Gibberellic Acid Pretreatment Research Articles

Effect of Salt (NaCl) Stress on Germination in Clary Sage (Salvia sclarea) Subjected to Gibberellic Acid Pre-treatment

Effect of Salt (NaCl) Stress on Germination in Clary Sage (Salvia sclarea) Subjected to Gibberellic Acid Pre-treatment

Embryo maturation, dormancy and seed storage behaviour of Gymnacranthera canarica (King) Warb., a threatened endemic tree species of Southern Western Ghats

Gymnacranthera canarica is a severely endangered endemic tree species found in the Myristica swamps of the Southern Western Ghats. Seed storage behaviour is an essential factor to consider when developing effective conservation methods for plant genetic resources whose ex-situ preservation is unclear. The seed storage behaviour, seed dormancy state, dormancy breaking treatments, germination, and phytohormonal analysis of G. canarica were explored in this work. G. canarica seed moisture at shedding was 28.86%, germinated to 34% at 25ºC, and had a low germination rate in natural conditions. Germination was considerably aided by Gibberellic acid pretreatment and drying stratification. G. canarica seeds may have non-deep simple morphophysiological dormancy, as evidenced by the fact that their embryos grew at temperatures between 20 and 25ºC (MPD). Seeds can be stored for up to 60 days at 20ºC after being desiccated to 19.37% suggest that G. canarica seeds are recalcitrant, with non-deep simple morphophysiological dormancy, and that seed pretreatment with Gibberellic acid prior to germination could be a viable approach for mass propagation and long term ex-situ conservation could be the potential storage of this critically endangered species.

The determination of gibberellic acid effects on seed germination of Echinacea purpurea (L.) Moench under salt stress

The research was conducted to determine the effect of gibberellic acid pre-treatments on germination of Echinacea purpurea seeds under salt stress. In the study, three different gibberellic acid concentrations (0, 100, 200 and 300 ppm) were pre-treated. Seeds planted in petri dishes were left to germinate after salt applications at 0, 50 and 100 mM (NaCl) concentrations. Responses of echinacea to priming and salt stress treatments were observed on the bases of some growth and viability (radicle and hypocotyl length, radicle fresh and dry weight, hypocotyl fresh and dry weight, germination power, germination speed, mean germination time, germination and sensitivity index) parameters. According to the result of the research; when the salt concentrations increase, the germination and growth parameters of echinacea seeds were inhibited. It was conducted determined that increasing doses of gibberellic acid pre-treatments had significant and positive effects on the germination and growth parameters of echinacea seeds under salt stress conditions. In physiological enhancement of echinacea seeds, the best results were obtained from the 300 ppm GA3+0 mM (control) salt combination.

Effects of benzyl adenine and gibberellic acid pre-treatments on dormancy release, flowering time and multiplication of oriental lily (Lilium longiflorum) bulbs

Effects of benzyl adenine and gibberellic acid pre-treatments on dormancy release, flowering time and multiplication of oriental lily (Lilium longiflorum) bulbs

Optimization of seed germination in Prunus species combining hydrogen peroxide or gibberellic acid pre-treatment with stratification

Optimization of seed germination in Prunus species combining hydrogen peroxide or gibberellic acid pre-treatment with stratification

In vitro rescue of immature avocado (Persea americana Mill.) embryos

An in vitro culture protocol was developed as a means of avocado embryo rescue. Different factors including presence of cotyledons, medium texture and cold or gibberellic acid pretreatments, were studied. To better understand the germination process in this recalcitrant species, immature zygotic embryos at different stages were used in these experiments. Optimum results were dependant on the embryo developmental stage. Whereas smaller embryos (5 mm long) germinated better in M1 liquid medium, 15 mm long embryos responded better when precultured in B5m medium supplemented with 1 mg l −1 GA 3 , and fully mature embryos were capable of germinating directly in solid M1 medium. Our results suggest the existence of two types of dormancy in avocado embryos: an embryo-dormancy caused by cotyledons, and another type of dormancy, mainly occurring in 35 mm long embryos and revealed by the formation of dwarfing rosette seedlings, that can be released by a GA 3 pretreatment.

The influence of seed pre-treatments and soil conditions on the emergence of sesame seedlings

Poor and uneven emergence of seedlings decreases the efficiency of sesame (Sesamum indicum) seed production. In a glasshouse study, seedling emergence was reduced by low soil moisture content (less than 20%, w/v) and by waterlogging (common in soils with small soil particles). Watering events that failed to raise soil moisture content above 20% caused most seeds to germinate (more than than 80%), but only some of these seeds emerged from the soil (less than 50%). Gibberellic acid pre-treatment of seeds (50 or 1000 mg/L) failed to improve emergence of seeds from soils with an initial soil moisture content less than 20%. This result supports previous reports suggesting that gibberellic acid treatment does not influence seedling emergence, and may only be useful to overcome seed dormancy in those sesame varieties where dormancy is a problem. For maximum emergence it is recommended that sesame seeds be sown in non-waterlogged soils and that soil moisture content be maintained above 20% for a number of days after sowing.

Improved germination in seeds of guayule (Parthenium argentatum Gray) following polyethylene glycol and gibberellic acid pretreatments

SummarySuitable conditions for the pretreatment of seeds of guayule were determined with a view to improving germination. These included the addition of thiram (500 mg litre‐1), and applications of GA4+7 alone, or in combination with polyethylene glycol. Significant improvements in the seed germination were seen following applications of PEG at ‐0.10 MPa. Simultaneous application of GA4+7 with priming improved soil emergence and germination over a wide range of temperatures. No beneficial effects of PEG priming were evident on seed storage.

Physiology of Sugarcane Under Water Stress: Invertase, ATP-ase and Amylase Behavior in Plants Experiencing Water Deficiency, Night Flooding and Continuous Flooding

Effects of water stress on growth, sugar production and enzymology of sugarcane were evaluated in two greenhouse experiments in which sugarcane of the variety P.R. 980 was grown in sand culture with controlled nutrient supply. At 14 weeks of age, four water regimes were created for each of the two experiments: No water, normal water (2 liters daily), normal water plus night flooding, and continuous flooding. One experiment was pretreated with a 0.01-percent solution of active gibberellic acid (GA) 10 days before water variables were initiated. Samples of leaf, leaf sheath, immature storage tissue and stalk tissue were harvested at 0, 2, 5, and 9 days. Enzyme assays were conducted with leaf and immature storage tissue preparations for acid invertase, adenosine triphosphatase (ATP-ase), and ß-amylase. The following results were obtained: 1. Foliar symptoms appeared between the fifth and ninth day among the low-water and continuous flooding regimes. Wilting of leaves and leaf sheaths, yellowing of leaf tips, extensive yellowing of older leaves and leaf sheaths, and severe curling of spindle tissues was general among both treatments. Symptoms were delayed but not prevented by GA pretreatment. Normal water and night flooding produced no visible effects. Whorls of adventitious roots grew from submerged nodes of continuously flooded plants. 2. Sheath moisture values ultimately declined in water-deficient and water-toxic plants regardless of GA treatment. Continuously flooded plants increased total fresh weight, regardless of leaf and sheath desiccation, when pretreated with GA. A GA role in promoting water uptake is suggested. 3. Leaf sucrose declined in water-deficient and continuously flooded sugarcane but increased in immature storage tissues. This was taken as evidence of continued sucrose transport under moisture conditions restrictive against sugar synthesis. Polarization values for milled juice indicated that GA pretreatment caused a decline of storage sucrose under a normal water regime, but GA prevented storage sucrose losses under a regime of continuous flooding. The former GA effect is interpreted in terms of growth stimulation, the latter in terms of GA involvement in sugar accumulation processes effective in transport of sucrose to storage areas. 4. Invertase was suppressed both by deficient and excessive water regimes and by GA pretreatment. Night flooding produced little effect. 5. ATP-ase was strongly suppressed by night flooding but no consistent effects were produced by the other water regimes. The ATP-ase suppression by excessive night water was interpreted as a perturbation of normal diurnal-nocturnal rhythms rather than a sensitivity of synthesis mechanisms to flooding per se. GA pretreatment suppressed ATP-ase among all water regimes. Assuming that foliar ATP-ase is a functional entity of photosynthetic phosphorylation, the GA effect was taken as further evidence of a GA influence upon sugarcane photosynthesis. 6. Foliar amylase remained at a constant level in water-deficient cane, while other water regimes tended to increase the enzyme. Amylase was less sensitive to water regime than invertase and appeared to be synthesized under flood conditions highly repressive for invertase. It is concluded that low- and high-water regimes tend to produce common effects upon the overall synthesis and utilization of sugar in the cane plant. Hormone level may affect the rate of sugar utilization within high and low water regimes without altering the outward manifestations of these regimes. Hydrolytic enzyme level is apparently affected indirectly by prolonged water stress or by perturbation of endogenous day-night rhythms. However, the enzymes measured were not sufficiently sensitive to changing water supply to serve as indicators of water status.

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