scholarly journals Development of Intra- and Interxylary Secondary Phloem in Coccinia indica (Cucurbitaceae)

IAWA Journal ◽  
2011 ◽  
Vol 32 (4) ◽  
pp. 475-491 ◽  
Author(s):  
Vidya S. Patil ◽  
Carmen R. Marcati ◽  
Kishore S. Rajput
Keyword(s):  
Vascular Bundle ◽  
Secondary Xylem ◽  
Secondary Growth ◽  
Cambial Activity ◽  
Vascular Bundles ◽  
Secondary Phloem ◽  
Stem Anatomy ◽  
Axial Parenchyma ◽  
Vessel Elements ◽  
Coccinia Indica

Stem anatomy and the development of intraxylary phloem were investigated in six to eight years old Coccinia indica L. (Cucurbitaceae). Secondary growth in the stems was achieved by the normal cambial activity. In the innermost part of the thicker stems, xylem parenchyma and pith cells dedifferentiated into meristematic cells at several points. In some of the wider rays, ray cells dedifferentiate and produce secondary xylem and phloem with different orientations and sometimes a complete bicollateral vascular bundle. The inner cambial segments of the bicollateral vascular bundle (of primary growth) maintained radial arrangement even in the mature stems but in most places the cambia were either inactive or showed very few cell divisions. Concomitant with the obliteration and collapse of inner phloem (of bicollateral vascular bundles), parenchyma cells encircling the phloem became meristematic forming a circular sheath of internal cambia. These internal cambia produce only intraxylary secondary phloem centripetally and do not produce any secondary xylem. In the stem, secondary xylem consisted mainly of axial parenchyma, small strands of thick-walled xylem derivatives, i.e. vessel elements and fibres embedded in parenchymatous ground mass, wide and tall rays along with exceptionally wide vessels characteristic of lianas. In thick stems, the axial parenchyma de-differentiated into meristem, which later re-differentiated into interxylary phloem. Fibre dimorphism and pseudo-vestured pits in the vessels are also reported.

scholarly journals The stem anatomy of the Clematis species (Ranunculaceae) in Taiwan

2021 ◽  
Author(s):  
Sheng-Zehn Yang ◽  
Po-Hao Chen ◽  
Chien-Fan Chen
Keyword(s):  
Secondary Xylem ◽  
Secondary Growth ◽  
Restriction Pattern ◽  
Vascular Bundles ◽  
Stem Anatomy ◽  
Primary Xylem ◽  
Morphological Studies ◽  
Arc Shape ◽  
Key Features ◽  
Cambial Variants

Abstract Background Studies on the stem anatomical characteristics of Taiwanese species from the Clematis genus (Ranunculaceae) are scarce. This study aimed to investigate and compare the patterns of secondary growth in stems of 22 Clematis species. Results The rhytidome is composed of periderm and non-conducting phloem and formed either cogwheel-like or continuous segment bark. Key features of the genus were stem with an irregular conformation, wedge-like phloem and rays, indentations in the axial parenchyma, ray dilatation, and narrow rays. Approximately eight Clematis species formed bark arc shape, which developed the cogwheel- like rhytidome. There were with approximately 27% of the Clematis species in Taiwan having 12 vascular bundles. The vessels dispersed throughout the stem were semi-ring-porous in most species but were ring-porous in others. No species had diffuse-porous vessels. The vessel restriction pattern was only found in the two shrubs, C. psilandra and C. tsugetorum. The primary xylem ring was located around the pith in C. uncinata var. uncinata, making its pith cavity hexagon in shape. Four species had the pith cavity feature. Narrow rays that occurred in the secondary xylem increased with increasing stem diameter. Conclusions The cambial variants described in this study provide a foundation for further morphological studies of the Clematis genus.

Xylem Structure of Successive rings in the stem of Abuta Grandifolia (Menispermaceae) a Statistical Approach

IAWA Journal ◽  
2010 ◽  
Vol 31 (3) ◽  
pp. 309-316 ◽  
Author(s):  
Neusa Tamaio ◽  
Arno Fritz das Neves Brandes
Keyword(s):  
Statistical Approach ◽  
Secondary Xylem ◽  
Vascular Ring ◽  
Vessel Diameter ◽  
Secondary Phloem ◽  
Axial Parenchyma ◽  
Xylem Structure ◽  
Qualitative And Quantitative ◽  
Tracheid Length ◽  
Vessel Elements

Abuta grandifolia (Mart.) Sandwith varies in habit and can be a shrub, tree or liana. Its stem shows successive cambia that produce secondary phloem and xylem. This study analyses qualitative and quantitative differences between the secondary xylem of lianas and shrubs of A. grandifolia, as well as between the successive rings within each habit category. The lianas had wider vessels, shorter vessel elements and thinner fibre-tracheid walls. In the first five successive rings, lianas showed an increase in vessel diameter and fibre-tracheid length, while fibre-tracheid wall thickness decreased. The shrubs showed an increase in the diameter and length of vessel elements and length of fiber-tracheids. In qualitative features the secondary xylem of lianas and shrubs did not differ, except in their type of parenchyma (axial parenchyma diffuse in the liana habit and diffuse to diffuse in-aggregates in the shrub habit). Since significant quantitative differences were found between the successive rings, the first vascular ring is recommended for comparing both habits. Whether this is generally valid in Menispermaceae requires further study.

Stem Anatomy and Development of Successive Cambia in the Neotropical Liana Securidaca Rivinifolia (Polygalaceae)

IAWA Journal ◽  
2012 ◽  
Vol 33 (4) ◽  
pp. 391-402 ◽  
Author(s):  
Kishore S. Rajput ◽  
Marina B. Fiamengui ◽  
Carmen R. Marcati
Keyword(s):  
Secondary Xylem ◽  
Secondary Growth ◽  
Stem Anatomy ◽  
Growth Rings ◽  
Cross Sectional ◽  
Axial Parenchyma ◽  
Successive Cambia ◽  
Bordered Pits ◽  
Perforation Plates ◽  
Diffuse Porous

The pattern of secondary growth and structure of secondary xylem was studied in the stem of the Neotropical liana Securidaca rivinifolia A. St.-Hil. (Polygalaceae). Increase in thickness of the stem was achieved by formation of successive cambia, from which initially two or three successive rings formed complete oval to circular cambia. Thereafter, the successive cambia were always crescent-shaped and never formed a complete cylinder, resulting in dumbbell-shaped cross-sectional outlines of the stems. The first successive cambium originated in the pericyclic parenchyma located outside the crushed protophloem. Prior to the development of cambium, pericyclic parenchyma formed a meristematic band of radially arranged cells. From this band, cells located in the middle of the band became the new ring of cambium. Cells on the inner face of the xylem produced by newly formed cambium differentiated into conjunctive tissue. The first elements to be differentiated from the newly developed cambium were always xylem fibres but differentiation of vessels was also observed occasionally. The xylem was diffuse porous with relatively distinct growth rings and composed of mostly solitary vessels with simple perforation plates, fibres with bordered pits, paratracheal axial parenchyma, and exclusively uniseriate rays.

scholarly journals Bark and Cambial Variation in the Genus Clematis (Ranunculaceae) in Taiwan

2020 ◽  
Author(s):  
Sheng-Zehn Yang ◽  
Po-Hao Chen ◽  
Chien-Fan Chen
Keyword(s):  
Vascular Bundle ◽  
Secondary Xylem ◽  
Vascular Bundles ◽  
Outer Bark ◽  
Axial Parenchyma ◽  
Primary Xylem ◽  
Second Stage ◽  
Morphological Studies ◽  
Key Features ◽  
Sclerenchyma Fibers

Abstract BackgroundStudies on the anatomical characteristics of stems of Taiwanese species from the Clematis genus (Ranunculaceae) are scarce. The aim of this study was to investigate and compare cambial variation in stems of 22 Clematis species. ResultsThe rhytidome (outer bark) was either cogwheel-like or continuous, except for in the species Clematis tashiroi. Key features of the genus were eccentric to elliptical or polygonous-lobed stems, wedge-like phloem, wedge-like rays, indentations in the axial parenchyma, and ray dilatation. The cortical sclerenchyma fibers were embedded in the phloem rays with approximately 23% of the Clematis species. Both C. psilandra and C. tsugetorum had restricted vessels. There were three vascular bundle patterns, with approximately 27% of the Clematis species in Taiwan having 12 vascular bundles. The vessels dispersed throughout the stem were semi-ring-porous in most species, but were ring-porous in others. No species had diffuse-porous vessels. Only two species had a primary xylem ring located around the pith. Secondary xylem rays split the secondary xylem into parts, increasing stem diameter. The developmental stage of each sample was determined, with the initial ring-like periderm being produced in the primary phloem during the second stage. ConclusionsThe cambial variations described in this study provide a foundation for further morphological studies of the Clematis genus.

Structure of the secondary xylem and development of a cambial variant in Serjania mexicana (Sapindaceae)

IAWA Journal ◽  
2021 ◽  
pp. 1-11
Author(s):  
Kishore S. Rajput ◽  
Amit D. Gondaliya ◽  
Roger Moya
Keyword(s):  
Secondary Xylem ◽  
Secondary Growth ◽  
Stem Anatomy ◽  
The Family ◽  
Ray Cells ◽  
Cambial Variant ◽  
Proportional Increase ◽  
Plant Families ◽  
Ray Parenchyma Cells ◽  
Cambial Variants

Abstract The lianas in the family Sapindaceae are known for their unique secondary growth which differs from climbing species in other plant families in terms of their cambial variants. The present study deals with the stem anatomy of self-supporting and lianescent habit, development of phloem wedges, the ontogeny of cambial variants and structure of the secondary xylem in the stems of Serjania mexicana (L.) Willd. Thick stems (15–20 mm) were characterized by the presence of distinct phloem wedges and tangentially wide neo-formed cambial cylinders. As the stem diameter increases, there is a proportional increase in the number of phloem wedges and neo-formed vascular cylinders. The parenchymatous (pericyclic) cells external to phloem wedges that are located on the inner margin of the pericyclic fibres undergo dedifferentiation, become meristematic and form small segments of cambial cylinders. These cambia extend tangentially into wide and large segments of neoformations. Structurally, the secondary xylem and phloem of the neo-formed vascular cylinders remain similar to the derivatives produced by the regular vascular cambium. The secondary xylem is composed of vessels (wide and narrow), fibres, axial and ray parenchyma cells. The occurrence of perforated ray cells is a common feature in both regular and variant xylem.

scholarly journals Adventitious Root Formation in Stem Cuttings of Quercus bicolor and Quercus macrocarpa and Its Relationship to Stem Anatomy

2008 ◽  
Vol 133 (4) ◽  
pp. 479-486 ◽  
Author(s):  
J. Naalamle Amissah ◽  
Dominick J. Paolillo ◽  
Nina Bassuk
Keyword(s):  
Secondary Growth ◽  
Adventitious Root Formation ◽  
Fiber Bundles ◽  
Vascular Bundles ◽  
Stem Cuttings ◽  
Root Primordia ◽  
Stem Anatomy ◽  
Indole Butyric Acid ◽  
Quercus Macrocarpa ◽  
Quercus Bicolor

This study investigated the relationship of stem anatomy to differences in rooting ability between Quercus bicolor Wild. and Quercus macrocarpa Michx. cuttings. Quercus bicolor cuttings were found to have a significantly greater proportion of parenchymatous gaps in the sclerenchyma sheath over a 9-week period compared with Q. macrocarpa cuttings. In Q. macrocarpa, the percentage gap was generally low, coinciding with the low percentage rooting observed in this species. Percentage rooting correlated well (r2 = 0.75) with the percentage parenchymatous gap in the perivascular region of Q. bicolor cuttings. The problems with accepting this relationship as causal are stated in the discussion. Untreated cuttings showed normal stem organization: a dermal tissue system that included the initial stages of phellem formation, a cortex, and a ring of closely arranged vascular bundles in early stages of secondary growth. The locations of the five distinct lobes of the pith were coordinated with the locations of root primordia. Callus growth was first detected in the cortex (i.e., external to the fiber bundles), followed by proliferation within the phloem, opposite the lobes of the pith, 8 to 12 days after cuttings were treated with indole butyric acid (6000 mg·L−1 dissolved in 50% v/v ethanol in water). By 14 to 16 days, root primordia had developed within the proliferative tissue in the secondary phloem. In both species, root primordia penetrated parenchymatous gaps in the fiber sheath directly, the fiber bundles being displaced laterally as the roots increased in size.

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.

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.

Stem anatomy at various developmental stages of secondary growth in Turbina corymbosa (Convolvulaceae)

2018 ◽  
Vol 151 (2) ◽  
pp. 219-230 ◽  
Author(s):  
Manoj M. Lekhak ◽  
Amit D. Gondaliya ◽  
Shrirang R. Yadav ◽  
Kishore S. Rajput
Keyword(s):  
Secondary Xylem ◽  
Secondary Growth ◽  
Growth Patterns ◽  
Stem Anatomy ◽  
Successive Cambia ◽  
Background Population ◽  
Short Period ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
Ray Parenchyma Cells

Background – Population growth of lianas in the tropical forest is credited to their ability of CO2 sequestration and efficiency of the narrow stems to supply water required for the amount of foliage it bears. Turbina corymbosa (L.) Raf. (Convolvulaceae Juss.) is one of the fast-growing invasive species of scrambling woody lianas. It covers trees entirely within a short period to compete with above-ground resources (particularly sunlight). However, no information is available on how it manages to cope up with an increasing demand of water supply and mineral nutrients. What are the structural and developmental patterns adapted by this species to expand the stem diameter for efficient supply of below-ground resources? Therefore, our aim was to investigate the secondary growth patterns and structure of secondary xylem and phloem in T. corymbosa.Methods – Several samples of the stem with various diameters were studied using a histological method. Morphological and anatomical analyses were carried out using light microscopy.Key results – With the initiation of secondary growth, stems lose their circular outline rapidly due to unequal deposition of secondary xylem and formation of successive cambia. New successive cambia initiate from parenchymatous cells as small crescent-shaped fragments on asymmetric/opposite sides and result in a different stem conformation. Though several segments of successive cambia are formed, very few stem samples form complete cambium rings. The secondary xylem formed by successive cambia is diffuse porous with indistinct growth rings and is composed of both wide and narrow (fibriform) vessels, tracheids, fibres, axial and ray parenchyma cells. The secondary phloem consists of sieve tube elements, companion cells, axial and ray parenchyma cells. In fully grown plants, cambial action (internal cambium) occurrs between the intraxylary phloem and protoxylem and produces secondary xylem and phloem near the pith region.Conclusion – Structural alterations and unequal deposition of conducting elements, occurrence of intraxylary phloem and flattening of the stem are suggested to facilitate rapid growth of the plants by providing required minerals and nutrients. Internal cambium formed at the periphery of the pith is bidirectional and produces secondary xylem externally and intraxylary phloem internally. Continued development of intraxylary phloem from the internal cambium provides an additional path for rapid and safe translocation of photosynthates.

Structure and ontogeny of the fissured stems of Callaeum (Malpighiaceae)

IAWA Journal ◽  
2017 ◽  
Vol 38 (1) ◽  
pp. 49-66 ◽  
Author(s):  
Pablo A. Cabanillas ◽  
Marcelo R. Pace ◽  
Veronica Angyalossy
Keyword(s):  
Secondary Xylem ◽  
Vascular System ◽  
Secondary Growth ◽  
Natural Fracture ◽  
Production Rates ◽  
Axial Parenchyma ◽  
Parenchyma Cells ◽  
Ray Cells ◽  
Cambial Variant ◽  
Stem Development

Stem ontogeny and structure of two neotropical twining vines of the genus Callaeum are described. Secondary growth in Callaeum begins with a typical regular cambium that gradually becomes lobed as a result of variation in xylem and phloem production rates in certain portions of the stem aligned with stem orthostichies. As development progresses, lignified ray cells of the initially formed secondary xylem detach on one side from the adjacent tissues, forming a natural fracture that induces the proliferation of both ray and axial nonlignified parenchyma. At the same time, parenchyma proliferation takes place around the pith margin and generates a ring of radially arranged parenchyma cells. The parenchyma generated in this process (here termed disruptive parenchyma) keeps dividing throughout stem development. As growth continues, the parenchyma finally cleaves the lignified axial parts of the vascular system into several isolated fragments of different sizes. Each fragment consists of xylem, phloem and vascular cambium and is immersed in a ground matrix of disruptive parenchyma. The cambium present in each fragment divides anticlinally to almost encircle each entire fragment and maintains its regular activity by producing xylem to the centre of the fragment and phloem to the periphery. Additionally, new cambia arise within the disruptive parenchyma and produce xylem and phloem in various polarities, such as xylem to the inside and phloem to the outside of the stem, or perpendicularly to the original cambium. Unlike the very distinctive stem anatomical architecture resulting from this cambial variant in Callaeum, its secondary xylem and phloem exhibit features typical of lianas. These features include very wide conducting cells, abundant axial parenchyma, high and heterocellular rays and gelatinous fibres.

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