scholarly journals Ontogenia de la semilla de Yucca periculosa (Agavaceae)

2017 ◽  
pp. 5
Author(s):  
Eduardo García-Villanueva ◽  
E. Mark Engleman
Keyword(s):  
Cell Wall ◽  
Embryo Development ◽  
Seed Coat ◽  
Outer Integument ◽  
Triangular Prism ◽  
Seed Shape ◽  
Food Reserve ◽  
Seed Maturity ◽  
Nuclear Development ◽  
Black Color

Seeds of several Yucca species have been studied by Arnott and Horner. They mainly studied the nature condition and stated that the extra-embryonic food reserve tissue is a perisperm. This paper provides ontogenic evidence that this tissue is an endosperm with nuclear development type. The seed shape is nearly a triangular prism less than 1 cm long, black color and the raphe groove is conspicuous. The seed coat is derived exclusively from the outer integument. The exotesta external periclinal cell wall appears with irregular thickness. Both mesotesta and endotesta grow irregularly inward the seed confering to the endosperm a ruminate appearance. Toward seed maturity, the inner integument tissues disappear, thus fusion between intertegumentary and tegmen-nucellar cuticles occurs; valuable ontogenic information is showed by the cuticles, due to its persistence in spite of its generative tissue disappearance. The embryo development increases until 10 weeks after anthesis, it is cylindric, folds like "S" and two thirds of its chalazal lenght correspond to the cotyledon.

scholarly journals 4-CPA (4-Chlorophenoxyacetic Acid) Induces the Formation and Development of Defective “Fenghou” (Vitis vinifera × V. labrusca) Grape Seeds

Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 515
Author(s):  
Zhenhua Liu ◽  
Yan Wang ◽  
Wenjiang Pu ◽  
Haifeng Zhu ◽  
Jinjun Liang ◽  
...  
Keyword(s):  
Vitis Vinifera ◽  
Outer Integument ◽  
Underlying Mechanism ◽  
Grape Seeds ◽  
Endosperm Tissue ◽  
Seed Shape ◽  
Seed Formation ◽  
Significant Difference ◽  
Fruit Setting ◽  
Chlorophenoxyacetic Acid

For some horticultural plants, auxins can not only induce normal fruit setting but also form fake seeds in the induced fruits. This phenomenon is relatively rare, and, so far, the underlying mechanism remains unclear. In this study, “Fenghou” (Vitis vinifera × V. labrusca) grapes were artificially emasculated before flowering and then sprayed with 4-CPA (4-chlorophenoxyacetic acid) to analyze its effect on seed formation. The results show that 4-CPA can induce normal fruit setting in “Fenghou” grapes. Although more seeds were detected in the fruits of the 4-CPA-treated grapevine, most seeds were immature. There was no significant difference in the seed shape; namely, both fruit seeds of the grapevines with and without 4-CPA treatment contained a hard seed coat. However, the immature seeds lacked embryo and endosperm tissue and could not germinate successfully; these were considered defective seeds. Tissue structure observation of defective seeds revealed that a lot of tissue redifferentiation occurred at the top of the ovule, which increased the number of cell layers of the outer integument; some even differentiated into new ovule primordia. The qRT-PCR results demonstrated that 4-CPA application regulated the expression of the genes VvARF2 and VvAP2, which are associated with integument development in “Fenghou” grape ovules. Together, this study evokes the regulatory role of 4-CPA in the division and continuous redifferentiation of integument cells, which eventually develop into defective seeds with thick seed coats in grapes.

Seed morphology and ultrastructure in Citrus garrawayi (Rutaceae) in relation to germinability

2007 ◽  
Vol 55 (6) ◽  
pp. 618 ◽  
Author(s):  
Kim N. Hamilton ◽  
Sarah E. Ashmore ◽  
Rod A. Drew ◽  
Hugh W. Pritchard
Keyword(s):  
Moisture Content ◽  
Seed Size ◽  
Seed Coat ◽  
Outer Integument ◽  
Dry Weight ◽  
Seed Morphology ◽  
Embryonic Axis ◽  
Morphological Development ◽  
Seed Moisture Content ◽  
Immature Seeds

Combinational traits of seed size and seed-coat hardness in Citrus garrawayi (F.M.Bailey) (syn. of Microcitrus garrowayi) were investigated as markers for estimation of seed morphological and physiological maturity. Seed size (length) and coat hardness correlated well with changes in seed coat and embryo morphological development, dry-weight accumulation, decreases in moisture content and a significant increase in germinability. Seed moisture content decreased from 82 ± 1% in immature seeds to 40 ± 1% at seed maturation. The outer integument of immature seeds consisted of thin-walled epidermal fibres from which outgrowths of emerging protrusions were observed. In comparison, mature seed coats were characterised by the thickening of the cell walls of the epidermal fibres from which arose numerous protrusions covered by an extensive mucilage layer. Immature seeds, with incomplete embryo and seed-coat histodiffereniation, had a low mean germination percentage of 4 ± 4%. Premature seeds, with a differentiated embryonic axis, were capable of much higher levels of germination (51 ± 10%) before the attainment of mass maturity. Mature seeds, with the most well differentiated embryonic axis and maximum mean dry weight, had the significantly highest level of germination (88 ± 3%).

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 Seed micromorphological study on endemic and subendemic species of Veronica L. (Plantaginaceae Juss.) in Iran

2019 ◽  
Vol 26 (2) ◽  
pp. 315-324
Author(s):  
Soghra Ramzi ◽  
Shahryar Saedi-Mehrvarz
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Seed Coat ◽  
Seed Morphology ◽  
Seed Shape ◽  
Sem Micrographs ◽  
Qualitative And Quantitative ◽  
Quantitative Characters ◽  
Micromorphological Characters ◽  
Scanning Electron

Seed morphology of 12 Iranian endemic and subendemic species of Veronica was studied using scanning electron microscope (SEM). Seven qualitative and quantitative characters were measured using SEM micrographs and stereomicroscopy. The seed shape of most species is ovate and plano-convex. The size of seeds ranges from 1.25 x 0.75 mm in V. khorassanica to 2.5 x 1.75 mm in V. viscosa Boiss. The ornamentation of seed coat is reticulate-verrucate in V. khorassanica, V. czerniakowskiana, V. mazanderanae and V. rubrifolia, reticulate-rugate in V. acrotheca, V. aucheri, V. viscosa and V. intercedens, rugose in V. microcarpa, V. chionantha and V. rechingeri, and reticulate-porate in V. gaubae. The testa cells are polygonal in ten species and irregular in two species. Micromorphological characters of seeds are useful in specific and subspecific delimitations of Iranian Veronica.

Scanning electron microscopy examination of soybean testa development

1987 ◽  
Vol 65 (11) ◽  
pp. 2420-2424 ◽  
Author(s):  
Daniel M. Baker ◽  
Harry C. Minor ◽  
Billy G. Cumbie
Keyword(s):  
Seed Size ◽  
Seed Coat ◽  
Secondary Wall ◽  
Outer Integument ◽  
Scanning Electron Microscopy Examination ◽  
Glycine Max L ◽  
Well Differentiated ◽  
Harvest Maturity ◽  
Microscopy Examination ◽  
Scanning Electron

Seeds of soybean (Glycine max (L.) Merr.) were harvested from greenhouse-grown plants and fractures of the seed coat were examined with a scanning electron microscope. The seed coat was well differentiated from the outer integument when the seed had reached approximately 30% maximum seed size. At this time, the osteosclereids began to separate, becoming fully detached along their radial walls by 50% maximum seed size. Macrosclereid secondary wall development occurred during growth of the seed from 50 to 100% maximum seed size. Near R6 (100% maximum seed size) the endothelium began differentiation from the integumentary tapetum (inner integument) and was fully differentiated by physiological maturity (R7). From R7 to harvest maturity (R8) the seed lost moisture content and decreased in size. The parenchyma of the seed coat collapsed in response to this dehydration.

Hugo field pea

2009 ◽  
Vol 89 (1) ◽  
pp. 73-75 ◽  
Author(s):  
Deng-Jin Bing ◽  
Don Beauchesne ◽  
Al Sloan ◽  
Yantai Gan ◽  
Cecil Vera ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Pisum Sativum ◽  
Seed Coat ◽  
Field Pea ◽  
Western Canada ◽  
Seed Shape ◽  
Leaf Type ◽  
Pisum Sativum L ◽  
Cultivar Description ◽  
Round Seed

Hugo is a high-yielding field pea (Pisum sativum L.) cultivar with yellow cotyledons. It has a semi-leafless leaf type, and is powdery mildew resistant. It has round seed shape, medium seed size and high seed coat integrity. The cultivar is adapted to field pea growing regions in western Canada. Key words: Field pea, Pisum sativum, cultivar description

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