Preparation and staining of hard seed tissue for backscatter imaging

1988 ◽  
Vol 46 ◽  
pp. 412-413
Author(s):  
R. N. Paul ◽  
G. H. Egley
Keyword(s):  
Seed Coat ◽  
Structural Information ◽  
Uranyl Acetate ◽  
Ferrous Chloride ◽  
Hard Seed ◽  
Eds Analysis ◽  
Specific Tissue ◽  
Hard Seed Coat ◽  
Insoluble Precipitate ◽  
Coat Material

Hard seed coat material is extremely difficult to prepare for observation at the EM level. Seed coat segments are usually removed for embedding and sectioning, which results in loss of tissue juxtaposition. Observation and monitoring reactions of the intact seed coat under experimental procedures such as tracking dye penetration into seeds make seed coat dissection unfeasible. Efforts to apply analytical EM methods such as STEM/EDS analysis, are restricted by the limiting effect of section thickness on X-ray signal. We investigated the ultrastructure of dry seeds by treating them with various metallic staining solutions and observing the trimmed block faces with the SEM in backscatter mode. Good structural information was obtained as well as visualization of a specific tissue layer that accumulates lead.Intact seeds were incubated in several aqueous solutions including: 2% w/v uranyl acetate; 1% w/v OsO4; 2% ferrous chloride (Followed by 5% potassium ferricyanide to form an insoluble precipitate) ; and various lead solutions including Reynolds lead citrate.

Dormancy in Pinusmonticola seed related to stratification time, seed coat, and genetics

1987 ◽  
Vol 17 (4) ◽  
pp. 294-298 ◽  
Author(s):  
R. J. Hoff
Keyword(s):  
Seed Coat ◽  
White Pine ◽  
Hard Seed ◽  
Physiological Conditions ◽  
Western White Pine ◽  
Minor Site ◽  
Coat Layer ◽  
A Minor ◽  
Hard Seed Coat

The inner layer of the seed coat, a papery membrane, and physiological conditions of the gametophyte–embryo were shown to be major sites of dormancy in seed of western white pine. The hard seed coat layer was a minor site. With no stratification, 7% of the seeds were not dormant, 9% were dormant because of the hard seed coat, 34% were dormant because of the inner seed coat, and 50% were dormant because of physiological conditions of the gametophyte–embryo. These values varied with stratification times and seed lots (families).

scholarly journals Emergence of `Genesis' Triploid Watermelon following Mechanical Scarification

1999 ◽  
Vol 124 (4) ◽  
pp. 430-432 ◽  
Author(s):  
John R. Duval ◽  
D. Scott NeSmith
Keyword(s):  
Seed Coat ◽  
Citrullus Lanatus ◽  
Crop Improvement ◽  
Coarse Sand ◽  
Financial Risks ◽  
Hard Seed ◽  
Series Of Experiments ◽  
Triploid Watermelon ◽  
Slow Growing ◽  
Hard Seed Coat

Production of triploid watermelon [Citrullus lanatus (Thunb.) Matsum & Nakai] transplants is hindered by poor, inconsistent emergence, and frequent seed coat adherence to cotyledons. Seed coat adherence leads to weakened and slow growing plants. High seed costs, coupled with stand establishment problems, discourages transplant producers from growing this crop. Improvement of triploid watermelon emergence will lessen financial risks to growers and transplant producers and will provide a more reliable production system. Mechanical scarification was evaluated as a means to overcome inconsistent emergence and seed coat adherence. Seeds of `Genesis' triploid watermelon were placed in a cylinder with 100 g of very coarse sand (1.0 to 2.0 mm diameter) and rotated at 60 rpm for 0, 6, 12, 24, and 48 hours in a series of experiments. Number of emerged seed was recorded daily, to obtain emergence dynamics. No significant differences were observed in seed coat adherence among treatments. The longest duration of scarification However, enhanced emergence as compared to the control in three of four experiments. These data support earlier suggestions that a thick or hard seed coat is a factor contributing to poor germination and emergence of triploid watermelons.

scholarly journals Subsidies for propagation of native species in Brazil with medicinal potential: Calophyllum brasiliense Cambess

2019 ◽  
Vol 41 (3) ◽  
pp. 318-327
Author(s):  
Rosemeire Carvalho da Silva ◽  
Andreza Cerioni Belniaki ◽  
Elisa Serra Negra Vieira ◽  
Francine Lorena Cuquel ◽  
Maristela Panobianco
Keyword(s):  
Seed Coat ◽  
Native Species ◽  
Seedling Morphology ◽  
Hard Seed ◽  
Commercial Use ◽  
Calophyllum Brasiliense ◽  
Complete Extraction ◽  
Long Stem ◽  
Cotyledonary Petioles ◽  
Hard Seed Coat

Abstract: Calophyllum brasiliense Cambess. (guanandi) is a native species with medicinal potential and also generates expectation for commercial use (wood) and for recovery of degraded areas. These seeds have physical and mechanical dormancy, requiring techniques for dormancy release; knowledge of seed and seedling morphology that assists laboratory analysis and propagation of the species is also necessary. The objective of this study was to describe the morphological structures of the seeds and normal and abnormal seedlings of guanandi, and also investigate if complete extraction of the endocarp and the seed coat to overcome dormancy will affect the morphology and initial plant development, and consequently production of transplants. Guanandi seeds are large (1000 seed weight of 1480.9 g) with a hard seed coat; cotyledons account for most of the embryo and serve as a reserve; the embryonic axis is small (1.0-2.0 mm) in relation to the seed, yet it is differentiated. The seedlings have hypogeal cryptocotylar germination, with cotyledonary petioles, taproot, and epicotyl developing into a long stem and a tip protected by cataphylls. The main abnormalities in seedlings are related to the root system. Extraction of the endocarp and seed coat does not alter the morphology of seedlings and promotes their greater development, which may be an advantageous strategy.

scholarly journals Using endocarp-remains of seeds of wild apricot Prunus armeniaca to identify rodent seed predators

2009 ◽  
Vol 55 (6) ◽  
pp. 396-400
Author(s):  
Hongmao Zhang ◽  
Wei Wang
Keyword(s):  
Seed Coat ◽  
Prunus Armeniaca ◽  
Linear Discriminant ◽  
Hard Seed ◽  
Seed Predators ◽  
Quantitative Studies ◽  
Chinese White ◽  
Wild Apricot ◽  
Field Mice ◽  
Hard Seed Coat

Abstract Some rodent-dispersed seeds have a hard seed-coat (e.g.woody endocarp). Specific scrapes or dental marks on the hard seed-coat left by rodents when they eat these seeds can be used to identify seed predators. In this study we measured the morphological traits of endocarp-remains of seeds of wild apricot Prunus armeniaca used by Chinese white-bellied rats Niviventor confucianus and Korean field mice Apodemus peninsulae. We established their Fisher’s linear discriminant functions to separate endocarp-remains between the two predators. A total of 90.0% of the endocarp-remains left by Korean field mice and 88.0% of those left by Chinese white-bellied rats were correctly classified. The overall percentage of correct classification was 89.0%. One hundred and sixty endocarp-remains of unknown what species predated them were classified using the functions. The method may allow more reliable quantitative studies of the effects of Chinese white-bellied rats and Korean field mice on seed consumption and dispersal of wild apricot and this study might be used for reference in other studies of seed predators identification on hard seeds.

scholarly journals Ecophysiology of Mimosa pudica L. at Biratnagar, Eastern Nepal

Our Nature ◽  
1970 ◽  
Vol 7 (1) ◽  
pp. 177-181 ◽  
Author(s):  
B. Niroula ◽  
D. Parajuli ◽  
S. Jha
Keyword(s):  
Seed Coat ◽  
Crude Protein ◽  
Dry Weight ◽  
Germination Percentage ◽  
Mimosa Pudica ◽  
Crude Fibre ◽  
Hard Seed ◽  
Total Plant ◽  
Mature Seeds ◽  
Hard Seed Coat

All the freshly collected mature seeds of M. pudica were greenish in colour, whereas 7 year old stored seeds were a mixture of greenish and brownish seeds. The greenish seeds had hard seed coat and acid treated as well as sand rubbing for 6-10 min greatly enhanced their germination percentage. The brownish seeds were simply the deteriorated form of greenish seeds. Leaves and pods had higher contribution to total plant dry weight in ungrazed field and in pot-cultured plants clipped a month before flowering. The young shoots of the plant had 18.9% crude protein, 0.46% phosphorus and 25.4% crude fibre on dry weight basis.Key words: Hard seed coat, Mimosa pudica, scarification, dry matter productionDOI: 10.3126/on.v7i1.2568Our Nature (2009) 7:177-181  

Venice Mallow (Hibiscus trionum) Seed Production and Persistence in Soil in Colorado

1996 ◽  
Vol 10 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Philip Westra ◽  
Calvin H. Pearson ◽  
Randal Ristau ◽  
Frank Schweissing
Keyword(s):  
Seed Production ◽  
Seed Dormancy ◽  
Seed Coat ◽  
Crop Production ◽  
Hard Seed ◽  
Hibiscus Trionum ◽  
Soil Seedbank ◽  
Hard Seed Coat ◽  
Insight Into

This study was conducted to gain insight into the soil seedbank dynamics of Venice mallow in two irrigated Colorado soils. Venice mallow plants produced an average of 3100 seeds per plant under noncompetitive irrigated conditions. Venice mallow seeds collected from three regions of Colorado and stored at 25 C averaged 95% dormancy and less than 4% nonviable seeds 6 mo after harvesting. Percent nonviable seeds in soil remained relatively constant over 2 yr. Most seeds germinated within the first 3 mo after burial in the first crop production year. Seed dormancy decreased to an average of 40% after 3 mo of burial in cultivated soil at Fruita and Rocky Ford, and thereafter remained relatively constant for 21 mo. Fruita seeds underwent lessin situgermination than seeds from Greeley or Rocky Ford. Innate seed dormancy was lower at Fruita (27%) than at Rocky Ford (39%). Enforced dormancy remained constant over a 21-mo period and was similar for both locations (32%). Seeds buried for 2 yr at Fruita underwent greaterin situgermination (42%) than at Rocky Ford (27%). At Fruita, the level of enforced dormancy was higher and the level of innate dormancy lower at the 20-cm than the 2-cm depths. Venice mallow seed dormancy likely is due to an impermeable hard seed coat.

scholarly journals The crypsis hypothesis explained: a reply to Jayasuriya et al. (2015)

2015 ◽  
Vol 25 (4) ◽  
pp. 402-408 ◽  
Author(s):  
Torbjørn R. Paulsen ◽  
Louise Colville ◽  
Matthew I. Daws ◽  
Sigrunn Eliassen ◽  
Göran Högstedt ◽  
...  
Keyword(s):  
Seed Coat ◽  
Generation Time ◽  
Dormancy Release ◽  
Hard Seed ◽  
Theory Of Evolution ◽  
Key Features ◽  
Evolution By Natural Selection ◽  
Hard Seed Coat ◽  
Seed Coats ◽  
By Products

AbstractIn imbibing seeds, resumption of metabolism leads to the unavoidable release of volatile by-products that are perceived as cues by rodent seed predators. The crypsis hypothesis proposes that the primary function of a water-impermeable, hard seed coat is to reduce rodent seed predation by rendering seeds olfactorily cryptic. In an opinion paper, Jayasuriya et al. (2015) find the crypsis hypothesis unscientific and ‘not consistent with Darwin's theory of evolution by natural selection’. It is unfortunate that Jayasuriya et al. (2015) did not appreciate that the crypsis hypothesis offers an alternative explanation for the evolution of water-impermeable seeds: released seed volatiles are cues used by rodents to locate seeds, and variation in seed-coat permeability leading to differences in seed volatile release represents the variable under selection. Furthermore, the sealing of water-impermeable seed coats imposes a cost of increased generation time and, therefore, dormancy-release mechanisms are expected to subsequently evolve in response to local environmental conditions. We also disagree with most other claims by Jayasuriya et al. (2015), who failed to appreciate how species with dimorphic seeds – one morph with permeable and the other with impermeable seed coats – benefit from rodent caching behaviour and population dynamics. We welcome this opportunity to clarify and elaborate on key features and the evolution of water-impermeable seed coats according to the crypsis hypothesis.

scholarly journals Seed Breaking Dormancy Technique and Growth of Screw Tree (Helicteres isora Linn.) seedlings

2021 ◽  
Vol 9 (1) ◽  
pp. 43-58
Author(s):  
Nazhira Firda Yulia ◽  
◽  
Supriyanto Supriyanto ◽  
Diana Prameswari ◽  
◽  
...  
Keyword(s):  
Seed Coat ◽  
Hot Water ◽  
Water Cool ◽  
Hard Seed ◽  
Breaking Dormancy ◽  
Helicteres Isora ◽  
Npk Fertilizer ◽  
Tree Fruits ◽  
Hard Seed Coat ◽  
Tree Seed

Screw tree is a shrub from family Malvaceae that has many benefits in pharmacy. Screw tree seed has very hard seed coat, so the seed must be treated before germination. The aim of this research was to assess the characteristic of fruit and seeds, effect of seed breaking dormancy, and effect of NPK fertilizer dosage on the growth of screw tree (Helicteres isora) seedlings. The results indicated that screw tree fruits belong to dry fruits with capsule form and has 5 follicles that has different direction. Screw tree seed is orthodox type that has 9 ̶ 36 seeds in one follicle with triangle and square shape. Germination technique in laboratory with soaking the seeds in hot water 100oC until the water cool for 48 hours treatment produced the best germination amounting to 65.0%. Germination technique in green house with soaking the seeds in hot water 100oC until the water cool for 24 hours treatment was the best germination amounting to 77.0%. Seedlings fertilized with 1 g NPK doses increased screw tree growth in diameter parameter of 6.35 mm and shoot-root ratio parameter of 3.9 compared to control.

scholarly journals Propagation of threatened climber species Entada rheedii Spreng. – a medicinal plant with extremely thick and hard seed coat

Dendrobiology ◽  
2021 ◽  
Vol 85 ◽  
pp. 92-104
Author(s):  
Md. Aktar Hossain ◽  
Joyeta Dey ◽  
Mohammed Abdur Rahman
Keyword(s):  
Medicinal Plant ◽  
Growth Performance ◽  
Seed Coat ◽  
Dry Mass ◽  
Germination Percentage ◽  
Stem Cutting ◽  
Hard Seed ◽  
Collar Diameter ◽  
Survival And Growth ◽  
Hard Seed Coat

The study explored propagation techniques of Entada rheedii Spreng., a threatened medicinal climber species with extremely hard seed coat. Propagation trials included both pre-sowing treatments of seeds for germination and clonal propagation by stem cutting. Pre-sowing treatments included (a) soaking of both cut (notched) and uncut (intact) seeds in water for 0 h, 24 h, 48 h, and 72 h and (b) immersion of intact seeds in 5% acetone solution for 5 min, 10 min, and 20 min before sowing in germination media in polybags. On the other hand, stem cutting involved treating the summer or autumn cuttings with 0%, 0.4%, and 0.8% IBA solution before rooting in non-mist propagator. Notched seeds soaked in water for 48 h showed the fastest seed germination with the highest germination percentages (73.3) and better seedling growth in terms of plant height, collar diameter, leaf number and total dry mass followed by notched seeds soaked in water for 72 h. The slowest germination and the lowest germination percentage (3.3), as well as the poorest growth performance was for intact seeds without any treatment. The highest rooting percent­age with maximum number of roots (36.6) was obtained from the summer cuttings treated with 0.4% IBA solution followed by autumn cuttings with 0.8% IBA and the lowest (43.3% and 8.3 roots) was for summer cuttings in control. The factors also dictated the survival and growth performance of rooted cuttings in the nursery conditions. The outcomes of these trials i.e., notched seeds soaking in water for 48 h will help to enhance the propagation of this valuable medicinal plant species.

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