scholarly journals Priming improves germination and seed reserve utilization, growth, antioxidant responses and membrane stability at early seedling stage of Saudi sorghum varieties under drought stress

2020 ◽  
Vol 48 (2) ◽  
pp. 938-953
Author(s):  
Taieb TOUNEKTI ◽  
Mosbah MAHDHI ◽  
Zarraq AL-FAIFI ◽  
Habib KHEMIRA
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Seed Germination ◽  
Seedling Growth ◽  
Seedling Emergence ◽  
Stability Index ◽  
Stress Conditions ◽  
Water Stress Condition ◽  
Significant Difference ◽  
Early Seedling

Seeds of three sorghum (Sorghum bicolor (L.) Moench.) varieties from Southwest Saudi Arabia were used to investigate the potential of osmopriming with polyethylene glycol (PEG 8000) to improve germination performance, seed reserve utilization and early seedling growth and drought stress tolerance. The primed (PS) and unprimed (UPS) seeds of the three sorghum varieties were germinated for 8 days under increasing PEG-induced osmotic stress. The treatments were arranged in a completely randomized design, in a factorial arrangement, with three sorghum cultivars (‘Zaydia’, ‘Shahbi’ and ‘Ahmar’) and four osmotic potentials (0.0; -0.4; -0.8 and -1.2 MPa) with four replicates of 50 seeds each. The results showed that drought stress affected seed germination and seedling emergence and establishment, but increased the activity of the antioxidant enzyme catalase (CAT). The strongest inhibition of germination and growth occurred at the highest PEG concentration and a significant difference was noticeable between the studied varieties. We confirmed also that seed osmopriming improved seed germination performance, seedling growth and enhanced the CAT activities while reduced malonyldialdehyde (MDA) accumulation and electrolyte leakage (EL) in the drought-stressed seedlings. Seed priming have enhanced also the α-amylase and total proteases activities in all varieties. The largest increase of these hydrolysing enzymes was shown in ‘Ahmar’. Furthermore, the PEG priming lead to improvement of the weight of utilized (mobilized) seed reserve (WUSR), seed reserve depletion percentage (SRDP) and total seedling dry weight (SLDW) of sorghum seedlings under water stress conditions. Still, the highest values or all three parameters were found in the ‘Ahmar’ variety. Under increasing drought stress conditions, ‘Ahmar’ showed the highest yield stability index (YSI) and the least EL and MDA contents in comparison to the other two varieties during the seedling establishment stage. Therefore, the former variety can tolerate better a rigorous water stress condition. ‘Zaydia’ appears to be the most vulnerable to drought stress. Thus, the use of species or varieties with eminent seed metabolic quality is an advantageous trait in drought-prone regions.

scholarly journals Genotypic Variability in Photosynthesis, Water Use, and Light Absorption among Red and Freeman Maple Cultivars in Response to Drought Stress

2003 ◽  
Vol 128 (3) ◽  
pp. 337-342 ◽  
Author(s):  
William L. Bauerle ◽  
Jerry B. Dudley ◽  
Lawrence W. Grimes
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Light Absorption ◽  
Acer Rubrum ◽  
Stress Conditions ◽  
Photochemical Quenching ◽  
Red Maple ◽  
Psii Efficiency ◽  
Fluorescence Measurements ◽  
Water Stress Condition

Cultivars of red (Acer rubrum L.) and Freeman maple (Acer ×freemanii E. Murray) are popular ornamental plants which are commonly placed in a variety of landscapes. To date, little information quantifies the capacity to tolerate and recover from drought among cultivars of red and Freeman maple. The objective of this study was to compare the effects of water stress on the physiology of five different maple cultivars of marketable size including four red maple genotypes, `Summer Red', `October Glory' (October Glory), `Autumn Flame', and `Franksred' (Red Sunset), as well as one hybridized Freeman maple genotype, `Jeffersred' (Autumn Blaze). Two-year-old cloned genotypes of red and Freeman maple were subjected to two treatments: irrigated daily to container capacity or irrigation withheld for one drought and recovery cycle. Light absorption, gas exchange, and chlorophyll fluorescence measurements were conducted under well-watered and drought stress conditions that approached 0.070 m3·m-3. Compared to well-watered conditions, drought stress conditions of 0.090 m3·m-3 had a significant main effect that reduced the amount of light absorption in four of the five genotypes. Additionally, absorption among genotypes was different under both well-watered and water stress conditions. Over the course of drought stress and a recovery phase, net photosynthesis and stomatal conductance were different among genotypes. Maximum photosystem II (PSII) efficiency of dark-adapted leaves (Fv/Fm) was lowered by the water stress condition. The efficiency of excitation capture by open PSII reaction centers (Fv`/Fm') was variable among genotypes. Photochemical quenching was higher in Autumn Blaze, October Glory, and `Summer Red' under drought conditions, which corresponded with a low degree of closure of PSII centers. Additionally, the fraction of excess excitation energy was also lower. Lastly, water deficit caused an increase in PSII efficiency in all genotypes except Autumn Blaze. This research demonstrated physiological variation among commercially available red and Freeman maple genotypes that may be selected for drought tolerance based on site moisture characteristics.

scholarly journals Phenological, Physiological and yield markers as efficient tools to identify drought tolerant rice genotypes in Eastern India

2020 ◽  
Author(s):  
Soumya Kumar Sahoo ◽  
Goutam Kumar Dash ◽  
Arti Guhey ◽  
Mirza Jaynul Baig ◽  
Madhusmita Barik ◽  
...  
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Grain Yield ◽  
Stress Conditions ◽  
Eastern Region ◽  
Eastern India ◽  
Drought Tolerant ◽  
Significant Difference ◽  
Rice Genotypes ◽  
Highly Correlated

ABSTRACTRice production is severely threatened by drought stress in Eastern India. To develop drought tolerant varieties, selection of donors for breeding programme is crucial. Twenty one selected rice genotypes including both tolerant and sensitive to drought were grown under well-watered and drought stress conditions in dry seasons of two successive years of 2017 and 2018. Leaf water potential, relative water content displayed significant difference among the genotypes during vegetative screening. At reproductive stage drought screening, days to 50% flowering was delayed in all genotypes except N22 and Anjali (showed early flowering) however grain yield and other yield related traits decreased significantly compared to well watered condition. Correlation analysis of phenological and yield related traits with grain yield revealed that tiller numbers and panicle numbers are highly correlated with grain yield both under well-watered and water stress conditions and contributes maximum towards grain yield. The dendrogram grouped Mahamaya, Sahabhagidhan, Poornima, IBD 1, Hazaridhan, Samleshwari and Danteshwari into one cluster which performed better under water stress conditions and had grain yield more than 1.69 tha−1. Sahabhagidhan, Poornima, Vandana, and N22 displayed tolerance to drought both under vegetative and reproductive conditions which could be a good selection for the breeders to develop drought tolerant rice cultivars for eastern region of India.

scholarly journals Germination and seedling growth of rice (Oryza sativa L.) as affected by varying concentrations of loom-dye effluent

2019 ◽  
Vol 17 (2) ◽  
pp. 153-160 ◽  
Author(s):  
Md. Arifur Rahman ◽  
Md. Sohanur Rahman ◽  
K.M. Mohiuddin ◽  
Md. Akhter Hossain Chowdhury ◽  
Md. Abul Khair Chowdhury
Keyword(s):  
Oryza Sativa ◽  
Seed Germination ◽  
Seedling Growth ◽  
Oryza Sativa L ◽  
Industrial Effluent ◽  
Rice Seed ◽  
Early Seedling Growth ◽  
Significant Difference ◽  
Early Seedling ◽  
Radical Length

Indiscriminate discharge of industrial effluent has become a serious problem for the agro-ecological environment in most of the areas of Bangladesh. The effects of loom-dye effluents on seed germination and early seedling growth of rice (Oryza sativa L.) were investigated by conducting an experiment in the laboratory of the Department of Agricultural Chemistry of Bangladesh Agricultural University, Mymensingh. Three types of loom-dye effluents were applied in sterilized petridishes at different loading ratios. Seven treatments (i.e., T0, T1, T2, T3, T4, T5 and T6 with 0, 5, 10, 25, 50, 75 and 100% effluent, respectively) of each effluent were used following completely randomized design (CRD) and replicated three times. Subsequently, Pb, Fe, Zn, Mn and Cr accumulation were also investigated in the harvested rice seedlings. Rice seed showed a significant difference in germination percentage with varying levels of effluent application at different days after setting of germination. The decreased seed germination rate and seedling growth of rice were observed with increased concentration of loom-dye effluents. The highest germination speed (97.8%) was obtained from control whereas the lowest germination speeds were obtained from T5 of black, and T6 of both black and violet effluents. Phytotoxic effects of loom-dye effluents on germination and radical length were extreme at 100% effluent concentration having the order of black > violet > pink. The maximum radical length (6.4 cm) and plumule length (7.5 cm) were observed with T1 of pink dye effluent whereas the minimum length of radical and plumule were obtained from T6 treatment of the effluents. The highest fresh weight (39.8 mg petridish–1), dry weight (5.7 mg petridish–1) and seedling vigor index (746.7%) were also observed from T1 of pink dye effluent. The maximum uptake of Pb, Fe, Mn and Zn was 0.48, 3.81, 0.79 and 0.13 μg g−1, respectively. The uptake of Cr was below the detectable limit. Total heavy metal accumulation in rice was in the following order: Fe>Mn>Pb>Zn>Cr. Results showed that the higher concentration of loom-dye effluent showed the higher toxic effects on different parameters of germination and early seedling growth compared with the lower effluent concentrations. J. Bangladesh Agril. Univ. 17(2): 153–160, June 2019

scholarly journals Developing mathematical model for diurnal dynamics of photosynthesis in Saccharum officinarum responsive to different irrigation and silicon application

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10154
Author(s):  
Krishan K. Verma ◽  
Kai-Chao Wu ◽  
Chhedi Lal Verma ◽  
Dong-Mei Li ◽  
Mukesh Kumar Malviya ◽  
...  
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Biomass Accumulation ◽  
Saccharum Officinarum ◽  
Stress Conditions ◽  
Growth Potential ◽  
Plant Performance ◽  
Water Stress Condition ◽  
Soil Irrigation ◽  
Photosynthetic Responses

In the dynamic era of climate change, agricultural farming systems are facing various unprecedented problems worldwide. Drought stress is one of the serious abiotic stresses that hinder the growth potential and crop productivity. Silicon (Si) can improve crop yield by enhancing the efficiency of inputs and reducing relevant losses. As a quasi-essential element and the 2nd most abundant element in the Earth’s crust, Si is utilized by plants and applied exogenously to combat drought stress and improve plant performance by increasing physiological, cellular and molecular responses. However, the physiological mechanisms that respond to water stress are still not well defined in Saccharum officinarum plants. To the best of our knowledge, the dynamics of photosynthesis responsive to different exogenous Si levels in Saccharum officinarum has not been reported to date. The current experiment was carried out to assess the protective role of Si in plant growth and photosynthetic responses in Saccharum officinarum under water stress conditions. Saccharum officinarum cv. ‘GT 42’ plants were subjected to drought stress conditions (80–75%, 55–50% and 35–30% of soil moisture) after ten weeks of normal growth, followed by the soil irrigation of Si (0, 100, 300 and 500 mg L−1) for 8 weeks. The results indicated that Si addition mitigated the inhibition in Saccharum officinarum growth and photosynthesis, and improved biomass accumulation during water stress. The photosynthetic responses (photosynthesis, transpiration and stomatal conductance) were found down-regulated under water stress, and it was significantly enhanced by Si application. No phytotoxic effects were monitored even at excess (500 mg L−1). Soil irrigation of 300 mg L−1 of Si was more effective as 100 and 500 mg L−1 under water stress condition. It is concluded that the stress in Saccharum officinarum plants applied with Si was alleviated by improving plant fitness, photosynthetic capacity and biomass accumulation as compared with the control. Thus, this study offers new information towards the assessment of growth, biomass accumulation and physiological changes related to water stress with Si application in plants.

scholarly journals Reaction of some rapeseed (Brassica napus L.) genotypes to different drought stress levels during germination and seedling growth stages

OCL ◽  
2019 ◽  
Vol 26 ◽  
pp. 23 ◽  
Author(s):  
Souhail Channaoui ◽  
Imane Saghouri El Idrissi ◽  
Hamid Mazouz ◽  
Abdelghani Nabloussi
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Seed Germination ◽  
Seedling Growth ◽  
Stress Level ◽  
Elongation Rate ◽  
Growth Stages ◽  
Severe Drought ◽  
Oilseed Crop ◽  
Stress Levels

Drought is a major abiotic stress that affects seed germination and plant growth in arid and semi-arid regions. Rapeseed is an oilseed crop adapted to Mediterranean area; however, it is reported that it is sensitive to water stress occurring during seed germination. In this study, we investigated how seed germination and early seedling growth of six rapeseed genotypes were influenced by different water stress levels. In addition to the control (absence of drought stress), three drought levels were simulated using three osmotic potentials of polyethylene glycol (PEG-6000), −9, −10 and −11 bars. A completely randomized design with three replications was used for this experiment. Germination percentage (GP), shoot length (SL), root length (RL), shoot elongation rate (SER) and root elongation rate (RER) were determined to evaluate the genotypes response to PEG-induced drought stress. Results showed drought stress, genotype and interaction stress × genotype had a significant effect on the studied parameters. GP decreased with the increase in stress level. The genotype ‛Nap9’ was the most interesting, having the highest GP values, namely 63.33, 62.67 and 28% under the stress levels −9, −10 and −11 bars, respectively. The genotype ‛H2M-5’, which ranked second with respect to this parameter, was statistically comparable to ‛Nap9’. Also, SL, RL, SER and RER decreased with the increase in drought stress level. However, the studied genotypes reacted differently to various water stress levels. Once again, the genotype ‛H2M-5’ exhibited the highest average RL and RER under all drought levels. Particularly, for severe drought conditions (−11 bars), ‛H2M-5’ had an average RL of 1.54 cm and RER of 0.36 cm/d. Field evaluation under controlled conditions is needed to confirm findings of the present experiment. The mutant ‛H2M-5’ could be a valuable and promising germplasm for developing a performant and adapted variety to be designed for harsh environments particularly characterized by early drought coinciding with germination and seedling growth stages.

scholarly journals Stress tolerance of Xerocomus badius and its promotion effect on seed germination and seedling growth of annual ryegrass under salt and drought stresses

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Binghua Liu ◽  
Xinghong Liu ◽  
Fangchun Liu ◽  
Hailin Ma ◽  
Bingyao Ma ◽  
...  
Keyword(s):  
Salt Stress ◽  
Drought Stress ◽  
Seed Germination ◽  
Seedling Growth ◽  
Mycelial Growth ◽  
Seed Priming ◽  
Stress Conditions ◽  
Mild Stress ◽  
Annual Ryegrass ◽  
Salt And Drought Stresses

AbstractComparative evaluations were conducted to assess the effects of different pH levels, NaCl-induced salt stress, and PEG-induced drought stress on the mycelial growth of Xerocomus badius. The results showed that X. badius mycelium grew well at a wide pH range of 5.00 ~ 9.00. Although the mycelium remained viable, mycelial growth of X. badius was significantly inhibited with increasing salt and drought stresses. Furthermore, a soilless experiment in Petri dishes was performed to investigate the potential of X. badius to induce beneficial effects on seed germination and seedling growth of annual ryegrass (Lolium multiflorum Lam.) under salt and drought stresses. Seed priming with X. badius enhanced the seedling growth of L. multiflorum Lam. under NaCl-induced salt stress and PEG-induced drought stress. However, X. badius did not significantly improve the seed germination under non-stress and mild stress conditions. It suggested that X. badius inoculation with seeds was not essential for seed germination under non-stress and mild stress conditions, but contributed highly to seedling growth under severe stress conditions. Therefore, seed priming with X. badius on ryegrass could be an effective approach to enhance plant tolerance against drought and salt stresses. X. badius could be a good candidate for the inoculation of ectomycorrhizal plants cultivation programs in mild saline and semiarid areas.

scholarly journals Ameliorative effects of TiO2 nanoparticles and sodium nitroprusside on seed germination and seedling growth of wheat under PEG-stimulated drought stress

2019 ◽  
Vol 41 (3) ◽  
pp. 309-317 ◽  
Author(s):  
Javad Faraji ◽  
Ali Sepehri
Keyword(s):  
Drought Stress ◽  
Seed Germination ◽  
Sodium Nitroprusside ◽  
Tio2 Nanoparticles ◽  
Seedling Growth ◽  
Severe Drought ◽  
Fresh Weight ◽  
Tio2 Nps ◽  
Early Seedling Growth ◽  
Early Seedling

Abstract: Seed germination and early seedling growth are sensitive to drought stress in wheat. A factorial experiment was arranged based on a completely randomized design with three replicates to study the impacts of TiO2 nanoparticles (TiO2 NPs: 0, 500, 1000 and 2000 mg.L) and sodium nitroprusside (SNP: 0 and 100 μM), as NO donor, on seed germination and seedling growth of wheat under polyethylene glycol (PEG)-induced drought stress (0, -0.4 and -0.8 MPa). Our results revealed that PEG-stimulated drought stress significantly decreased germination percentage (GP), germination energy (GE), germination rate (GR), root length (RL), shoot length (SL), root fresh weight (RFW), shoot fresh weight (SFW) and vigor index (VI) but increased mean germination time (MGT) in wheat seeds. However, application of TiO2 NPs and SNP alone or in combination significantly enhanced GP, GE, GR, RL, SL, RFW, SFW and VI up to 23.72%, 50%, 33.74%, 85.38%, 93.28%, 73%, 91.91% and 91.04% respectively, but significantly reduced MGT up to 28.36% under severe drought stress. Our results showed that application of TiO2 NPs and SNP alone or in combination can significantly alleviate the adverse effects of PEG-stimulated drought stress on seed germination and early seedling growth of wheat.

scholarly journals Effects of extracts of two Ulva spp. seaweeds on tomato germination and seedling growth

2020 ◽  
Vol 9 (11) ◽  
pp. e61691110174
Author(s):  
Renata Perpetuo Reis ◽  
Antônio Carlos Silva de Andrade ◽  
Ana Carolina Calheiros ◽  
Jéssica Carneiro Oliveira ◽  
Beatriz Castelar
Keyword(s):  
Seed Germination ◽  
Seedling Growth ◽  
Growth Parameters ◽  
Seedling Emergence ◽  
Brown Seaweed ◽  
Stem Diameter ◽  
Tomato Seedling ◽  
Green Macroalgae ◽  
Significant Difference ◽  
Aged Seeds

Brown seaweed extracts are commercially used as agricultural biostimulants, and the green macroalgae Ulva spp. has shown promise for that purpose. We evaluated the ideal dosage of U. lactuca ulvan and flour on seed germination invigoration and the effects of U. flexuosa and U. lactuca extracts on tomato seedling growth (Solanun lycopersicum). The germination recovery of aged seeds after the application of U. lactuca was evaluated by seed germination rates and seedling emergence. Greenhouse cultivated seedlings were irrigated with 0.2 and 0.4 g×L-1 of the flour, or an ulvan solution of Ulva spp. Seedling growth parameters (height, stem diameter, height/stem diameter ratio, biomass, and number of leaves) were compared with the control (seedlings irrigated with distilled water). All dosages of U. lactuca ulvan and flour were found to increase the germination rates of aged seeds as compared to controls. No significant difference in seedling emergence rates were seen. After treatment with Ulva spp. extracts no significant differences in seedling growth were detected. We concluded that low doses of the U. lactuca extract will increase the germination rates of S. lycopersicum seeds and, while different dosages of the extracts of two Ulva’s species did not stimulate tomato seedling growth, they were also not lethal.

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