L'androcée centripète d’Ochna atropurpurea

1978 ◽  
Vol 56 (20) ◽  
pp. 2500-2511 ◽  
Author(s):  
Fernand Pauzé ◽  
Rolf Sattler
Keyword(s):  
Floral Development ◽  
Fundamental Importance ◽  
Reliable Criterion ◽  
Early Stages ◽  
Stamen Primordia ◽  
Family Level ◽  
Definite Pattern ◽  
Phylogenetic Lineages ◽  
Floral Bud

After the inception of usually five sepals and five petals, five primary androecial primordia are initiated as broad bulges in alternation with the narrow petal primordia. On each of these primary androecial primordia, usually seven stamen primordia (i.e., secondary androecial primordia) are formed centripetally in a definite pattern. The fasciculate pattern of the androecium is noticeable only in very early stages of floral development since the stamen primordia of adjacent primary androecial primordia approach each other as closely as the stamen primordia of the same primary androecial primordium. Furthermore, the number and arrangement of the stamen primordia on the primary androecial primordia may vary even within the same floral bud. The total number of stamens per floral bud varied from 26 to 43, while the number of petals varied from 4 to 6. Some of the stamen primordia, especially among the inner ones, sometimes develop into filament-like staminodia. The findings support the view that the Dilleniidae cannot be generally characterized by a centrifugal androecium. The sequence of stamen inception is not necessarily of such fundamental importance that it is a reliable criterion for the reconstitution of major phylogenetic lineages at or above the rank of families. Shifts from a centrifugal to a centripetal androecium or vice versa may have occurred during the evolution of taxa at the ordinal (or even family) level. [Translated by the journal]

Photoperiod and floral-bud development in Caryopteris × clandonensis

1978 ◽  
Vol 56 (16) ◽  
pp. 1844-1851
Author(s):  
David B. Layzell ◽  
Roger F. Horton
Keyword(s):  
Floral Development ◽  
Anther Wall ◽  
Stages Of Development ◽  
Bud Development ◽  
Early Stages ◽  
Floral Bud ◽  
Short Days

Floral development in Caryopteris × clandonensis A. Simmonds (C. incana (Houtt.) Miq. × C. mongholica Bunge) from cyme initiation through to anthesis is described, with emphasis on the development of the anthers. The later stages of development and anthesis are completed only on mature plants under short days (SD, 8 h light per day). Under long days (LD, 20 h light per day) senescence occurs in the early stages of anther wall differentiation.

Patterns of floral development in Agalinis and allies (Scrophulariaceae). I. Floral development of Agalinis fasciculata and A. tenuifolia

1987 ◽  
Vol 65 (11) ◽  
pp. 2255-2262 ◽  
Author(s):  
Christine M. Kampny ◽  
Judith M. Canne-Hilliker
Keyword(s):  
Floral Development ◽  
Floral Character ◽  
Sequence Of Events ◽  
Stamen Primordia ◽  
Lateral Posterior ◽  
Floral Bud ◽  
Two Sides

The sequence of events and morphology of structures were similar during early floral development of Agalinis tenuifolia and A. fasciculata. The lateral-posterior calyx primordia were initiated first, followed by the middle-posterior primordium, and lastly by the two anterior primordia. The corolla primordia arose in an anterior to posterior succession, then the four stamen primordia were initiated simultaneously. Later the gynoecium originated as an oval-shaped ridge. Two depressions within it became locules, and the two sides of the cleaved ridge separating them met and formed a septum. A placenta formed in each locule and numerous ovules were initiated on it. Zygomorphy was apparent in the calyx, corolla, and androecium during the primordial stage. Organogenesis in the calyx was rapid so that the calyx lobes and tube were well formed before organogenesis of other floral parts. Except for those of the calyx, floral character states distinctive for each species were manifested late in development of the floral bud.

scholarly journals Ethylene and 1-methylcyclopropene action over senescence of nasturtium flowers

2015 ◽  
Vol 33 (4) ◽  
pp. 453-458 ◽  
Author(s):  
Tania P Silva ◽  
Fernando L Finger
Keyword(s):  
Floral Development ◽  
Development Stage ◽  
Flower Senescence ◽  
Premature Senescence ◽  
Flower Opening ◽  
Development Stages ◽  
Post Harvest ◽  
The Third ◽  
Exogenous Ethylene ◽  
Floral Bud

ABSTRACT: This work describes ethylene and 1-methylcyclopropene (1-MCP) action on post-harvest shelf life of four development stages of nasturtium flowers. To reach this goal, we carried out three experiments. In the first and second experiments, we studied five ethylene (0; 0.1; 1; 10; 100 and 1000 μL/L) and three 1-MCP concentrations (0.25; 0.5 and 0.75 μL/L), respectively. In the third experiment, 1-MCP was followed by combined with ethylene (only 1-MCP; only ethylene; and 24 hours of exposure to 0.75 μL/L 1-MCP followed by 24 hours of exposure to 100 μL/L ethylene). All experiments had two control treatments, one keeping non-exposed flowers inside and another outside exposure chambers. Experiments were set in factorial design, in complete blocks at random, with four 10-flower replications each. Flower senescence was determined by a pre-established visual scale and by observing floral bud development. Ethylene dose above 10 μL/L induced flower wilting and premature senescence from the second floral development stage. Furthermore, higher concentrations of exogenous ethylene promoted irregular flower opening and/or morphological abnormalities in opened flowers. 1-MCP effectively extended post-harvest longevity of nasturtium flowers, independent of the concentration and even in the presence of exogenous ethylene.

Floral development of Potamogeton densus

1973 ◽  
Vol 51 (3) ◽  
pp. 647-656 ◽  
Author(s):  
U. Posluszny ◽  
R. Sattler
Keyword(s):  
Floral Development ◽  
The Other ◽  
Floral Meristem ◽  
Developmental Sequence ◽  
Initial Activity ◽  
The Third ◽  
Stamen Primordia ◽  
Procambial Strand ◽  
Inflorescence Axis ◽  
Rates Of Growth

The floral appendages of Potamogeton densus are initiated in an acropetal sequence. The first primordia to be seen externally are those of the lateral tepals, though sectioning young floral buds (longitudinally, parallel to the inflorescence axis) reveals initial activity in the region of the lower median (abaxial) tepal and stamen at a time when the floral meristem is not yet clearly demarcated. The lateral (transversal) stamens are initiated simultaneously and unlike the median stamens each arises as two separate primordia. The upper median (adaxial) tepal and stamen develop late in relation to the other floral appendages, and in some specimens are completely absent. Rates of growth of the primordia vary greatly. Though the lower median tepal and stamen are initiated first, they grow slowly up to gynoecial inception, while the upper median tepal appears late in the developmental sequence but grows rapidly, soon overtaking the other tepal primordia. The four gynoecial primordia arise almost simultaneously, although variation in their sequence of inception occurs. The two-layered tunica of the floral apices gives rise to all floral appendages through periclinal divisions in the second layer. The third layer (corpus) is involved as well in the initiation of the stamen primordia. Procambial strands develop acropetally, lagging behind primordial initiation. The lateral stamens though initiating as two primordia each form a single, central procambial strand, which differentiates after growth between the two primordia of the thecae has occurred. A great amount of deviation from the normal tetramerous flower is found, including completely trimerous flowers, trimerous gynoecia with tetramerous perianth and androecium, and organs differentiating partially as tepals and partially as stamens.

Requirement of the Auxin Polar Transport System in Early Stages of Arabidopsis Floral Bud Formation

1991 ◽  
Vol 3 (7) ◽  
pp. 677 ◽  
Author(s):  
Kiyotaka Okada ◽  
Junichi Ueda ◽  
Masako K. Komaki ◽  
Callum J. Bell ◽  
Yoshiro Shimura
Keyword(s):  
Transport System ◽  
Polar Transport ◽  
Bud Formation ◽  
Early Stages ◽  
Auxin Polar Transport ◽  
Floral Bud

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.

The vegetative and floral development of the hybrid grape cultivar ‘Ventura’

1986 ◽  
Vol 64 (8) ◽  
pp. 1620-1631 ◽  
Author(s):  
Usher Posluszny ◽  
Jean M. Gerrath
Keyword(s):  
Fourth Order ◽  
Floral Development ◽  
Upper Arm ◽  
Grape Cultivar ◽  
Stamen Primordia ◽  
Short Style

The vegetative and floral development of the hybrid grape cultivar ‘Ventura’ was studied. A tendril forms opposite the last-formed leaf on the shoot but is slightly delayed in its initiation. Six nodes and 10 primordia complete one leaf–tendril initiation cycle. The inflorescence develops at the same site and is initially indistinguishable from the tendril. Inflorescence primordia are initiated on the upper arm, first opposite each other in a decussate arrangement and then apparently spirally. Each inflorescence primordium may subsequently initiate two lateral primordia, which become subtended by bracts. These in turn may repeat the pattern so that ultimately third- or fourth-order cysmose inflorescence branches may be produced. During floral development the calyx is initiated at first as three primordia, followed by a ring, which ultimately develops five lobes. The five corolla primordia alternate with the sepals. The five stamen primordia are initiated opposite the petals. The gynoecium initiates as five primordia, which later become a ring. Two septae are initiated opposite each other on the inner flank of the ring, forming the two-loculed ovary. Each septum forms a placenta, giving rise to two ovules. The upper portion of the gynoecial ring grows up over the ovules and forms the short style and discoid stigma.

Interpretations of determination and canalisation of stamen development in a tomato mutant

1979 ◽  
Vol 57 (22) ◽  
pp. 2471-2477 ◽  
Author(s):  
V. K. Sawhney ◽  
R. I. Greyson
Keyword(s):  
Gibberellic Acid ◽  
Single Gene ◽  
Progressive Increase ◽  
Stamen Development ◽  
Early Stages ◽  
Floral Buds ◽  
Stamen Primordia ◽  
Recessive Mutant ◽  
Tomato Mutant

Floral buds of different sizes of the single-gene recessive mutant stamenless-2 (sl2/sl2) of tomato were treated with gibberellic acid (GA3) and the development of staminal features in each bud was followed. The results show that the application of GA3 to buds with stamen primordia at the early stages of initiation (up to 0.1 mm in length) induced the formation of normal-looking stamens. However, with a progressive increase in stamen size, less and less of the normal stamen features were produced following the GA3 treatment. Ultimately, buds with stamen primordia 0.8 mm long or longer failed to respond to GA3 and produced all the mutant characteristics. These results are discussed in terms of Waddington's concept of “determination” and “canalisation” of development.

Developmental morphology of the flower of Anthurium jenmanii: a new element in our understanding of basal Araceae

Botany ◽  
2008 ◽  
Vol 86 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Denis Barabé ◽  
Christian Lacroix
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Floral Development ◽  
Developmental Morphology ◽  
Calcium Oxalate Crystals ◽  
Stages Of Development ◽  
Early Stages ◽  
Floral Primordia ◽  
Scanning Electron

The early stages of development of the inflorescence of Anthurium jenmanii Engl. were examined using scanning electron microscopy. The inflorescence of A. jenmanii consists of more than 100 flowers arranged in recognizable spirals. Each flower has four broad tepals enclosing four stamens that are not visible prior to anthesis. The gynoecium consists of two carpels. The floral primordia are first initiated on the lower portion of the inflorescence, they then increase in size and appear as transversely extended bulges. The two lateral tepals are the first organs to be initiated, followed shortly thereafter by the two median tepals. The two lateral stamens are initiated first, directly opposite the lateral tepals, and are followed by two median stamens initiated directly opposite the median tepals. A two-lobed stigma is clearly visible during the early stages of development of the gynoecium. On some of the young inflorescences, all floral parts were covered by extracellular calcium oxalate crystals. The release of these prismatic crystals occurs before the stamens and petals have reached maturity. The mode of floral development observed in Anthurium has similarities with that reported for Gymnostachys . However, contrary to Gymnostachys, the development of the flower of A. jenmanii is not unidirectional.

Floral development in Melaleuca and Callistemon (Myrtaceae)

1998 ◽  
Vol 11 (6) ◽  
pp. 689 ◽  
Author(s):  
D. A. Orlovich ◽  
A. N. Drinnan ◽  
P. Y. Ladiges
Keyword(s):  
Floral Development ◽  
Flower Bud ◽  
Variable Expression ◽  
Total Absence ◽  
Stamen Primordia ◽  
Intermediate Morphology ◽  
Floral Apex

Floral development of seven species of Melaleuca and four species of Callistemon is compared. The multistaminate fascicles of Melaleuca develop from stamen primordia initiated on antepetalous pre-staminal bulges (PSBs); the resultant bundles of stamens become separated by hypanthial expansion as the flower bud enlarges. In most species of Callistemon examined the stamen primordia are initiated directly on the floral apex, and the stamens are distributed evenly around the hypanthium at anthesis. The possession of large and prominent PSBs, and thus stamen fascicles, is a feature of most species of Melaleuca and their total absence is a feature of most species of Callistemon; however, there is a continuum between these two extremes. Several taxa of both genera exhibit intermediate morphology. In C. glaucus (Bonpl.) Sweet, small but distinct PSBs develop, which influence antepetalous stamen groups that remain contiguous at anthesis. This also occurred in M. leucadendra (L.) L. This variable expression of PSBs is the result of differences in the timing of stamen initiation. Other variable features are determined by the space available for primordium initiation and the patterns of growth and expansion of the developing flower.

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