scholarly journals Formation of medullary phloem in Argyreia nervosa (Burm. f.) Bojer

2019 ◽  
Vol 6 (2) ◽  
pp. 151-159 ◽  
Author(s):  
Kilas K Kapadane ◽  
Ravindra A Shelke ◽  
Amit D Gondaliya ◽  
Kishore S. Rajput
Keyword(s):  
Secondary Growth ◽  
Sieve Elements ◽  
Successive Cambia ◽  
Primary Growth ◽  
Interxylary Phloem ◽  
Argyreia Nervosa ◽  
Internal Phloem

Histologically, family Convolvulaceae is characterised by the presence of successive cambia, medullary (internal/intraxylary) and interxylary phloem in majority of the species, whereas some of the members are devoid of successive cambia and medullary bundles. The present study on Argyreia nervosa (Burm. f.) Bojer showed the presence of medullary bundles while internal phloem was absent during the primary growth. As the secondary growth progressed, successive cambia initiated from the pericyclic parenchyma. Development of medullary bundles began along with the regular protoxylem and protophloem while formation of intraxylary phloem was observed only after the initiation of secondary growth. Medullary/intraxylary sieve elements began to develop from the marginal pith cells. In thick stems, small segments of internal cambium initiated between the protoxylem and internal phloem. This internal cambium was functionally unidirectional and produced internal phloem centripetally. Developmental particulars are described in details along with its significance.

scholarly journals Linking the Evolution of Development of Stem Vascular System in Nyctaginaceae and Its Correlation to Habit and Species Diversification

2021 ◽  
Author(s):  
Israel L. Cunha Neto ◽  
Marcelo Rodrigo Pace ◽  
Rebeca Hernández-Gutiérrez ◽  
Veronica Angyalossy
Keyword(s):  
Developmental Stages ◽  
Vascular System ◽  
A Priori ◽  
Secondary Growth ◽  
Stem Anatomy ◽  
Species Diversification ◽  
Successive Cambia ◽  
The Family ◽  
Interxylary Phloem ◽  
Cambial Variants

Abstract Background: The presence of alternative patterns of secondary growth in stems of Nyctaginaceae has been known for a long time. Still, the interpretation of types of cambial variants are controversial. The knowledge on stem anatomical diversity in Nyctaginaceae, which is diverse also in habits, offers the unique opportunity not only to investigate the evolution of complex developments, but also to address how these anatomies shifted within habits and how the acquisition of novel cambial variants and habit transitions impacted the diversification of the family. Methods: We integrated developmental data with a phylogenetic framework to investigate the diversity and evolution of stem anatomy in Nyctaginaceae using phylogenetic comparative methods, reconstructing ancestral states, and examining whether anatomical shifts correspond to species diversification rate shifts in the family. Results: Two types of cambial variants, interxylary phloem and successive cambia, were recorded in Nyctaginaceae, which result from four different ontogenies. These ontogenetic trajectories depart from two distinct primary vascular structures (regular or polycyclic eustele) yet, they contain shared developmental stages which generate stem morphologies with deconstructed boundaries of morphological categories (continuum morphology). Unlike our a priori hypotheses, interxylary phloem is reconstructed as the ancestral character for the family, with three ontogenies characterized as successive cambia evolving in few taxa. Cambial variants are not contingent in habits, and their transitions are independent from species diversification.Conclusions: Our findings suggests that multiple developmental mechanisms, such as heterochrony and heterotopy generate the transitions between interxylary phloem and successive cambia. Intermediate between these two extremes are present in Nyctaginaceae, suggesting a continuum morphology across the family as a generator of anatomical diversity.

scholarly journals Comparative stages of atretic oocytes between Episesarma versicolor and E. singaporense from Thailand: Implication on the reproductive success

2020 ◽  
Vol 19 (1) ◽  
pp. 75-86
Author(s):  
Chanyut Sudtongkong ◽  
◽  
Sinlapachai Senarat ◽  
Supparat Kong-oh ◽  
Pisit Poolprasert ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Secondary Growth ◽  
Follicular Cell ◽  
Ovarian Maturation ◽  
Natural Habitats ◽  
Degenerative Process ◽  
Mangrove Area ◽  
Primary Growth

Informative reviews on the oocyte atresia referring to degeneration and resorptive mechanism are warranted in common animals, but it is rarely still found in carbs. In this current study, we focused on characteristics and stage of the atretic oocyte from two important female sesarmid carbs (violet vinegar crab, Episesarma versicolor, and Singapore vinegar crab, E. singaporense) during ovarian maturation. A total of 30 female samples in each carb species were collected from the Palian mangrove area of Trang province, Thailand. The results shared among those carb samples that both primary growth (PGs) and secondary growth (SGs) phases underwent a degenerative process of atresia. The latter of atresia during SGs was also divided into five stages (I, II, III, IV, and V). The degeneration of follicular cell and yolk architecture identifying in the SGs were highlighted. The number of atresias was slightly compared between E. versicolor and E. singaporense; therefore, there were no significant differences. Our observation suggested that the low number of atresia might be associated with the increased reproductive success of two female sesarmid carb living in natural habitats.

EFFECT OF UREA AND AMMONIUM NITRATE ON YIELDS AND NITROGEN CONCENTRATION OF TIMOTHY AND BROMEGRASS AND LOSS OF AMMONIA FROM UREA SURFACE APPLICATIONS

1987 ◽  
Vol 67 (1) ◽  
pp. 185-192 ◽  
Author(s):  
H. T. KUNELIUS ◽  
J. A. MACLEOD ◽  
K. B. MCRAE
Keyword(s):  
Ammonium Nitrate ◽  
Total Nitrogen ◽  
Dry Matter ◽  
Field Experiments ◽  
Nitrogen Concentration ◽  
Secondary Growth ◽  
Nitrogen Sources ◽  
Primary Growth ◽  
Total Nitrogen Concentration ◽  
Harvest Year

Urea and ammonium nitrate were applied at 30, 60, 90 and 120 kg N ha−1 in spring and after cutting the primary growth of timothy and bromegrass in three field experiments. Dry matter yields of timothy and bromegrass and total nitrogen concentration of tissue and nitrogen yields of timothy were determined. Loss of nitrogen as ammonia was monitored on microplots between the end of May and early July. Primary growth yields were usually similar for ammonium nitrate and urea but in the secondary growth timothy fertilized with ammonium nitrate outyielded timothy fertilized with urea in four out of six harvest years. Dry matter response to applied nitrogen was usually curvilinear in primary growth but linear in secondary growth over the nitrogen rates studied. Total nitrogen concentration in primary and secondary growths of timothy increased linearly with nitrogen rate during the initial 2–3 yr; ammonium nitrate and urea were equally effective in all but one harvest year. Total nitrogen production of timothy also increased linearly over the range of 30–120 kg N ha−1, while ammonium nitrate outyielded urea-fertilized timothy during one season in primary and two seasons out of four in secondary growth. Nitrogen losses increased from spring to summer, in general, with 68–75% of the variation explained by air temperature. Urea and ammonium nitrate were considered equivalent nitrogen sources for the primary growth of timothy but urea was less efficient in the secondary growth under summer conditions.Key words: Urea, ammonium nitrate, timothy, bromegrass, ammonia losses

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.

Structure And Development Of Internal Phloem In Solanum Pseudocapsicum (Solanaceae)

IAWA Journal ◽  
2014 ◽  
Vol 35 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Vidya S. Patil ◽  
Rina D. Koyani ◽  
Gaurav V. Sanghvi ◽  
Kishore S. Rajput
Keyword(s):  
Sieve Elements ◽  
Parenchyma Cells ◽  
Gradual Variation ◽  
Internal Phloem

The development of internal phloem in the Jerusalem cherry, Solanum pseudocapsicum L. (Solanaceae), was studied in young and mature stems. The early presence of primary internal phloem is succeeded by the development of secondary internal phloem from an internal cambium situated between the protoxylem and primary internal phloem. In the second and third visible internodes of the young stem, procambial derivatives begin to differentiate as discrete strands of internal protophloem in a perimedullary position prior to the differentiation of protoxylem and external protophloem. In 6–8 mm diameter stems, sieve elements of the internal phloem become non-conducting, begin to collapse, and undergo obliteration. In 15–20 mm diameter stems internal cambium is initiated from the parenchyma cells situated between the protoxylem and primary internal phloem. The development of internal phloem and an internal cambium in S. pseudocapsicum is compared with that in other taxa. There seems to be a gradual variation in the origin of an internal cambium from either remnants of the procambium or dedifferentiation of peripheral pith cells across dicotyledons with an internal cambium.

scholarly journals Procambial and cambial variants in Serjania and Urvillea species (Sapindaceae: Paullinieae)

2017 ◽  
Vol 11 (2) ◽  
pp. 421-432
Author(s):  
Willian Adriano Lira Lopes ◽  
Luiz Antonio de Souza ◽  
Odair José Garcia de Almeida
Keyword(s):  
Secondary Growth ◽  
Structural Knowledge ◽  
Peripheral Vascular ◽  
Primary Growth ◽  
Cambial Variants

For the purpose of comparing the structure of vascular cylinders, and procambial and cambial variants of Serjania Miller and Urvillea Kunth species, we studied the stems of five species, in order to add to the structural knowledge of these genera belonging to the widely distributed Sapindaceae family. Stems of sampled species were collected at “Estação Ecológica do Caiuá,” Diamante do Norte (PR), Brazil; and were analyzed using traditional anatomical techniques. We analyzed five species of two genera from the Paullinieae tribe: three species of Serjania (S. communis, S. fuscifolia, and S. meridionalis) and two of Urvillea (U. leavis and U. ulmacea); in which we describe the primary and secondary growths, the number of peripheral cylinders, the type of cylinders concerning its origin, the type of stem, and the origin of the cambial or tissue variant. Serjania stems exhibit the compound and corded types, while the cleft and mixed (cleft/corded) types have been recorded in Urvillea species. All species have peripheral vascular cylinders in which the stems of S. communis and S. fuscifolia form the procambial and cambial variants during primary growth, whereas the stems of S. meridionalis, U. leavis, and U. ulmacea develop the cambial variants during secondary growth.

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.

Initiation and structure of the secondary vascular system in Phytolacca dioica (Phytolaccaceae)

1984 ◽  
Vol 62 (12) ◽  
pp. 2580-2586 ◽  
Author(s):  
Bruce K. Kirchoff ◽  
Abraham Fahn
Keyword(s):  
Vascular System ◽  
Secondary Growth ◽  
Tissue Response ◽  
Vascular Cambium ◽  
Vascular Cylinder ◽  
Primary Growth ◽  
Secondary Thickening ◽  
Dividing Cells ◽  
Cathodic Side ◽  
Vascular Connections

Phytolacca dioica (L.) is characterized by anomalous secondary thickening by means of supernumerary cambia. After a period of primary growth and the formation of an initial (normal) vascular cambium, supernumerary cambia are initiated outside of the primary vascular cylinder. The initiation of the first supernumerary cambium takes place through approximately the number of nodes equal to the denominator of the phyllotactic fraction characterizing a given axis. At each node a segment of supernumerary cambium is initiated opposite the leaf traces supplying the leaf inserted at that node. The segments of differentiated cambium are preceded by regions of obliquely and anticlinally dividing cells. In the single juvenile axis studied supernumerary cambial segments also appear above the node to the cathodic side of the entering leaf traces, and opposite the medullary bundle immediately anodic to these traces. Vascular connections among the primary and supernumerary vascular cylinders occur between leaf insertions on the same orthostichy. The levels at which these connections occur vary among stems. The switch from ordinary to anomalous secondary growth may be caused by a change in tissue response to stimuli produced by leaves.

MENISPERMACEAE WOOD ANATOMY AND CAMBIAL VARIANTS

IAWA Journal ◽  
2007 ◽  
Vol 28 (2) ◽  
pp. 139-172 ◽  
Author(s):  
Frédéric M.B. Jacques ◽  
Dario De Franceschi
Keyword(s):  
Wood Anatomy ◽  
Secondary Growth ◽  
Successive Cambia ◽  
General Overview ◽  
The Family ◽  
Growth Types ◽  
Perforation Plates ◽  
Cambial Variants

Menispermaceae are comprised almost entirely of lianas. Study of its wood anatomy is of interest for understanding adaptation to the liana habit. We set out here to present a general overview of Menispermaceae wood. The wood anatomy of 77 species of 44 genera, representative of an tribes and from an continents, is described. The wood of 18 of these genera was previously unknown. We observed two secondary growth types within the family: wood with successive cambia and wood with a single cambium. The distribution of these types is partly consistent with the c1assification of the family by Diels. General characters of the family are: wide rays, enlarged vessel pits near the perforation plates, and pitted tyloses. The fun range of wood anatomical diversity is given in Table 1.

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