Replacement of an Alternating Temperature Requirement for Germination by Gibberellic Acid

Nature ◽  
1961 ◽  
Vol 192 (4797) ◽  
pp. 83-84 ◽  
Author(s):  
J. M. TAGER ◽  
BRENDA CLARKE
Keyword(s):  
Gibberellic Acid ◽  
Temperature Requirement ◽  
Alternating Temperature

Afterripening and germination of seeds of American highbush cranberry (Viburnum trilobum)

1973 ◽  
Vol 51 (10) ◽  
pp. 1761-1764 ◽  
Author(s):  
Paul Fedec ◽  
R. H. Knowles
Keyword(s):  
Seed Germination ◽  
Gibberellic Acid ◽  
Prolonged Exposure ◽  
Inductive Effect ◽  
Polar Lipids ◽  
Lipid Degradation ◽  
Lipid Reserve ◽  
High Lipid ◽  
Alternating Temperature

Seed of the American highbush cranberry, Viburnum trilobum Marsh., kept at germinative conditions of 20 °C, required 328 days to reach 92% germination. Initially, about one-half the seed germinated within 120 days. After a 120-day lag, the balance germinated. Afterripening, with as little as one cycle of alternating temperature (1 week at 20 °C and 1 week at 2 °C) shortened the time to total germination by [Formula: see text] months. The inductive effect of afterripening was studied in relation to utilization of the high lipid reserve present in the endosperm. No appreciable changes in polar and non-polar lipids occurred during prolonged exposure to either afterripening or germinative conditions, indicating that afterripening is not associated with lipid degradation. Gibberellic acid (GA3) had little effect on seed germination but successfully overcame epicotyl dormancy of the seedling.

Germination of leafy spurge (Euphorbia esula L.) seeds under alternating temperatures: the effects of amplitude, midpoint, and imbibition in gibberellic acid

2016 ◽  
Vol 96 (3) ◽  
pp. 321-328
Author(s):  
Michael E. Foley
Keyword(s):  
Gibberellic Acid ◽  
Constant Temperature ◽  
Temperature Regime ◽  
Initial Temperature ◽  
Leafy Spurge ◽  
Euphorbia Esula ◽  
Amplitude Difference ◽  
Temperature Regimes ◽  
Alternating Temperature

Germinability of dormant seeds or the capacity to germinate under particular conditions is sometimes enhanced by a diurnal alternating temperature regime relative to a constant temperature. Alternating temperature regimes vary in amplitude (difference between the minimum and maximum) and midpoint (average). The aim of this research was to test the effects of amplitude and midpoint regimes on germination of dormant leafy spurge seed from a Fargo, ND population in water and gibberellic acid (GA3). The optimal regimes for germination in both water and GA3 were 20:30 °C (16 h:8 h) and 20:35 °C (19 h:5 h), which provided amplitudes of 10 °C and 15 °C, respectively, with both conditions having a midpoint temperature of 23.3 °C. However, midpoint temperature of 22 °C to 27 °C were equally effective for germination under the 20:30 °C and 20:35 °C alternating temperature regimes. Additional alternating temperature regimes with amplitudes of 15 °C (15:30 °C and 10:25 °C), 20 °C (10:30 °C), and 25 °C (10:35 °C) generally displayed reduced germination in both water and GA3, which is likely attributable to the low initial alternating temperature (≤15 °C) component of the regime relative to the higher initial temperature of 20 °C for the optimum regimes of 20:30 °C and 20:35 °C. Under the alternating temperature regimes tested, seeds germinated in GA3 generally displayed higher germination (≥80%) compared with seeds in water (30%–50%).

scholarly journals Growth Regulators and Storage Temperature Govern Germination of Coreopsis Seed

HortScience ◽  
1992 ◽  
Vol 27 (11) ◽  
pp. 1190-1193 ◽  
Author(s):  
William J. Carpenter ◽  
Eric R. Ostmark
Keyword(s):  
Relative Humidity ◽  
Gibberellic Acid ◽  
Growth Regulators ◽  
Storage Temperature ◽  
Seed Storage ◽  
Temperature Regimes ◽  
Alternating Temperature ◽  
And Storage ◽  
Storage Temperatures ◽  
Growth Regulator Treatment

The storage and germination environments were evaluated to determine the cause of low total germination percentages and highly irregular germination of Coreopsis lanceolata L. seed. Highest total germination and most rapid and uniform germination of seed occurred at constant 15C, other constant temperatures and all alternating temperature regimes caused lower total germination or delayed it. Seeds tolerated -20C during storage, but total germination was reduced below -5C. Recently harvested seeds had 44% total germination, but 54% to 81% germination was achieved after 6 hours of soaking seeds in 1000 ppm GA3, 1000 ppm ethephon, or 25 ppm kinetin alone or in combination. Growth regulators reduced the number of days to 50% of final germination (T50), and the span in days between 10% and 90% of germination (T90 - T10). Storing fresh seeds without chemical treatment for > 6 months at 5C and 10% to 20% relative humidity (RH), or 15C at 20% to 35% RH, increased total germination to 75% and 80%, respectively. Ten days were required to achieve T50 after 5 to 6 months of storage at 5C and 10% to 20% RH or 15C and 10% to 40% RH, with longer periods to T50 at other storage durations and RH levels. The germination spans (T90 - T10) were lengthened the higher the seed storage temperatures between 5 to 25C, with longer spans as seed storage durations and relative humidities increased. Total germination was similar after storing seeds at 5 or 15C and 10% to 30% RH and after soaking recently harvested seeds in GA3 + ethephon, but the days to T50 and T90 - T10 were shorter after growth regulator treatment. Chemical names used: (2-chloroethyl) phosphonic acid (ethephon); gibberellic acid (GA3); 6-furfurylaminopurine (kinetin).

Can alternating temperature, moist chilling, and gibberellin interchangeably promote the completion of germination in Clematis vitalba seeds?

Botany ◽  
2017 ◽  
Vol 95 (8) ◽  
pp. 847-852 ◽  
Author(s):  
Rosangela Picciau ◽  
Marco Porceddu ◽  
Gianluigi Bacchetta
Keyword(s):  
Seed Germination ◽  
Gibberellic Acid ◽  
Plant Species ◽  
Temperature Regime ◽  
Fluctuating Temperature ◽  
Temperature Regimes ◽  
Moist Chilling ◽  
Clematis Vitalba ◽  
Alternating Temperature ◽  
Positive Effect

Each plant species has particular requirements for seed germination, and some of them respond differently to constant or alternating temperature regimes. In this study, the interchangeable effects of different treatments and temperatures on the completion of seed germination of Clematis vitalba L. were investigated. The seeds were tested with a constant (from 5 °C to 25 °C) or a fluctuating (25/10 °C) temperature regime, and the effect of gibberellic acid (GA3), incubation at warm (W) or cold (C) temperatures while being imbibed, and drying after ripening (DAR) were evaluated. The final germination percentages and the time in days required to reach 50% of germination (T50) were calculated. GA3 and C significantly enhanced completion of seed germination at all of the temperatures tested. A strong positive effect of alternating temperature was observed, which triggered completion of seed germination regardless of treatment. Under the fluctuating temperature, the chilled seeds had the most rapid germination. Low germination rates were observed for both control and DAR treatments. Seeds of C. vitalba display a certain degree of dormancy, which can be broken by moist chilling and GA3 treatments. Moreover, alternating temperature stimulates the completion of seed germination by satisfying certain physiological requirements for germination under constant temperatures.

Effects of Gibberellic Acid and Alternating Temperature on Breaking Seed Dormancy of Panax ginseng C. A. Meyer

2016 ◽  
Vol 24 (4) ◽  
pp. 284-293 ◽  
Author(s):  
Jung Woo Lee ◽  
◽  
Young Chang Kim ◽  
Jang Uk Kim ◽  
Ick Hyun Jo ◽  
...  
Keyword(s):  
Gibberellic Acid ◽  
Panax Ginseng ◽  
Seed Dormancy ◽  
Breaking Seed Dormancy ◽  
Alternating Temperature

Factors that influence dormancy in milkweed seeds

1972 ◽  
Vol 50 (4) ◽  
pp. 713-718 ◽  
Author(s):  
T. Oegema ◽  
R. A. Fletcher
Keyword(s):  
Abscisic Acid ◽  
Synergistic Effect ◽  
Gibberellic Acid ◽  
Growth Regulators ◽  
Seed Coat ◽  
Germination Percentage ◽  
Endogenous Gibberellin ◽  
Growth Promoters ◽  
Asclepias Syriaca ◽  
Alternating Temperature

Seeds of Asclepias syriaca L. (milkweed) have an inherent dormancy and these seeds could be forced to germinate by various treatments including stratification, cutting or removal of the seed coat, gases, alternating temperature, and a number of chemicals. Of the various treatments, the growth regulators kinetin and gibberellic acid were most effective in overcoming dormancy and a combination of these two had a synergistic effect. The increased germination percentage after 5 weeks of stratification was not accompanied by an increase in endogenous gibberellin levels. Treatment of the seeds with abscisic acid after stratification resulted in a complete inhibition of germination whereas treatment with kinetin resulted in an increase in germination. It is concluded that dormancy in milkweed seeds could be broken by many factors and regulated by an intricate interplay between growth promoters and inhibitors.

scholarly journals Optimal germination conditions for monitoring seed viability in wild populations of fescues

2021 ◽  
Vol 19 (3) ◽  
pp. e0804-e0804
Author(s):  
Pablo Vivanco ◽  
Keyword(s):  
Gibberellic Acid ◽  
Seed Dormancy ◽  
Seed Viability ◽  
Cold Stratification ◽  
Wild Populations ◽  
Negative Effect ◽  
Species Area ◽  
Northwestern Spain ◽  
Alternating Temperature ◽  
Germination Requirements

Aim of study: Germination assays are vital in the management of material preserved in germplasm banks. The rules published by the International Seed Testing Association (ISTA) are generally those followed in such assays. In wild species, seed dormancy and inter-population variability increase the difficulty in estimating seed viability. The aim of the present work was to determine the germination requirements of the seeds from different wild populations of pasture grasses species. Area of study: Northwestern Spain Material and methods: Seeds from eight wild populations of different species of Festuca, all from northwestern Spain, were studied. Germination assays were performed under constant and alternating temperature conditions. Treatments for removing seed dormancy (cold stratification and gibberellic acid application) were also applied. A full parametric time-to event model was used for data analysis. Main results: In general, the optimum environmental temperature for germination was around 15°C for the populations of Festuca group ovina, F. gr. rubra and F. gigantea; temperatures of 20-30ºC had a negative effect. All the examined populations, except that of tall fescue (Lolium arundinaceum), showed non-deep physiological dormancy at suboptimal germination temperatures, but this was breakable by the application of gibberellic acid and by cold stratification. Research highlights: There are clear inter- and intra-specific differences in germination requirements that might be associated with place of origin. The ISTA germination assay recommendations for wild members of fescues may not be the most appropriate.

Sign in / Sign up

Export Citation Format

Share Document