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.

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.

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.

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.

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.

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.

scholarly journals Asymbiotic germination of Vanilla planifolia in relation to the timing of seed collection and seed pretreatments

2021 ◽  
Vol 62 (1) ◽  
Author(s):  
Chih-Hsin Yeh ◽  
Kai-Yi Chen ◽  
Yung-I. Lee
Keyword(s):  
Seed Germination ◽  
Seed Development ◽  
Seed Coat ◽  
Germination Percentage ◽  
Vanilla Planifolia ◽  
Outermost Layer ◽  
Seed Collection ◽  
Seed Pretreatment ◽  
Immature Seeds ◽  
Mature Seeds

Abstract Background Vanilla planifolia is an important tropical orchid for production of natural vanilla flavor. Traditionally, V. planifolia is propagated by stem cuttings, which produces identical genotype that are sensitive to virulent pathogens. However, propagation with seed germination of V. planifolia is intricate and unstable because the seed coat is extremely hard with strong hydrophobic nature. A better understanding of seed development, especially the formation of impermeable seed coat would provide insights into seed propagation and conservation of genetic resources of Vanilla. Results We found that soaking mature seeds in 4% sodium hypochlorite solution from 75 to 90 min significantly increased germination. For the culture of immature seeds, the seed collection at 45 days after pollination (DAP) had the highest germination percentage. We then investigated the anatomical features during seed development that associated with the effect of seed pretreatment on raising seed germination percentage. The 45-DAP immature seeds have developed globular embryos and the thickened non-lignified cell wall at the outermost layer of the outer seed coat. Seeds at 60 DAP and subsequent stages germinated poorly. As the seed approached maturity, the cell wall of the outermost layer of the outer seed coat became lignified and finally compressed into a thick envelope at maturity. On toluidine blue O staining, the wall of outer seed coat stained greenish blue, indicating the presence of phenolic compounds. As well, on Nile red staining, a cuticular substance was detected in the surface wall of the embryo proper and the innermost wall of the inner seed coat. Conclusion We report a reliable protocol for seed pretreatment of mature seeds and for immature seeds culture based on a defined time schedule of V. plantifolia seed development. The window for successful germination of culturing immature seed was short. The quick accumulation of lignin, phenolics and/or phytomelanins in the seed coat may seriously inhibit seed germination after 45 DAP. As seeds matured, the thickened and lignified seed coat formed an impermeable envelope surrounding the embryo, which may play an important role in inducing dormancy. Further studies covering different maturity of green capsules are required to understand the optimal seed maturity and germination of seeds.

scholarly journals Dormancy break in seeds of "quina" (Strychnos pseudoquina A. St.-Hil.)

2011 ◽  
Vol 13 (4) ◽  
pp. 507-511 ◽  
Author(s):  
J.M. Vasconcelos ◽  
M.A. Rodrigues ◽  
S.C. Vasconcelos Filho ◽  
J.F. Sales ◽  
F.G. Silva ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Medicinal Plant ◽  
Gibberellic Acid ◽  
Plant Species ◽  
Germination Percentage ◽  
Boiling Water ◽  
Medicinal Plant Species ◽  
Distilled Water ◽  
Brazilian Cerrado ◽  
Germination Speed

"Quina" (Strychnos pseudoquina A. St. Hil) is a medicinal plant species from the Brazilian Cerrado. As its seeds show dormancy, they were subjected to the treatments pre-cooling at 5ºC during 7 days, pre-heating at 40ºC during 7 days, pre-soaking in sulfuric acid PA during 5 and 15 min, pre-soaking in boiling water during 5 and 15 min, pre-soaking in 100 and 200 ppm gibberellic acid during 48 h, pre-soaking in distilled water during 24 and 48 h, and mechanical scarification to break dormancy. Counts were daily conducted from the 2nd day after the experiment implementation until the germination stabilization at the 65th day. The germination speed index (GSI) and the germination percentage were evaluated. Germination rates above 96% were reached in seeds pre-soaked in water during 48 h and substrate moistened with water or KNO3.

Note. Effect of Storage Temperature on the Shelf Life of Hass Avocado (Persea Americana)

2004 ◽  
Vol 10 (2) ◽  
pp. 73-77 ◽  
Author(s):  
K. Perez ◽  
J. Mercado ◽  
H. Soto-Valdez
Keyword(s):  
Weight Loss ◽  
Shelf Life ◽  
Respiration Rate ◽  
Ethylene Production ◽  
Storage Temperature ◽  
Persea Americana ◽  
Co2 Production ◽  
Hass Avocado ◽  
Storage Temperatures

The effect of storage temperature on the shelf life, weight loss, respiration rate and ethylene production of Hass avocado (Persea americana Mill) was studied. Two batches of green mature avocado fruits, classified as ‘‘super extra’’ were stored at 10 and 20 C (first batch) and at 7 and 25 C (second batch). The avocado shelf lives were 22, 8, 32 and 6 days at 10, 20, 7 and 25 C, respectively. Based on the data of the first assay Q10 was calculated as 2.75, with this value the predicted shelf life at 7 and 25 C were 29.8 and 4.8 days, respectively. That meant shelf life was underestimated 7 and 20% at 7 and 25 C, respectively. Weight loss was linear at both the storage temperatures, it was 4.3% in fruits at 20 C for 8 days and 3.0% at 10 C for 22 days. The maximum CO2 production at 20 C was reached during the second day of storage, while at 10 C it was reached at the 17th day (176.17 15.98 and 74.73 7.32 mL/kg h, respectively). The maximum ethylene production at 20 C was reached the second day of storage, and at 10 C the 6th day (239.06 54.55 and 28.00 8.12 mL/kg h, respectively).

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