Seed Coat Impermeability and Germination of Showy Crotalaria (Crotalaria spectabilis) Seeds

Showy crotalaria (Crotalaria spectabilisRoth) seed dormancy was due to seed coat impermeability to water. The seed coats became impermeable during later stages of maturation on the plant. When incubated immediately after harvest, 9% of the mature, black seeds (11% water content) imbibed water and germinated. The remaining 91% had impermeable coats and did not germinate. After dry storage for 3 months at 23 C, 24% of the seeds imbibed water and germinated. Seeds of another seed lot, which contained seeds of different maturity stages, attained 47% imbibition and germination after storage for 1 yr. The dry, less mature green seeds had a higher percentage (51%) of permeable seeds than did the black seeds (31%) from the same lot. Several seed coat treatments induced imbibition of water and germination of previously impermeable seeds. Effective treatments included piercing of seed coats, scarification with sandpaper, soaking in 70 C water, and simply applying pressure on the strophiole area. Covering the pressed strophiole with petroleum jelly significantly blocked imbibition and indicated that water entered the seeds at only the pressed area. However, studies indicated natural loss of impermeability in showy crotalaria seeds may occur at other sites as well.

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The role of fractures and lipids in the seed coat in the loss of hardseededness of six Mediterranean legume species

The Journal of Agricultural Science ◽

10.1017/s0021859605005034 ◽

2005 ◽

Vol 143 (1) ◽

pp. 43-55 ◽

Cited By ~ 20

Author(s):

L. W. ZENG ◽

P. S. COCKS ◽

S. G. KAILIS ◽

J. KUO

Keyword(s):

Seed Coat ◽

Lipid Content ◽

Environmental Scanning Electron Microscopy ◽

Environmental Scanning ◽

Petroleum Jelly ◽

Physicochemical Changes ◽

Ornithopus Sativus ◽

Seed Coats ◽

Seed Coat Morphology

Changes in the seed coat morphology of 12 annual legumes were studied using environmental scanning electron microscopy (ESEM). The seeds of Biserrula pelecinus L. cv. Casbah, Ornithopus sativus cv. Cadiz, Trifolium clypeatum L., T. spumosum L., T. subterraneum L. cv. Bacchus Marsh, Trigonella balansae Boiss. & Reuter., Trigonella monspeliaca L. and Vicia sativa subsp. amphicarpa Dorthes (morthes.) were examined by ESEM after exposure to field conditions for 6 months, while those of Medicago polymorpha L. cv. Circle Valley, Trifolium clypeatum L., T. glanduliferum Boiss., T. lappaceum L., T. spumosum L., and T. subterraneum L. cv. Dalkeith, were examined after 2 years' exposure. The entry of water into seeds was followed by covering various parts of the seed coat with petroleum jelly and soaking the treated seeds in dyes.As the seeds softened over time, more and larger fractures appeared on the seed coat. Water entered the seed either through fractures, over the seed coat as a whole or through the lens. It is hypothesized that the formation of fractures occurs after physicochemical changes in the seed coat, probably associated with changes in the amount and nature of seed coat lipids.The newly matured whole seeds of M. polymorpha cv. Circle Valley, T. clypeatum, T. glanduliferum, T. lappaceum, T. spumosum, and T. subterraneum cv. Dalkeith were analysed for lipid content in 1997. The seed coats of T. subterraneum cv. Dalkeith and T. spumosum were separated from the cotyledons and examined in detail for lipid content.The lipid content of whole seeds ranged from 48 (T. lappaceum) to 167 mg/g (T. subterraneum cv. Dalkeith). Total lipid of the whole seeds of T. subterraneum cv. Dalkeith and T. glanduliferum declined by about 9 mg/g over 2 years, while in T. spumosum it declined by about 17 mg/g.In contrast, the major fatty acids in the seed coat declined by 0·67 mg/g over the 2 years. Change in seed coat lipids showed a marked similarity to changes in hardseededness for both T. subterraneum cv. Dalkeith and T. spumosum. The results strongly suggest that seed softening is associated with loss of lipids in the seed coat, because lipids have physical characteristics that are altered at temperatures experienced in the field.

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Germination of Developing Prickly Sida Seeds

Weed Science ◽

10.1017/s004317450006584x ◽

1976 ◽

Vol 24 (2) ◽

pp. 239-243 ◽

Cited By ~ 28

Author(s):

G. H. Egley

Keyword(s):

Water Content ◽

Seed Coat ◽

Mother Plant ◽

Dry Storage ◽

Water Imbibition ◽

Immature Seeds ◽

Sida Spinosa ◽

Prickly Sida ◽

Mature Seeds ◽

Days After Anthesis

Freshly-produced, mature prickly sida (Sida spinosaL.) seeds (18 to 21 days after anthesis, < 20% water content) were dormant and neither imbibed water nor germinated when incubated for up to 4 weeks under several light and temperature conditions. Over 80% of the freshly-produced, immature seeds (12 to 16 days after anthesis, > 20% water content) germinated when removed from the mother-plant before dehydration and incubated in alternating 20 to 30 C for 4 weeks. The onset of dormancy coincided with the later stages of seed dehydration and coat-hardening. Over 90% of the mature seeds imbibed water and germinated when incubated at 35 C after 4 months dry storage at 25 C. A puncture through the seed coat, either over the radicle or cotyledons, permitted water imbibition by all mature seeds, but the puncture over the radicle was significantly more effective in inducing germination. Seed coat impermeability was important, but was not the only factor responsible for prickly sida dormancy.

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RESPECTIVE EFFECTS OF ENDOCARP, TESTA AND ENDOSPERM, AND EMBRYO ON THE GERMINATION OF RASPBERRY (Rubus idaeus L.) SEEDS

Canadian Journal of Plant Science ◽

10.4141/cjps85-017 ◽

1985 ◽

Vol 65 (1) ◽

pp. 125-130 ◽

Cited By ~ 8

Author(s):

XAVIER NESME

Keyword(s):

Seed Coat ◽

Rubus Idaeus ◽

Immature Embryos ◽

Varietal Differences ◽

Seed Coats ◽

Embryonic Dormancy ◽

Germinated Seeds

Scarification or seed coat removal was carried out on seeds of five varieties of raspberry, Rubus idaeus L. Regardless of the variety, 100% germination was reached in less than 15 days, at 20 °C, with naked embryos or if the three seed coats were nicked. Intact nutlets never germinated. Seeds with nicked endocarps did not germinate until the testa and the endosperm were injured. Therefore, germination appeared physically prevented by the testa and/or the endosperm while, except for immature embryos, there was no embryonic dormancy. In addition there were varietal differences in the germination of the seeds at high or low temperatures.Key words: Rosaceae, Rubus idaeus L., germination, seeds

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Mechanisms regulating germination in seeds of Stylosanthes

Australian Journal of Agricultural Research ◽

10.1071/ar9750281 ◽

1975 ◽

Vol 26 (2) ◽

pp. 281 ◽

Cited By ~ 13

Author(s):

CJ Gardener

Keyword(s):

Water Content ◽

Seed Coat ◽

Initial Level ◽

Soil Surface ◽

Germination Inhibitors ◽

Hard Seed ◽

Embryo Dormancy ◽

Seed Coats ◽

Water Contents ◽

Soil Water Contents

Seed coat impermeability, embryo dormancy, decline in embryo vigour and the effect of adhering pods on germination were measured monthly on 15 lines of Stylosanthes which had weathered on the soil surface. The effect of pod and seed coat on imbibition was investigated in S. humilis over a range of soil water contents. The level of impermeability of newly harvested seed was initially high for all lines, but the rates of loss varied both between and within species, which indicated the possibility of screening for residual hard seed. The lines also differed in their ability to maintain impermeability over a 14-day germination period. The initial level of embryo dormancy varied between species but the protection afforded against germination was short lived. Decline in embryo vigour appeared to be partly caused by the testa restricting the radicle mechanically. The presence of pods enclosing the seed reduced germination by a mean of 15.4%, but this ranged from 1% in a line of S. guyanensis with thin papery pods to 42% in a line of S. viscosa with thick strong pods. There was no evidence of germination inhibitors in either pods or seed coats, but both restricted the entry of water into the seed. Imbibed seed could be dehydrated without damage provided the radicle had not emerged from the seed coat. This occurred when the water content of the seed reached 90%.

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Germination and the Potential Persistence of Weedy and Domestic Okra (Abelmoschus esculentus) Seeds

Weed Science ◽

10.1017/s004317450002676x ◽

1987 ◽

Vol 35 (1) ◽

pp. 45-51 ◽

Cited By ~ 7

Author(s):

Grant H. Egley ◽

C. Dennis Elmore

Keyword(s):

Seed Dormancy ◽

The Other ◽

Abelmoschus Esculentus ◽

Persistent Problem ◽

Hard Seed ◽

Dry Storage ◽

Seed Trait ◽

Hard Seeds ◽

Seed Coats

Germination and longevity of weedy and three domestic okra [Abelmoschus esculentus(L.) Moench. # ABMES] cultivars were investigated. Hard seed coats are the major reason for okra seed dormancy. Hard seeds of weedy okra, induced to germinate by scarification of seed coats, produced plants yielding 94 to 99% hard seeds. Of these, 40% remained hard but viable after overwintering in the soil at 5 cm deep. Nonhard seeds of weedy okra produced plants that yielded 95 to 99% hard seeds, but only 20% remained hard after overwintering in the soil at 5 cm deep. The ‘White Velvet’ cultivar of okra produced a few hard seeds, but none survived longer than 3 months in the soil. The other domestic cultivars, ‘Dwarf Green Long Pod’ and ‘Clemson Spineless', produced no hard seeds. None of these seeds survived over winter in the soil. Some seeds of White Velvet became slightly harder during dry storage based on time in concentrated H2SO4necessary to induce 80% germination. Although the hard-seed trait existed in the population of this domestic cultivar, it is unlikely that the seeds would overwinter. Seeds that overwinter in a dry condition may be the exception. Because a high percentage of hard seeds overwinter and germinate the following spring, weedy okra has the potential to become a persistent problem.

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Antioxidant Contributors in Seed, Seed Coat, and Cotyledon of γ-ray-Induced Soybean Mutant Lines with Different Seed Coat Colors

Antioxidants ◽

10.3390/antiox10030353 ◽

2021 ◽

Vol 10 (3) ◽

pp. 353

Author(s):

You Jin Lim ◽

Soon-Jae Kwon ◽

Shanshan Qu ◽

Dong-Gun Kim ◽

Seok Hyun Eom

Keyword(s):

Antioxidant Activity ◽

Seed Coat ◽

Antioxidant Activities ◽

Seed Color ◽

Breeding Programs ◽

Γ Ray ◽

Metabolic Basis ◽

Black Seeds ◽

Mutant Lines ◽

Seed Coats

The development of soybean with high antioxidant activities for use in the food and cosmetics industries is a target of breeding programs. In soybean, antioxidants are associated with seed color, although the metabolic basis for seed coloration remains incompletely understood. We selected six γ-ray-induced mutant lines that exhibited black, partially black, brown, partially brown, or yellowish-white pigmentation in the seed coat. Antioxidant activity and contents of anthocyanins, flavan-3-ols, and isoflavones were evaluated in the seed coat and cotyledons. The lines with black or brown seeds showed the highest antioxidant activities. The cotyledons showed no significant differences in seed coat components or antioxidant activities among lines. Black and brown seed coat components showed the highest antioxidant activities. The black seed coat contained five anthocyanins, whereas seed coats of brown- and yellow-seeded lines entirely lacked anthocyanins. Both black and brown seeds were rich in flavan-3-ols, including catechin and epicatechin, which were the predominant antioxidant contributors in brown seeds. Isoflavone contents showed weaker correlations with antioxidant activity than anthocyanins and flavan-3-ols. These results demonstrated that antioxidant activities were determined by anthocyanins in black seeds and flavan-3-ols in brown and black seeds, whereas relatively low antioxidant activities in yellow seeds reflected their high isoflavone contents.

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Grevillea (Proteaceae) seed coats contain inhibitors for seed germination

Australian Journal of Botany ◽

10.1071/bt15085 ◽

2015 ◽

Vol 63 (7) ◽

pp. 566 ◽

Cited By ~ 4

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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Physical seed dormancy in Abrus precatorious (Ratti): a scientific validation of indigenous technique

Experimental Results ◽

10.1017/exp.2020.64 ◽

2021 ◽

Vol 2 ◽

Author(s):

Rajender Kumar Sharma

Keyword(s):

Indigenous People ◽

Seed Dormancy ◽

Seed Coat ◽

Seed Weight ◽

Mass Measurement ◽

Storage Period ◽

Abrus Precatorius ◽

Moisture Storage ◽

Moisture Conditions ◽

Scientific Validation

Abstract Seeds of Abrus precatorius L. (Fabaceae) were used as weight measure by Indigenous people. Where, the seeds were referred as Ratti; a traditional Indian unit of mass measurement. Seed weight fluctuates depending upon age, moisture, storage-period/conditions. Therefore, use of seeds as a weighing unit become dubious and need to be validated. For this purpose, seeds of A. precatorious were subjected to different moisture conditions and periodically monitored. Surprisingly, there was no change in seed weight was observed, indicating the impermeability of seed coat. The later was confirmed by scarification of seed coat which resulted in 53% increase in seed weight against 0% in control. Further, presence of a potent toxin (abrin) in the seed coat protects it from pests and microbes, and contributes to the maintenance of impermeability for longer period of time. The data validates the use of A. precatorious seeds as a weighing unit (ratti) by the indigenous people and discussed.

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An Untargeted Metabolomics Approach for Correlating Pulse Crop Seed Coat Polyphenol Profiles with Antioxidant Capacity and Iron Chelation Ability

Molecules ◽

10.3390/molecules26133833 ◽

2021 ◽

Vol 26 (13) ◽

pp. 3833

Author(s):

Fatma M. Elessawy ◽

Albert Vandenberg ◽

Anas El-Aneed ◽

Randy W. Purves

Keyword(s):

Antioxidant Capacity ◽

Seed Coat ◽

Iron Chelation ◽

Iron Bioavailability ◽

Untargeted Metabolomics ◽

Black Bean ◽

Pulse Crops ◽

Pulse Crop ◽

Seed Coats ◽

Crop Seed

Pulse crop seed coats are a sustainable source of antioxidant polyphenols, but are typically treated as low-value products, partly because some polyphenols reduce iron bioavailability in humans. This study correlates antioxidant/iron chelation capabilities of diverse seed coat types from five major pulse crops (common bean, lentil, pea, chickpea and faba bean) with polyphenol composition using mass spectrometry. Untargeted metabolomics was used to identify key differences and a hierarchical analysis revealed that common beans had the most diverse polyphenol profiles among these pulse crops. The highest antioxidant capacities were found in seed coats of black bean and all tannin lentils, followed by maple pea, however, tannin lentils showed much lower iron chelation among these seed coats. Thus, tannin lentils are more desirable sources as natural antioxidants in food applications, whereas black bean and maple pea are more suitable sources for industrial applications. Regardless of pulse crop, proanthocyanidins were primary contributors to antioxidant capacity, and to a lesser extent, anthocyanins and flavan-3-ols, whereas glycosylated flavonols contributed minimally. Higher iron chelation was primarily attributed to proanthocyanidin composition, and also myricetin 3-O-glucoside in black bean. Seed coats having proanthocyanidins that are primarily prodelphinidins show higher iron chelation compared with those containing procyanidins and/or propelargonidins.

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Effects of Different Pretreatments and Seed Coat on Dormancy and Germination of Seeds of Senna obtusifolia (L.) H.S. Irwin & Barneby (Fabaceae)

International Journal of Biology ◽

10.5539/ijb.v8n2p77 ◽

2016 ◽

Vol 8 (2) ◽

pp. 77

Author(s):

Stephen I. Mensah ◽

Chimezie Ekeke

Keyword(s):

Sulfuric Acid ◽

Seed Dormancy ◽

Water Uptake ◽

Seed Coat ◽

Critical Factor ◽

Potassium Nitrate ◽

Ex Situ ◽

Mechanical Resistance ◽

Physical Dormancy ◽

Senna Obtusifolia

The seed dormancy of Senna obtusifolia was investigated through various methods, namely pretreatments in concentrated sulfuric acid, 2% potassium nitrate (KNO3), 99% ethanol, 99% methanol, and in hydrogen perioxide; examination of the seed coverings; and the determination of water uptake by the seeds in order to ascertain the most effective technique for breaking dormancy and also determine the dormancy type. The results showed that sulfuric acid treatment recorded the highest germination (100%); followed by 2% hydrogen peroxide treatment (24%) in 15minutes immersion. The methanol and ethanol pretreatments gave 18.33% and 16.5% germinations respectively. Pretreatment in 2% potassium nitrate gave the lowest germination (8.50%), while the intact seeds of S. obtusifiolia (control) gave 0% germination. The anatomy of the seed coat indicated the presence of hard, thickened and specialized cells of cuticle, macrosclereids, osteoscereids, and disintegrated parenchyma layers. The water uptake of intact seeds was low (13.5%) after 24 hr imbibitions. These findings revealed that the seed coat acts as barrier to germination by preventing water absorption, possibly gaseous diffusion in and out of the seed and conferring mechanical resistance to the protrusion of embryo. Pretreatments, such as immersion in H2SO4 will soften the seed coat and permit germination. Seed dormancy in S. obtusifolia can be considered of physical nature and classified as physical dormancy. The results obtained in this study may serve as useful information in the production and improvement of S. obtusifolia seedlings, as knowledge on seed dormancy and germination is a critical factor and requirements to the understanding of the propagation of this plant either in situ or ex-situ, in view of the economic potentials/attributes of this species.

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