Organogénèse de la fleur pistillée du Begonia dregei et de l’Hillebrandia sandwicensis (Begoniaceae)

1989 ◽  
Vol 67 (12) ◽  
pp. 3625-3639 ◽  
Author(s):  
Anne Charpentier ◽  
Luc Brouillet ◽  
Denis Barabé
Keyword(s):  
Vascular Anatomy ◽  
Pistillate Flower ◽  
Ovary Wall ◽  
Gradual Transition ◽  
Evolutionary Status ◽  
Developmental Study ◽  
Intermediate Structure ◽  
Inferior Ovary ◽  
Floral Apex ◽  
Mixed Nature

The pistillate flower organogenesis of Begonia dregei Otto Dietr. (section Augustia) and Hillebrandia sandwicensis Oliver is described. Vascular anatomy and scanning electron microscopy show that the inferior ovary of B. dregei develops below the perianth, whereas the semi-inferior ovary of H. sandwicensis grows both above and below the insertion level of the perianth. A developmental study of both species showed that placental tissues have a mixed nature: parietal placentae develop from the ovary wall, whereas axile placentae are derived from the floral apex, with a gradual transition zone between the two tissues. Depending on the rate of growth of the two placental regions, the ovary becomes mostly axile or parietal, all intermediates being possible. Our study does not allow us to determine unambiguously which of the two types of placentation is the most primitive. Also, it is impossible to clearly ascertain the evolutionary status of the semi-inferior ovary of H. sandwicensis. However, ontogenetic results allowed us to shed new light on the nature of the ovary wall in Begonia. One may hypothesize that it is an intermediate structure between axial and appendicular organs, difficult to compare directly with a set of fused carpels and perianth parts, as postulated by the classical theory of the flower.

Floral development of two species of Stylidium (Stylidiaceae) and some remarks on the systematic position of the family Stylidiaceae

1992 ◽  
Vol 70 (2) ◽  
pp. 258-271 ◽  
Author(s):  
Claudia Erbar
Keyword(s):  
Key Words ◽  
Floral Development ◽  
Floral Biology ◽  
Systematic Position ◽  
Inferior Ovary ◽  
Stamen Primordia ◽  
Floral Apex ◽  
The Family ◽  
Transversal Plane

The early floral development of Stylidium adnatum and Stylidium graminifolium is characterized by an initial circular primordium whose areas in the transversal plane of the floral primordium show enhanced growth. The spiral inception of the five sepals starts before the differentiation of the initial circular primordium into two stamen primordia in transversal position (in relation to the floral diagram) and the corolla ring primordium below the stamen primordia. Then five petal primordia, which alternate with the sepals, arise on the corolla ring primordium (early sympetaly). Peculiar to the flowers of Stylidiaceae is the column that bears at its top both stigma and anthers. Probably this column should be interpreted as a receptacular tube. No distinct carpel primordia have been observed. The inferior ovary results from intercalary growth in the peripheral parts of the receptacle below the calyx, corolla, and stamen primordia. The residual floral apex gives rise to a transversal septum, by which the ovary becomes bilocular. None of the morphological, palynological, and embryological characters discussed contradicts a position of the Stylidiaceae near the Campanulales, and several of these characters support this position. Key words: Stylidiaceae, Campanulales, floral development, systematic position, floral biology.

Vascularisation de la fleur pistillée de Begonia handelii

1981 ◽  
Vol 59 (5) ◽  
pp. 819-825 ◽  
Author(s):  
Denis Barabé
Keyword(s):  
Pistillate Flower ◽  
Vascular Bundles ◽  
Vascular Pattern ◽  
Serial Sections ◽  
Inferior Ovary

The pistillate flower of Begonia handelii Irmscher has a tetramerous gynoecium. The analysis of serial sections shows that the anatomical pattern observed by Gauthier (1950) on trimerous gynoecia also occurs in tetramerous gynoecia. For each carpel there are theoretically seven vascular bundles which leave the stele. The vascular pattern of the pistillate flower of B. handelii leads us to adopt the appendicular theory of the inferior ovary. The position of vascular bundles, the presence of gaps, and the absence of recurrent bundles show that the ovary is formed by the union of appendicular organs. In this case, the inferior ovary results from the close union of carpels and perianth parts. In the pistillate flower of B. handelii, the perianth parts are disposed on two dimerous whorls: the first corresponds to a whorl of sepals, and the second to a whorl of petals.

A description of the phospholipid arrangement in DOPE:DOPC mixture and its modification by trehalose as studied by freeze-fracture

1990 ◽  
Vol 48 (3) ◽  
pp. 964-965
Author(s):  
Tihova Mariana
Keyword(s):  
Freeze Fracture ◽  
Water Systems ◽  
Gradual Transition ◽  
Intermediate Structure ◽  
Fracture Face ◽  
Lipid Mixture ◽  
Vortex Mixer ◽  
New Type ◽  
Ripple Phase ◽  
Unusual Appearance

The effect of trehalose on the lamellar/HII phase transition in hydrated dioleoylphosphatidylethanolamine:dioleoylphosphatidylcholin mixtures as a function of temperature (t°) was investigated.DOPE:DOPC/3:I or DOPE only (at concentrations 60wt%)(Avanti Pol.Lip.) were hydrated in 1.8M trehalose solution at t°>TH and shaken 5-10 times on a vortex mixer ai this t° by the technique of exhaustively cycling the t° through TH. Suspensions were equilibrated at the t° desired and quenching was achieved by liquid nitrogen jet freezing.A gradual transition of HII phase into a new type of bilayer - sinusoidal ripple phase in the lipid mixture quenched from 22°C is shown in fig.1. The HII phase exhibits unusual appearance presented by bent cylinders situated at an angle to each other. The sinusoidal ripples described as a stable intermediate structure between Lα and HII phases is different from Pβ’ripple phase in saturated lipid-water systems. Upon cooling the ripple bilayers transform at 0°C into smooth lamellae (figs.2a,2b) with non typical fracture face.

Organogenèse de la fleur pistillée du Begonia horticola (Begoniaceae)

1989 ◽  
Vol 67 (2) ◽  
pp. 559-572 ◽  
Author(s):  
Anne Charpentier ◽  
Luc Brouillet ◽  
Denis Barabé
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Developmental Stages ◽  
Female Flower ◽  
Mature Female ◽  
Evolutionary Status ◽  
Inferior Ovary ◽  
Points Of View ◽  
Scanning Electron

The placentation of the inferior ovary of the female flower of Begonia horticola Irmscher (section Tetraphila) is mostly axile with the upper part parietal. A study of the vascular organisation and of the organogenesis of this species allows us to better understand the transition from axile to parietal placentation observed in other Begoniaceae, from both morphological and evolutionary points of view. The anatomy of the mature female flower is similar to that of other Begonia species. Anatomical sections and scanning electron microscopy of young developmental stages show that the inferior ovary grows underneath the perianth primordia. The two types of placentation are established early. The axile part develops from an axial meristem, while the parietal placentas are formed by the development of septa towards the inside of the cavity. It is however impossible to draw a clear boundary between the two tissues. The present data do not allow us to infer the evolutionary status of placentation types in Begonia.

STUDIES IN THE FLORAL MORPHOLOGY OF THE MARANTACEAE: I. VASCULAR ANATOMY OF THE FLOWER OF SCHUMANNIANTHUS VIRGATUS ROLFE, WITH SPECIAL REFERENCE TO THE LABELLUM

1966 ◽  
Vol 44 (10) ◽  
pp. 1365-1370 ◽  
Author(s):  
V. D. Tilak ◽  
R. M. Pai
Keyword(s):  
Special Reference ◽  
Floral Morphology ◽  
Floral Anatomy ◽  
Vascular Anatomy ◽  
Vascular Bundles ◽  
Inferior Ovary ◽  
Anatomical Evidence ◽  
Floral Whorls

The floral anatomy of Schumannianthus virgatus Rolfe is described in detail. Anatomical observations indicate fusion of vascular bundles of various floral whorls commensurate with their adnation, and, in that sense, the inferior ovary is considered to be appendicular in nature. Anatomical evidence demonstrates reduction in part of the labellum and of the functional stamen. The anther is one-celled. The labellum is shown to be a unitary organ representing an anterolateral member of the inner androecial whorl.

Floral development of Najas flexilis

1976 ◽  
Vol 54 (10) ◽  
pp. 1140-1151 ◽  
Author(s):  
U. Posluszny ◽  
R. Sattler
Keyword(s):  
Floral Development ◽  
Staminate Flower ◽  
Pistillate Flower ◽  
Axillary Meristem ◽  
Short Style ◽  
Najas Flexilis ◽  
Floral Apex ◽  
Cell Layers ◽  
The One ◽  
Floral Bud

Two subopposite leaves form at a node. The lower one arises almost simultaneously with the axillary meristem which it subtends. The upper leaf initiates after the lower one and does not subtend any structure. The axillary meristem gives rise to a renewal growth apex and a floral bud almost at its inception. In some cases the axillary meristem forms only a floral bud. The floral bud may be either staminate or pistillate. The main axis and the renewal growth in the axil of the lower leaf repeat this pattern of development. Staminate and pistillate flowers are almost indistinguishable at inception. They form as dome-like protuberances and both initiate girdling primordia, which become lobed at or immediately after inception. In the staminate flower the girdling primordium becomes the outer envelope, while a second girdling primordium formed acropetally becomes the inner envelope. Both envelopes overgrow the one-celled anther, which is the transformed staminate floral apex. In the pistillate flower the girdling primordium becomes the gynoecial wall that encloses the single bitegmic ovule, which is the transformed pistillate floral apex. On a short style a stigma with two to four branches develops. The renewal growth apices have a one-layered tunica. The two subopposite leaves are initiated through cell division in both tunica and corpus cells. The axillary meristem arises through periclinal divisions in the corpus cells. The girdling primordia of both staminate and pistillate floral buds are epidermal in origin as are the integuments of the ovule. Procambial development is acropetal following closely primordia inception. Each leaf, floral bud, and renewal growth apex receives a single strand. No vascularization is seen in envelopes of the staminate flower or the gynoecial wall of the pistillate flower, all of which remain two cell layers thick even at maturity.

Gynoecium structure and development in core Caryophyllales: a matter of proportions

2020 ◽  
Author(s):  
Louis P Ronse de Craene
Keyword(s):  
Complete Loss ◽  
Ovary Wall ◽  
Growth Forms ◽  
Common Trend ◽  
Floral Apex ◽  
Ovule Number ◽  
Wall Growth ◽  
Further Development ◽  
Delayed Growth ◽  
Carpel Wall

Abstract This review based on a morphological and developmental perspective reveals a striking diversity in shapes and evolutionary trends in the gynoecium of core Caryophyllales that have affected the number of carpels, the formation of septa and the number of ovules. Two major developmental shifts are responsible for the diversity in gynoecial forms and are linked to the proportional development of carpellary tissue (ovary wall) and the floral apex. (1) Meristic change is caused by an expansion or reduction of the diameter of the floral apex. An expansion leads to polygyny linked with the development of more numerous small carpels; a reduction of space leads to lower carpel numbers, eventually resulting in a single carpel. (2) Different ovary shapes can be recognized at a mid-developmental stage predicting the further development of ovaries. With an equal growth of the ovary wall and floral apex, young ovaries take the shape of a salt-shaker; with more extensive development of the floral apex and delay of the ovary wall, a club-shaped ovary is formed; with faster growth of the ovary wall linked with intercalary expansion and a delayed growth of the floral apex, a (half-) inferior cup-shaped ovary develops. The different growth forms are the results of heterochronic shifts and affect the development of septa and ovule numbers. A common trend in the order implies a weakening and break-up of septa during development, leading to residual apical and basal septa and the shift to free-central and basal placentation. The club-shaped ovary is linked with an almost complete loss of septa and a reduction of the ovule number to one. The salt-shaker shape leads to ovaries with a massive placental column and several ovules. The cup-shaped ovary leads to a shift of ovules away from the floral apex. Developmental flexibility is responsible for a disconnection of carpel wall growth from ovular tissue. Subtle shifts in proportional growth lead to a high diversification of ovaries in core Caryophyllales and the establishment of predictable developmental trends. These trends clearly represent apomorphic tendencies, affecting different families of core Caryophyllales in different degrees. The ancestral gynoecium was probably pentamerous and isomerous with the other floral whorls, with ovules clearly separated from the carpellary wall and inserted on axile placentas corresponding to the central axis of the flower.

A Developmental Study of Intonation Recognition

1968 ◽  
Vol 11 (4) ◽  
pp. 825-832 ◽  
Author(s):  
Marilyn M. Corlew
Keyword(s):  
Significant Interaction ◽  
Multiple Choice ◽  
Semantic Content ◽  
First Grade ◽  
Choice Test ◽  
Developmental Study ◽  
Multiple Choice Test ◽  
The Third ◽  
Matching Test ◽  
Better Than

Two experiments investigated the information conveyed by intonation from speaker to listener. A multiple-choice test was devised to test the ability of 48 adults to recognize and label intonation when it was separated from all other meaning. Nine intonation contours whose labels were most agreed upon by adults were each matched with two English sentences (one with appropriate and one with inappropriate intonation and semantic content) to make a matching-test for children. The matching-test was tape-recorded and given to children in the first, third, and fifth grades (32 subjects in each grade). The first-grade children matched the intonations with significantly greater agreement than chance; but they agreed upon significantly fewer sentences than either the third or fifth graders. Some intonation contours were matched with significantly greater frequency than others. The performance of the girls was better than that of the boys on an impatient question and a simple command which indicates that there was a significant interaction between sex and intonation.

Welfare, Children, and Families: A Three-City Study (Boston, Chicago, and San Antonio) Embedded Developmental Study, Wave 1,1999

1999 ◽  
Author(s):  
P. Lindsay Chase-Lansdale ◽  
◽  
Ronald Angel ◽  
Linda Burton ◽  
Andrew Cherlin ◽  
...  
Keyword(s):  
San Antonio ◽  
Developmental Study ◽  
Children And Families
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