Floral organogenesis of Limnocharis flava

1977 ◽  
Vol 55 (9) ◽  
pp. 1076-1086 ◽  
Author(s):  
R. Sattler ◽  
V. Singh
Keyword(s):  
Floral Organogenesis ◽  
Stamen Primordia ◽  
Mature Flower ◽  
Stamen Pairs ◽  
Primary Pattern

Besides a trimerous calyx and corolla, the mature flower exhibits a polyandric androecium and an apocarpous gynoecium consisting of a whorl of carpels. Yet the primary pattern of the flower is completely trimerous and tetracyclic. After the inception of three sepals and three petals, three antesepalous primary androecial primordia are initiated each of which forms three stamens (i.e. secondary androecial primordia). Opposite these three groups of three stamen primordia, three groups of three carpels are initiated, possibly on three extremely inconspicuous primary gynoecial primordia. Additional carpel primordia are formed in varying numbers between the original three groups. Even before carpel inception, the three primary androecial primordia merge laterally thus forming an androecial ring. Additional stamen primordia arise on this ring first between the three groups of three stamen primordia and then in centrifugal direction as the androecial ring broadens basally. Eventually four whorls of stamens and two to three whorls of staminodia are formed secondarily on the androecial ring which arose from the primary primordia. Morphogenesis and construction of the flowers of Limnocharis flava differs in two major respects from those of all other taxa of the Alismatales studied thus far: (1) there are no stamen pairs primarily associated with the petals, and (2) the first-formed carpel primordia do not alternate with the stamen primordia of the preceding whorl, thus violating Hofmeister's rule of alternation.

Studies in the Alismataceae. X. Floral organogenesis in Luronium natans (L.) Raf.

2000 ◽  
Vol 77 (11) ◽  
pp. 1560-1568
Author(s):  
W A Charlton
Keyword(s):  
Floral Organ ◽  
Floral Organogenesis ◽  
Stamen Primordia ◽  
Floral Apex ◽  
Stamen Pairs

Floral organogenesis of Luronium natans (L.) Raf. occurs at first in an alternating trimerous pattern typical of Alismataceae, with the formation of three sepals, then three bulges, corresponding to the petal-stamen primordia described in some other Alismataceae, alternating with the sepals. A petal is initiated on each bulge and a pair of stamens is initiated either on it or close to it. After this, development no longer follows a trimerous plan. Six carpels are initiated in positions alternating with the six stamens, and further carpels may then arise above and between the first six. The carpels ultimately lie in a whorled arrangement if there are only six; if more, they may appear whorled or irregularly arranged. After the initiation of the stamen pairs, floral organ primordia appear simply to be positioned between pre-existing primordia as in other phyllotactic systems. It is suggested that the number of carpel primordia formed is probably determined by the size of primordia relative to the floral apex, and the extent of continued growth of the floral apex. Luronium reinforces the concept that a form of trimery is fundamental for the Alismataceae up to the formation of three stamen pairs and adds to the possibilities for variation after this point. It is suggested for the Alismataceae in general that, according to taxon, trimerous development may be terminated at any point after the initiation of the stamen pairs, and after this the primordia are positioned individually in relation to pre-existing primordia. The switch from stamen to carpel initiation is not necessarily correlated with these phyllotactic changes.

Studies in the Alismataceae. XII. Floral organogenesis in Damasonium alisma and Baldellia ranunculoides, and comparisons with Butomus umbellatus

2004 ◽  
Vol 82 (4) ◽  
pp. 528-539 ◽  
Author(s):  
W A Charlton
Keyword(s):  
Floral Development ◽  
De Novo ◽  
Fundamental Feature ◽  
Floral Organogenesis ◽  
General Plan ◽  
Stamen Pairs

Floral organogenesis of Damasonium alisma Mill. occurs at first in an alternating trimerous pattern typical of Alismataceae, with the formation of three sepals, then three bulges, corresponding to the CA (common perianth–androecium) primordia described in some other Alismataceae, alternating with the sepals. A petal is initiated on each bulge, and a pair of stamens is initiated either on or close to it. Three carpels are initiated in positions alternating with the petals and stamen pairs, and three further carpels then arise above and between the first three. At maturity and in fruit the carpels lie in a whorled arrangement. Floral development in Baldellia ranunculoides (L.) Parl. is identical up to the initiation of the six stamens. After this, six carpel primordia are formed alternating with the stamens, and further carpel primordia arise alternating with those previously formed. In Butomus, up to the initiation of the first six stamens, the general plan of development resembles that of the two Alismataceae. Three further whorls of organs arise in alternation: a whorl of three stamens arises over the stamen pairs followed by two whorls each of three carpel primordia. It is argued that the trimerous appearance of the whorl of sepals (or outer perianth in Butomus) arises de novo and represents a genuine expression of trimery. However, most of the subsequent features of development in these flowers can be seen as arising from phyllotactic mechanisms that cause new primordia to arise between and above pre-existing ones. Consequently the appearance of trimerous or hexamerous whorls above the first whorl of perianth does not represent a fundamental feature of development. The nature of variations in the positional relationships of inner perianth, stamen, and carpel primordia in various Alismataceae and Butomus strengthen the case that there is a significant developmental association between inner perianth members and associated pairs of stamens, which may be connected with the evolution of the flowers from pseudanthial structures.Key words: Baldellia, Butomus, Damasonium, Alismatidae, flower, organogenesis.

Comparative development of perianth and androecial primordia of the single flower and the homeotic double-flowered mutant in Hibiscus rosa-sinensis (Malvaceae)

1996 ◽  
Vol 74 (12) ◽  
pp. 1871-1882 ◽  
Author(s):  
Judith P. Maclntyre ◽  
Christian R. Lacroix
Keyword(s):  
Floral Development ◽  
Developmental Pathways ◽  
Partial Replacement ◽  
Double Flower ◽  
Flower Petal ◽  
Hibiscus Rosa Sinensis ◽  
Stamen Primordia ◽  
Staminal Tube ◽  
Mature Flower ◽  
Single Flower

The double-flowered variety of Hibiscus rosa-sinensis L. (Malvaceae) displays a divergent floral morphology that appears to fit the criteria for homeosis. A comprehensive definition defines homeosis as the complete or partial replacement of one part of an organism with another part. The corolla of the single flower is pentamerous. The mature flower has a staminal tube bearing 60 – 70 stamens that surrounds an exserted synstylous gynoecium with five fused stigmas. In double flowers, the outermost whorl of petals is similar in appearance to that of the single flower. The remaining floral appendages have a morphology that is intermediate between petals and stamens, to varying degrees. No two double flowers are exactly the same, even on the same plant. As with other members of the Malvaceae, floral development in both floral types is unusual: once the calyx has been initiated, a ring meristem is formed from which both petal and stamen primordia are initiated. In the single flower, petal primordia are initiated on the flank of the ring, and then stamen primordia arise in five distinct and orderly clusters. In the double flower, petal primordia are also initated on the abaxial flank, but the remainder of the ring initiates primordia that form a mixture of petals, petal – stamen intermediates, and stamens. A common ring meristem that has two different developmental pathways provides a novel opportunity to study homeosis from the perspective of comparative developmental morphology. Keywords: homeosis, Hibiscus rosa-sinensis, androecium, intermediates, ring meristem, floral development.

Floral development of Butomus umbellatus

1974 ◽  
Vol 52 (1) ◽  
pp. 223-230 ◽  
Author(s):  
V. Singh ◽  
R. Sattler
Keyword(s):  
Floral Development ◽  
Stamen Primordia ◽  
Procambial Strand ◽  
Tunica Layer ◽  
Rapid Sequence ◽  
Floral Apex ◽  
Outer Tepal ◽  
Primary Pattern

The primordia of the floral appendages appear in acropetal succession and develop in the order in which they appear. The primordia of each whorl of appendages are formed in a rapid sequence. After the inception of outer tepal primordia, the floral apex becomes triangular. On each angle, one inner tepal primordium together with the primordia of a pair of outer stamens and an inner stamen is formed. The triangularity of the floral apex might be interpreted as an indication of the formation of petal–stamen (CA) primordia as reported for Alisma and Hydrocleis. If this is the case, the primary pattern of organogenesis of the Butomus flower is trimerous and tetracyclic, i.e. one whorl of outer tepals, one complex of inner tepals and stamens, and two whorls of pistils. The floral apices have a two-layered tunica surrounding a central corpus. The initiating divisions in the formation of all floral appendages occur in the second tunica layer. In the case of stamen primordia, the outer corpus is also involved. Procambial development is acropetal. One procambial strand differentiates into each floral appendage shortly after its inception. Additional procambial strands are formed in the pedicel and the perianth and gynoecium. The relationships of Butomus to the Magnoliidae are discussed.

Development of the inflorescence and flower of Sagittaria cuneata

1977 ◽  
Vol 55 (9) ◽  
pp. 1087-1105 ◽  
Author(s):  
V. Singh ◽  
R. Sattler
Keyword(s):  
Male Flower ◽  
Female Flower ◽  
Point Of View ◽  
Stamen Primordia ◽  
Tunica Layer ◽  
Mature Flower ◽  
Floral Apex ◽  
Developmental Point ◽  
Floral Bud ◽  
Developmental Modification

The reproductive region of Sagittaria cuneata is basically trimerous. This trimery is exhibited in the arrangement of the bracts, sepals, petals, pairs of stamens in the male flower, and pairs of staminodia in the female flower. In the male flower after the inception of three sepal primordia, each of the three petal primordia arises with one pair of stamen primordia on an alternisepalous bulge of the floral apex, i.e., a petal–stamen (CA) primordium. Subsequent stamen primordia are formed in alternation with the six first-formed primordia. If, for convenience sake, the first six primordia are referred to as the first whorl of stamens up to four additional whorls may be produced. Depending on the size of the floral bud, the third and fourth whorls (if present) consist of two to six stamen primordia, whereas the fifth whorl (if present) contains one to five stamen primordia. Finally, primordia of pistillodes are formed in varying numbers. In the female flower the presence of CA primordia could not be as clearly established as in the male flower. However, again each petal primordium is definitely associated with a pair of antepetalous primordia. The latter primordia develop into staminodia. In alternation with the first six staminodia six additional staminodia are formed and then again in alternation many whorls of pistils (carpels). Even in the mature flower the basic trimery is reflected in the triangular shape of the globose and massive gynoecium. From a developmental point of view, the male and female flowers are primarily trimerous. The polyandric androecium and the large pleiomerous gynoecium are superimposed on the primary trimery. It appears quite possible that this developmental modification also reflects a phylogenetic derivation. This means that the pleiomerous gynoecium and androecium are not primitive but rather advanced. There is no indication of a spiral arrangement of stamens and carpels.Whereas the foliage leaves, bracts, and sepals are initiated as dorsiventral primordia, the petals, stamens, staminodia, pistils, and pistillodes arise as more or less hemispherical mounds and become dorsiventral thereafter. The vegetative apices, inflorescence apices and the floral apices have a two-layered tunica over a massive corpus. Foliage leaves, bracts, sepals, petals, stamens, staminodia, carpels, and pistillodes are initiated by periclinal divisions in the second tunica layer. In the case of the stamens and staminodia the corpus may also contribute. Ovules are initiated by periclinal divisions of the second layer of the carpel primordium.

Floral development in the 'Symphyomyrtus group' of Eucalypts (Eucalyptus: Myrtaceae)

1991 ◽  
Vol 4 (3) ◽  
pp. 553 ◽  
Author(s):  
AN Drinnan ◽  
PY Ladiges
Keyword(s):  
Floral Development ◽  
Developmental Stages ◽  
Growth Centre ◽  
Superficial Resemblance ◽  
Stamen Primordia ◽  
Mature Flower ◽  
Floral Apex ◽  
Bud Growth ◽  
Early Developmental ◽  
Complete Interpretation

Floral development is described in selected species of informal subgenus Symphyomyrtus (Pryor and Johnson 1971). The corolline operculum in most species is equivalent to those of informal subgenera Eudesmia, Idiogenes (E. cloëziana) and Monocalyptus. It is formed by growth centre continuity, and shows characters consistent with the dorsal components of Angophora and bloodwood corolline parts. Stamen primordia form on a corolline buttress that develops into the stemonophore of the mature flower. This feature is a synapomorphy for Symphyomyrtus sens. strict., Eudesmia, Idiogenes and Monocalyptus. Eucalyptus microcoiys has the plesiomorphic conditions of four free imbricate petals that show no evidence of compound development, and stamens arising directly on the floral apex, not on a stemonophore precursor. The apparent bundling of stamens is a result of differential bud growth, and bears only a superficial resemblance to stamen groups in Eudesmia eucalypts. The corollas of E. brachyandra (informal subgenus Telocalyptus) and E. guilfoylei (Symphyomyrtus) also consist of free, simple petals, but the unavailability of early developmental stages precludes a complete interpretation of these and the remaining three species of Telocalyptus.

Effect of High Temperatures on the Postharvest Flowering of Specialty Floral Crop Species

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 447f-448
Author(s):  
Millie S. Williams ◽  
Terri Woods Starman ◽  
James E. Faust
Keyword(s):  
United States ◽  
Heat Tolerance ◽  
Flower Development ◽  
Consumer Satisfaction ◽  
The United States ◽  
Plant Canopy ◽  
Flower Number ◽  
Flower Bud ◽  
Crop Species ◽  
Mature Flower

Flower growers experience decreased consumer satisfaction with plant species that cease flowering during the summer. The objective of this experiment was to characterize the heat tolerance of four specialty floral crop species in order to predict their summer performance in the different climatalogical regions of the United States. The effect of increasing temperatures on the duration of postharvest flower development was determined for Ageranthemum frutescens `Butterfly' and `Sugar Baby', Brachycome hybrid `Ultra', and Sutera cordata `Snowflake'. Plants were grown in a 18 °C greenhouse until marketable with foliage covering the container and flowers distributed evenly across the plant canopy. Plants were then placed in a phytotron to determine their heat tolerance. Temperature set points of 18, 23, 28, and 33 °C were delivered serially at 2-week intervals, starting at 18 °C. Plants were then returned to 18 °C after the 33 °C treatment. Immature flower bud, mature flower bud, flower and senesced flower numbers were collected once per week. Sutera `Snowflake', and Brachycome `Ultra' had the greatest flower number at the 23 °C temperature, decreasing in the 28 °C environment. Argeranthemum `Butterfly' and `Sugar Baby' had greatest flower number at 28 °C, but flowers were smaller and of lower quality than at 23 °C. Flower development of all cultivars ceased at 33 °C, but when plants were returned to the 18 °C production greenhouse, flower development resumed. According to normal average daily temperatures in Knoxville, Tenn., Ageranthemum frutescens `Butterfly' and `Sugar Baby' would flower until mid-June, while Brachycome hybrid `Ultra' and Sutera cordata `Snowflake' would flower until mid-May.

Ontogenetical and experimental studies of the floral apex of Portulaca grandiflora. 1. Histology of transformation of the shoot apex into the floral apex

1969 ◽  
Vol 47 (1) ◽  
pp. 133-140 ◽  
Author(s):  
Siti Raswati Soetiarto ◽  
Ernest Ball
Keyword(s):  
Shoot Apex ◽  
Experimental Studies ◽  
Floral Meristem ◽  
Vegetative Shoot ◽  
Floral Organs ◽  
Mature Flower ◽  
Floral Apex ◽  
Portulaca Grandiflora ◽  
Floral Primordia ◽  
Vegetative Shoot Apex

The vegetative apex was a low dome consisting of two layers of tunica surmounting a very small corpus. Foliar primordia originated as periclines in the flanks of T2. The transition apex became first a steep cone and then a hemisphere. All floral primordia—the two bracts, the two sepals, the several whorls of petals, the several whorls of stamens, and the carpels—originated in the manner of leaves, as periclines in T2 on the flanks of the apex. All appendages, including carpels, were therefore lateral. In the early transition, the apex had a brief stage in which there were three tunica layers, but the inner one was lost with the onset of the sepals. The bracts and the first sepal continued the normal positions of primordia for the vegetative phyllotaxy of 3/8, but with the second sepal, this phyllotaxy was lost, and petals, stamens, and carpels were produced in whorls. While leaves, bracts, sepals, and petals were produced in acropetal sequence, stamens were produced in basipetal sequence, and carpels appeared simultaneously. After carpels were formed, the rest of the floral apex underwent a brief period of expansion growth, achieving a diameter comparable to that of a shoot apex, but its substance was eventually incorporated into the carpel margins, which later produced the ovules. This agrees with the determinate nature of the floral apex. During the development of the first series of floral organs, the floral apex underwent continued increase in area, finally achieving a diameter several times that of the vegetative shoot apex. Its size and form were such that they were compared to those of some inflorescence apices. After development of the first series of floral organs, the subjacent tissues to the floral meristem underwent divisions and elongation at right angles to the axis, causing at first a flattening of the meristem, and eventually a cup-shaped form, with the carpels attached in the bottom of a bowl. The mature flower was thus perigynous, but this development arose quite differently from the perigyny as it is known from ontogenetic studies in the Rosaceae.

In vitro shoot and floral organogenesis from stamen explants from a Rhododendron PJM group clone

1993 ◽  
Vol 56 (2) ◽  
pp. 163-170 ◽  
Author(s):  
A. Shevade ◽  
John E. Preece
Keyword(s):  
Floral Organogenesis

Manufacturing Metamaterials Using Synchrotron Lithography

2010 ◽  
Vol 75 ◽  
pp. 230-239
Author(s):  
Herbert O. Moser ◽  
Linke Jian ◽  
Shenbaga M.P. Kalaiselvi ◽  
Selven Virasawmy ◽  
Sivakumar M. Maniam ◽  
...  
Keyword(s):  
Electromagnetic Waves ◽  
Cost Effective ◽  
Pattern Generation ◽  
Geometrical Parameters ◽  
X Ray ◽  
Spectral Bands ◽  
Left Handed ◽  
Aspect Ratios ◽  
Multi Level ◽  
Primary Pattern

The function of metamaterials relies on their resonant response to electromagnetic waves in characteristic spectral bands. To make metamaterials homogeneous, the size of the basic resonant element should be less than 10% of the wavelength. For the THz range up to the visible, structure details of 50 nm to 30 μm are required as are high aspect ratios, tall heights, and large areas. For such specifications, lithography, in particular, synchrotron radiation deep X-ray lithography, is the method of choice. X-ray masks are made via primary pattern generation by means of electron or laser writing. Several different X-ray masks and accurate mask-substrate alignment are necessary for architectures requiring multi-level lithography. Lithography is commonly followed by electroplating of metallic replica. The process can also yield mould inserts for cost-effective manufacture by plastic moulding. We made metamaterials based on rod-split-rings, split-cylinders, S-string bi-layer chips, and S-string meta-foils. Left-handed resonance bands range from 2.4 to 216 THz. Latest is the all-metal self-supported flexible meta-foil with pass-bands of 45% up to 70% transmission at 3.4 to 4.5 THz depending on geometrical parameters.

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