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.

scholarly journals Emergence rate of seedlings from hard okra seed coats and seedling growth of some genotypes of West African okra (Abelmoschus caillei)

2019 ◽  
Vol 11 (2) ◽  
pp. 118-122
Author(s):  
P.M. Jonah ◽  
G. K. Farauta ◽  
Y. M. Kwaga ◽  
H. E. Shehu ◽  
N. M. Fakuta ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seedling Growth ◽  
Seedling Emergence ◽  
West African ◽  
Permeability Barrier ◽  
State University ◽  
Cropping Season ◽  
Emergence Rate ◽  
Emergence Percentage ◽  
Seed Coats

Abstract. In 2017 and 2018 cropping season, field experiment was conducted at the Food and Agricultural Organization and Tree Crop Plantation, Department of Crop Science, Adamawa State University, Mubi using fifteen genotypes of West African okra. The study was undertaken to study the emergence rate of seedlings from hard okra seed coats, seedling growth and their development. The seeds of the genotypes were soaked in NaCl solution for 24 hours to accelerate the breaking of seed dormancy and to ease seed germination. Tough seed coat usually impairs seed germination by establishing a permeability barrier which can interrupt water uptake required for imbibition, radicle and seedling emergence. The combined analysis results revealed a highly significant (P≤0.01) difference among these genotypes with respect to days to first and 50% flowering including days to first harvest. Furthermore, accession 3 (NG/SA/DEC/07/0448) and accession 11 (Yar kwadon) flowered earlier, had shortest days to first harvest, recorded the highest number of seedlings and emergence percentage than the other genotypes studied.

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 Elucidation of seed dormancy and phytohormones by germination after exogenous foliage whey application

1970 ◽  
pp. 08-14
Author(s):  
Jadhav Rajesh K, Pranay Mulam, Khot Vidhesh
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Seedling Growth ◽  
Rapid Growth ◽  
Germination Rate ◽  
Exogenous Application ◽  
Paper Towel ◽  
Leguminous Seeds ◽  
Growth Of Seedlings ◽  
Leaf Juice

A study was conducted with an aim of achieving 100% seed germination and to evaluate the rate of dormancy upon exogenous application of the deproteinised leaf juice (DPJ) in various leguminous and non leguminous seeds. DPJ if inducing retardation of dormancy, the activity of enzyme was analysed to prove the presence of phytohormones. DPJ from the three non leguminous foliages of brinjal, radddish and dasheen were prepared by green crop fractionation. The seed germination results obtained by the paper towel method and the activity of enzyme protease in DPJ of radish and Colocasia leaves separately. There was variation in germination rate by different DPJ influence. Some seeds showed fast germination while some germinated late. Few seeds were not germinated by control. In some seeds, DPJ decreased the rate of germination while on the contrary there was rapid growth of seedlings by the potentiality of DPJ. DPJ found mutagenic by its influencing inhibitory expression in seedling growth in some cases. The enzyme protease released by phytohormone gibberellin during the seed germination. Positive glyoxlic test indicated presence of auxins in whey.

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.

Inhibition Effect of Extraction from Seed of Phoebe Bournei

2013 ◽  
Vol 726-731 ◽  
pp. 4468-4472
Author(s):  
Wei Zhang ◽  
Tie Hua Li ◽  
Shi Zhi Wen ◽  
Gong Xiu He ◽  
Zhan Shen ◽  
...  
Keyword(s):  
Solvent Extraction ◽  
Seed Germination ◽  
Ethyl Acetate ◽  
Seed Coat ◽  
Inhibition Effect ◽  
Seed Embryo ◽  
Cabbage Seed ◽  
Seed Coats ◽  
Phoebe Bournei ◽  
Radical Length

In order to approach the dormant property of Phoebe bournei seeds, the inhibition effects of the different concentrations and different solvent extraction from seed coats and embryo of Phoebe bournei was studied through bioassay method.The results showed that there were inhibition effects of extracts on the germination and radical growing of cabbage seeds, and the inhibition effects became stronger as the contents of extracting solutions increased.Germination rate of cabbages in seed embryo extracts was lower than that in the seed coat extracts in the same concentrations, and the radical length in the seed embryo extracts was also shorter than that in the seed coat extracts. The seed embryo and coat extractions phase of ethyl acetate on the germination and radical growing of cabbage seeds had the strongest inhibition effect. The results indicated that inhibiting substances were existed both in the seed coats and embryo of Phoebe bournei seeds, and embryo extracts had stronger inhibition effect on the seed germination and radical growing of cabbage seed than the seed coats extracts had, and the inhibiting substances were mainly soluble in the methanol and ethyl acetate.

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.

scholarly journals Seed Coat Permeability Influences Sinapine Leakage from Non-germinable Brassica Seeds

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 777C-777
Author(s):  
P.C. Lee ◽  
A.G. Taylor ◽  
T.G. Min
Keyword(s):  
Seed Germination ◽  
Chemical Analysis ◽  
Seed Coat ◽  
False Negative ◽  
Rapid Test ◽  
Leakage Rate ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Single Seed ◽  
Seed Coats

Sinapine leakage to detect seed germination potential on a single-seed basis in Brassica has been developed as a rapid test. In this test, sinapine leakage predicts that a seed is non-germinable; however, the major source of errors in this method are false-negative (F–)—i.e., the method predicted a seed was germinable because the seed did not leak, and it did not germinate. The sinapine leakage index (SLI) was used to asses the F– for any seed lot by dividing the number of non-germinable seeds that leaked sinapine by the total number of non-germinable seeds. Seed lots including cabbage, cauliflower, and broccoli (B. oleracea L., Captitata, Botrytis, and Italica groups, respectively) were used to examine the F–. The leakage rate as measured by T50, the time for 50% of heat-killed seeds to leak, was linearly correlated to SLI. Cabbage seeds were viewed by scanning electronic microscopy and leaking non-germinable seeds either had cracks or were shrunken. NaOCl pretreatment has been found to increase the rate of sinapine leakage and SLI. The mode of NaOCl was due to high pH altering the seed coat permeability. Chemical analysis was conducted on isolated seed coats for pectin, tannins, hemicellulose, cellulose, phenolic lignin, and cutin. It was found that the higher SLI (more permeable) lots contained lower amounts of cutin, suggesting that cutin may restrict the diffusion of sinapine through the testa.

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.

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.

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