Germination and dormancy breaking by ethephon in mature and immature seeds of Medicago truncatula (medic) and Trifolium subterraneum (clover)

1978 ◽  
Vol 29 (1) ◽  
pp. 43 ◽  
Author(s):  
D Globerson
Keyword(s):  
Carbon Dioxide ◽  
Seed Germination ◽  
Medicago Truncatula ◽  
Germination Rate ◽  
Trifolium Subterraneum ◽  
Dormancy Breaking ◽  
Controlled Conditions ◽  
Immature Seeds ◽  
Mature Seeds

The effects of ethephon (2-chloroethylphosphoric acid) and temperature on seed germination were studied in two cultivars of Medicago truncatula (medic) and one cultivar of Trifolium subterraneum (clover) grown under different controlled conditions. Ethephon promoted germination of immature and fresh mature seeds and increased the germination rate of old mature seeds. Ethephon thiourea and carbon dioxide had different effects on the germination of seeds of the medic cultivars. At 30°C, untreated seeds germinated poorly while the presence of 10 ppm ethephon increased germination significantly.

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 Non-Deep Physiological Dormancy in Seed and Germination Requirements of Lysimachia coreana Nakai

Horticulturae ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 490
Author(s):  
Saeng Geul Baek ◽  
Jin Hyun Im ◽  
Myeong Ja Kwak ◽  
Cho Hee Park ◽  
Mi Hyun Lee ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Germination Rate ◽  
Seed Viability ◽  
Cold Stratification ◽  
Dormancy Breaking ◽  
Viability Test ◽  
Physiological Dormancy ◽  
Different Temperatures ◽  
Germination Requirements

This study aimed to determine the type of seed dormancy and to identify a suitable method of dormancy-breaking for an efficient seed viability test of Lysimachia coreana Nakai. To confirm the effect of gibberellic acid (GA3) on seed germination at different temperatures, germination tests were conducted at 5, 15, 20, 25, 20/10, and 25/15 °C (12/12 h, light/dark), using 1% agar with 100, 250, and 500 mg·L−1 GA3. Seeds were also stratified at 5 and 25/15 °C for 6 and 9 weeks, respectively, and then germinated at the same temperature. Seeds treated with GA3 demonstrated an increased germination rate (GR) at all temperatures except 5 °C. The highest GR was 82.0% at 25/15 °C and 250 mg·L−1 GA3 (4.8 times higher than the control (14.0%)). Additionally, GR increased after cold stratification, whereas seeds did not germinate after warm stratification at all temperatures. After cold stratification, the highest GR was 56.0% at 25/15 °C, which was lower than the GR observed after GA3 treatment. We hypothesized that L. coreana seeds have a non-deep physiological dormancy and concluded that 250 mg·L−1 GA3 treatment is more effective than cold stratification (9 weeks) for L. coreana seed-dormancy-breaking.

scholarly journals Asymbiotic Germination of Mature Seeds and the Seed Development of Vanilla Planifolia

2021 ◽  
Author(s):  
Chih-Hsin Yeh ◽  
Kai-Yi Chen ◽  
Yung-I Lee
Keyword(s):  
Cell Wall ◽  
Seed Germination ◽  
Seed Development ◽  
Seed Coat ◽  
Germination Percentage ◽  
Vanilla Planifolia ◽  
Outermost Layer ◽  
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, sexual propagation with seed germination of V. planifolia is intricate and unstable because of the extremely hard seed coat. 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 and that immature seeds collected 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. After 60 DAP, the cell wall of the outermost layer of the outer seed coat became lignified and finally compressed into a thick envelope. These features matches the significant decreases of immature seed germination percentage after 60 DAP. 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 thickened and lignified seed coat formed an impermeable envelope surrounding the embryo, and might play an important role in seed dormancy of V. plantifolia.

scholarly journals Studies of Dormancy in the Seeds of Subterranean Clover (Trifolium Subterraneum L.) II. The Interaction of Time, Temperature, and Carbon Dioxide During Passage Out of Dormancy

1961 ◽  
Vol 14 (2) ◽  
pp. 173 ◽  
Author(s):  
LAT Ballard
Keyword(s):  
Carbon Dioxide ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dormancy Breaking ◽  
Temperature Dependent

The dormancy-breaking action of C02 on imbibed seeds of subterranean clover ('1'rijolium 8ubterraneum L.) is temperature dependent, the efficiency falling off sharrlly above 25�C and approaching zero at 30�C. Within the effective temp. erature range the action is rapid, exposure of seeds to CO2 for 6 hr having signifiC!,fit effect.

scholarly journals A Study on Germination Biology of Wild Mustard (Sinapis arvensis L.)

2021 ◽  
Vol 9 (4) ◽  
pp. 728-732
Author(s):  
Bahadir Şin ◽  
İzzet Kadıoğlu
Keyword(s):  
Seed Germination ◽  
Germination Rate ◽  
Optimum Temperature ◽  
Dormancy Breaking ◽  
Future Studies ◽  
Sinapis Arvensis ◽  
Wheat Field ◽  
Wild Mustard ◽  
Mustard Seeds

This study has been carried out in 2017-2018 in order to determine seed dormancy and effective germination depth wild mustard (Sinapis arvensis L.). The in-vitro dormancy breaking experiments (tip breaking, sanding, H2SO4 application, holding in flowing and still water, GA3, KNO3 and GA3+KNO3 combination application) has been applied to wild mustard seeds collected from wheat field in Tokat province and has been applied to wild mustard seeds collected from wheat field in Tokat province and the most effective method was determined as 1000 ppm GA3+KNO3 with 98% impact on seed germination at 15°C within 72 hours. In contrast germination rate has been calculated as 5% in control plants. Furthermore 15°C was assessed as optimum temperature for seed germination was the most effective temperature and during depth studies 100% of wild mustard seeds germinated at 3-5 cm. Because of the difficulies with the work with seeds and plants that have dormancy, these data will contribute future studies.

scholarly journals Abscisic Acid Inhibits Asymbiotic Germination of Immature Seeds of Paphiopedilum armeniacum

2020 ◽  
Vol 21 (24) ◽  
pp. 9561
Author(s):  
Xin Xu ◽  
Lin Fang ◽  
Lin Li ◽  
Guohua Ma ◽  
Kunlin Wu ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Large Scale ◽  
Germination Rate ◽  
Endogenous Hormone ◽  
Mature Stage ◽  
Physical Dormancy ◽  
Immature Seeds ◽  
Lignin Accumulation ◽  
Aba Content ◽  
Mature Seeds

Paphiopedilum armeniacum is a rare orchid native to China with high ornamental value. The germination of P. armeniacum seeds is difficult, especially for the mature seeds, which is the major limitation for their large-scale reproduction. This study explored the reasons for seed germination inhibition from the aspects of the important plant endogenous hormone—abscisic acid (ABA). The major endogenous hormone contents of seeds were determined at different developmental stages. The ABA content was 5.8 ng/g in 73 days after pollination (DAP) for the immature seeds, peaked at 14.6 ng/g in 129 DAP seeds, and dropped to 2.6 ng/g in the late mature stage of the 150 DAP seeds. The reduction of ABA content in the mature seed suggests a possible contribution to the increased expression of CYP707A, an ABA catabolism gene. The germination rate of the immature seeds was reduced to 9% from 69% when 5 μg/mL ABA was added to the Hyponex N026 germination medium. The result showed that ABA can inhibit the germination of P. armeniacum immature seeds. However, for the heavily lignified mature seeds, reduction in endogenous ABA level does not result in an increase in the germination rate. Lignin accumulation in the seed coat imposes the physical dormancy for P. armeniacum. In summary, the germination of P. armeniacum is regulated by both ABA and lignin accumulation.

scholarly journals Promotion of Immature Seed Germination in Jacaranda mimosifolia

HortScience ◽  
2005 ◽  
Vol 40 (5) ◽  
pp. 1485-1486
Author(s):  
Ikuo Miyajima ◽  
Adriana Kato ◽  
Juan Carlos Hagiwara ◽  
Diego Mata ◽  
Gabriela Facciuto ◽  
...  
Keyword(s):  
Seed Germination ◽  
Gibberellic Acid ◽  
Seedling Stage ◽  
Immature Seed ◽  
In Vitro Germination ◽  
Immature Seeds ◽  
Mature Seeds ◽  
Jacaranda Mimosifolia

In vitro germination of immature seeds of Jacaranda mimosifolia treated with gibberellic acid (GA3) was studied. Immature seeds were collected monthly after crossings and sown on Murashige and Skoog (1962) medium with 3.0% sucrose and 0.6% agar after soaked 24 hours with 0, 10, 100, and 500 mg·L–1 GA3 solutions. Though germination was observed in the immature seeds harvested 2 months after crossing (2 MAC), the rate was quite low. When immature seeds of 3 MAC treated with 100 or 500 mg·L–1 GA3 solution were cultured, >60% germination were obtained within 2 weeks after culturing. These results indicate that immature seeds of 3 MAC treated with adequate GA3 solutions, seedlings can be obtained precociously and the period from crossing to the seedling stage was shorter than for mature seeds.

Durum wheat (Triticum durum Desf.) seed storage under controlled conditions

2020 ◽  
pp. 105-115
Author(s):  
O.A. Zadorozhna ◽  
T. P. Shyianova ◽  
M.Yu. Skorokhodov
Keyword(s):  
Seed Germination ◽  
Moisture Content ◽  
Durum Wheat ◽  
Germination Rate ◽  
Seed Storage ◽  
Seed Longevity ◽  
Forest Steppe ◽  
Controlled Conditions ◽  
Seed Moisture ◽  
Wheat Seeds

Aim. The aim of this work was to determine the longevity of durum wheat seeds according to the results of seed germination monitoring after seed storage for up to 19 years under controlled conditions in the National Plant Gene Bank of Ukraine. Results and Discussion. 36 accessions of spring durum wheat were investigated. These accessions belonged to var. hordeiforme, var. leucurum, var. melanopus, var. alexandrinum, var. apulicum, var. australe from seven countries; seven samples of durum winter wheat belonged to var. hordeiforme, var. leucurum were from Ukraine. Accessions were received by the Ukrainian genebank from seven countries: Ukraine, Russia, Mexico, France, Portugal, Kazakhstan and Tunisia. Seed accessions for storage were grown mainly in the eastern forest-steppe of Ukraine, stored in the National depositary in this region at unregulated temperature and at 4°C with seed moisture content of 5.5-8.0%. The mode of seed drying, which took place at temperature not higher than 25°C is discussed. The obtained results indicate high seed longevity of durum wheat under these conditions with initial seed germination rate more than 90% even in a storage facility at unregulated temperature. There were no differences in seed longevity between varieties of durum wheat under the studied storage conditions. Conclusions. Seeds of durum wheat remain unchanged for at least 10 years with a high initial germination of seeds, storage in sealed containers with moisture content 5.5-8.0% even at unregulated temperature of the eastern forest-steppe of Ukraine. Durum wheat seeds should be storage at temperature 4°C to increase seed longevity at seed moisture 5.5-8.0%.

Dormancy-breaking Studies on Echinacea angustifolia

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 456f-457 ◽  
Author(s):  
Ali O. Sari ◽  
Mario R. Morales ◽  
James E. Simon
Keyword(s):  
Native Americans ◽  
Seed Germination ◽  
Tap Water ◽  
The United States ◽  
Market Demand ◽  
Dormancy Breaking ◽  
Echinacea Angustifolia ◽  
Native Populations ◽  
Percent Germination ◽  
Dry Heating

Echinacea is a medicinal plant native to North America. It was used extensively by native Americans in the treatment of their ailments. It is presently one of the most popular medicinal plants in the United States. Its popularity has created a large market demand for the roots and foliage of the plant. The gathering of echinacea from the wild is leading to the reduction of native populations and the destruction of its genetic diversity. Cultivation of medicinal echinaceas is hindered by a low seed germination. Dormancy breaking studies were done on freshly harvested seeds of Echinacea angustifolia. Seed lots were placed under light at a constant temperature of 25 °C and at alternate temperatures of 25/15 °C for 14/10 h, respectively. Germination was more rapid and uniform and percent germination higher at 25 °C than at 25/15 °C. Seed tap-water soaking, dry heating, and sharp heating alteration did not increase germination. The application of 1.0 mM ethephon (2-chloroethylphosphoric acid) increased seed germination to 94% at 25 °C and 86% at 25/15 °C. Untreated seeds gave 65% germination at 25 °C and 11% at 25/15 °C. The application of 2500 mg·L–1 and 3500 mg·L–1 of GA to dry seeds and 2500 mg·L–1 to seeds that have been soaked under tap water and then dried increased germination to 82%, 83%, and 83% at 25 °C and 64%, 78%, and 64% at 25/15 °C, respectively.

Sign in / Sign up

Export Citation Format

Share Document