Effect of Ga 3 , Aba and Kinetin on the Response of the Halophyte Atriplex Halimus to Salinity During Germination (original) (raw)
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Acta Universitatis Sapientiae Agriculture and Environment, 2024
The soils of arid rangelands contain a variety of salts that have differential effects on seed germination. In these regions, Atriplex halimus (L .) (Amaranthaceae) is one of the most commonly used medicinal and fodder plants. Little is known about its germination under saline stress operated by various soluble salts. The present work was designed to determine the effect of four soluble salts (NaCl, Na 2 SO 4 , CaCl 2 , and CaCO 3) on the germination of A. halimus seeds. We tested the effect of salinity on final germination percentage (FGP%) and germination tolerance index (GTI%) using five concentrations (0, 200, 300, 400, and 600 mM) of each salt (NaCl, Na 2 SO 4 , CaCl 2 , and CaCO 3). In addition, experiments were also conducted to assess the effects of salinity on germination recovery (GRP%) from high saline conditions (600 mM). Salinity level and salt composition significantly influenced germination characteristics. A. halimus seeds were non-dormant, exhibited approximately 90% germination in distilled water. Both FGP and GTI gradually decreased with increasing salinity. This study showed that the seeds of A. halimus can germinate under 400 mM in all tested salts. The salts causing germination inhibition exhibited specificity, with an increasing trend observed in the following sequence: Na 2 SO 4 > NaCl > CaCl 2 > CaCO 3. When ungerminated seeds are transferred from 600 mM to distilled water, their germination ability is recovered according to the type of salt used. A. halimus is a highly salt-tolerant species that can tolerate a variety of salts and can be, therefore, a promising species for improving ecological balance in saline soils .
Effect of Salinity on Germination and Seedling Growth of two Atriplex species (Chenopodiaceae
Salinity is one of the environmental factors that has a critical influence on the germination of halophyte seeds and plant establishment. Salinity affects imbibition, germination and root elongation. However, the way in which NaCl exerts its influence on these vital processes, whether it is through an osmotic effect or a specific ion toxicity, is still not resolved. Dimorphic seeds of the halophytes Atriplex prostrata and A. patula were treated with various isoosmotic solutions of NaCl and polyethylene glycol (PEG). For each treatment, imbibition, germination rate, percent germination, germination recovery and nuclear area of root tip cells were compared. Higher concentrations of NaCl (k1n0 MPa) were more inhibitory to imbibition, germination and seedling root elongation than iso-osmotic PEG solutions. All seeds recovered from a pre-treatment with k2n0 MPa NaCl and PEG solutions, except large seeds of A. prostrata which failed to germinate following transfer from k2n0 MPa NaCl. NaCl caused a greater increase in nuclear volume than iso-osmotic PEG solutions. These data suggest that the influence of NaCl is a combination of an osmotic effect and a specific ion effect.
American Journal of Botany, 1996
Marigold has special importance and application in landscape designing. Nowadays, various species and cultivars of this plant are grown in many climates, where different environmental stresses such as freezing, salinity and drought can lead to vegetative disorders. This study was carried out to investigate the interactions between salinity and ammonium nitrate on seed germination, vegetative growth and sodium and potassium concentrations in French marigold flowers (Tegeta patula). The experiment was conducted as a factorial arrangement based on a completely randomized design with two factors: salinity (0, 2, 4, 6 and 8 mmos cm-1) and ammonium nitrate (0, 15 and 30 g l-1) with four replications. Based on the obtained results, different salinity concentrations were negatively influenced all studied parameters except germination rate. The application of ammonium nitrate recovered the studied parameters to the same level as the control plants. Plant height was decreased by increasing salinity concentrations. The tallest plant was observed in the control treatments. Salinity levels negatively influenced shoot fresh weight. Different levels of ammonium nitrate had significant effects on root dry weight and potassium and sodium contents. Ammonium nitrate led to reductions in root dry weight and potassium content, and an enhancement in sodium content in the shoot. Sodium and potassium levels were increased and root dry weight was decreased by increasing salinity. Enhancement of potassium ions in the marigold following salinity stress can improve its tolerance to salinity stress.
Pak. J. Bot, 2007
The effects of salinity on growth, water relations, glycinebetaine content, and ion accumulation in the perennial halophyte Atriplex griffithii var. stocksii were determined. The following questions were addressed : (1) What effect does salinity have on growth responses at different ages ? (2) Is A. griffithii an ion accumulator ? (3) Does A. griffithii accumulate glycinebetaine in response to salinity ? Atriplex griffithii plants were grown in pots at 0, 90, 180 and 360 m NaCl in sand culture in a plant growth chamber and plants were harvested after 30, 60 and 90 d. Plant total dry weight was significantly inhibited at 360 m NaCl. Root growth showed a substantial promotion at 90 m NaCl. The water potential and osmotic potential of shoots became more negative with increasing salinity and time of growth. The Na + and Cl − content in both shoots and roots increased with increases in salinity. Increased treatment levels of NaCl induced decreases in Ca + , K + and Mg# + in plants. Atriplex griffithii accumulated a large quantity of ions, with the ash content reaching 39 % of the dry weight in leaves. Inorganic ion accumulation is significant in osmotic adjustment and facilitates water uptake along a soil-plant gradient. Glycinebetaine concentration was low in roots, and in stems it increased with increases in salinity. Total amounts of glycinebetaine in leaves increased with increases in salinity, and its concentration increased substantially at 360 m NaCl.
Germination capacity of some halophytic plants species under increasing salinity
African Journal of Agricultural Research, 2016
In Tunisia, more particularly in semiarid and arid areas, the drought accentuated by the surface evaporation of water lead to gradual increase in salinity of the soil which a major hurdal in development of vegetation. In these highly salted ecosystems, some plants are growing naturally; however, various species show different tolerance levels to salinity during their development. Seed germination is the stage which is most susceptible to this abiotic constraint. The aim of this study is to investigate the influence of increasing NaCl concentrations from 0 to 200 mM on the germination behavior of some halophytic plants species (Acacia cyanophylla, Acacia ampliceps, Medicago arborea, Hedysarum carnosum, Casuarina glauca and Ceratonia siliqua) whose seeds, were collected from Tunisian stands. The germination is evaluated through the daily and the cumulated rates of germination, the corrected seed germination rate and the recovery rate. The effect of salt stress revealed that the elevation of NaCl concentration induces a reduction of germination capacity as good as germination speed. In this setting, 200 mM concentrations of NaCl constitute a physiological limit of germination for all studied species. However, the interspecific variability is relatively important. According to the principal component analysis (PCA), seeds of C. glauca were the most salt tolerant, followed by M. arborea. Seeds of A. ampliceps were the least salt tolerant. The increase of the recovery rate with high salinity supposed that the latter has an osmotic reversible effect and not a toxic irreversible one on the studied species seeds.
Salinity effects on germination, growth, and seed production of the halophyte Cakile maritima
Plant and Soil, 2004
Cakile maritima (Brassicaceae) is a halophyte that thrives on dunes along the Tunisian seashore. Besides its ecological interest for soil fixation, this plant produces seeds rich in lipids (40% on dry weight basis), making it a potential source of oil for industrial use. The purpose of the present work was to study the salt tolerance of this species at germination, vegetative growth and fruiting stages. NaCl inhibited germination only at concentrations higher than 200 mM, mainly by an osmotic effect (fully reversible after seed transfer to water). At the vegetative stage, the plant exhibited a typical halophytic behaviour, requiring the presence of a moderate salt concentration (50 to 100 mM NaCl) to express its maximal growth potentialities. Growth activity was maintained up to 500 mM NaCl. Salt tolerance of C maritima at the vegetative stage seemed to be mainly based on: (i) the capacity to preserve the biomass production within the range of optimal salt concentrations; (ii) the ability to maintain the tissue water status; and (iii) the efficiency of selective K+ uptake, in spite of high Na+ concentration in the medium. Indirect evidence of Na+ utilisation by the plant for osmotic adjustment was obtained. Seed production was stimulated at 50 to 100 mM NaCl as compared to control treatment, and severely restricted at higher salt levels. Individual seed mass was moderately diminished by increasing NaCl concentrations.
Seed germination of Atriplex undulata under saline and alkaline conditions
Seed Science and Technology, 2014
In this study the germination response of seeds of Atriplex undulata (Chenopodiaceae), a native of Argentina, to saline and alkaline conditions was evaluated. This species has potential as a rehabilitation crop for saline soils and is used as salt land pasture. The study involved three aspects: (1) germination response to three temperature regimes (20, 25 and 30°C); (2) the effects of saline (NaCl) and alkaline (Na 2 CO 3) stresses, osmotic potential (0,-1,-2 MPa) and the removal of the bracteole on germination; (3) the recovery of germination with and without the bracteole following exposure to a high level of alkalinity and salinity stress. The best germination temperature was 20°C. There were no significant differences in the response to salt and alkali treatments. Seeds failed to germinate at-2 MPa, while-1 MPa reduced germination, more so for the seeds with the bracteole removed. After a pre-treatment with salt or alkali stress, seeds exposed to alkali showed lower germination percentage if bracteoles were removed from the fruit.
Seed Science and Technology, 2009
The effect of different salts on the germination and early seedling growth of Atriplex cordobensis was investigated. Seeds were germinated at 20°C in solutions containing NaCl, KCl, Na 2 SO 4 and K 2 SO 4 at concentrations corresponding to osmotic potentials equal to 0.0 (control); -0.4; -0.8; -1.2 and -1.5 MPa. Germination recovery under optimum conditions after exposure to salinity was also studied. A cordobensis was tolerant to saline conditions depending on salt type. When the primary source of salt was NaCl and osmotic potentials were lower than -0.8 MPa, reduced germination was because of reduced water uptake. The presence of Na 2 SO 4 , K 2 SO 4 and KCl at concentrations which induced osmotic potentials below -0.8 MPa, impaired germination performance because of toxic effects.