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

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.

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How Seed Size and Wate r Stress Effect the Seed Germination and Seedling Growth in Wheat Varieties?

Current Agriculture Research Journal ◽

10.12944/carj.3.1.08 ◽

2015 ◽

Vol 3 (1) ◽

pp. 60-68 ◽

Cited By ~ 12

Author(s):

Charu Shahi ◽

Vibhuti Vibhuti ◽

Kiran Bargali ◽

S Bargali

Keyword(s):

Water Stress ◽

Seed Germination ◽

Seed Size ◽

Seedling Growth ◽

Stress Level ◽

Resistant Variety ◽

Stress Effect ◽

Wheat Varieties ◽

Size Classes ◽

Stress Levels

Water stress has adverse impacts on crop growth, yield and quality parameters thus, considered among serious constraints to agriculture production. Under depleting natural resources, environmental fluctuation and increased risk of epidemic outbreak, the task of sufficient wheat production has become a serious problem. In this study, effect of seed size and water stress was analyzed in three wheat varieties (PBW-154, UP-2338, and UP-2425). Three seed size classes (large, medium, small) of each wheat variety were kept under four water stress levels. It was observed that the shoot length and root length were highly sensitive to water stress and showed minimum growth at highest water stress level. The comparison of varieties, seed size classes and water stress levels showed that in terms of seedling growth variety UP-2338 was more resistant to water stress as compared to other varieties, whereas in terms of germination variety PBW-154 was more resistant. Variety UP-2425 showed maximum reduction in seed germination with increasing water stress (33.3% at -15 bar stress level). Among seed size, large sized seeds showed highest seed germination (91.9%) followed by medium (89.7%) and small (82.8%) sized seeds.

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

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha48211841 ◽

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.

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First Report of Sesame Mutants Tolerant to Severe Drought Stress during Germination and Early Seedling Growth Stages

Plants ◽

10.3390/plants10061166 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1166

Author(s):

Mohamed Kouighat ◽

Hafida Hanine ◽

Mohamed El Fechtali ◽

Abdelghani Nabloussi

Keyword(s):

Drought Stress ◽

Seedling Growth ◽

Germination Rate ◽

Germination Percentage ◽

Growth Stages ◽

Severe Drought ◽

First Report ◽

Early Seedling Growth ◽

Early Seedling ◽

Sesame Genotypes

In the context of climate change and water scarcity, there is a need to develop and use drought-tolerant sesame cultivars. This study was conducted to evaluate the response of 13 sesame genotypes, including 11 mutants and their wild-types, to drought during germination and early seedling growth. Moderate and severe drought stress was simulated by applying polyethylene glycol (PEG) at two osmotic potentials, −0.6 MPa and −1.2 MPa, respectively, on seeds of two successive mutant generations, M2 and M3. The parameters measured or calculated were germination percentage (GP), germination rate (GR), mean germination time (MGT), root length (RL), shoot length (SL), root to shoot ratio (RSR), and the seedling vigor index (SVI). Results showed the significant effect of genotype, drought, and drought × genotype interaction on all parameters investigated. Under severe drought, seeds of seven genotypes, including wild types, were not able to germinate. There was a drastic decline of all parameters for the rest, except MGT and RSR, which markedly increased. Interestingly, two mutants, “ML2-5” and “ML2-10”, were identified as the most tolerant to severe drought and the most stable over both generations. The present work is the first report of sesame germplasm with such a high level of tolerance to drought during germination and early seedling growth stages.

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

Journal of Seed Science ◽

10.1590/2317-1545v41n3213139 ◽

2019 ◽

Vol 41 (3) ◽

pp. 309-317 ◽

Cited By ~ 3

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.

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Does N deposition mitigate the adverse impacts of drought stress on plant seed germination and seedling growth?

Acta Oecologica ◽

10.1016/j.actao.2020.103650 ◽

2020 ◽

Vol 109 ◽

pp. 103650

Author(s):

Shu Wang ◽

Mei Wei ◽

Bingde Wu ◽

Huiyuan Cheng ◽

Kun Jiang ◽

...

Keyword(s):

Drought Stress ◽

Seed Germination ◽

Seedling Growth ◽

N Deposition ◽

Plant Seed ◽

Adverse Impacts

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Summer drought stress: differential effects on cane anatomy and non-structural carbohydrate content in overwintering Cabernet Sauvignon and Syrah vines

BIO Web of Conferences ◽

10.1051/bioconf/20191303007 ◽

2019 ◽

Vol 13 ◽

pp. 03007 ◽

Cited By ~ 2

Author(s):

Rachele Falchi ◽

Elisa Petrussa ◽

Marco Zancani ◽

Valentino Casolo ◽

Paola Beraldo ◽

...

Keyword(s):

Water Stress ◽

Drought Stress ◽

Biochemical Characterization ◽

Carbon Allocation ◽

Starch Accumulation ◽

Cabernet Sauvignon ◽

Severe Drought ◽

Summer Drought ◽

Long Term Effects ◽

Experimental Conditions

Grapevines store non-structural carbohydrates (NSC) during late summer to sustain plant development at the onset of the following spring’s growth. Starch is the main stored carbohydrate, found in the wood-ray parenchyma of roots and canes. Although the relationship between hydraulic and plant photosynthetic performance is well-recognized, little research has been done on the long-term effects of drought in grapevines adopting different strategies to cope with water stress (i.e. isohydric and anisohydric). We performed our study by exposing two different grape cultivars (Syrah and Cabernet Sauvignon) to a short but severe drought stress, at two stages of the growing season (July and September). No marked differences in the physiological and hydraulic responses of the two varieties were found, probably due to our experimental conditions. However, anatomical and biochemical characterization of overwintering canes pointed out several interesting outcomes. We found a significant and parallel increase of starch and medullar ray number in both cultivars exposed to early water stress. We hypothesize that stressed vines limited their carbon allocation to growth, while shifting it to starch accumulation, with a most evident effect in the period of intense photosynthetic activity. We also speculate that a different aptitude to osmotic adjustment may underlay variation in starch increase and the specific involvement of bark NSC in the two cultivars.

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Impact of priming on seed germination and seedling growth of Oldenlandia diffusa under drought stress

China Journal of Chinese Materia Medica ◽

10.4268/cjcmm20140807 ◽

2014 ◽

Keyword(s):

Drought Stress ◽

Seed Germination ◽

Seedling Growth ◽

Oldenlandia Diffusa

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Castor bean (Ricinus communis L.) responses to drought stress and foliar application of Zn-nano fertilizer and humic acid: grain yield, oil content, antioxidant activity, and photosynthetic pigments

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha49412003 ◽

2021 ◽

Vol 49 (4) ◽

pp. 12003

Author(s):

Ali RAHBARI ◽

Jafar MASOUD SINAKI ◽

Ali DAMAVANDI ◽

Shahram REZVAN

Keyword(s):

Drought Stress ◽

Humic Acid ◽

Photosynthetic Pigments ◽

Castor Bean ◽

Yield Components ◽

Foliar Application ◽

Severe Drought ◽

Mild Stress ◽

Oilseed Crop ◽

Number Of Seeds

Castor bean is considered as an important non-edible oilseed crop and source of castor oil, which has many applications ranging from cosmetics to the biofuels industry. Humic acid (HA) results from organic matter decomposition and is beneficial to plant growth and development. In the present study, a two-year experiment was conducted in Damghan, Iran, to study the physiological responses of castor bean to foliar application of zinc nano-chelate (Zn-nano) and HA under drought stress. The drought stress was used as the main treatment in three levels: normal irrigation as control, irrigation up to 75 BBCH scale (Biologische Bundesantalt, Bundessortenamt und Chemische Industrie) (mild stress), and irrigation up to 65 BBCH (severe stress). Foliar application of HA in three levels (non-application, application of the recommended rate and two times more than the recommended rate), as well as Zn-nano fertilizer in two levels (application at 1.5 part per thousand (ppt) and non-application) as subplots. The drought stress, HA, and Zn-nano fertilizer could significantly affect the number of capsules, the number of seeds, 100-seed weight, seed yield, oil yield, protein percentage and yield, activities of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD), and chlorophyll a (Chl a), chlorophyll b (Chl b), and total chlorophyll (total Chl) contents. In addition, severe drought stress resulted in reducing the number of capsules (33.9%), the number of seeds (32.7%), 100-grain weight (16.0%), as well as seed (43.0%), oil (59.3%), and protein (29.9%) yield. Based on the results, the highest yield components, oil and protein contents, and photosynthetic pigments were achieved in the foliar application of HA (recommended rate) and Zn-nano fertilizers under normal irrigation during the second year. Further, the foliar application of Zn-nano fertilizer led to a decrease in the activities of CAT, SOD, and POD enzymes. According to partial regression analysis, the recommended rate of HA application the changed the nature of relationships governing the characteristics, especially under drought stress conditions. Finally, the foliar application of HA (recommended rate) and Zn-nano fertilizers could create an excellent resistance to drought stress in castor under dry and semi-arid climate conditions by improving yield and yield components and physiological traits.

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