Dormancy in seeds of Hibbertia cuneiformis and H. huegelii (Dilleniaceae)

1997 ◽  
Vol 45 (6) ◽  
pp. 1045 ◽  
Author(s):  
A. Schatral ◽  
J. M. Osborne ◽  
J. E. D. Fox
Keyword(s):  
Abscisic Acid ◽  
Gibberellic Acid ◽  
Seed Coat ◽  
Diurnal Cycle ◽  
Plant Hormones ◽  
Germination Percentage ◽  
Complete Darkness ◽  
Embryo Dormancy ◽  
Chemical Inhibition ◽  
Germination Experiments

Dormancy delays the germination of seeds in two species of the primitive angiosperm genus Hibbertia (H. cuneiformis and H. huegelii, family Dilleniaceae). After seed coat removal, germination increased in 18-month-old seeds of H. cuneiformis and 6- to 8-month-old seeds of H. huegelii. Hence, seeds of the two species exhibit seed coat dormancy. The removal of the seed coat may stimulate germination, as the result of increased water uptake, and/or the removal of mechanical and chemical inhibition. However, the occurrence of imbibitional injury and a reduced percentage of vigorous seedlings in decoated seeds suggest that embryo dormancy, as a second type of dormancy, impedes germination in H. cuneiformis. Embryo dormancy also delays the germination of seeds of H. huegelii, since a high percentage of seeds did not germinate after removal of the seed coat. Embryo dormancy appears to vary among individual seeds and between species. The germination experiments suggest a high percentage of non-dormant and weakly dormant embryos for 18-month-old seeds of H. cuneiformis. By contrast, many seeds of H. huegelii appear to contain deeply dormant embryos. In H. cuneiformis, the depth of the seed dormancy varied with the age of the seeds. Freshly harvested seeds did not germinate for 3 months. Treatment with gibberellic acid (GA3) (120 mg L-1) significantly enhanced germination of freshly harvested and 18-month-old, intact seeds of H. cuneiformis and the germination of decoated 18-month-old seeds of H. huegelii. The plant hormones kinetin and abscisic acid did not affect the final germination percentage in 18-month-old seeds of H. cuneiformis. For H. huegelii, germination was reduced in decoated seeds and seeds with cracked coats exposed to an 8 h day: 16 h night diurnal cycle compared with complete darkness.

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 Influence of Seed Treatments on Germination and Initial Growth of Ornamental Palms

HortScience ◽  
1997 ◽  
Vol 32 (4) ◽  
pp. 604E-604 ◽  
Author(s):  
Jose P. Morales-Payan ◽  
Bielinski M. Santos
Keyword(s):  
Nitric Acid ◽  
Gibberellic Acid ◽  
Seed Coat ◽  
Acid Treatment ◽  
Date Palm ◽  
Germination Percentage ◽  
Initial Growth ◽  
Chemical Treatments ◽  
Phoenix Canariensis ◽  
Physical And Chemical

Experiments were conducted in the Dominican Republic to determine the effect of physical and chemical treatments on the germination of the ornamental palms Roystonea hispaniolana Bailey (Royal palm), Acrocomia quisqueyana Bailey (Corozo palm), Sabal umbraculifera Mart (Cana palm), Phoenix canariensis (Canary Islands date palm), Veitchia merrillii (Becc) Bailey (Manila palm), Chrysalidocarpus lutescens Wendl (Areca palm), and Caryota urens (Fishtail palm). Treatments were seed immersion in water or gibberellic acid 3 (GA3) solution for 72 hours, immersion in concentrated nitric acid for 5 minutes, or cracking of the seed coat. Rate and percentage of emergence 90 days after treatment were measured. The best results for Roystonea, Phoenix, Veitchia, Caryota, and Chrysalidocarpus were obtained soaking the seeds in water or a 200-ppm gibberellic acid solution. Nitric acid and seed coat cracking significantly reduced the germination percentage in all the species, except Acrocomia guisqueyana and Sabal umbraculifera. Seeds of Acrocomia did not germinate as a response to any of the treatments tested. Sabal seeds germinated only after coat cracking or nitric acid treatment.

Dormancy-break and germination in seeds of Prunus campanulata (Rosaceae): role of covering layers and changes in concentration of abscisic acid and gibberellins

2007 ◽  
Vol 17 (1) ◽  
pp. 21-32 ◽  
Author(s):  
Shun-Ying Chen ◽  
Ching-Te Chien ◽  
Jeng-Der Chung ◽  
Yuh-Shyong Yang ◽  
Shing-Rong Kuo
Keyword(s):  
Abscisic Acid ◽  
Seed Coat ◽  
Carotenoid Biosynthesis ◽  
Inhibitory Effect ◽  
Germination Percentage ◽  
Biosynthesis Inhibitor ◽  
Breaking Dormancy ◽  
Aba Content ◽  
Ga Biosynthesis

AbstractIntact seeds (seed+endocarp) from freshly harvested fruits of Prunus campanulata were dormant, and required 4–6 weeks of warm followed by 8 weeks of cold stratification for maximum germination percentage. Removing both endocarp and seed coat, however, promoted germination in a high percentage of non-stratified seeds. Treatment of intact, non-stratified seeds with gibberellic acid (GA3) was only partially effective in breaking dormancy. However, GA3 promoted germination of non-stratified seeds in which the endocarp (but not the seed coat) had been removed. The order of abscisic acid (ABA) concentration in fresh seeds was endocarp > seed coat > embryo, and its concentration in endocarp plus seed coat was about 6.2-fold higher than that in the embryo. Total ABA contents of seeds subjected to warm and/or cold moist stratification were reduced 6- to 12-fold. A higher concentration of GA4 was detected in embryos of non-dormant than in those of dormant seeds. Fluridone, a carotenoid biosynthesis inhibitor, was efficient in breaking dormancy of Prunus seeds. Paclobutrazol, a GA biosynthesis inhibitor, completely inhibited seed germination, and the inhibitory effect could be partially reversed by GA4, but not by GA3. Thus, dormancy in P. campanulata seeds is imposed by the covering layers. Dormancy break is accompanied by a decrease in ABA content of the covering layers and germination by an increase of embryonic GA4 content.

Corrigendum to: Improved germination of the Australian natives: Hibbertia commutata, Hibbertia amplexicaulis (Dilleniaceae), Chamaescilla corymbosa (Liliaceae), and Leucopogon nutans (Epacridaceae)

2004 ◽  
Vol 52 (4) ◽  
pp. 559
Author(s):  
Sally M. Allan ◽  
Steve W. Adkins ◽  
Christine A. Preston ◽  
Sean M. Bellairs
Keyword(s):  
Gibberellic Acid ◽  
Acid Solution ◽  
Seed Coat ◽  
Shock Treatment ◽  
Dormancy Breaking ◽  
Australian Species ◽  
Germination Response ◽  
Embryo Dormancy ◽  
Site Rehabilitation ◽  
Smoke Water

Hibbertia commutata Steudel, H. amplexicaulis Steudel, Chamaescilla corymbosa (R.Br.) F.Muell. Ex Benth. and Leucopogon nutans E.Pritzel are four Australian species that are difficult to germinate during mine-site rehabilitation. Laboratory germination trails were conducted to identify dormancy mechanisms and to improve germination response. Treatments applied to all species included scarification and scarification followed by soaking seeds in smoke water (1, 5 or 10%) or gibberellic acid solution (50, 200 or 1000 μM). Additional treatments with kinetin solution (50, 200 or 1000 μM) and smoke water (50 or 100%) were applied to scarified or unscarified seeds of C. corymbosa. Thermal-shock treatment was applied to L. nutans fruit, some of which were subsequently scarified and subjected to both smoke water (10%) and gibberellic-acid solution (1000 μM). Significant germination increases were obtained by using dormancy-breaking treatments on H. commutata (12.8 to 76.0%), H. amplexicaulis (6.8 to 55.1%) and C. corymbosa (48.5 to 86.4%). Scarification alone increased germination of both Hibbertia species, suggesting that these species display a physical seed coat-imposed dormancy mechanism. Germination of H. amplexicaulis was further increased by the application of gibberellic-acid solution, indicating a possible embryo-imposed dormancy mechanism. Scarification followed by the application of smoke water produced the highest germination response for C. corymbosa seeds. Scarification alone did not significantly increase germination, inferring the existence of a smoke-responsive embryo dormancy mechanism. Seeds of L.�nutans, although viable, failed to germinate and are thought to display complex seed coat- and embryo-imposed dormancy mechanisms.

Weed Seed Germination Responses to Chemical and Physical Treatments

Weed Science ◽  
1972 ◽  
Vol 20 (2) ◽  
pp. 150-153 ◽  
Author(s):  
R. E. Holm ◽  
M. R. Miller
Keyword(s):  
Abscisic Acid ◽  
Seed Germination ◽  
Gibberellic Acid ◽  
Seed Coat ◽  
Hot Water ◽  
Weed Seed ◽  
Weed Species ◽  
Germination Response ◽  
Weed Seeds ◽  
Physical Treatments

The germination responses of seeds from 11 weed species to various chemical and physical treatments were studied. Germination of nine species was promoted by gibberellic acid and inhibited by abscisic acid, suggesting that germination of some weed seeds may be controlled by appropriate levels of these substances. Most of the weeds that germinated better after a hot-water soak treatment responded to sonication and infrared treatment, indicating that temperature was a factor in the germination response obtained with these methods, although physical disruption of the seed coat also was involved.

Germination of Cocklebur Seeds: Interactions Between Gibberellic Acid, Benzyladenine, Thiourea, KNO3 and Gaseous Factors

1975 ◽  
Vol 2 (4) ◽  
pp. 569 ◽  
Author(s):  
Y Esashi ◽  
Y Hata ◽  
H Katoh
Keyword(s):  
Gibberellic Acid ◽  
Seed Coat ◽  
Ethylene Production ◽  
Germination Percentage ◽  
Co2 Production ◽  
Ambient Atmosphere ◽  
Germination Period ◽  
Germination Response ◽  
Germination Stimulants ◽  
Underground Habitat

The germination response of small, upper seeds of cocklebur (Xanthium pensylvanicum Wallr.) was examined with respect to the germination stimulants oxygen, CO2, ethylene, gibberellic acid, benzyladenine, thiourea and KNO3. Thiourea, benzyladenine, ethylene and oxygen-enriched air (50% O2) stimulated germination, but gibberellic acid was only slightly effective and KNO3 had little effect. In contact with thiourea or CO2, seeds usually germinated by extrusion of the radicle without any change of germination pattern, but while in O2-enriched air the seed coat was predominantly ruptured at the cotyledon end. In about half of the seeds germinated with ethylene, benzyladenine and gibberellic acid, the seed coat split at the cotyledon side. Trapping of endogenously evolved ethylene and CO2 from the ambient atmosphere did not affect the actions of benzyladenine and gibberellic acid, but the action of thiourea was significantly reduced by trapping CO2. Except for thiourea, with which the CO2 production was enhanced, benzyladenine, gibberellic acid and KNO3 did not increase CO2 and ethylene production from the seed in the germination period. The maximum germination percentage was obtained by a combi- nation of CO2, ethylene, gibberellic acid and benzyladenine, but the interaction of gibberellic acid and benzyladenine was not significant. In contrast, the interaction of gibberellic acid and ethylene was very effective, and further addition of CO2 to this combination hastened the germination in air and also facilitated it under the semi-anaerobiosis assumed to exist in a natural underground habitat, although the effect of benzyladenine alone was nearly completely suppressed by semi- anaerobiosis. Thus the particular importance of CO2, ethylene and gibberellic acid in the normal germination regulation of this seed is suggested.

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).

Improved germination of the Australian natives: Hibbertia commutata, Hibbertia amplexicaulis (Dilleniaceae), Chameascilla corymbosa (Liliaceae), and Leucopogon nutans (Epacridaceae)

2004 ◽  
Vol 52 (3) ◽  
pp. 345 ◽  
Author(s):  
Sally M. Allan ◽  
Steve W. Adkins ◽  
Christine A. Preston ◽  
Sean M. Bellairs
Keyword(s):  
Gibberellic Acid ◽  
Acid Solution ◽  
Seed Coat ◽  
Shock Treatment ◽  
Dormancy Breaking ◽  
Australian Species ◽  
Germination Response ◽  
Embryo Dormancy ◽  
Site Rehabilitation ◽  
Smoke Water

Hibbertia commutata (Steudel), H. amplexicaulis (Steudel), Chameascilla corymbosa [(R.Br.) F.Muell. Ex Benth.] and Leucopogon nutans (E.Pritzel) are four Australian species that are difficult to germinate during mine-site rehabilitation. Laboratory germination trails were conducted to identify dormancy mechanisms and to improve germination response. Treatments applied to all species included scarification and scarification followed by soaking seeds in smoke water (1, 5 or 10%) or gibberellic acid solution (50, 200 or 1000 μM). Additional treatments with kinetin solution (50, 200 or 1000 μM) and smoke water (50 or 100%) were applied to scarified or unscarified seeds of C. corymbosa. Thermal-shock treatment was applied to L. nutans fruit, some of which were subsequently scarified and subjected to both smoke water (10%) and gibberellic-acid solution (1000 μM). Significant germination increases were obtained by using dormancy-breaking treatments on H. commutata (12.8 to 76.0%), H. amplexicaulis (6.8 to 55.1%) and C. corymbosa (48.5 to 86.4%). Scarification alone increased germination of both Hibbertia species, suggesting that these species display a physical seed coat-imposed dormancy mechanism. Germination of H. amplexicaulis was further increased by the application of gibberellic-acid solution, indicating a possible embryo-imposed dormancy mechanism. Scarification followed by the application of smoke water produced the highest germination response for C. corymbosa seeds. Scarification alone did not significantly increase germination, inferring the existence of a smoke-responsive embryo dormancy mechanism. Seeds of L.�nutans, although viable, failed to germinate and are thought to display complex seed coat- and embryo-imposed dormancy mechanisms.

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