scholarly journals Silene thymifolia Sibth. et Sm. (Caryophyllaceae) – A vulnerable species in Romania: Anatomical aspects of vegetative organs

2021 ◽  
Vol 13 (1) ◽  
pp. 10875
Author(s):  
Loreley D. JIANU ◽  
Rodica BERCU ◽  
Dan R. POPOVICIU
Keyword(s):  
Cross Section ◽  
Secondary Xylem ◽  
Coastal Dunes ◽  
Vascular Bundles ◽  
Vulnerable Species ◽  
Spongy Tissue ◽  
Specific Staining ◽  
Vegetative Organs ◽  
Glandular Hairs ◽  
Near Threatened

Silene thymifolia (Caryophyllaceae) is considered a rare, near-threatened species in Romania, growing only on Black Sea coastal dunes.  Anatomical aspects of the root, stem and leaf of this species are presented in this study. Root, stem and leaves were analysed by brightfield microscopy, with specific staining. The root in cross section exhibited a secondary structure, generated by the activity of phellogen, and vascular cambium, with thick cork, continuous secondary xylem rings. no pith rays, but with cortical air lacunes. The stem had a primary structure with a number of collateral vascular bundles arranged on a single circle, with thick cortical schlerenchymal layers and oxalate crystals in pith cells. The epidermis showed stomata and glandular hairs. The leaf was amphystomatic leaf, with a heterogeneous mesophyll (equifacial type) and embedded vascular bundles, with a rounded mid rib surrounded by a parenchyma sheath. The spongy tissue has some large intercellular air spaces with druses. The mechanical tissue is well developed in the root and stem and poorly developed, represented by few collenchyma elements in the mesophyll, being represented by a continuous schlerenchyma fibers band present in root and stem and collenchyma in the leaf. The secretory histological elements were represented by epidermal glandular hairs and oxaliferous cells (druses) present in stem and leaf.

scholarly journals Anatomy of Brazilian Cereeae (subfamily Cactoideae, Cactaceae): Arrojadoa Britton & Rose, Stephanocereus A. Berger and Brasilicereus Backeberg

2007 ◽  
Vol 21 (4) ◽  
pp. 813-822 ◽  
Author(s):  
Patricia Soffiatti ◽  
Veronica Angyalossy
Keyword(s):  
Secondary Xylem ◽  
Sieve Tube ◽  
Vascular Bundles ◽  
Campos Rupestres ◽  
Espinhaço Range ◽  
Diagnostic Characters ◽  
Bordered Pits ◽  
Companion Cells ◽  
Southern Bahia ◽  
Perforation Plates

(Anatomy of Brazilian Cereeae (subfamily Cactoideae, Cactaceae): Arrojadoa Britton & Rose, Stephanocereus A. Berger wâBrasilicereus Backeberg). Arrojadoa, Stephanocereus and Brasilicereus are endemic Brazilian Cereeae, occurring along the Espinhaço Range, in the campos rupestres, cerrados and caatingas, from northern Minas Gerais to southern Bahia. The genera are columnar, erect to semi-erect cacti, except for one species, A bahiensis, which is globose. This study describes the anatomy of dermal, fundamental and vascular systems, aiming to find diagnostic characters for the genera and species. Basal portions of stems were sectioned transversely and longitudinally, and stained with Astrablue and Safranin. The species share a uniseriate epidermis, with thick cuticle; well developed collenchymatic hypodermis, containing prismatic crystals; cortex with numerous mucilage cells, druses and vascular bundles; outside cortex as a palisade parenchyma; periderm composed of lignified cork cells alternating with suberized cells; pheloderm consisting of a few layers of thin-walled cells; phloem composed of solitary or multiple of two to three sieve tube elements, companion cells, axial and radial parenchyma; secondary xylem with solitary to multiple vessels, with simple perforation plates and alternate bordered to semi-bordered pits; axial parenchyma scanty vasicentric to incomplete; libriform septate fibres; large rays. Unlignified parenchyma is seen in the secondary xylem, varying from a few cells to bands among axial and radial elements. The following are considered diagnostic characters: the shape of lignified phellem cells, cubic to radially elongate, which individualizes S. leucostele; an underdeveloped hypodermis and the occurrence of sclereids in the cortex are exclusive to Brasilicereus markgrqfii.

Bycatch and landings of young of the year sharks in the Malaysian South China Sea: implications for conservation

2015 ◽  
Vol 8 ◽  
Author(s):  
Azie Azri ◽  
Takaomi Arai
Keyword(s):  
South China Sea ◽  
South China ◽  
Fishing Gear ◽  
Shark Species ◽  
Vulnerable Species ◽  
Critical Levels ◽  
Sphyrna Lewini ◽  
China Sea ◽  
Young Of The Year ◽  
Near Threatened

A total of 104 sharks were landed at fishing ports in the Malaysian South China Sea between 30 October and 24 December 2014, comprising the four families, Carcharhinidae, Hemiscylliidae, Sphyrnidae and Scyliorhinidae, and 11 of these shark species were examined. Measurements of size and weight were different and varied among species, ranging from 0.1 to 7.5 kg in body weight and from 31.1 to 105 cm in total length. Five of the 11 sharks,Carcharhinus sealei, Loxodon macrorhinus, Rhizoprionodon acutus, Hemigaleus microstomaandSphyrna lewini, were in the range of, or even less than, the lengths of those measured at birth in previous reports. The results suggest that these sharks were born just before they were landed.Sphyrna lewiniand H.microstomaare categorized as Endangered and Vulnerable species, respectively, and other sharks included in the landings are also categorized as Near Threatened. Thus, the current fishing methods could lead to critical levels of shark species in these waters, and even the future extinction of species. An improvement in the species selectiveness of fishing gear is needed to protect and conserve sharks in the area.

scholarly journals RESILIENCE OF FERNS: WITH REFERENCE TO DESICCATION AND REHYDRATION STRESS OFFER NEW INSIGHTS

2017 ◽  
Vol 4 (2) ◽  
pp. 89-94
Author(s):  
Kavitha C.H ◽  
Meenu Krishnan ◽  
Murugan K
Keyword(s):  
Vascular Plants ◽  
Stress Proteins ◽  
Secondary Xylem ◽  
Plant Water Relations ◽  
Vascular Bundles ◽  
Late Cenozoic ◽  
Primary Xylem ◽  
Hydraulic Failure ◽  
Pit Membrane ◽  
Selection For

Ferns are one of the oldest vascular plants in existence and they are the second most diverse group of vascular plants followed to angiosperms. To unravel fern success has focused on the eco-physiological power and stress tolerance of their sporophyte and the gametophyte generations. In this context, those insightsencompass plant water relations, as well as the tolerance to and recovery from drought or desiccation stresses in the fern life cycle are reviewed. Lack of secondary xylem in ferns is compensated by selection for efficient primary xylem composed of large, closely arranged tracheids with permeable pit membranes.Protection from drought-induced hydraulic failure appears to arise from a combination of pit membrane traits and the arrangement of vascular bundles. Features such as tracheid-based xylem and variously sized megaphylls are shared between ferns and more derived lineages, and offer an opportunity to compare convergent and divergent hydraulic strategies critical to the success of xylem-bearing plants. Similarly the synthesis and accumulation of sugar, proline and stress proteins along with the production of pool of polyphenols add strength to desiccation stress. Thus, it can possible to suggest that selection acted on the physiology in a synchronous manner that is consistent with selection for drought tolerance in the epiphytic niche, and the increasingly diverse habitats of the mid to late Cenozoic.

scholarly journals Development of successive cambia and wood structure in stem of Rivea hypocriteriformis (Convolvulaceae)

2016 ◽  
Vol 61 (1) ◽  
pp. 89-98 ◽  
Author(s):  
Kishore S. Rajput
Keyword(s):  
Secondary Xylem ◽  
Monsoon Season ◽  
Secondary Growth ◽  
Vascular Bundles ◽  
Growth Rings ◽  
Successive Cambia ◽  
Initial Stage ◽  
Ray Cells ◽  
Cell Layers ◽  
Ray Parenchyma Cells

Abstract This study examined the formation of successive rings of cambia in Rivea hypocriteriformis Choisy (Convolvulaceae). The mature stem is composed of four to five rings of xylem alternating with phloem. Successive cambia originate as smaller and larger segments; union and anastomosing of small cambial segments often leads to the formation of discontinuous rings. In the initial stage of growth, several vascular bundles interconnect to form the first ring of vascular cambium. The cambium remains functional for one complete season and becomes dormant during summer; a new ring of cambium is completed prior to the subsequent monsoon season and sprouting of new leaves. Successive cambia are initiated from the pericyclic parenchyma situated three to four cell layers outside of the protophloem. Functionally, all the successive cambia are bidirectional and produce secondary xylem centripetally and phloem centrifugally. The secondary xylem is diffuse-porous, with indistinct growth rings and consisting of wide fibriform vessels, fibre tracheids, and axial and ray parenchyma cells. The xylem rays are uni- to multiseriate and heterocellular. The multiseriate rays contain lignified marginal ray cells and thin-walled, unlignified central cells. The central ray cells also show accumulations of starch and druses. Discrete strands of intraxylary phloem occur at the periphery of the pith, and additional intraxylary phloem develops from adjacent cells as secondary growth progresses. Earlier-formed phloem shows heavy accumulation of callose, followed by its compaction. The development of successive cambia is correlated with extension growth and with the phenology of the plant.

Structural bionic design for thin-walled cylindrical shell against buckling under axial compression

2011 ◽  
Vol 225 (11) ◽  
pp. 2619-2627 ◽  
Author(s):  
D Xing ◽  
W Chen ◽  
J Ma ◽  
L Zhao
Keyword(s):  
Cylindrical Shell ◽  
Axial Compression ◽  
Cross Section ◽  
Cylindrical Shells ◽  
High Load ◽  
Vascular Bundles ◽  
Bionic Design ◽  
Load Bearing ◽  
Thin Walled ◽  
The Cross

In nature, bamboo develops an excellent structure to bear nature forces, and it is very helpful for designing thin-walled cylindrical shells with high load-bearing efficiency. In this article, the cross-section of bamboo is investigated, and the feature of the gradual distribution of vascular bundles in bamboo cross-section is outlined. Based on that, a structural bionic design for thin-walled cylindrical shells is presented, of which the manufacturability is also taken into consideration. The comparison between the bionic thin-walled cylindrical shell and a simple hollow one with the same weight showed that the load-bearing efficiency was improved by 44.7 per cent.

scholarly journals Morphological and Anatomical Studies of Hippocrepis L. Genus in Turkey

2019 ◽  
Vol 37 ◽  
Author(s):  
K. YETISEN ◽  
C. ÖZDEMIR
Keyword(s):  
Cross Section ◽  
Vascular Bundle ◽  
The Other ◽  
Vascular Bundles ◽  
Stem Anatomy ◽  
Anatomical Studies ◽  
Anatomical Features

ABSTRACT: In this study, the morphological and anatomical features were investigated of three taxon of Hippocrepis L. species which spreading naturally in Turkey. In the morphological part of the study, H. unisiliquosa subsp. unisiliquosa’s stem is erect or decumbent. The species H. ciliata’s Willd. stem is erect. H. multisiliquosa’s L. stem is decumbent. The fruit of H. multisiliquosa is much more convoluted than the other two taxa. There are cilia on the fruit of H. ciliata, but there are not found any cilia the other two taxa. The stem anatomy of all the studied taxa is hexagonal. In the stem cross section of H. ciliata 12-14 vascular bundle are found, H. unisiliquosa subsp. unisiliquosa 12-15 and H. multisiliquosa 12-13. Leaf vascular bundles are arranged regularly, H. unisiliquosa subsp. unisiliquosa have 18-20, H. ciliata have 6-8, H. multisiliquosa have 9-13 vascular bundles.

scholarly journals Efficiently, accurately, intelligently dissecting bamboo: characteristic of vascular bundle in Phyllostachys

2021 ◽  
Author(s):  
Haocheng Xu ◽  
Ying Zhang ◽  
Jiajun Wang ◽  
Tuhua Zhong ◽  
Xinxin Ma ◽  
...  
Keyword(s):  
Cross Section ◽  
Radial Distribution ◽  
Vascular Bundle ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Width Ratio ◽  
Vascular Bundles ◽  
Fiber Volume ◽  
Detection Model ◽  
Gradient Change

AbstractA comprehensive understanding of vascular bundles is the key to elucidate the excellent intrinsic mechanical properties of bamboo. This research aims to investigate the gradient distribution of fiber volume fraction and the gradient changes in the shape of vascular bundles along the radial axis in Phyllostachys. We constructed a universal transfer-learning-based vascular bundle detection model with high precision of up to 96.97%, which can help to acquire the characteristics of vascular bundles quickly and accurately. The total number of vascular bundles, total fiber sheath area, the length, width and area of fiber sheath of individual vascular bundles within the entire cross-section were counted, and the results showed that these parameters had a strongly positive linear correlation with the outer circumference and wall thickness of bamboo culms, but the fiber volume fraction (around 25.5 %) and the length-to-width ratio of the vascular bundles (around 1.226) were relatively constant. Furthermore, we layered the cross section of bamboo according to the wall thickness finely and counted the characteristics of vascular bundle in each layer. The results showed that the radial distribution of fiber volume fraction decreased exponentially, the radial distribution of the length-to-width ratio of vascular bundle decreased quadratically, the radial distribution of the width of vascular bundle increased linearly. The trends of the gradient change in vascular bundle’s characteristics were found highly consistent among 29 bamboo species in Phyllostachys.One sentence summaryA universal vascular bundle detection model can efficiently dissect vascular bundles in Phyllostachys, and the radial gradient change of vascular bundles in cross-section are found highly consistent.

Anatomical characteristics and antioxidant properties of Euphorbia nicaeensis ssp. glareosa

2009 ◽  
Vol 4 (2) ◽  
pp. 214-223 ◽  
Author(s):  
Jadranka Luković ◽  
Djordje Malenčić ◽  
Lana Zorić ◽  
Biljana Kiprovski ◽  
Ljiljana Merkulov ◽  
...  
Keyword(s):  
Antioxidant Properties ◽  
Vascular Bundles ◽  
Oxygen Species ◽  
Phytochemical Screening ◽  
Spongy Tissue ◽  
Abaxial Side ◽  
Typical Steppe ◽  
Effective Antioxidant ◽  
Palisade Cells ◽  
Stem Structure

AbstractAnatomical analyses found that leaves of Euphorbia nicaeensis ssp. glareosa are isolateral, amphistomatous, with two layers of palisade cells on the adaxial and one on the abaxial side. Laticifers are present by vascular bundles, in palisade and spongy tissue. Stem laticifers are located in the pericyclic ring, adjacent to the phloem, in cylinder parenchyma and medullar rays. The structure of pleiochasium and dichasium peduncle is similar to the stem structure. Plants from typical steppe habitat show more xeromorphic features. Phytochemical screening of extracts showed presence of catecholes, flavonoids, tannins, saponins, free quinone derivatives and absence of anthocyanins, leucoanthocyanins, alkaloids, steroid compounds and essential oils. Our results showed that the examined taxon was partially susceptible to the action of reactive oxygen species, such as O2·− and ·OH. The higher quantities of ROS thus provoked an antioxidative response from the plant, both in an enzymatic and non-enzymatic manner. Stable anatomical structure, presence and distribution of laticifers and effective antioxidant properties when exposed to ROS, make Euphorbia nicaeensis subsp. glareosa potentially interesting for further pharmaceutical and phytochemical examinations.

scholarly journals Leaf and inflorescence axis anatomy of Brazilian species of Rapateoideae (Rapateaceae, Poales)

2015 ◽  
Vol 87 (1) ◽  
pp. 157-171 ◽  
Author(s):  
Ângela L. Daltin ◽  
Aline Oriani ◽  
Vera L. Scatena
Keyword(s):  
Cross Section ◽  
Leaf Blade ◽  
Diagnostic Value ◽  
Fiber Bundles ◽  
Vascular Bundles ◽  
Abaxial Epidermis ◽  
Cross Section Shape ◽  
Inflorescence Axis ◽  
Section Shape ◽  
The Cross

The anatomy of leaves and inflorescence axes of Spathanthus (2 spp.), Rapatea (2 spp.), Cephalostemon(1 sp.), and Duckea(1 sp.) (Rapateoideae, Rapateaceae) was studied to identify useful characters for taxonomy. The cross-section shape of inflorescence axis differentiates the genera, while the cross-section shape and structure of leaf midrib has a specific value. The following characteristics are exclusive of Spathanthus: silica cells randomly distributed in the leaf epidermis; plicate chlorenchyma in the leaf blade; presence of fiber bundles in the mesophyll and in the inflorescence axis parenchyma. Spathanthus is also distinguished by the number, type and distribution of vascular bundles in the inflorescence axis. The genus Rapatea is characterized by the presence of stomata and silica cells only on the abaxial epidermis of the leaves and chlorenchyma composed of arm cells in the leaf blade. Characteristics with diagnostic value for Cephalostemon riedelianusare: leaf epidermal cells with straight to slightly sinuous walls in frontal view, inflorescence axes presenting a defined cortex, fiber bundles facing the larger vascular bundles and a fistulous pith. The anatomical characteristics of the leaves and inflorescence axes thus proved to be of taxonomic value in generic and specific levels. They are also useful to differentiate Rapateoideae from other subfamilies of Rapateaceae.

A model of nitric oxide tubulovascular cross talk in a renal outer medullary cross section

2007 ◽  
Vol 292 (2) ◽  
pp. F711-F722 ◽  
Author(s):  
Wensheng Zhang ◽  
Aurélie Edwards
Keyword(s):  
Blood Flow ◽  
Cross Section ◽  
Cross Talk ◽  
Vascular Bundle ◽  
Flow Distribution ◽  
Structural Heterogeneity ◽  
No Production ◽  
Vascular Bundles ◽  
Outer Medulla ◽  
Blood Flow Ratio

We developed a two-dimensional model of NO transport in a cross section of the inner stripe (IS) of the rat outer medulla to determine whether tubular and vascular generation of NO result in significant NO concentration (CNO) differences between the periphery and the center of vascular bundles and thereby affect medullary blood flow distribution. Following the approach of Layton and Layton (Layton AT, Layton HE. Am J Physiol Renal Physiol 289: F1346–F1366, 2006), the structural heterogeneity of the IS was incorporated in a representative unit consisting of four concentric regions centered on a vascular bundle. Our model suggests that the diffusion distance of NO in the interstitium is limited to a few micrometers. We predict that, under basal conditions, epithelial NO generation raises the average CNO in pericytes surrounding peripheral descending vasa recta (DVR) by a few nanomoles relative to that in pericytes surrounding central DVR. The short descending limbs and long ascending limbs are found to exert the greatest effect on CNO in pericytes; long descending limbs and short ascending limbs only have a moderate effect, whereas outer medullary collecting ducts, which are situated far from the vascular bundle center, do not affect pericyte CNO. Our results suggest that selective stimulation of epithelial NO production should significantly raise the periphery-to-center DVR diameter ratio, thereby increasing the outer medulla-to-inner medulla blood flow ratio. However, concomitant increases in epithelial superoxide (O2−) production would counteract this effect. This model confirms the importance of NO and O2− interactions in mediating tubulovascular cross talk.

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