ◽

Author(s):

K.D. Nkoana ◽

Abe Shegro Gerrano ◽

E.T. Gwata

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Water Content ◽

Relative Water Content ◽

Evaluation Method ◽

Moisture Stress ◽

Proline Content ◽

Drought Tolerant ◽

Relative Water ◽

Germplasm Accessions

The genetic potential for drought tolerance in cowpea within the small holder sector has not been fully exploited in South Africa. Thus, a drought evaluation experiment was conducted at the ARC-VOP to evaluate 28 cowpea germplasm accessions including two controls viz. IT96D-602 (drought tolerant) and TVU7778 (susceptible to drought) in the drought screening house using plastic box evaluation method in January, 2017. Genotypes raised for three weeks were subjected to 5 weeks of water stress treatment to determine their physiological response through leaf wilting index, relative water content and proline content followed by re-watering to determine genotype (s) with ability to recover from drought stress. Analyses of variance showed highly significant differences in response to moisture stress among the cowpea accessions for the selected physiological traits except for leaf wilting index at week two of drought stress. Stem greenness and recovery appeared to be a reliable indicator of drought tolerant genotypes which was readily observed in Acc1257, Acc1168, Acc2355, IT96D-602 and Acc5352 which also correlated significantly and positively with relative water content and proline content. The genotypes responded differently to drought stress indicating that there is sufficient genetic variability that can be utilized further in breeding for drought stress within the cowpea species.

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Capillary Mats Alter the Water Content in Medium during Mist Propagation of Dendranthema

HortScience ◽

10.21273/hortsci.39.3.584 ◽

2004 ◽

Vol 39 (3) ◽

pp. 584-587 ◽

Cited By ~ 1

Author(s):

R.L. Geneve ◽

S.T. Kester ◽

J.W. Buxton

Keyword(s):

Water Content ◽

Water Table ◽

Relative Water Content ◽

Water Status ◽

Internal Water ◽

Relative Water ◽

Reduced Water ◽

Water Contents

A capillary mat-mist system was developed to provide near constant media water contents at differing quantities of mist. Media water contents were reduced by increasing the capillary mat height above a constant water table maintained at bench level. Increased tensions from 0 to 10 cm above the water table reduced water content in Oasis, rockwool, and peat-perlite by 35.4%, 27.6%, and 17.4%, respectively. There was no difference in water content for each medium when the mist quantity ranged between 600 and 1800 mL·m-2·h-1, except when the capillary mat was at 9 cm above the water table and mist volume was 300 mL·m-2·h-1. Chrysanthemum cuttings rooted best when water content was highest regardless of media. Using the peat-perlite medium, water content had the greatest impact on rooting when the mist volume was low (600 mL·m-2·h-1). Relative water content of cuttings was lowest during the first 5 days of sticking and both reduced media water content and mist quantity resulted in the lowest internal water status for the cuttings.

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Differential characterization of physiological and biochemical responses during drought stress in finger millet varieties

10.1101/603944 ◽

2019 ◽

Author(s):

Asunta Mukami ◽

Alex Ngetich ◽

Cecilia Mweu ◽

Richard O. Oduor ◽

Mutemi Muthangya ◽

...

Keyword(s):

Drought Stress ◽

Water Content ◽

Relative Water Content ◽

Finger Millet ◽

Drought Tolerant ◽

Early Seedling Growth ◽

Relative Water ◽

Early Seedling ◽

Physiological And Biochemical ◽

Selection Of

AbstractDrought is the most perilous abiotic stress that affects finger millet growth and productivity worldwide. For the successful production of finger millet, selection of drought tolerant varieties is necessary and critical stages under drought stress, germination and early seedling growth, ought to be fully understood. This study investigated the physiological and biochemical responses of six finger millet varieties (GBK043137, GBK043128, GBK043124, GBK043122, GBK043094 and GBK043050) under mannitol-induced drought stress. Seeds were germinated on sterile soil and irrigated with various concentrations of mannitol (200, 400 and 600 mM) for two weeks. Comparative analysis in terms of relative water content (RWC), chlorophyll, proline, and malondialdehyde (MDA) contents were measured the physiological and biochemical characteristics of drought stress. The results showed that increased level of drought stress seriously decreased germination and early seedling growth of finger millet varieties. However, root growth was increased. In addition, exposition to drought stress triggered a significant decrease in relative water content and chlorophyll content reduction the biochemical parameters assay showed less reduction of relative water content. Furthermore, oxidative damage indicating parameters such as proline concentration and MDA content increased. Varieties GBK043137 and GBK043094 were less affected by drought as shown by significant change in the physiological parameters. Our findings reveal the difference and linkage between the physiological responses of finger millet to drought and are vital for breeding and selection of drought tolerant varieties of finger millet. Further investigations on genomic and molecular to deeply insight the detail mechanisms of drought tolerance in finger millet need to explored.

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Physiological parameters in sugarcane cultivars submitted to water deficit

Brazilian Journal of Plant Physiology ◽

10.1590/s1677-04202010000300006 ◽

2010 ◽

Vol 22 (3) ◽

pp. 189-197 ◽

Cited By ~ 35

Author(s):

José Perez da Graça ◽

Fabiana Aparecida Rodrigues ◽

José Renato Bouças Farias ◽

Maria Cristina Neves de Oliveira ◽

Clara Beatriz Hoffmann-Campo ◽

...

Keyword(s):

Water Content ◽

Water Deficit ◽

Photosynthetic Rate ◽

Relative Water Content ◽

Photosynthetic Apparatus ◽

Experimental Treatment ◽

Photosynthetic Performance ◽

Physiological Parameters ◽

Drought Tolerant ◽

Relative Water

To investigate the processes involved in the susceptibility of sugarcane plants to water deficit, several physiological parameters were evaluated in drought tolerant (SP83-2847 and CTC15) and sensitive (SP86-155) cultivars. The water deficit affected the photosynthetic apparatus of all the plants in different ways, within and among cultivars. The photosynthetic rate and stomatal conductance decreased significantly in all cultivars submitted to water deficit. In control plants of the tolerant cultivars (SP83-2847 and CTC15) the photosynthetic rate was higher than in the sensitive cultivar (SP86-155). Cultivar CTC15 showed the highest relative water content during the dry period. The quantum efficiency photosystem II of cultivar SP83-2847 was more stable in the last days of the experimental treatment, suggesting that the decline in relative water content stimulated an adjustment of photosynthetic capacity to tolerate the changes in water availability. As a whole, the tolerant SP83-2847 and CTC15 cultivars exhibited a better photosynthetic performance than the sensitive SP86-155 cultivar. The data suggest that these physiological parameters can be used in the evaluation and distinction of drought tolerant and sensitive sugarcane genotypes.

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Agronomic and Physiological Responses of Soybean and Sorghum Crops to Water Deficits. III. Components of Leaf Water Potential, Leaf Conductance, 14co2 Photosynthesis and Adaptation to Water Deficits.

Functional Plant Biology ◽

10.1071/pp9780179 ◽

1978 ◽

Vol 5 (2) ◽

pp. 179 ◽

Cited By ~ 51

Author(s):

NC Turner ◽

JE Begg ◽

HM Rawson ◽

SD English ◽

AB Hearn

Keyword(s):

Water Potential ◽

Water Content ◽

Soil Water ◽

Leaf Water Potential ◽

Relative Water Content ◽

Leaf Conductance ◽

Leaf Water ◽

Starch Accumulation ◽

Water Deficits ◽

Relative Water

Concurrent measurements of leaf water potential, leaf osmotic potential, leaf relative water content, quantum flux density, leaf conductance, 14CO2 photosynthesis, soluble and insoluble sugars, starch and potassium concentrations were made diurnally on six occasions between flowering and maturity on upper leaves of irrigated and rainfed crops of soybean (cvv. Ruse and Bragg) and a rainfed crop of sorghum (cv. TX 610). With adequate soil water, sorghum had lower values of leaf conductance than did soybeans at high light and yet had higher rates of photosynthesis. Stage of plant development had no effect on either leaf conductance or photosynthesis of the youngest fully expanded leaves of both sorghum and soybean, but starch accumulation in the leaf over the day was less at grain-filling than at flowering in the soybean. Starch and sugar levels in the leaf had no apparent effect on photosynthesis. The daily minimum leaf water potential decreased in Ruse soybean from - 1.5 to -2.7 MPa as soil water was depleted. Late in the drying cycle, the daily minimum leaf water potential was higher in Bragg than in Ruse. In both cultivars, stomatal closure and decrease in 14CO2 photosynthesis commenced at leaf water potentials below - 1.5 MPa. Thus, the effect of water deficits on leaf conductance and photosynthesis occurred later in the drying cycle in Bragg than Ruse. As photosynthesis decreased with the depletion of soil water, starch accumulation in leaves of both cultivars of soybean decreased; changes in soluble and insoluble sugars and in potassium were small. The relationships among leaf water potential, osmotic potential, turgor potential, and leaf relative water content did not change with season or soil water depletion. Bragg and Ruse soybeans showed a similar response and both approached zero turgor at the same relative water content (82-83 %) and the same leaf water potential (- 1.5 to - 1.7 MPa). No evidence ofr osmotic adjustment was found in either soybean cultivar.

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Water content, carbohydrate accumulation, and secondary metabolites in Allium victorialis sprouts exposed to shoot cutting in varied irradiations

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha49412524 ◽

2021 ◽

Vol 49 (4) ◽

pp. 12524

Author(s):

Changwei ZHOU ◽

Wenjing CUI ◽

Ting YUAN ◽

Huayan CHENG ◽

Qian SU ◽

...

Keyword(s):

Secondary Metabolites ◽

Water Content ◽

Sugar Content ◽

Soluble Sugar ◽

Red Light ◽

Dry Mass ◽

Interactive Effects ◽

Starch Accumulation ◽

Sugar Accumulation ◽

Light Spectrum

Victory onion (Allium victorialis) is an edible vegetation that has significant value as a non-structural carbohydrate and secondary metabolite supplier. Easily measured leaf variables will be useful to predict for the flexible adjustment of physiochemical parameters in a cultural regime in plant factory conditions. Red, green, and blue light-emitting diode (LED) spectra were used to culture victory onion sprouts. Compared to the green-light spectrum, the red-light spectrum promoted leaf width and area, specific leaf area, and dry mass, water content, fine root growth, and starch accumulation in shoots, but lowered concentrations of total flavonoids and saponins. Sprouts had their shoots cut, but there were limited interactive effects with light spectra on most variables. In general, shoot-cutting depressed growth of leaf morphology, shoot weight, water content, and soluble sugar content, but enhanced accumulation of secondary metabolites. We did not find any relationship between leaf variables and secondary metabolites. Instead, wider leaves with a larger area generally had greater dry mass, water content, and soluble sugar accumulation. Leaves with deeper green colours generally had the opposite effects.

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Pretreatment with different molecular weight chitosans encourages drought tolerance in rice (Oryza sativa L.) seedling

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha48412018 ◽

2020 ◽

Vol 48 (4) ◽

pp. 2072-2084

Author(s):

Namphueng MOOLPHUERK ◽

Wattana PATTANAGUL

Keyword(s):

Molecular Weight ◽

Drought Stress ◽

Water Content ◽

Relative Water Content ◽

Starch Accumulation ◽

Sugar Accumulation ◽

Guaiacol Peroxidase ◽

Rice Seedlings ◽

Relative Water ◽

Different Molecular Weight

Drought is a critical environmental constraint limiting plant growth and productivity. Chitosan has been utilized as a potential biostimulant and proven to be effective against drought stress in many plant species. The objective of this study was to determine the effects of pretreatment with different molecular weight (MW) chitosans on some physiological characteristics of rice seedlings under drought stress. Rice seedlings were treated with low (50-190 kDa), medium (190-310 kDa) and high (310-375 kDa) MW chitosans by seed priming and foliar spray. The seedlings were subjected to drought by withholding water for four days. The relative water content (RWC) was reduced from 93% in the control plants to 74% in the droughted plants. The results revealed that treating with chitosan, especially with low MW chitosan, promoted root growth under drought stress. All chitosan treatments led to higher relative water content and photosynthetic pigment under drought condition. Pretreatment with chitosan also induced sugar accumulation, and treating with low MW chitosan significantly increased starch accumulation under drought stress. In addition, chitosan treatments alleviated the effects caused by drought stress as represented by the decreases in electrolyte leakage, malondialdehyde (MDA) as well as hydrogen peroxide (H2O2), corresponding with the increases in activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and guaiacol peroxidase (GPX) activity.

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The Method of Plant Water Status Measurement in Sweet Potato (Ipomoea Batatas (L) Lam.)

Beccariana Botanical Research Bulletin ◽

10.30862/bbrp.v7i1.274 ◽

2010 ◽

Vol 7 (1) ◽

Author(s):

Saraswati Prabawardani

Keyword(s):

Water Content ◽

Sweet Potato ◽

Relative Water Content ◽

Water Status ◽

Plant Water Status ◽

Equilibration Time ◽

Plant Water ◽

Font Size ◽

Potato Leaf ◽

Relative Water

The measurement of plant water status such as leaf water potential (LWP) and leaf relative water content (RWC) is important part of understanding plant physiology and biomass production. Preliminary study was made to determine the optimum amount of leaf abrasion and equilibration time of sweet potato leaf inside the thermocouple psychrometer chambers. Based on the trial, the standard equilibration time curve of a Peltier thermocouple for sweet potato leaf was between 2 and 3 hours. To increase the water vapour conductance across the leaf epidermis the waxy leaf cuticle should be removed or broken by abrasion. The result showed that 4 times leaf rubbings was accepted as the most effective way to increase leaf vapour conductance of sweet potato in the psychrometer chambers. In calculating the leaf relative water content, unstressed water of sweet potato leaves require 4 hours imbibition, whereas water stressed of sweet potato leaves require 5 to 6 hours to reach the saturation time. Either leaf water potential or relative water content can be used as a parameter for plant water status in sweet potato.

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Palmer Amaranth (Amaranthus palmeri) Competition for Water in Cotton

Weed Science ◽

10.1614/ws-d-15-00062.1 ◽

2015 ◽

Vol 63 (4) ◽

pp. 928-935 ◽

Cited By ~ 11

Author(s):

Sarah T. Berger ◽

Jason A. Ferrell ◽

Diane L. Rowland ◽

Theodore M. Webster

Keyword(s):

Water Content ◽

Relative Water Content ◽

Yield Loss ◽

Linear Trend ◽

Palmer Amaranth ◽

Cotton Production ◽

Excess Water ◽

Relative Water ◽

Competition For Light ◽

Daily Water

Palmer amaranth is a troublesome weed in cotton production. Yield losses of 65% have been reported from season-long Palmer amaranth competition with cotton. To determine whether water is a factor in this system, experiments were conduced in 2011, 2012, and 2013 in Citra, FL, and in Tifton, GA. In 2011, infrequent rainfall lead to drought stress. The presence of Palmer amaranth resulted in decreased soil relative water content up to 1 m in depth. Cotton stomatal conductance (gs) was reduced up to 1.8 m from a Palmer amaranth plant. In 2012 and 2013 higher than average rainfall resulted in excess water throughout the growing season. In this situation, no differences were found in soil relative water content or cottongsas a function of proximity to Palmer amaranth. A positive linear trend was found in cotton photosynthesis and yield; each parameter increased as distance from Palmer amaranth increased. Even in these well-watered conditions, daily water use of Palmer amaranth was considerably higher than that of cotton, at 1.2 and 0.49 g H20 cm−2d−1, respectively. Although Palmer amaranth removed more water from the soil profile, rainfall was adequate to replenish the profile in 2 of the 3 yr of this study. However, yield loss due to Palmer amaranth was still observed despite no change ings, indicating other factors, such as competition for light or response to neighboring plants during development, are driving yield loss.

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