scholarly journals The Impact of Changing Climate on the Cambial Activity during Radial Growth in Some Citrus Species

2021 ◽  
Author(s):  
Moin Ahmad Khan ◽  
M. Badruzzaman Siddiqui
Keyword(s):  
Radial Growth ◽  
Cambial Activity ◽  
Age Effects ◽  
Vascular Cambium ◽  
Citrus Species ◽  
The Third ◽  
Changing Climate ◽  
Fusiform Initials ◽  
Cambial Cells ◽  
The Impact

This study on radial growth in the stem of Citrus was carried out with an aim to notice the behavior of vascular cambium with respect to climatic and age effects. The fusiform initials vary in length from 137 to 363 μm in C. limon, 100 to 463 μm in C. paradisi, 137 to 413 μm in C. reticulata var. kinnow, and 137 to 375 μm in C. sinensis. The length rises with age, followed by decline and then again increase in C. limon. In C. paradisi, there is increase up to maximum and after decline is soon followed by constancy. In C. reticulata var. kinnow, increase in length from top to base in C. sinensis, increase up to maximum followed by a decline. Swelling of cambial cells occurs in the third week of March in C. limon, last week of March in C. paradisi, third week of April in C. reticulata var. kinnow, and second week of April in C. sinensis. The cambium turns dormant in early October in C. limon, late December in C. paradisi, early December in C. reticulata var. kinnow, and early November in C. sinensis. Thus, the cambium remains active for about 6 months in C. limon and C. sinensis, 9 months in C. paradisi, and 7 months in C. reticulata var. kinnow.

scholarly journals How Do Trees Grow in Girth? Controversy on the Role of Cellular Events in the Vascular Cambium

2021 ◽  
Author(s):  
Anna Wilczek-Ponce ◽  
Wiesław Włoch ◽  
Muhammad Iqbal
Keyword(s):  
Woody Plants ◽  
Radial Growth ◽  
Apical Cell ◽  
Vascular Cambium ◽  
Cell Dynamics ◽  
Cellular Events ◽  
New Concepts ◽  
New Interpretation ◽  
Cambial Cells ◽  
Periclinal Walls

AbstractRadial growth has long been a subject of interest in tree biology research. Recent studies have brought a significant change in the understanding of some basic processes characteristic to the vascular cambium, a meristem that produces secondary vascular tissues (phloem and xylem) in woody plants. A new hypothesis regarding the mechanism of intrusive growth of the cambial initials, which has been ratified by studies of the arrangement of cambial cells, negates the influence of this apical cell growth on the expansion of the cambial circumference. Instead, it suggests that the tip of the elongating cambial initial intrudes between the tangential (periclinal) walls, rather than the radial (anticlinal) walls, of the initial(s) and its(their) derivative(s) lying ahead of the elongating cell tip. The new concept also explains the hitherto obscure mechanism of the cell event called ‘elimination of initials’. This article evaluates these new concepts of the cambial cell dynamics and offers a new interpretation for some curious events occurring in the cambial meristem in relation to the radial growth in woody plants.

Blocking phloem transport triggers bimodal radial growth in Pinus sylvestris at a xeric site

2021 ◽  
Author(s):  
Walter Oberhuber ◽  
Anton Landlinger-Weilbold ◽  
Andreas Gruber ◽  
Gerhard Wieser
Keyword(s):  
Cell Wall ◽  
Pinus Sylvestris ◽  
Radial Growth ◽  
Experimental Studies ◽  
Growing Season ◽  
Phloem Transport ◽  
Cambial Activity ◽  
Wall Thickening ◽  
Summer Drought ◽  
The Impact

<p>A bimodal radial grow pattern, i.e. growth peaks in spring and autumn, was repeatedly found in trees in Mediterranean regions, where summer drought causes reduction or cessation of cambial activity. In a dry inner Alpine valley of the Eastern Alps (Tyrol, Austria, <em>c</em>. 750 m asl), which is characterized by drought periods at the start of the growing season in spring and more favorable conditions during summer, <em>Pinus sylvestris</em> shows an unimodal growth pattern with onset and cessation of cambial activity in early April and late June, respectively. Although xylem cell differentiation (cell wall thickening) may last until end of August, a resumption of cambial activity after intense summer rainfall was not observed in this region. In a field experiment we therefore tested the hypothesis that early cessation of cambial activity under drought is an adaptation to limited water availability during the growing season (April through June), leading to an early and irreversible switch of carbon (C) allocation to belowground. To accomplish this, the C status of <em>c</em>. 20 year old <em>Pinus sylvestris</em> saplings (mean stem height 1.5 m) was manipulated at a xeric site by physical blockage of phloem transport (girdling) in mid-July (doy 199), i.e. <em>c</em>. four weeks after cessation of cambial cell division. The influence of manipulated C availability on radial growth was continuously recorded by stem dendrometers, which were mounted 5 cm above girdling. In response to blockage of phloem flow, resumption of radial growth was detected above the girdling zone after about 2 weeks, i.e., bimodal growth could be triggered above girdling by increasing C availability. Although the experimentally induced second growth surge lasted for the same period as in spring (i.e., <em>c</em>. 2 months), the increment was more than twice as large. Below girdling radial growth was not affected (i.e., no reactivation of cambial activity occurred), but cell wall thickness of last latewood cells was significantly reduced indicating lack of C after girdling. Intense radial growth resumption in <em>Pinus sylvestris</em> saplings after girdling indicates that cessation of stem cambial activity can be reversed by manipulating the C status of the stem suggesting a high belowground C demand on the drought-prone, nutrient deficient site. This work highlights the need of in-depth experimental studies in order to understand the impact of endogenous and exogenous factors on cambial activity more clearly.</p><p>The research was funded by the Austrian Science Fund (FWF; project number P25643-B16).</p>

Correlation of intrusive growth of cambial initials to rearrangement of rays in the vascular cambium

IAWA Journal ◽  
2011 ◽  
Vol 32 (3) ◽  
pp. 313-331 ◽  
Author(s):  
Anna Wilczek ◽  
Joanna Jura-Morawiec ◽  
Paweł Kojs ◽  
Muhammad Iqbal ◽  
Wiesław Włoch
Keyword(s):  
Pinus Sylvestris ◽  
Vascular Cambium ◽  
Tilia Cordata ◽  
Intrusive Growth ◽  
Hippophaë Rhamnoides ◽  
Fusiform Initials ◽  
Cambial Cells ◽  
The One ◽  
Fusiform Initial ◽  
Ray Initials

It is well documented that apical elongation of fusiform cambial initials through extension of their longitudinal edges, and their intrusion between tangential walls of the neighbouring initials and their closest derivatives cause rearrangement of fusiform cells, without increasing the cambial circumference. However, the concurrent rearrangement of rays is not fully understood. This study deals with Pinus sylvestris L., Tilia cordata Mill. and Hippophaë rhamnoides L., possessing a nonstoreyed, storeyed and double-storeyed type of cambium, respectively, and shows that the mechanism for rearrangement of ray initials is similar to the one proposed for fusiform initials, and includes multiplication of ray initials by anticlinal divisions, intrusive growth of ray initials, elimination of ray initials caused by intrusive growth of neighbouring fusiform initials, and transformation of ray initials into fusiform initials. Intrusive growth of a ray initial does not necessarily lead to the formation of a new fusiform initial, as it is dependent on the extent of the intrusive growth taken place. The extent of rearrangement of cambial cells is determined by the intensity of events occurring among the fusiform as well as ray initials. Intrusive growth of these initials does not influence the size of the cambial circumference.

Vascular cambium and wood development in Carboniferous plants. III. Arthropitys (Equisetales; Calamitaceae)

1986 ◽  
Vol 64 (3) ◽  
pp. 688-695 ◽  
Author(s):  
Michael A. Cichan
Keyword(s):  
Cambial Activity ◽  
Vascular Cambium ◽  
Quantitative Evidence ◽  
Wood Development ◽  
Ray Cells ◽  
Anticlinal Division ◽  
Fusiform Initials ◽  
Cambium Activity ◽  
Developmental Characteristics ◽  
Ray Initials

Vascular cambium activity was examined in Arthropitys communis (Binney) Hirmer et Knoell, and A. deltoides Cichan et Taylor, anatomically preserved calamite stems from the Pennsylvanian of Kentucky. Developmental characteristics of the meristem were inferred from changes in the size and number of tracheids and ray cells determined from serial tangential sections of the secondary xylem. In A. communis, circumferential enlargement of the cambium seems to have been accommodated primarily by the enlargement of fusiform initials. Qualitative and quantitative evidence is also presented indicating that “marginal” interfascicular ray initials were converted to fusiform initials during the early stages of cambial activity. In A. deltoides, circumferential enlargement of the meristem was accommodated by the enlargement of fusiform initials and by an increase in size and number of interfascicular ray initials. Multiplicative division of the fascicular ray initials appears to have been an important feature of cambial activity in both species. There is no qualitative or quantitative evidence that the number of fusiform initials in either species was augmented by anticlinal division as in extant seed plants.

scholarly journals Modelling for rearrangement of fusiform initials during radial growth of the vascular cambium in Pinus sylvestris L.

Trees ◽  
2013 ◽  
Vol 27 (4) ◽  
pp. 879-893 ◽  
Author(s):  
Wiesław Włoch ◽  
Anna Wilczek ◽  
Joanna Jura-Morawiec ◽  
Paweł Kojs ◽  
Muhammad Iqbal
Keyword(s):  
Pinus Sylvestris ◽  
Radial Growth ◽  
Vascular Cambium ◽  
Fusiform Initials

RING WIDTH, TRACHEID SIZE, AND RAY VOLUME IN STEM WOOD OF THUJA OCCIDENTALIS L.

1954 ◽  
Vol 32 (3) ◽  
pp. 466-479 ◽  
Author(s):  
M. W. Bannan
Keyword(s):  
Ring Width ◽  
Cambial Activity ◽  
Thuja Occidentalis ◽  
Stem Wood ◽  
Rate Of Growth ◽  
Fusiform Initials ◽  
Similar Range ◽  
Cambial Cells ◽  
Rates Of Growth

The interrelations between varied growth rates and those phases of cambial activity involved in determination of tracheid size and ray volume were investigated in Thuja occidentalis. Length of tracheids at the time of pseudotransverse division of the initiating cambial cells was determined from the peripheral wood of stems which fell within a similar range of size but differed in their rates of growth. The circumstances which favored accelerated growth, as shown in more frequent periclinal divisions in the cambium, encouraged earlier pseudotransverse division of fusiform initials and hence the production of shorter tracheids. Among trees of similar size decline in growth rate was accompanied by lengthening of cambial cells to a maximum associated with annual radial increments of 0.7 to 0.8 mm. Tracheid diameter was only slightly influenced by the rate of growth. Tangential width underwent minor increase in suppressed trees and radial diameter was slightly augmented in fast-growing trees. A positive correlation was revealed between ray volume and rate of growth.

GIRTH INCREASE IN WHITE CEDAR STEMS OF IRREGULAR FORM

1957 ◽  
Vol 35 (4) ◽  
pp. 425-434 ◽  
Author(s):  
M. W. Bannan
Keyword(s):  
Radial Pressure ◽  
Cell Length ◽  
Vascular Cambium ◽  
White Cedar ◽  
Anticlinal Division ◽  
Fusiform Initials ◽  
Irregular Form ◽  
Cambial Cells

In coniferous stems the rate of multiplication of fusiform initials in the vascular cambium by means of pseudotransverse division often fluctuates considerably around the circumference. In fluted stems the frequency of these divisions is appreciably higher and the ratio of survival of the newly formed initials relative to the rate of production lower in the depressions than in the adjoining convex portions of the perimeter. The probability that compression is a factor tending to accelerate the frequency of anticlinal division is indicated by the decided increase in rate in areas of the stem subjected to radial pressure. Higher frequencies of pseudotransverse division are accompanied by reduction in mean cell length of the cambial cells and hence of the derived wood elements.

THE VASCULAR CAMBIUM AND RADIAL GROWTH IN THUJA OCCIDENTALIS L

1955 ◽  
Vol 33 (1) ◽  
pp. 113-138 ◽  
Author(s):  
M. W. Bannan
Keyword(s):  
Secondary Xylem ◽  
Cambial Activity ◽  
Vascular Cambium ◽  
Mature Trees ◽  
General Sense ◽  
Thuja Occidentalis ◽  
Steady Rate ◽  
Cambial Cells ◽  
The One ◽  
Mother Cells

The vascular cambium, to use the term in the general sense as designation for the entire meristem producing secondary xylem and phloem, consists of the self-perpetuating uniseriate initiating layer and the derived tissue mother cells. In the dormant condition the cambium in the stems of mature trees is one to four, usually two to three, cells wide. The one to three tangential tiers of cells toward the xylem are made up of xylem mother cells, and the single tier next the phloem is composed of initial cells. On reactivation all cambial cells expand radially. Periclinal divisions soon follow, usually according to a sequence in which the xylem mother cells in the tier contiguous to the late wood are the first to divide and the initial cells last, although some variation occurs. The zone of periclinal division rapidly widens to 100-300 μ in vigorous open-grown trees, the center of activity during this vernal surge of growth clearly being among the dividing and redividing xylem mother cells. Thereafter, from mid-June to August, a continued decline in cell production follows as the zone of xylem mother cells decreases from many tangential rows to few. The initiating layer becomes relatively more important as the center of cell generation, and toward the end of the growing season the initial cells undergo those changes which modify the cellular pattern of the cambium and hence of the derived tissues. Phloem development begins later than that of xylem, and at the end of May the new phloem varies from none to four cells as compared with a xylemward production of 30-60 cells in vigorous trees. Phloem expansion continues at a more or less steady rate from June to the termination of cambial activity in August or early September. The annual phloem increments vary less in width than those of xylem.

THE RATE OF ELONGATION OF FUSIFORM INITIALS IN THE CAMBIUM OF PINACEAE

1965 ◽  
Vol 43 (4) ◽  
pp. 429-435 ◽  
Author(s):  
M. W. Bannan
Keyword(s):  
Cell Elongation ◽  
Radial Growth ◽  
Ring Width ◽  
Total Width ◽  
Mature Trees ◽  
Cambial Cell ◽  
Anticlinal Division ◽  
Fusiform Initials ◽  
Wide Ring ◽  
Cambial Cells

This report deals with the rate and amount of elongation of fusiform initials in the cycle of cell elongation and multiplication by pseudotransverse division which accompanies circumferential expansion of the cambium. In the recent growth of mature trees the yearly amount of cambial cell elongation drops as ring width decreases, but not in proportion to the decline in ring width. The cumulative elongation through lineal series of cells, per centimeter of xylem increment, increases as ring width decreases. The amount of cell elongation during the production of several narrow rings greatly exceeds that through a single wide ring having the same total width. It seems clear that the time factor is important in the elongation of cambial cells, and to some extent the interrelated frequency of anticlinal division, particularly when radial growth declines.

Social and political dimension of stigmatization: The development of Natasha and Maria images for immigrants in Istanbul

2016 ◽  
Vol 13 (1) ◽  
pp. 159-168
Author(s):  
Bayram Unal
Keyword(s):  
Public Perception ◽  
Daily Life ◽  
Legal Framework ◽  
State Law ◽  
Migrant Women ◽  
Political Dimension ◽  
Security Forces ◽  
Official Discourse ◽  
The Third ◽  
The Impact

This study aims at understanding how the perceptions about migrants have been created and transferred into daily life as a stigmatization by means of public perception, media and state law implementations.  The focus would be briefly what kind of consequences these perceptions and stigmatization might lead. First section will examine the background of migration to Turkey briefly and make a summary of migration towards Turkey by 90s. Second section will briefly evaluate the preferential legal framework, which constitutes the base for official discourse differentiating the migrants and implementations of security forces that can be described as discriminatory. The third section deals with the impact of perceptions influential in both formation and reproduction of inclusive and exclusive practices towards migrant women. Additionally, impact of public perception in classifying the migrants and migratory processes would be dealt in this section.

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