THE EFFECT OF GIBBERELLIN AND TEMPERATURE ON THE GERMINATION OF SEED OF BELLS OF IRELAND

1963 ◽  
Vol 43 (4) ◽  
pp. 522-527 ◽  
Author(s):  
J. G. S. Trelawny ◽  
D. J. Ballantyne
Keyword(s):  
Gibberellic Acid ◽  
Naphthaleneacetic Acid ◽  
Untreated Seed ◽  
Intact Seed ◽  
Excised Embryos

Gibberellic acid (GA) at constant temperatures partially replaced the alternate temperatures required to break dormancy of intact seed of Bells of Ireland (Moluccella laevis L.). In the presence of GA optimum germination occurred at 10 °C. and declined to almost nil at 25 °C. When 2-naphthaleneacetic acid (NAA) at 10−5 M. was combined with GA the effect on germination at 20 °C. was synergistic. Higher concentrations of NAA antagonized the stimulatory effect of GA. All excised embryos germinated whether from chilled or unchilled seed. Embryos with attached endosperms from chilled seed showed a marked increase in germination over those from unchilled seed. GA induced 100 per cent germination of embryos with attached endosperms, irrespective of chilling, at 20 °C, but not at 25 °C. The presence of the pericarp completely prevented the germination of untreated seed at constant temperatures. Chilling whole seeds for 6 weeks at 5 °C. greatly enhanced penetration of external solutions to the embryo.

Carbohydrate concentrations and interactions in afterripening-responsive dormantAvena fatuacaryopses induced to germinate by gibberellic acid

1993 ◽  
Vol 3 (4) ◽  
pp. 271-278 ◽  
Author(s):  
M. E. Foley ◽  
M. B. Nichols ◽  
S. P. Myers
Keyword(s):  
Gibberellic Acid ◽  
Avena Fatua ◽  
Wild Oat ◽  
Sugar Production ◽  
Carbohydrate Utilization ◽  
Per Se ◽  
Induced Changes ◽  
Over Time ◽  
Excised Embryos

AbstractIt has been proposed that gibberellic acid (GA3) promotes germination by overcoming restrictions in sugar production and utilization in afterripening-responsive dormant caryopses. While their germination rates were similar, germination commenced sooner in afterripened wild oat (Avena fatuaL.) caryopses than in dormant caryopses treated with GA3and dormant excised embryos treated with GA3plus fructose (Fru). Limited germination occurred in dormant excised embryos cultured with GA3alone. Carbohydrate concentrations were measured over time in dormant caryopses and excised embryos whose germination was induced with GA3and GA3plus Fru. The concentration of sucrose (Suc) in the endosperm declined prior to germination of dormant GA3-treated caryopses. Raffinose (Raf) family oligosaccharides in the embryos of dormant GA-treated caryopses remained relatively constant prior to and shortly after the onset of germination. In contrast, Raf family oligosaccharides in the embryos of afterripened caryopses declined prior to germination. Together this suggests Raf family oligosaccharide utilization is not associated with germinationper se.Increased starch levels, which occurred in dormant excised embryos treated with Fru and GA3plus Fru, were associated with dormancy because similar effects were not apparent in afterripened embryos cultured with Fru. An initial decline in the concentration of Raf family oligosaccharides in dormant embryos cultured with GA3or GA3plus Fru seems to be a result of the excision process. GA3appears to stimulate the germination of dormant embryos by enhancing the uptake or utilization of Fru. It appears that GA3and afterripening-induced changes in carbohydrate utilization in dormant caryopses are different.

DORMANCY STUDIES IN SEED OF AVENA FATUA: 3. A RELATIONSHIP BETWEEN MALTASE, AMYLASES, AND GIBBERELLIN

1962 ◽  
Vol 40 (12) ◽  
pp. 1659-1673 ◽  
Author(s):  
G. M. Simpson ◽  
J. M. Naylor
Keyword(s):  
Energy Source ◽  
Gibberellic Acid ◽  
Avena Fatua ◽  
Starch Granules ◽  
Raw Starch ◽  
Endosperm Starch ◽  
Hydrolysis Of ◽  
Exogenous Sugar ◽  
Excised Embryos

Initiation of germination in excised embryos requires an exogenous energy source. Normally this is obtained from the endosperm. In dormant seeds the hydrolysis of starch is blocked despite the fact that dormant and non-dormant seeds contain similar amounts of α- and β-amylases. Alone or in combination the amylases are unable to break down raw endosperm starch granules to simple sugars in vitro. Exogenous maltase in combination with α-amylase hydrolyzes raw starch to glucose. Exogenous maltase eliminates the requirement for exogenous sugar. Examination of the maltase content of imbibed dormant and non-dormant seeds showed a marked increase in non-dormant seeds during the first 40 hours. This does not occur in dormant seeds unless they are treated with gibberellic acid. The results lead to the conclusion that an important effect of gibberellic acid is to induce the synthesis of maltase or in some way activate the preformed enzyme.

scholarly journals Long-term Effect of Winter Gibberellic Acid Sprays and Auxin Applications on Crop Value of `Clausellina' Satsuma

2006 ◽  
Vol 131 (5) ◽  
pp. 586-592 ◽  
Author(s):  
Amílcar M.M. Duarte ◽  
Amparo García-Luis ◽  
Rosa Victoria Molina ◽  
Consuelo Monerri ◽  
Vicente Navarro ◽  
...  
Keyword(s):  
Gibberellic Acid ◽  
First Grade ◽  
Dichlorophenoxyacetic Acid ◽  
Flower Formation ◽  
Naphthaleneacetic Acid ◽  
Marginal Effect ◽  
Variable Effect ◽  
Long Term Effect ◽  
2,4 Dichlorophenoxyacetic Acid

A winter gibberellic acid (GA3) spray consistently reduced flower formation, but had a variable effect on the amount of first-grade fruit in the early harvest of `Clausellina' satsuma (Citrus unshiu Marc.), and in the long term these applications had no significant effect on the value of the crop. Auxin applications increased the amount of first grade-early harvested fruit, and increased crop value as compared to hand-thinned trees. No significant differences in yield or fruit grade could be found among the different auxin applications tried, namely an application of 20 mg·L-1 2,4-dichlorophenoxyacetic acid (2,4-D) at flowering, or applications of 25 mg·L-1 naphthaleneacetic acid (NAA), or 50 mg·L-1 2,4-dicholorophenoxypropionic acid (2,4-DP) at the end of fruitlet abscission. Apart from their effect on size, the auxin applications had only a marginal effect on fruit quality.

scholarly journals Micropropagation of Two Selected Male Kiwifruit and Analysis of Genetic Variation with AFLP Markers

HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 740-746 ◽  
Author(s):  
M.J. Prado ◽  
M.T. Herrera ◽  
R.A. Vázquez ◽  
S. Romo ◽  
M.V. González
Keyword(s):  
Genetic Variation ◽  
Gibberellic Acid ◽  
Shoot Multiplication ◽  
Aflp Markers ◽  
Naphthaleneacetic Acid ◽  
Multiplication Rate ◽  
Variation Analysis ◽  
Half Strength ◽  
Species Being ◽  
Regenerated Plantlets

A simple and reliable protocol for micropropagation during 12 subcultures of two field growth male plants of kiwifruit [Actinidia deliciosa (A.Chev.) Liang and Ferguson] is described. The best results of shoot multiplication and elongation were obtained in Cheng's K(h) medium in the presence of 0.5 μm NAA, 22 μm BA and 1.4 μm GA3 for `Tomuri' explants, and of 0.1 μm NAA, 4.4 μm BA, and 0.3 μm GA3 for clone A explants. In addition, the cytokinin compounds TDZ and mT were also tested allowing improving the multiplication rate in `Tomuri' explants. For rooting, `Tomuri' and clone A developed shoots were treated by basal immersion in a 5 mm IBA solution for 15 seconds. Treated shoots were then cultured in half-strength K(h) medium without growth regulators showing 100% rooting after 30 days. Regenerated plantlets were successfully transplanted to soil (90% survival) and they are actively growing in the field. Somaclonal variation analysis by AFLP was carried out using 15 primer combinations, yielding reproducible and well-resolved bands with a 57% of polymorphism. AFLP markers showed to be effective to discriminate genetic variation in this species, being greater in clone A than `Tomuri'. Chemical names used: N6-benzyladenine (BA); gibberellic acid (GA3); indole-3-butyric acid (IBA); meta-topolin (mT); naphthaleneacetic acid (NAA); thidiazuron (TDZ).

scholarly journals Residual effect of growth regulators in etiolation and regeneration of in vitro pineapple plants

2010 ◽  
Vol 32 (2) ◽  
pp. 612-617 ◽  
Author(s):  
Fernanda Vidigal Duarte Souza ◽  
Ana Maria Mascarenhas Eloy Canto ◽  
Antônio da Silva Souza ◽  
Maria Angélica Pereira de Carvalho Costa
Keyword(s):  
Gibberellic Acid ◽  
Culture Medium ◽  
Residual Effect ◽  
Nodal Segments ◽  
Naphthaleneacetic Acid ◽  
Proliferation Medium ◽  
Regenerated Plants ◽  
Subsequent Regeneration ◽  
Previous Step

This work aimed to evaluate the influence of naphthaleneacetic acid (NAA) and gibberellic acid (GA3) plant regulators in in vitro etiolation and subsequent regeneration of the PE x SC-60 pineapple hybrid. Nodal segments of in vitro plants with approximately 5-7 cm height were incubated in basic MS culture medium supplemented with 0.0; 0.5 and 1.0 mg L-1 of naphthaleneacetic acid (NAA) in combination with gibberellic acid (GA3) in concentrations of 0.0; 0.5 and 1.0 mg L-1, and maintained at 27 ºC under dark condition. Evaluations were carried out at 90 and 180 days after incubation period. The best results for length of etiolated stems were obtained with 1.0 mg L-1 of NAA. In the experiment followed by the regeneration, stems with 3 cm from the etiolation treatment, were cultivated in proliferation medium and the number of regenerated plants per treatment was evaluated at 60 days of cultivation. The treatment that promoted the best etiolation of plants also promoted the worst regeneration rates, demonstrating the residual effect of the auxin used in the previous step in the regeneration of plants of the pineapple hybrid evaluated.

Hormonal enhancement of cone production in Douglas-fir grafts and seedlings

1979 ◽  
Vol 9 (2) ◽  
pp. 193-200 ◽  
Author(s):  
George S. Puritch ◽  
Eleanor E. McMullan ◽  
Michael D. Meagher ◽  
Clarence S. Simmons
Keyword(s):  
Seed Germination ◽  
Gibberellic Acid ◽  
Douglas Fir ◽  
Naphthaleneacetic Acid ◽  
Viable Seed ◽  
Seed Orchards ◽  
Cone Production ◽  
Seed Cone ◽  
Pollen Cone ◽  
Production Response

Gibberellic acid (GA) and naphthaleneacetic acid (NAA) were applied alone and in combination to both girdled and nongirdled branches of Douglas-fir in four seed orchards (two containing seedlings and two containing grafts). GA significantly increased seed-cone buds and cones and caused a nonsignificant increase in pollen-cone buds. Cone production was not significantly affected by girdling or the application of NAA. Trees treated with the combination of GA + NAA responded similarly to those treated with GA alone. Cone production response to GA varied according to the orchard locations, with better response in the normally more productive orchards. The percentage of trees flowering was increased by GA. Hormone treatments had no effect on seeds per cone but they significantly reduced filled seed per cone. Owing to increased cone number, however, the GA treatments greatly increased the yield of viable seed. NAA increased the percentage of seed germinating and the rate of seed germination, while GA had no effect.

Effects of Growth Regulators on Fruiting and Yield of Black Gram (Phaseolus Mungo, Roxb.) in India

1968 ◽  
Vol 4 (4) ◽  
pp. 339-344 ◽  
Author(s):  
O. N. Mehrotra ◽  
H. K. Saxena ◽  
A. N. Roy ◽  
Shiva Nath
Keyword(s):  
Grain Size ◽  
Gibberellic Acid ◽  
Grain Yield ◽  
Growth Regulators ◽  
Grain Filling ◽  
Naphthaleneacetic Acid ◽  
Black Gram ◽  
Economic Returns ◽  
Phaseolus Mungo ◽  
Chlorophenoxyacetic Acid

SUMMARYAn experiment was conducted in 1964 and 1965 to study the effects of hormone sprays on pod setting, pod filling and grain yield of black gram. Sprays of 2-naphthoxyacetic acid and p-chlorophenoxyacetic acid, alone and in 'mixture, and gibberellic acid and 1-naphthaleneacetic acid increased pod setting, but grain filling in pods and grain size were only slightly improved. 2-naphthoxyacetic acid gave the highest yield, followed by p-chlorophenoxyacetic acid, 1-naphthaleneacetic acid and a mixture of the first two, which increased yield by 56, 39, 36 and 35 per cent respectively over the control and gave economic returns.

scholarly journals Regeneration of Pharbitis nil from immature embryos by somatic embryogenesis

2014 ◽  
Vol 66 (2) ◽  
pp. 159-163 ◽  
Author(s):  
Alina Trejgell ◽  
Andrzej Tretyn
Keyword(s):  
Somatic Embryogenesis ◽  
Gibberellic Acid ◽  
Growth Medium ◽  
Somatic Embryos ◽  
Immature Embryos ◽  
Pharbitis Nil ◽  
Naphthaleneacetic Acid ◽  
Photoperiodic Induction ◽  
Root Region

Immature embryos of <em>Pharbitis nil</em> Chois. were used for the study. They were isolated from previously sterilized fruits and afterwards transferred to Murashige and Skoog (MS) growth medium with 0.8% agar. Immature embryos were cut across their axis. After 6-8 weeks of cultivation in the injury place (hypocotyl-root region) somatic embryos were formed. These embryos were isolated and each of them was transferred into a separate tube containing MS supplemented with naphthaleneacetic acid (NAA; in concentration 0.1 mg•dm<sup>-3</sup> ) and gibberellic acid (GA<sub>3</sub>; in concentration 0.5 mg•dm<sup>-3</sup>). Under these conditions about 26% of somatic embryos regenerated into complete plants. Two-three weeks after the photoperiodic induction flowers appeared on these plants. A few weeks after pollination normal seeds were developed from these flowers.

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