Seed ontogeny and endosperm chemical analysis in Smilax polyantha (Smilacaceae)

2012 ◽  
Vol 60 (8) ◽  
pp. 693 ◽  
Author(s):  
Aline Redondo Martins ◽  
Sandra Maria Carmello-Guerreiro ◽  
Marcos Silveira Buckeridge ◽  
Clovis Oliveira Silva ◽  
Beatriz Appezzato-da-Glória
Keyword(s):  
Seed Germination ◽  
Cell Walls ◽  
Folk Medicine ◽  
Vascular Bundles ◽  
Chemical Analyses ◽  
Endosperm Cell ◽  
Brazilian Cerrado ◽  
Chemical Factors ◽  
Histochemical Tests ◽  
Mature Seeds

Smilax polyantha Grisebach is a species native to the Brazilian Cerrado biome and is known as sarsaparilla in folk medicine. Despite its popular use, little is known about the propagation of this species, which is still actively illegally exploited. The present study aims to analyse the seed ontogeny and perform endosperm chemical analyses in S. polyantha to elucidate the structural and chemical factors that could be associated with the low germination rates and structural organisation of the seed. The ovules are orthotropic and bitegmic, have short funicles, single collateral vascular bundles that end in the chalaza, and a hypostasis that is composed of chalazal and nucellar cells. The seed covering is non-multiplicative. In mature seeds, the cellularised endosperm has thick-walled cells, the embryo is small and the tegmen comprises two layers of periclinal elongated cells with a red–orange content, which are covered by a cuticle. Histochemical tests detected the presence of lipids, proteins and polysaccharides in the cellular content of mature seeds. Chemical analyses indicated 46.7% hemicellulose per total weight, 67.3% glucose, 30.7% mannose, 1.9% galactose and an absence of fucose, arabinose and rhamnose. In conclusion, the delayed seed germination in S. polyantha is associated with the seed endosperm cell walls.

scholarly journals Leaf and stem microscopic identification of Tithonia diversifolia (Hemsl.) A. Gray (Asteraceae)

2012 ◽  
Vol 48 (1) ◽  
pp. 109-116 ◽  
Author(s):  
Márcia do Rocio Duarte ◽  
Cláudia Bonissoni Empinotti
Keyword(s):  
Vascular System ◽  
Folk Medicine ◽  
Vascular Bundles ◽  
Tithonia Diversifolia ◽  
Mature Leaves ◽  
Therapeutic Uses ◽  
Different Types ◽  
Anomocytic Stomata ◽  
Histochemical Tests ◽  
Secretory Ducts

Tithonia diversifolia (Hemsl.) A. Gray is an Asteraceae shrub, popularly known as Mexican sunflower and cultivated for ornamental and therapeutic uses in different countries. In folk medicine, it is of value for treating diabetes, malaria and infectious diseases. These indications have been corroborated by various pharmacological assays. Given the lack of data on anatomical aspects of T. diversifolia, this work aimed to investigate the leaf and stem microscopic characters of this medicinal plant and potential vegetal drug. Samples of mature leaves and young stems were sectioned and stained. Histochemical tests and scanning electron microscopy were also performed. The leaf has anomocytic stomata on both sides, dorsiventral mesophyll and several collateral vascular bundles arranged as a ring in the midrib. The stem shows angular-tangential collenchyma, an evident endodermis and sclerenchymatic caps adjoining the phloem. The main characters for anatomical identification are the different types of trichome (non-glandular, capitate and non-capitate glandular), the midrib features and the localization of the secretory ducts near the vascular system.

scholarly journals Anatomical characters of the medicinal leaf and stem of Gymnanthemum amygdalinum (Delile) Sch.Bip. ex Walp. (Asteraceae)

2013 ◽  
Vol 49 (4) ◽  
pp. 719-727 ◽  
Author(s):  
Márcia do Rocio Duarte ◽  
Ariane Gonçalves Silva
Keyword(s):  
Sesquiterpene Lactones ◽  
Glandular Trichomes ◽  
Folk Medicine ◽  
Bioactive Metabolites ◽  
Vascular Bundles ◽  
Medicinal Species ◽  
Convex Shape ◽  
Leaf Surfaces ◽  
Anomocytic Stomata ◽  
Histochemical Tests

Gymnanthemum amygdalinum (Delile) Sch.Bip. ex Walp. (Asteraceae), better known by its former name Vernonia amygdalina Delile, is a small shrub used in folk medicine as an antipyretic, laxative, antimalarial and anthelmintic. Studies have demonstrated that different vegetal extracts possess antioxidant, antimicrobial and antiparasitic activities. Among the bioactive metabolites, there are sesquiterpene lactones, saponins, polyphenols and flavonoids. This study investigated the leaf and stem microscopic characters of G. amygdalinum, aiming to expand the knowledge on this medicinal species and indicate anatomical structures. Plant material was fixed and sectioned by freehand and using a microtome. The sections were either stained or underwent standard histochemical tests. Scanning electron microscopy was performed to investigate epidermal relief. The leaf is amphistomatic with anomocytic stomata. There are striate cuticle, glandular and non-glandular trichomes and dorsiventral mesophyll. In transverse section, the midrib and the petiole have a plano-convex shape. Both show several collateral vascular bundles and few crystals of calcium oxalate. In the stem, the epidermis persists and the phellogen has a peripheral origin. It presents typical endodermis and sclerenchymatic caps adjoining the phloem. The aspects that contribute to characterizing the species are stomata on both leaf surfaces, midrib and petiole features, the endodermis and sclerenchymatic caps in the stem, as well as the different types of trichome on both aerial organs.

scholarly journals Asymbiotic germination of Vanilla planifolia in relation to the timing of seed collection and seed pretreatments

2021 ◽  
Vol 62 (1) ◽  
Author(s):  
Chih-Hsin Yeh ◽  
Kai-Yi Chen ◽  
Yung-I. Lee
Keyword(s):  
Seed Germination ◽  
Seed Development ◽  
Seed Coat ◽  
Germination Percentage ◽  
Vanilla Planifolia ◽  
Outermost Layer ◽  
Seed Collection ◽  
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, 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.

scholarly journals Analysis of the arabinoxylan arabinofuranohydrolase gene family in barley does not support their involvement in the remodelling of endosperm cell walls during development

2012 ◽  
Vol 63 (8) ◽  
pp. 3031-3045 ◽  
Author(s):  
Hunter K. C. Laidlaw ◽  
Jelle Lahnstein ◽  
Rachel A. Burton ◽  
Geoffrey B. Fincher ◽  
Stephen A. Jobling
Keyword(s):  
Gene Family ◽  
Cell Walls ◽  
Endosperm Cell ◽  
Arabinoxylan Arabinofuranohydrolase

Spectroscopic Analysis of Diversity of Arabinoxylan Structures in Endosperm Cell Walls of Wheat Cultivars (Triticum aestivum) in the HEALTHGRAIN Diversity Collection

2011 ◽  
Vol 59 (13) ◽  
pp. 7075-7082 ◽  
Author(s):  
Geraldine A. Toole ◽  
Gwénaëlle Le Gall ◽  
Ian J. Colquhoun ◽  
Phil Johnson ◽  
Zoltan Bedö ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Cell Walls ◽  
Spectroscopic Analysis ◽  
Wheat Cultivars ◽  
Endosperm Cell

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.

Prevention of Weld Metal Reheat Cracking During Cr-Mo-V Heavy Reactors Fabrication

2009 ◽  
Author(s):  
Ce´dric Chauvy ◽  
Sylvain Pillot
Keyword(s):  
Weld Metal ◽  
Mechanical Testing ◽  
Chemical Analyses ◽  
Root Cause ◽  
Reheat Cracking ◽  
Chemical Factors

CrMoV heavy reactors fabrication has undergone some weld metal reheat cracking issues during the end 2007 / beginning 2008. This paper addresses this particular problem and explains the methodology used to solve it. Usual techniques, such as chemical factors and required NDE, have shown their limits, underlining the fact that this problem was unpredictable. Special mechanical testing as well as very accurate chemical analyses have allowed the authors to find the root cause. Very small amounts of particular impurities were responsible for the cracking and a criterion is then proposed to ensure that the problem will not come out again.

Clausospicula, a new Australian genus of grasses (Poaceae, Andropogoneae)

1991 ◽  
Vol 4 (2) ◽  
pp. 391
Author(s):  
M Lazarides ◽  
J Lenz ◽  
L Watson
Keyword(s):  
Cell Walls ◽  
Transverse Section ◽  
Northern Territory ◽  
Vascular Bundles ◽  
Monotypic Genus ◽  
Prominent Feature ◽  
Abaxial Epidermis ◽  
Diagnostic Characters ◽  
Adaxial Epidermis

Clausospicula, a new monotypic genus from the Darwin and Gulf District, Northern Territory, Australia, is described and illustrated. Its diagnostic characters include cleistogamous spikelets, reduced panicles, racemes and spikelets, and pedicelled spikelets which are poorly developed and deciduous, or suppressed. Also, the glumes of the bisexual spikelet are awned and slightly keeled or without keels. A prominent feature is the extension of the peduncle into an appendage to which the callus of the bisexual spikelet is attached. The epidermis is notable for its distinct costal and intercostal zones, rectangular intercostal long-cells with tessellated, pitted cell walls, stomata inserted beneath the overlapping interstomatals and arranged in definite rows bordering the costal zones, the presence of macrohairs, narrow microhairs 39–46.5 µm long, silica-celllcork-cell pairs with dumbbell-shaped silica bodies costally and butterfly-shaped silica bodies intercostally. The transverse section shows a distinct midrib with the vascular bundles arranged in a conventional arc abaxially and colourless tissue adaxially, and a symmetrically ordered lamina. The primary vascular bundles are accompanied by sclerenchyma as girders abaxially and adaxially; the adaxial epidermis is extensively bulliform and the abaxial epidermis is of bulliform-like cells.

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