scholarly journals Seed development in Paeonia ostii (Paeoniaceae), with particular reference to embryogeny

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Keliang Zhang ◽  
Weizhang Cao ◽  
Jerry M. Baskin ◽  
Carol C. Baskin ◽  
Jing Sun ◽  
...  

Abstract Background Seeds of Paeonia ostii have been proposed as a source of raw material for the production of edible oil; however, lack of information about the developmental biology of the seeds hampers our ability to use them. Our aim was to investigate development of the seed coat, endosperm and embryo of P. ostii in relation to timing of accumulation of nutrient reserves from pollination to seed maturity. Ovules and developing seeds of P. ostii were collected at various stages of development from zygote to maturity. Seed fresh mass, dry mass, germination, moisture, soluble sugars, starch, protein and oil content were determined. Ontogeny of seeds including embryo, endosperm and seed coat were analyzed histologically. Results The ovule of P. ostii is anatropous, crassinucellate and bitegmic. The zygote begins to divide at about 5 days after pollination (DAP), and the division is not accompanied by cell wall formation. By 25 DAP, the proembryo begins to cellularize. Thereafter, several embryo primordia appear at the surface of the cellularized proembryo, but only one matures. Endosperm development follows the typical nuclear type. The seed coat is derived from the outer integument. During seed development, soluble sugars, starch and crude fat content increased and then decreased, with maximum contents at 60, 80 and 100 DAP, respectively. Protein content was relatively low compared with soluble sugars and crude fat, but it increased throughout seed development. Conclusions During seed development in P. ostii, the seed coat acts as a temporary storage tissue. Embryo development of P. ostii can be divided into two stages: a coenocytic proembryo from zygote (n + n) that degenerates and a somatic embryo from peripheral cells of the proembryo (2n → 2n). This pattern of embryogeny differs from that of all other angiosperms, but it is similar to that of gymnosperms.

Plants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 333
Author(s):  
Keliang Zhang ◽  
Yin Zhang ◽  
Yusong Ji ◽  
Jeffrey L. Walck ◽  
Jun Tao

Lepidium apetalum (Brassicaceae) is an annual or biennial weed widely distributed in Asia and Europe. The outer surface of L. apetalum seeds produces a large amount of mucilage. The primary aim of this study was to explore the dormancy characteristics and to determine how mucilage develops. The role of mucilage in water absorption/dehydration, the effects of after-ripening, gibberellin acid (GA3), cold stratification and seed coat scarification on germination, the role of mucilage in germination and seedling growth during drought, and the progress of mucilage production during seed development were investigated. The results indicate that the best temperature regime for germination was 10/20 °C. After-ripening, GA3 and seed coat scarification helped to break dormancy. Light promoted germination. Seedling growth of mucilaged seeds were significantly higher than those of demucilaged seeds at −0.606 and −1.027 MPa. Anatomical changes during seed development showed that mucilage was derived from the outer layer of the outer integument cells. Our findings suggest that seeds of L. apetalum exhibited non-deep physiological dormancy. The dormancy characteristics along with mucilage production give seeds of L. apetalum a competitive advantage over other species, and thus contribute to its potential as a weed. Effective control of this weed can be achieved by deep tillage.


2017 ◽  
pp. 43
Author(s):  
Guadalupe Espinosa-Osornio ◽  
E. Mark Engleman

Embryological studies of Hippocratea are restricted to few species, and they show similarity between Hippocratea and Celastraceae. Nevertheless, differences based on H. grahamii have originate controversy on the taxonomic position of the genus. We have examined the seed development of H. celastroides H.B.K, by ligth microscopy. This specie has anatropous and bitegmic ovules. At anthesis, the micropyle is formed only by the inner integument. In the endotegmen and exotesta there are tannin deposits beginning in early stages. After fertilization, the outer integument increases abundantly, it alone forms the wing. The endosperm development is of the nuclear type. After syngamy the zygote rests for 3 months before dividing. The mesoteste develops aerenquima, which differentiates gradually into tracheoidal cells. One layer of endosperm remains at madurity. The cotyledons are connate and rotate 90°. On the basis of these results, we consider that Hippocratea belongs the Celastraceae.


2013 ◽  
Vol 82 (2) ◽  
pp. 165-173 ◽  
Author(s):  
Jing Zhou ◽  
Yanrong Wang ◽  
Jason Trethewey

<p>The semi-permeable layer is a layer in the seeds of certain plants that restricts or impedes the exchange of the solute while allowing the permeability of internal and external water and gas, which is valuable protection to sustain the health and secure the growth, development and germination. In this study, the formation time and location of the semi-permeable layer in seed coats of <em>Elymus nutants</em> (Griseb.) and <em>Elymus sibiricus</em> (L.) were investigated. The experimental seed materials were gathered in the field from the flowering to seed maturation. The light microscopy and transmission electron microscopy for lanthanum nitrate identification were used to examine the characteristics of pericarp, seed coat and nucellus. The results showed that the semi-permeable layer was identified as the position, which can inhibit the penetration of the lanthanum, and it was checked as an amorphous membrane located at the outermost layer of the seed coat that is firmly attached to the seed coat. With seed development, the cells had differentiated and some parts of the ovary and the outer integument had disappeared. The semi-permeable layer originated from the outer layer of the inner integument, which was the original form of the seed coat. It can be stained by the Sudan III and clearly distinguished from other parts of the seed. The formation time of the semi-permeable layer in both species was nearly at 10 to 12 days post-anthesis (dpa), whereas seed physiological maturity was 24 to 26 dpa.</p>


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 523b-523 ◽  
Author(s):  
Erin James ◽  
Marc van Iersel

The quantity and quality of available water in the Southeastern United States continues to decline as demands on limited resources increase. Growers will soon be forced to comply with legal limitations on water consumption and limits on nutrient runoff from their operations. A lack of information on standard growing practices using alternative irrigation systems such as ebb and flow is hindering their acceptance and implementation. We are currently conducting a series of experiments to establish basic growing guidelines for the use of ebb and flow in the greenhouse in bedding plant production. In the third of these experiments, Petunia × hybrida Hort. Vilm.-Andr. `Blue Frost' and Begonia × hiemalis Fotsch. `Ambassador Scarlet' were grown for 5 weeks on ebb and flow tables with fertigation solutions (225 ppm N) containing three different levels of phosphorus (0, 50, and 100 ppm). Three soilless media were also used, which varied in their percentage content of vermiculite, perlite, pine bark and coconut coir. For both the begonias and petunias dry mass of the shoot was greatest in plants grown with higher levels of phosphorus. In comparison to plants grown with 0 ppm phosphorous, petunias and begonias grown with 50 or 100 ppm P were 44% and 25% greater in mass, respectively. However, begonias had 38% more flowers when fertigated with the higher levels of phosphorous while petunias flowered earlier with 0 ppm P fertigation solution. The electrical conductivity of the media did not change significantly over the course of the growing period, but the pH dropped by an average of 1 over the same time interval.


2021 ◽  
Vol 62 (1) ◽  
Author(s):  
Chih-Hsin Yeh ◽  
Kai-Yi Chen ◽  
Yung-I. Lee

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, propagation with seed germination of V. planifolia is intricate and unstable because the seed coat is extremely hard with strong hydrophobic nature. 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. For the culture of immature seeds, the seed collection 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. Seeds at 60 DAP and subsequent stages germinated poorly. As the seed approached maturity, the cell wall of the outermost layer of the outer seed coat became lignified and finally compressed into a thick envelope at maturity. On toluidine blue O staining, the wall of outer seed coat stained greenish blue, indicating the presence of phenolic compounds. As well, on Nile red staining, a cuticular substance was detected in the surface wall of the embryo proper and the innermost wall of the inner seed coat. 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 window for successful germination of culturing immature seed was short. The quick accumulation of lignin, phenolics and/or phytomelanins in the seed coat may seriously inhibit seed germination after 45 DAP. As seeds matured, the thickened and lignified seed coat formed an impermeable envelope surrounding the embryo, which may play an important role in inducing dormancy. Further studies covering different maturity of green capsules are required to understand the optimal seed maturity and germination of seeds.


2007 ◽  
Vol 55 (6) ◽  
pp. 618 ◽  
Author(s):  
Kim N. Hamilton ◽  
Sarah E. Ashmore ◽  
Rod A. Drew ◽  
Hugh W. Pritchard

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%).


2011 ◽  
Vol 79 (1) ◽  
pp. 21-25
Author(s):  
Agnieszka I. Piotrowicz-Cieślak ◽  
Maciej Niedzielski ◽  
Dariusz J. Michalczyk ◽  
Wiesław Łuczak ◽  
Barbara Adomas

Germinability and the content of soluble carbohydrates were analysed in cereal seed (winter rye, cv. Warko; spring wheat, cv. Santa; hexaploid winter triticale, cv. Fidelio and cv. Woltario). Seed moisture content (mc) was equilibrated over silica gel to 0.08 g H<sub>2</sub>O/g dry mass and stored in a desiccator at 20<sup>o</sup>C for up to 205 weeks or were equilibrated to mc 0.06, 0.08 or 0.10 g H<sub>2</sub>O/g dm and subjected to artificial aging at 35<sup>o</sup>C in air-tight laminated aluminium foil packages for 205 weeks. It was shown that the rate of seed aging depended on the species and seed moisture content. The fastest decrease of germinability upon storage was observed in seed with the highest moisture level. Complete germinability loss for winter rye, winter triticale cv. Fidelio, winter triticale cv. Woltario and spring wheat seed with mc 0.10 g H<sub>2</sub>O/g dm<sup>3</sup> occurred after 81, 81, 101 and 133 weeks, respectively. Fructose, glucose, galactose, myo-inositol, sucrose, galactinol, raffinose, stachyose and verbascose were the main soluble carbohydrates found in the seed. The obtained data on the contents of specific sugars and the composition of soluble sugars fraction in seed of rye, wheat and triticale did not corroborate any profound effect of reducing sugars, sucrose and oligosaccharides on seed longevity.


2021 ◽  
Author(s):  
Chih-Hsin Yeh ◽  
Kai-Yi Chen ◽  
Yung-I Lee

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.


2021 ◽  
pp. 201-209
Author(s):  
Kamola Vakhabjanova Raimova ◽  
Nodira Gulomzhanovna Abdulladzhanova ◽  
Farrukh Nazimovich Toshpulatov ◽  
Nurali Azamovich Ergashev ◽  
Alimzhan Davlatbaevich Matchanov

The results of studies of the content of polyphenolic compounds and their antioxidant activity in the Pontic hawthorn plant Crataegus pontica K.Koch., growing in the mountainous regions of the Tashkent region of the Republic of Uzbekistan are presented. The collection of raw materials took place in the spring at the beginning of October 2019 and at the end of April 2020. The conditions for the isolation of polyphenolic compounds were selected under various conditions. It was shown that the optimal content of polyphenols is extracted with 70% acetone, followed by fractionation of the aqueous residue with ethyl acetate and precipitation with hexane. It was shown that in the plants harvested in spring, the amount of polyphenols was 4.28%, and the collected volume was 2.6%, of the air-dry mass of the raw material. Chromatographic methods (BC and TLC) revealed that the composition of plant leaves collected in spring contains more polyphenols than those collected in autumn. This plant contains compounds belonging to the class of flavonols, phenolic acids and flavan-3-ols. Polyphenols were identified by rutin, quercetin, quercetin-3-O-β-galactoside, catechin, and gallic acid by BC and TLC methods. The antioxidant activity of the sum of polyphenolic compounds was studied in the model of lipid peroxidation (LPO) in rat liver mitochondria. It was found that polyphenols have a protective effect on mitochondria, a reduced damaging effect of Fe2+ / ascorbate and antioxidant activity depends on the concentration of the studied polyphenolic substances. The introduction of rutin into the incubation medium in 5 μM medium inhibits LPO processes by 32.0%, and at 10 μM – by 85.9% and in 20 μM – by 96.8%, compared with the control.


Sign in / Sign up

Export Citation Format

Share Document