Dormancy is modulated by seed structures in palms of the cerrado biome

2015 ◽  
Vol 63 (5) ◽  
pp. 444 ◽  
Author(s):  
V. S. Carvalho ◽  
L. M. Ribeiro ◽  
P. S. N. Lopes ◽  
C. O. Agostinho ◽  
L. J. Matias ◽  
...  
Keyword(s):  
Seed Germination ◽  
Water Absorption ◽  
Distribution Pattern ◽  
Seed Dormancy ◽  
Seed Coat ◽  
Distribution Patterns ◽  
Brazilian Savanna ◽  
Germination Capacity ◽  
Cerrado Biome ◽  
Acrocomia Aculeata

The aim of the present study was to evaluate the influence of the seed structures on the dormancy of the palms Attalea vitrivir Zona, Butia capitata (Mart.) Becc. and Acrocomia aculeata (Jacq.) Lodd. ex Mart., which are found in the cerrado biome (Brazilian savanna). The effects of seed structures on the imbibition and effects of the operculum on germination were evaluated. The effects of the collection area on the seed biometric characteristics and influence of the embryo mass and length on their germination capacity and vigour were also evaluated. The operculum was anatomically characterised, and the effects of the operculum thickness on seed germination were evaluated. The seed structures partially restricted water absorption by the embryos, but this did not affect germination; however, removing the operculum promoted germination. The mass of A. vitrivir and A. aculeata embryos positively influenced their germination capacity and vigour, and the thicknesses of the opercular seed coat and operculum negatively controlled the germination capacity of B. capitata. The greater thickness and rigidity of the operculum of A. aculeata increased the intensity of seed dormancy and possibly contributed to the wider distribution pattern of this species. The interaction between the embryo and operculum structures modulate the dormancy and possibly influence the distribution patterns of the palms in the cerrado biome.

scholarly journals Effects of Temperature, Scarification, Stratification, Phytohormones, and After-Ripening on the Dormancy and Germination of Eucommia ulmoides Oliv. Seeds

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1593
Author(s):  
Shiming Deng ◽  
Zhijun Deng ◽  
Xiaofeng Wang ◽  
Hai Lu ◽  
Hua Xue
Keyword(s):  
Seed Germination ◽  
Water Absorption ◽  
Seed Dormancy ◽  
Seed Coat ◽  
Underlying Mechanism ◽  
Germination Percentage ◽  
Growth Potential ◽  
Eucommia Ulmoides ◽  
Germplasm Resources ◽  
Type 3

Eucommia ulmoides Oliv., the only member of the family Eucommiaceae, is endemic to China and has great development and utilization prospects. The seeds of E. ulmoides show dormancy but the underlying mechanism remains unknown. The aim of this study was to determine the cause of the seed dormancy and provide fundamental knowledge for the breeding, genetic improvement, and conservation of the germplasm resources of this species. According to the seed dormancy classification system developed by Jerry M. Baskin and Carol C. Baskin, we compared the germination percentage between intact seeds and isolated embryos, constructed water absorption curves, and evaluated the germination of seeds treated with scarification, cold/warm-moist stratification, after-ripening during dry storage, and gibberellic acid (GA3). The results showed that the intact seeds germinated only at 10 °C with a low germination percentage of 13.3% whereas the isolated embryos had a high normal germination percentage among a wider range of temperatures. According to the results from the scarified seeds, half seeds, and intact seeds, the seed coat significantly restricted the embryo water absorption. The scarification, after-ripening, cold/warm-moist stratification, and GA3 treatments promoted seed germination. Among them, cold-moist stratification was the most effective method and the temperature range of seed germination increased in both directions from 10 °C with prolonged stratification. The germination percentage increased significantly at constant temperatures with the highest germination percentage of 93.7 ± 0.3% at 10 °C and a light/dark cycle after 90 days of cold-moist stratification. Therefore, the freshly harvested E. ulmoides seeds exhibited a combinational dormancy comprising physical and Type 3 non-deep physiological dormancy, causing limited embryo water absorption by the seed coat and a low embryo growth potential. Given the unique phylogenetic characteristics and utility of E. ulmoides, our findings should promote studies of seed dormancy evolution and the development and application of E. ulmoides germplasm resources.

Effects of Chemical Treatments on Seed Germination of Zoysia (Zoysia japonica Steud.)

2013 ◽  
Vol 850-851 ◽  
pp. 1295-1302
Author(s):  
Li Li Qian ◽  
Shan Wang ◽  
Kai Ye ◽  
Cheng Fang
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Seed Coat ◽  
Treatment Time ◽  
Warm Season ◽  
Dormancy Breaking ◽  
Zoysia Japonica ◽  
Chemical Treatments ◽  
Chemical Agents ◽  
The Right

Zoysia (Zoysia japonica Steud.) is a warm-season turf grass, which possess seed coat-imposed dormancy that hampers germination. The objective of the present study was to determine the most effective methods in breaking the seed dormancy of zoysia. This experiment was used to find the right concentration and treatment time. KOH, NaOH, C3H6O, and H2SO4solutions are the four kinds of chemical agents used which were evaluated and sixty four treatments were conducted. The results indicated that all chemical agents investigated can successfully remove glumes and promote seed germination of zoysia under certain concentrations and treatment times. The best method for seed dormancy breaking in zoysia was 20% KOH solution for 30 min.

scholarly journals Comparative metabolites profiling of Polygonatum cyrtonema Hua seed during sand storage and germination

2020 ◽  
Author(s):  
Qing Jin ◽  
Jinfeng Tong ◽  
Wenwu Zhang ◽  
Long Xia ◽  
Xiaoyun Zhu ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Seed Coat ◽  
Metabolic Pathways ◽  
Vital Role ◽  
Metabolic Pathway Analysis ◽  
Germination Process ◽  
Breaking Seed Dormancy ◽  
Metabolic Activities ◽  
Storage Times

Abstract Background: The seeds of Polygonatum cyrtonema Hua have dormancy phenomenon. Previous studies have shown that sand storage factors effects of the seed dormancy of P. cyrtonema Hua seeds and enhance the seed germination process. Subsequently, metabolic activities and different changes during the sand storage and germination process of P. cyrtonema Hua seed has not been heavily researched.Results: In this study the changes in the metabolites of P. cyrtonema Hua seeds at different sand storage times and germination stages, we used untargeted metabolomics to determine them. Most of the sugar and glycoside contents in seed coat increased after 30 d on the other hand, in peeled seeds increased at 30 d and decreased at 60 d after sand storage treatment. The content of proline and benzoic acid decreased in the seed coat after sand storage. PCA, OPLS-DA and HCA showed that the contents of most metabolites increased after 7 d and decreased after 14 d of seed germination. The process of 7 d to 14 d was the key stage of seed germination of P. cyrtonema Hua. Differential metabolic pathway analysis showed that seed germination was controlled by multiple metabolic pathways. Metabolic correlation revealed the interdependence between seed germination metabolites and metabolic pathways. Conclusion: Sand storage can significantly increase the rate of seed germination and play a vital role in seed dormancy of P. cyrtonema Hua. There was inherent differences in metabolites during different storage time and germination stages in P. cyrtonema Hua. Our work provides a first glimpse of the metabolome in seed germination of P. cyrtonema Hua, and provides a valuable informations for revealing the mechanism of breaking seed dormancy.

Seed germination and seedling establishment

2009 ◽  
Author(s):  
M. Anwar Maun
Keyword(s):  
Seed Germination ◽  
High Temperatures ◽  
Seed Dormancy ◽  
Seed Coat ◽  
Seedling Establishment ◽  
Sand Dunes ◽  
Early Summer ◽  
Cold Stratification ◽  
Ammophila Breviligulata ◽  
Mechanical Constraints

For the transformation of a seed to a seedling complex physical and biochemical changes occur within a seed before germination can proceed. Germination is controlled by diverse seed dormancy mechanisms in plant species that delays germination until the conditions are most favourable for seed germination and seedling establishment (Thompson 1970). Baskin and Baskin (1998) identified four benefits for the evolution of seed dormancy in plants: (i) persistence in risky environments as seed banks, (ii) decreased intraspecific competition, (iii) improved chances of seedling establishment and (iv) increased fitness (seed production) of the individual and the species as a whole. They showed that seed dormancy may be caused by any one of physiological, morphological, physical, chemical and mechanical constraints or by a combination of more than one of these factors. For instance, seeds may possess an embryo with a physiological inhibiting mechanism, immature embryo, impermeable seed coat or may contain chemical inhibitors and hard woody fruit walls. In all of these cases seed dormancy is eventually broken by one or more of the following treatments: after ripening, heat treatment, cold temperature stratification, prolonged exposure to high temperatures, exposure to light, softening of seed coat by microbes or physical scarification, leaching of inhibiting chemicals, ageing of seeds and other subtle changes in the habitat. In temperate North America with snow cover during winter months the seeds of a large majority of sand dune species—Cakile edentula, Ammophila breviligulata, Calamovilfa longifolia, Iva imbricata, Croton punctatus, Uniola paniculata—and others require cold stratification at <4°C for 4–6 weeks to break their dormancy requirements. Seeds of some species such as A. breviligulata and U. paniculata that require cold stratification at the northern end of their range lose this requirement in the south (Seneca 1972). At southern locations exposure to high temperatures may be required to fulfil the dormancy requirements. Winter annuals, Vulpia ciliata, Cerastium atrovirens, Mibora minima and Saxifraga tridactylites, that grow and mature their seeds in early summer on sand dunes at Aberffraw, North Wales, require exposure to high soil temperatures to overcome a state of dormancy in a certain proportion of seeds at the time of dispersal (Carey and Watkinson 1993; Pemadasa and Lovell 1975).

Population ecology of Cirsium pitcheri on Lake Huron sand dunes. III. Mechanisms of seed dormancy

1998 ◽  
Vol 76 (4) ◽  
pp. 575-586 ◽  
Author(s):  
Hua Chen ◽  
M A Maun
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Seed Coat ◽  
Threatened Species ◽  
Sand Dunes ◽  
Growth Chamber ◽  
Oenothera Biennis ◽  
Breaking Seed Dormancy ◽  
Cirsium Pitcheri ◽  
Germination Requirements

Growth chamber studies were conducted to examine seed dormancy and germination requirements of Pitcher's thistle (Cirsium pitcheri (Torr. ex Eaton) Torr. & Gray), a threatened species endemic to the shoreline sand dunes of the Great Lakes. We determined the effects of different environmental regimes on breaking seed dormancy of this monocarpic perennial. The data showed that seeds of C. pitcheri possessed innate dormancy that was caused by a hard seed coat as well as inhibitory compounds within the seed. Seed germination requirements were very specific. Exposure of seeds to different temperatures and photoperiods in a growth chamber had little effect on breaking seed dormancy unless the seeds had been pretreated. Pretreatment of seeds by cold stratification and its duration, scarification by sand paper or sulphuric acid, and application of gibberellic acid were also not very effective for breaking dormancy of C. pitcheri. High germination was obtained only when seeds were pretreated either by surgically removing the seed coat or by nicking the seed on the radicle or cotyledonary end. After this pretreatment seeds germinated over a temperature range of 15-30°C, but the highest proportion of seeds germinated when temperatures were above 20°C. Under natural conditions, germination of C. pitcheri seeds occurs in spring after they have overwintered and experienced the pretreatment of stratification and scarification through freezing and thawing of the substrate. Aqueous extract of C. pitcheri seeds had a strong inhibitory effect on germination of Oenothera biennis L. seeds indicating an allelopathic chemical in the seed. There was no relationship between the seed size of C. pitcheri and the germinability of seeds.Key words: Cirsium pitcheri, threatened species, seed dormancy, seed germination, scarification, stratification, nicking of seeds.

scholarly journals PERMEABILITY TO WATER AND VIABILITY IN HETEROMORPHIC COLOR SEEDS OF Bowdichia Virgilioides KUNTH

2021 ◽  
Vol 45 ◽  
Author(s):  
Raquel Gonçalves Silva ◽  
Denise Garcia de Santana ◽  
Cristiane Carvalho Guimarães ◽  
Edvaldo Aparecido Amaral da Silva
Keyword(s):  
Seed Germination ◽  
Water Absorption ◽  
Seed Coat ◽  
Coat Color ◽  
Seed Coat Color ◽  
Water Imbibition ◽  
Probable Relationship ◽  
Determining Factor ◽  
Yellowish Orange

ABSTRACT Species that produce seeds with a rigid integument represent a serious problem because their impermeable coat restricts the entry of water, which makes germination difficult. The heteromorphism of the integument in Bowdichia virgilioides causes water imbibition to vary substantially and, therefore, the objective of this work was to study the relation of seed coat color with permeability and viability in Bowdichia virgilioides. Seeds were separated into five different colors (yellowish-orange, orange, orange/reddish, reddish, and rusty red) and the following parameters were analyzed: water absorption, germination, mortality, viability, synchrony, and maximum potential of germination. The color was a determining factor for most of the evaluated parameters. The seeds with yellowish or orange/reddish coats tend to be little permeable to water while seeds with reddish or rusty red coats are highly permeable. The results indicated that seeds with reddish color had greater physiological potential indicating a probable relationship with the maturation point of the species. However, in the seeds of the species studied, irrespective of coloring, germination was late with low synchrony and low daily seed germination count, typical characteristics of dormancy.

Mechanisms of seed dormancy in an annual population of Zostera marina (eelgrass) from The Netherlands

1991 ◽  
Vol 69 (9) ◽  
pp. 1972-1976 ◽  
Author(s):  
Paul Garth Harrison
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Seed Coat ◽  
Zostera Marina ◽  
Early Winter ◽  
Physical Dormancy ◽  
Physiological Dormancy ◽  
Annual Population ◽  
Effects Of Temperature ◽  
Viable Seeds

Mechanisms of dormancy of seeds from an annual population of the seagrass Zostera marina L. (eelgrass) in the SW Netherlands were investigated in the laboratory. Both physiological dormancy (a requirement for reduced salinity for germination) and physical dormancy (imposed by the seed coat) existed in recently shed seeds. Physiological seed dormancy was partly released in the seed bank by early winter, but physical dormancy lasted longer. By March seeds germinated quickly in the dark in full-strength seawater without artificial weakening of the seed coat. Viable seeds were released with coats that ranged from green (easily ruptured by the embryo) to brown (not easily ruptured); this variation may account for the occasional seedlings that appear during winter. No significant effects of temperature or light on germination were detected. A reexamination of the literature suggests that the observed variation in timing of germination in eelgrass populations may be a result of hitherto overlooked aspects of dormancy. Key words: eelgrass, seagrass, seed coat, seed dormancy, seed germination, Zostera marina.

Dormancy breakage in Cercis chinensis seeds

2020 ◽  
Vol 100 (6) ◽  
pp. 666-673
Author(s):  
Yunpeng Gao ◽  
Mingwei Zhu ◽  
Qiuyue Ma ◽  
Shuxian Li
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Seed Coat ◽  
Germination Percentage ◽  
Physical Dormancy ◽  
Optimal Method ◽  
Hard Seed ◽  
Positive Effects ◽  
Physiological Dormancy ◽  
Hard Seed Coat

The seeds of Cercis chinensis Bunge are important for reproduction and propagation, but strong dormancy controls their germination. To elucidate the causes of seed dormancy in C. chinensis, we investigated the permeability of the hard seed coat and the contribution of the endosperm to physical dormancy, and we examined the effect of extracts from the seed coat and endosperm. In addition, the effectiveness of scarification methods to break seed dormancy was compared. Cercis chinensis seeds exhibited physical and physiological dormancy. The hard seed coat played an important role in limiting water uptake, and the endosperm acted as a physical barrier that restricted embryo development in imbibed seeds. Germination percentage of Chinese cabbage [Brassica rapa subsp. chinensis (L.) Hanelt] seeds was reduced from 98% (control) to 28.3% and 56.7% with a seed-coat extract and an endosperm extract, respectively. This demonstrated that both the seed coat and endosperm contained endogenous inhibitors, but the seed-coat extract resulted in stronger inhibition. Mechanical scarification, thermal scarification, and chemical scarification had positive effects on C. chinensis seed germination. Soaking non-scarified seeds in gibberellic acid (GA3) solution did not promote germination; however, treatment with exogenous GA3 following scarification significantly improved germination. The optimal method for promoting C. chinensis seed germination was soaking scarified seeds in 500 mg·L−1 GA3 for 24 h followed by cold stratification at 5 °C for 2 mo.

Role of seed coat in regulation of seed dormancy in houndstongue (Cynoglossum officinale)

Weed Science ◽  
1998 ◽  
Vol 46 (3) ◽  
pp. 344-350 ◽  
Author(s):  
Elisa Stabell ◽  
Mahesh K. Upadhyaya ◽  
Brian E. Ellis
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Seed Coat ◽  
Elevated Level ◽  
Quantitative Relationship ◽  
Total Phenolic ◽  
Cynoglossum Officinale ◽  
Saturated Water ◽  
Stimulation Of

To understand the role of the seed coat in regulation of houndstongue seed dormancy, the effects of manipulation of seed coat integrity on seed germination and O2uptake were studied. The results suggest that the seed coat of this weed regulates dormancy in part by interfering with the diffusion of O2to the embryo. Scanning electron microscopy showed a network of ridges on the seed coat surface that were partially dissolved following 1.5 min of sulphuric acid scarification. Mechanical scarification removed fragments of the seed coat surface. Both scarification treatments stimulated seed germination. Supply of an elevated level of O2also stimulated seed germination. O2uptake by seeds imbibed in O2-saturated water was 150% higher than that for seeds imbibed in air-saturated water. Although all treatments that stimulated seed germination also stimulated O2uptake, there was a lack of a consistent, quantitative relationship between increases in O2uptake and seed germination in various experiments. This suggests that limitation of O2availability to the embryo is not the only factor involved in regulation of houndstongue seed dormancy by the seed coat. Mechanical restriction of embryo expansion by the seed coat may also be important. Methanol-insoluble phenolics constituted < 1% of the total phenolic pool in the embryo. Their potential oxidation could not account for more than a small fraction of the previously reported massive stimulation of O2uptake by the embryo upon decoating. The present O2uptake and seed germination studies indicate that not all of the large increase in O2uptake following decoating is essential for houndstongue seed germination.

Grevillea (Proteaceae) seed coats contain inhibitors for seed germination

2015 ◽  
Vol 63 (7) ◽  
pp. 566 ◽  
Author(s):  
Xuanli Ma ◽  
Jingnan Guo ◽  
Xinyan Han ◽  
Guijun Yan
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Seedling Growth ◽  
Seed Coat ◽  
Germination Inhibitors ◽  
Half Seed ◽  
Seed Coats

The purpose of this research was to examine the effect of the seed coat on seed dormancy in Grevillea (Proteaceae) species, and to further investigate the existence of germination inhibitors in Grevillea seed coat extracts. Seed dormancy of 18 Grevillea accessions involving 17 species was investigated: results indicated that removal of seed coat increased seed germination from 0–6% (intact seeds) to 83–100% for the Grevillea accessions and removal of half seed coat resulted in no increase in seed germination. Grevillea seed coat extracts reduced germination of barley, canola, lupin and ryegrass seeds by 48, 57, 10 and 38% respectively. The extracts also reduced seedling growth of the above four species. Ryegrass seeds showed no germination on the 3rd day after imbibition in the presence of Grevillea seed coat extracts compared with 88% germination for the control. Thus, our results showed that seed coat is a major factor determining Grevillea seed dormancy and removal of seed coat dramatically increased seed germination. Grevillea seed coat extracts reduced seed germination and seedling growth of other species. We conclude that there is exogenous seed dormancy in Grevillea species and the chemical(s) in the seed coat is a major factor inhibiting seed germination.

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