scholarly journals Anatomía compara del tallo y de la raíz de las especies del género Neoevansia Marshall (Cactaceae)

2017 ◽  
pp. 5 ◽  
Author(s):  
Roberto Herrera-Cárdenas ◽  
Teresa Terrazas ◽  
Sofía Loza-Cornejo
Keyword(s):  
Cell Size ◽  
Secondary Xylem ◽  
Cell Divisions ◽  
Tuberous Roots ◽  
Vessel Elements ◽  
Anatomical Characters

Anatomical characters of Neoevansia species were studied to gain insight in their contribution to the systematics of the genus. Characters of the dermal, fundamental, and vascular systems of the stem and root were evaluated and compared with severl species of Peniocereus, Wilcoxia, and Echinocereus. The results revealed that N. striata is characterized by a noncollenchymatous unistratified hypodermis and alternate intervascular pits in vessel elements in the secondary xylem; while N. lazaro-cardenasii and N. zopilotensis can be distinguished by their epidermic cell size and hypodermis width. The increment in volume in Neoevansia tuberous roots is mainly related to cell divisions in rays. Neoevansia lazaro-cardenasii, N. zopilotensis, and N. striata share with Peniocereus the fibrous wood and the phloem fiber cap. The results support the proposals of several authors to transfer the species of Neoevansia to the genus Peniocereus

Geometric analysis of intrusive growth of wood fibres in Robinia pseudoacacia

IAWA Journal ◽  
2018 ◽  
Vol 39 (2) ◽  
pp. 191-208 ◽  
Author(s):  
Anna B. Wilczek ◽  
Muhammad Iqbal ◽  
Wieslaw Wloch ◽  
Marcin Klisz
Keyword(s):  
Secondary Xylem ◽  
Robinia Pseudoacacia ◽  
Geometric Analysis ◽  
Cell Types ◽  
Vascular Cambium ◽  
Tangential Plane ◽  
Intrusive Growth ◽  
Thin Sections ◽  
Growing Cell ◽  
Vessel Elements

ABSTRACTAll cell types of the secondary xylem arise from the meristematic cells (initials) of the vascular cambium and grow under mechanical constraints emerging from the circular-symmetrical geometry that characterises many tree trunks. The course of intrusive growth of cambial initials has been elucidated, but is yet to be described in the case of xylem fibres. This study explains the geometry of intrusive growth of the secondary xylem fibres in the trunk ofRobinia pseudoacacia.Long series of serial semi-thin sections of the vascular cambium and the differentiating secondary xylem were analysed. Since fibres grow in close vicinity to expanding cells of the derivatives of the vascular cambium, we assumed that they have similar growth conditions. Dealing with the cylindrical tissue of the vascular cambium in a previous study, we used a circularly symmetrical equation for describing the growth mechanism of cambial initials. Like the cambial initials, some of the cambial derivatives differentiating into the various cell types composing the secondary xylem also exhibit intrusive growth between the tangential walls of adjacent cells. As seen in cross sections of the cambium, intrusively growing initials form slanted walls by a gradual transformation of tangential (periclinal) walls into radial (anticlinal) walls. Similarly, the intrusive growth of xylem fibres manifests initially as slants, which are formed due to axial growth of the growing cell tips along the tangential walls of adjacent cells. During this process, the tangential walls of adjacent cells are partly separated and dislocated from the tangential plane. The final shape of xylem fibres, or that of vessel elements and axial parenchyma cells, depends upon the ratio of their intrusiveversussymplastic growths in the axial, circumferential and radial directions.

Changes in cell size and number associated with the effects of light intensity and temperature on the leaf morphology of wheat

1970 ◽  
Vol 48 (1) ◽  
pp. 85-90 ◽  
Author(s):  
D. J. C. Friend ◽  
Marion E. Pomeroy
Keyword(s):  
Light Intensity ◽  
Cell Size ◽  
Leaf Morphology ◽  
High Light ◽  
Cell Length ◽  
Optimal Temperature ◽  
Mesophyll Cells ◽  
Cell Divisions ◽  
Spring Variety ◽  
Growth Changes

In a spring variety of wheat an increase in light intensity over the range 200 to 5000 ft-c reduced the length of the lamina by reducing both the number and length of epidermal cells. The optimal temperature for cell length was 30 °C or above, but the number of cell divisions along the lamina decreased over the range 20 to 30 °C so that lamina length was greatest at 25 °C.Similar results were obtained with a winter variety of wheat chosen to avoid complications caused by possible interference between leaf and inflorescence growth. Changes in the size of the mesophyll cells were generally similar to those in the epidermis. The thicker leaves formed at high light intensities also had thicker mesophyll cells.

Wood Anatomy of Four Californian Mistletoe Species (Phoradendron, Viscaceae)

IAWA Journal ◽  
1997 ◽  
Vol 18 (3) ◽  
pp. 229-245 ◽  
Author(s):  
Vanessa E.T.M. Ashworth ◽  
Gracielza Dos Santos
Keyword(s):  
Wood Anatomy ◽  
Secondary Xylem ◽  
Intrusive Growth ◽  
Separate Species ◽  
Response Strategies ◽  
Vessel Elements ◽  
Ray Parenchyma ◽  
Ray Parenchyma Cells ◽  
Perforation Plates ◽  
Growth Features

Secondary xylem characteristics were compared in four species of Phoradendron Nutt. (Viscaceae) native to California. All have extremely short, thick-walled vessel elements with simple perforation plates. They also share high vessel density, radial vessel arrangement, thick-walled fibres, and multiseriate, heterocellular rays. The fibres show considerable intrusive growth. Features of the vessel elements (i.e. vessel dimensions, arrangement, type of wall sculpturing) and calcium oxalate crystals in the ray parenchyma cells are useful diagnostic traits to separate species. Grooved vessel walls are shared by the morphologically similar P. villosum and P. macrophyllum. Differences between these two species may reflect contrasting drought response strategies pursued by respective hosts. Vulnerability and mesomorphy ratios of the wood of P. californicum are higher than those of P. pauciflorum and P. macrophyllum. Phoradendron pauciflorum has the most xeromorphic wood of the four species studied.

scholarly journals Rescue and vegetative propagation of Eremanthus erythropappus (DC.) MacLeish in natural stand

2020 ◽  
Author(s):  
A. L. C. Fonseca ◽  
T. A. Magalhães ◽  
L. A. Melo ◽  
L. S. Oliveira ◽  
G. E. Brondani
Keyword(s):  
Secondary Xylem ◽  
Diameter Ratio ◽  
Shoot Length ◽  
Root Anatomy ◽  
Economic Potential ◽  
Phloem Parenchyma ◽  
Adult Trees ◽  
Vessel Elements ◽  
Management Plans ◽  
Silvicultural Practice

Abstract The native stands of ‘candeia’ (Eremanthus erythropappus) have been explored through management plans due to the economic potential of essential oil. The rescue of adult trees, as well as the application of silvicultural techniques that favor the restoration of the stand, can contribute to the genetic conservation of this species. This study’s objective was to assess the efficiency of propagation techniques for the rescue of 26 matrices of ‘candeia’ in a natural managed stand and discussion about the rhizogenesis. In August 2017, trees were induced to regrowth by coppice, followed by exposure and scarification of roots. The emergence of shoots and morphology were evaluated according to the origin (i.e., stump or root). After that period, 19 matrices had their sprouts collected for the preparation of apical cuttings. Indole-3-butyric acid (IBA) was applied at the base of the cuttings. Cutting survival at greenhouse exit (GE), rooting at shade house exit (SHE), morphology and root anatomy were evaluated. In 189 days, the scarification of roots promoted 76.92% of budding. The percentage of sprouted matrices, number of shoots per matrice, length, diameter, and shoot length/diameter ratio increased over time. Only 12.2% of the cuttings survived in GE, and of these, 7.9% rooted in SHE. The cutting resulted in the formation of a clonal mini-garden of ‘candeia’, with seven of the 19 matrices submitted to propagation. The anatomical analyses showed that bud formation occurs from cell redifferentiation in the phloem parenchyma, and presence of crystals on the walls of the vessel elements of the secondary xylem. The shoots induction from scarification of roots could be used as a silvicultural practice for the reestablishment of the native fragments handle.

scholarly journals Spindle assembly checkpoint strength is governed by cell size and PAR-mediated cell fate determination in C. elegans

2017 ◽  
Author(s):  
Abigail R. Gerhold ◽  
Vincent Poupart ◽  
Jean-Claude Labbé ◽  
Paul S. Maddox
Keyword(s):  
Cell Size ◽  
Cell Fate ◽  
Genome Stability ◽  
Spindle Assembly Checkpoint ◽  
Asymmetric Cell Division ◽  
Spindle Assembly ◽  
Cell Types ◽  
Cell Fate Determination ◽  
C Elegans ◽  
Cell Divisions

AbstractThe spindle assembly checkpoint (SAC) is a conserved mitotic regulator that preserves genome stability. Despite its central role in preserving the fidelity of mitosis, the strength of the SAC varies widely between cell types. How the SAC is adapted to different cellular contexts remains largely unknown. Here we show that both cell size and cell fate impact SAC strength. While smaller cells have a stronger SAC, cells with a germline fate show increased SAC activity relative to their somatic counterparts across all cell sizes. We find that enhanced SAC activity in the germline blastomere P1 requires proper specification of cell fate downstream of the conserved PAR polarity proteins, supporting a model in which checkpoint factors are distributed asymmetrically during early germ cell divisions. Our results indicate that size scaling of SAC activity is modulated by cell fate and reveal a novel interaction between asymmetric cell division and the SAC.

Morphology of the Vessel Elements in the Secondary Xylem of the Myristicaceae from Brazilian Amazonia

IAWA Journal ◽  
1987 ◽  
Vol 8 (3) ◽  
pp. 202-212 ◽  
Author(s):  
Pedro L. B. Lisboa ◽  
J. Cesar A. da Silva ◽  
A. A. Loureiro ◽  
Gracielza M. dos A. dos Santos
Keyword(s):  
Morphological Study ◽  
Secondary Xylem ◽  
Brazilian Amazon ◽  
Amazon Region ◽  
Simple Type ◽  
Brazilian Amazonia ◽  
Brazilian Amazon Region ◽  
Vessel Elements ◽  
Perforation Plates

A morphological study of vessel elements was carried out in species representing the five genera of Myristicaceae present in the Brazilian Amazon region. The results show that perforation plates of the scalariform type predominate in Compsoneura, Iryanthera and Otoba, where as perforation plates of the simple type predominate in Osteophloeum and Virola. The phylogenetic and taxonomie implications of these findings are discussed.

scholarly journals What do we know about growth of vessel elements of secondary xylem in woody plants?

2021 ◽  
Author(s):  
Adam Miodek ◽  
Aldona Gizińska ◽  
Wiesław Włoch ◽  
Paweł Kojs
Keyword(s):  
Woody Plants ◽  
Secondary Xylem ◽  
Vessel Elements

scholarly journals PRESENCE OR ABSENCE OF STONE CELLS IN THE ROOTS OF INDIAN ACONITES: AN AID TO IDENTIFICATION OF SPECIES

2018 ◽  
Vol 6 (3) ◽  
pp. 42-45
Author(s):  
A. B. D. Selvam
Keyword(s):  
World Wide ◽  
Species Level ◽  
Wild Animals ◽  
Human Beings ◽  
Storage Roots ◽  
Poisonous Plants ◽  
Plant Parts ◽  
Tuberous Roots ◽  
Identification Of Species ◽  
Anatomical Characters

The species of the genus Aconitum are commonly and collectively called Aconites in trade. Aconites are known to people since antiquity as deadly poisonous plants. They are being used world-wide either as an arrow poison to kill the wild animals illegally or to heal human beings legally. After detoxification of the roots of Aconites using conventional methods, they are being used in different traditional systems of medicine such as Chinese, Japanese, Nepalese, Ayurveda, Siddha, Unani and Tibetan, in addition to tribal and folk medicines. The roots of Aconites are highly exploited from wild sources and are traded illegally. Identification of traded roots of Aconites is a difficult task. To overcome this botanical problem, anatomical characters may be used. Sclereids, particularly brachysclereids are popularly known as stone cells because of their hardness. Stone cells protect other cells/tissues of the plants or plant parts. Since the presence of stone cells in plants is considered as one of the constant characters (marker characters), which may be very well utilized for identification or authentication of tuberous roots of Aconites. The present study highlights the presence or absence of stone cells (brachysclereids) in the tuberous storage roots of Indian Aconites as an aid for the identification or authentication at species level.

Wood Anatomy of Chenopodiaceae (Amaranthaceae s.l.)

IAWA Journal ◽  
2012 ◽  
Vol 33 (2) ◽  
pp. 205-232 ◽  
Author(s):  
Heike Heklau ◽  
Peter Gasson ◽  
Fritz Schweingruber ◽  
Pieter Baas
Keyword(s):  
Calcium Oxalate ◽  
Wood Anatomy ◽  
Secondary Xylem ◽  
Annual Species ◽  
Calcium Oxalate Crystals ◽  
Successive Cambia ◽  
Oxalate Crystals ◽  
Vessel Elements ◽  
Extreme Habitats

The wood anatomy of the Chenopodiaceae is distinctive and fairly uniform. The secondary xylem is characterised by relatively narrow vessels (<100 μm) with mostly minute pits (<4 μm), and extremely narrow vessels (<10 μm intergrading with vascular tracheids in addition to “normal” vessels), short vessel elements (<270 μm), successive cambia, included phloem, thick-walled or very thick-walled fibres, which are short (<470 μm), and abundant calcium oxalate crystals. Rays are mainly observed in the tribes Atripliceae, Beteae, Camphorosmeae, Chenopodieae, Hablitzieae and Salsoleae, while many Chenopodiaceae are rayless. The Chenopodiaceae differ from the more tropical and subtropical Amaranthaceae s.str. especially in their shorter libriform fibres and narrower vessels. Contrary to the accepted view that the subfamily Polycnemoideae lacks anomalous thickening, we found irregular successive cambia and included phloem. They are limited to long-lived roots and stem borne roots of perennials (Nitrophila mohavensis) and to a hemicryptophyte (Polycnemum fontanesii). The Chenopodiaceae often grow in extreme habitats, and this is reflected by their wood anatomy. Among the annual species, halophytes have narrower vessels than xeric species of steppes and prairies, and than species of nitrophile ruderal sites.

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