GERMINATION RESPONSE OF DORMOAT SEEDS TO LOW TEMPERATURE AND GIBBERELLIN

1972 ◽  
Vol 52 (3) ◽  
pp. 295-303 ◽  
Author(s):  
C. J. ANDREWS ◽  
V. D. BURROWS
Keyword(s):  
Abscisic Acid ◽  
Low Temperature ◽  
Gibberellic Acid ◽  
Seed Dormancy ◽  
Avena Sativa ◽  
Low Temperatures ◽  
Dry Storage ◽  
Secondary Dormancy ◽  
Derivatives Of ◽  
Different Levels

Dormoats are derivatives of crosses between Avena sativa L. and A. fatua L., designed to be sown in the fall to germinate the following spring. Strains vary in levels of seed dormancy at harvest and in their rates of after-ripening in dry storage. Germination of the seeds is stimulated by gibberellic acid. Embryos isolated from dormant seeds exhibit no dormancy but their germination is prevented by abscisic acid. Low temperatures (ca. 7 C) stimulate germination to different levels in various strains. Seeds enter a secondary dormancy when they fail to germinate in the imbibed state due to primary domancy. Seeds with secondary dormancy are not stimulated to germinate by low temperatures until partial after-ripening of the seeds in the dry state has occurred, but germination is stimulated by gibberellic acid without after-ripening. Secondary dormancy is proposed as a factor in the maintenance of undergerminated seed in the soil from fall planting into winter.

Enhancement by Low Temperatures of the Anaerobic Induction of Cocklebur Seed Germination

1977 ◽  
Vol 4 (6) ◽  
pp. 849 ◽  
Author(s):  
Y Esashi ◽  
Y Ohhara
Keyword(s):  
Seed Germination ◽  
Low Temperature ◽  
Gibberellic Acid ◽  
Low Temperatures ◽  
Anaerobic Treatment ◽  
Maximal Response ◽  
Benzyl Adenine ◽  
Anaerobic Induction ◽  
Time Period ◽  
Proportional Increase

Non-dormant, upper cocklebur (Xanthium pensylvanicum Wallr.) seeds, incapable of germinating under ordinary conditions, can germinate when previously subjected to anaerobiosis; this has been termed the anaerobic induction of seed germination. Aerobic presoaking of the seeds was also required for successful anaerobic induction, and exerted two counter-acting effects on seed germination. When the time period of aerobic presoaking was sufficiently prolonged, the increasing duration of an anaerobic treatment resulted in proportional increase of germination potential but, when it was short, the effect of the anaerobiosis was saturated in a few days. Prolonging the aerobic presoaking period caused less response of the seed to the anaerobic induction, suggesting the development of some germination-inhibiting system during the aerobic presoaking period. This system could not develop in the absence of O2 or at low temperature. Thus, low temperature during prolonged presoaking produced a maximal response to anaerobic induction. Various germination stimulants, CO2, ethylene, gibberellic acid and benzyl adenine, did not significantly alter the effects of the presoaking.

scholarly journals Rice GERMIN-LIKE PROTEIN 2-1 Functions in Seed Dormancy under the Control of Abscisic Acid and Gibberellic Acid Signaling Pathways

2020 ◽  
Vol 183 (3) ◽  
pp. 1157-1170 ◽  
Author(s):  
Haiting Wang ◽  
Yuman Zhang ◽  
Na Xiao ◽  
Ge Zhang ◽  
Fang Wang ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Gibberellic Acid ◽  
Signaling Pathways ◽  
Seed Dormancy ◽  
Gibberellic Acid Signaling

A Study of the Rubber-Metal Bond

1946 ◽  
Vol 19 (4) ◽  
pp. 956-967
Author(s):  
S. Buchan ◽  
J. R. Shanks
Keyword(s):  
Tensile Strength ◽  
Low Temperature ◽  
Low Temperatures ◽  
Moderate Increase ◽  
Progressive Reduction ◽  
Bonding Agents ◽  
Metal Bond ◽  
Permanent Set ◽  
Vulcanized Rubber ◽  
Derivatives Of

Abstract Although the practice of bonding rubber to metal has been in use for many years, no theories appear to have been advanced which explain adequately the mechanism of bonding. It has been stated that the brass bond between rubber and metal functions through chemical linkages, but this can only be regarded as tentative and has yet to be proved. No attempt has been made to find out how ebonite functions as a bonding medium or the more recently discovered derivatives of rubber, such as sulfonated rubber, chlorinated rubber, and rubber hydrohalides. Until it is properly elucidated just how bonding agents do act, further logical development of improved bonding media cannot be pursued. It is intended in this paper to show how the rubber-metal bond behaves at subnormal temperatures and how a low temperature technique may be used for studying the mechanism of bonding. The effect of low temperatures on the tensile strength and associated properties of vulcanized rubber, such as hardness, permanent set, flexibility, resilience and flexing, has been dealt with fairly comprehensively in the literature. Progressive reduction in temperature leads to only a moderate increase, for example, in tensile strength, until the point is reached at which the rubber stiffens and freezes, when a marked increase occurs. Examination of a brass-bonded unit at low temperatures revealed that the graph obtained for bond strength was very similar in slope and character to that for tensile strength. The similarity is illustrated by the data in Table 1 and in Figure 1.

Germination and Dormancy of Themeda australis, Danthonia Spp., Stipa bigeniculata and Bothriochloa macra

1976 ◽  
Vol 24 (3) ◽  
pp. 319 ◽  
Author(s):  
MW Hagon
Keyword(s):  
Gibberellic Acid ◽  
Low Temperatures ◽  
Germination Capacity ◽  
Dry Storage ◽  
Temperature Regimes ◽  
Maximum Temperatures

The germination and dormancy of Themeda australis, Danthonia spp., Stipa bigeniculata and Bothriochloa macra were investigated in whole dispersal units or caryopses. Germination of non-dormant units of the four species was not affected by light but was delayed by low temperatures. Such temperature regimes depressed the germination capacity of Themeda while alternating temperatures with a range greater than 10°C depressed the germination of Bothriochloa. The level of germination of Danthonia and Stipa was not affected by any of the temperature regimes used. Dormancy was reduced either by the application of gibberellic acid at concentrations of 100 ppm to 1000 ppm or by stratification. In addition, application of kinetin ( 10 -4M ) or opening the lemma suture broke the dormancy of Stipa dispersal units. The breakdown of dormancy during dry storage was also examined. Temperature alternations with maximum temperatures greater than 40°C reduced the level of dormancy of Themeda and Stipa within 1-2 months.

Seed afterripening and germination photoinhibition in the genusCrocus(Iridaceae)

2015 ◽  
Vol 25 (3) ◽  
pp. 306-320 ◽  
Author(s):  
Evangelia Skourti ◽  
Costas A. Thanos
Keyword(s):  
Seed Germination ◽  
Gibberellic Acid ◽  
Low Temperatures ◽  
Temperate Climate ◽  
Optimal Temperature ◽  
Continuous Darkness ◽  
Dry Storage ◽  
The Mediterranean ◽  
Germination Experiments ◽  
First Time

AbstractMediterranean characteristics are attributed to the genusCrocus, which is inadequately studied in terms of seed germination. An afterripening requirement is very common in environments with warm and dry periods, and photoinhibition has been detected in many angiosperms inhabiting dry and open areas. The effects of afterripening and light on seed germination were investigated for the first time in 23 native GreekCrocustaxa, collected from various localities with either a Mediterranean or a temperate climate. Germination experiments were conducted in continuous darkness and in light at the optimal temperature for each taxon, with both freshly collected and afterripened seeds; warm stratification (20°C, darkness) was also examined in 22 taxa. A number of selected taxa were additionally investigated with respect to afterripening outdoors, afterripening and warm stratification at higher temperatures (35 and 25°C, respectively), stratification at 20/10°C, dry storage at low temperatures, response to gibberellic acid and phenology of embryo growth. It was postulated that an afterripening requirement is a characteristic of the genusCrocus, and we found that it can be fulfilled in nature during the Mediterranean dry summer. Also, for the vast majority of the taxa, warm stratification and stratification at 20/10°C can both meet the afterripening requirement. Embryos of the taxa studied are underdeveloped and have to grow prior to germination. Intrageneric differences of seed germination were observed only towards light, with photoinhibition being predominant in taxa from drier environments.

Seed dormancy of Emex australis and E. spinosa

1978 ◽  
Vol 29 (3) ◽  
pp. 565 ◽  
Author(s):  
MW Hagon ◽  
DM Simmons
Keyword(s):  
Gibberellic Acid ◽  
Seed Dormancy ◽  
Temperature Regime ◽  
Oxygen Diffusion ◽  
Cultural Control ◽  
Emex Australis ◽  
Secondary Dormancy

Seed dormancy in Emex australis and E. spinosa was investigated by the application of light, gibberellic acid (GA3) or kinetin (KT) and by scarification of the fruits. Results from these experiments suggested that dormancy was controlled by the balance between promotive hormones and inhibitors and that a semipermeable barrier prevented leaching of inhibitors and/or uptake of exogenously applied GA3 or KT, and/or restricted oxygen diffusion. Storage of seed at alternating temperatures in the laboratory or the field reduced the level of dormancy, the reduction being more rapid for E. australis than for E. spinosa. The degree of dormancy also varied between populations within E. australis. Burial of non-dormant seeds of E. australis did not induce secondary dormancy even though dormancy was enforced by burial at a temperature regime of 25/20°C. Partly dormant (light-requiring) seeds of E. spinosa attained a degree of secondary dormancy following burial for 4 weeks at 25/20° and 9/9°. The results are discussed with reference to cultural control practices.

Population differentiation in Australian Cardamine. III. Variation in germination response

1966 ◽  
Vol 14 (2) ◽  
pp. 189 ◽  
Author(s):  
N Thurling
Keyword(s):  
Genetic Variation ◽  
Low Temperature ◽  
Sea Level ◽  
Seed Dormancy ◽  
Population Differentiation ◽  
Low Temperatures ◽  
New South ◽  
Adaptive Significance ◽  
Germination Response ◽  
South Wales

Genetic variation in germination response was observed among a series of Cardamine populations whose habitats range from sea-level to 7200 ft in southern New South Wales. This variation was closely related to altitude. In populations from below 2000 ft, germination was inhibited at high temperatures, whereas those from above 5500 ft did not germinate at low temperatures. Among populations in which germination was inhibited at low temperatures the intensity of low temperature inhibition increased with increasing altitude. The adaptive significance of high and low temperature seed dormancy in these populations of Cardamine is discussed.

Dormancy of Nicotiana benthamiana seeds can be broken by different compounds

Biologia ◽  
2009 ◽  
Vol 64 (4) ◽  
Author(s):  
Andrea Wünschová ◽  
Veronika Beňová ◽  
Helena Vlašínová ◽  
Ladislav Havel
Keyword(s):  
Abscisic Acid ◽  
Gibberellic Acid ◽  
Sodium Nitroprusside ◽  
Seed Dormancy ◽  
Plant Hormones ◽  
Nicotiana Benthamiana ◽  
Potassium Ferricyanide ◽  
Interesting Effect

AbstractThe influence of after-ripening, sodium nitroprusside, potassium ferricyanide, cyanide, paclobutrazol and nitrite on germination of seeds of Nicotiana benthamiana was investigated as well as the influence of plant hormones such as gibberellins and abscisic acid. Dormancy of N. benthamiana seeds was broken by all treatments except treatments with abscisic acid, paclobutrazol and gibberellic acid (GA3). Gibberellins had an interesting effect on dormancy breakage of studied seeds which was dependent on use of particular gibberellin: GA3 or GA4+7. Unlike GA3, GA4+7 had broken seed dormancy.

Hormonal Aspects of Seed Dormancy in Yellow Foxtail

Weed Science ◽  
1972 ◽  
Vol 20 (5) ◽  
pp. 472-477 ◽  
Author(s):  
G. E. Kollman ◽  
D. W. Staniforth
Keyword(s):  
Abscisic Acid ◽  
Gibberellic Acid ◽  
Seed Dormancy ◽  
Paper Chromatography ◽  
Plant Hormones ◽  
Effective Means ◽  
Paper Electrophoresis ◽  
Endogenous Inhibitor ◽  
Ph Values ◽  
Solvent Systems

Investigations with exogenous test solutions showed that abscisic acid (ABA) inhibited germination of nondormant seeds and that gibberellins (GA) promoted the germination of yellow foxtail (Setaria lutescens (Weigel) Hubb.) The effect of the promoters was much more readily demonstrated with excised caryopses than with intact seeds. Cytokinins reversed ABA inhibition of germination; GA did not, but the two promoters in combination were more effective than the cytokinin alone. The reversal occurred only at one end of the embryonic axis, the shoot end. An endogenous inhibitor was extracted from dormant and nondormant yellow foxtail seeds and compared with ABA by chromatography, electrophoresis, and bioassays. The extracted inhibitor was very similar to ABA in six paper-chromatography solvent systems, three paper electrophoresis runs at different pH values, and three bioassays. Paper electrophoresis was an effective means of separating the two plant hormones, ABA and gibberellic acid (GA3).

scholarly journals Identification and Bioinformatic Analysis of the GmDOG1-Like Family in Soybean and Investigation of Their Expression in Response to Gibberellic Acid and Abscisic Acid

Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 937
Author(s):  
Yingzeng Yang ◽  
Chuan Zheng ◽  
Umashankar Chandrasekaran ◽  
Liang Yu ◽  
Chunyan Liu ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Seed Germination ◽  
Gibberellic Acid ◽  
Seed Dormancy ◽  
Expression Patterns ◽  
Evolutionary Relationship ◽  
Soybean Seed ◽  
Bioinformatic Analysis ◽  
Chromosomal Distribution ◽  
Seed Dormancy And Germination

Seed germination is one of the most important stages during plant life cycle, and DOG1 (Delay of germination1) plays a pivotal regulatory role in seed dormancy and germination. In this study, we have identified the DOG1-Like (DOG1L) family in soybean (Glycine max), a staple oil crop worldwide, and investigated their chromosomal distribution, structure and expression patterns. The results showed that the GmDOG1L family is composed of 40 members, which can be divided into six subgroups, according to their evolutionary relationship with other known DOG1-Like genes. These GmDOG1Ls are distributed on 18 of 20 chromosomes in the soybean genome and the number of exons for all the 40 GmDOG1Ls varied greatly. Members of the different subgroups possess a similar motif structure composition. qRT-PCR assay showed that the expression patterns of different GmDOG1Ls were significantly altered in various tissues, and some GmDOG1Ls expressed primarily in soybean seeds. Gibberellic acid (GA) remarkably inhibited the expression of most of GmDOG1Ls, whereas Abscisic acid (ABA) inhibited some of the GmDOG1Ls expression while promoting others. It is speculated that some GmDOG1Ls regulate seed dormancy and germination by directly or indirectly relating to ABA and GA pathways, with complex interaction networks. This study provides an important theoretical basis for further investigation about the regulatory roles of GmDOG1L family on soybean seed germination.

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