Cambial Activity and Developmental Changes in Ray Initials of Some Tropical Trees

The periodicity of leaf change and flowering and fruiting of tropical trees is discussed. Cambial activity patterns in tropical trees are reviewed. Emphasis is put on research undertaken in South-East Asia on the most important timber tree family in that region, the Dipterocarpaceae. There is an urgent need for more information on the effects of rainfall patterns and phenological periodicity on cambial activity and ring formation in this family

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

Canadian Journal of Botany ◽

10.1139/b86-087 ◽

1986 ◽

Vol 64 (3) ◽

pp. 688-695 ◽

Cited By ~ 11

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.

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Developmental Changes in the Fusiform Cambial Cells of some Tropical Trees

Flora ◽

10.1016/s0367-2530(17)30165-2 ◽

1985 ◽

Vol 177 (3-4) ◽

pp. 187-194 ◽

Cited By ~ 4

Author(s):

K.S. Rao ◽

Y.S. Dave

Keyword(s):

Tropical Trees ◽

Developmental Changes ◽

Cambial Cells

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Developmental changes in habitat associations of tropical trees

Journal of Ecology ◽

10.1111/j.1365-2745.2007.01229.x ◽

2007 ◽

Vol 95 (3) ◽

pp. 482-492 ◽

Cited By ~ 126

Author(s):

LIZA S. COMITA ◽

RICHARD CONDIT ◽

STEPHEN P. HUBBELL

Keyword(s):

Tropical Trees ◽

Habitat Associations ◽

Developmental Changes

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Spherulitic crystal growth in the prodissoconch larval of Crassostrea virginica

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100076263 ◽

1983 ◽

Vol 41 ◽

pp. 518-519

Author(s):

George G. Cocks ◽

Louis Leibovitz ◽

DoSuk D. Lee

Keyword(s):

Crystal Structure ◽

Crassostrea Virginica ◽

Crystal Orientation ◽

Developmental Changes ◽

Gastrula Stage ◽

Orthorhombic Crystal ◽

Orthorhombic Crystal Structure ◽

Stages Of Growth ◽

Early Stages ◽

Initial Deposition

Our understanding of the structure and the formation of inorganic minerals in the bivalve shells has been considerably advanced by the use of electron microscope. However, very little is known about the ultrastructure of valves in the larval stage of the oysters. The present study examines the developmental changes which occur between the time of conception to the early stages of Dissoconch in the Crassostrea virginica(Gmelin), focusing on the initial deposition of inorganic crystals by the oysters.The spawning was induced by elevating the temperature of the seawater where the adult oysters were conditioned. The eggs and sperm were collected separately, then immediately mixed for the fertilizations to occur. Fertilized animals were kept in the incubator where various stages of development were stopped and observed. The detailed analysis of the early stages of growth showed that CaCO3 crystals(aragonite), with orthorhombic crystal structure, are deposited as early as gastrula stage(Figuresla-b). The next stage in development, the prodissoconch, revealed that the crystal orientation is in the form of spherulites.

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