An updated interpretation of the androecium of the Fumariaceae

1992 ◽  
Vol 70 (9) ◽  
pp. 1765-1776 ◽  
Author(s):  
L. P. Ronse Decraene ◽  
E. F. Smets
Keyword(s):  
Key Words ◽  
Floral Development ◽  
Flower Bud ◽  
Stamen Primordia ◽  
Outer Whorl ◽  
Spatial Median ◽  
Median Position

A study of the floral development of Dicentra formosa, Corydalis lutea, and Hypecoum procumbens was carried out to better understand the nature of the androecium in Fumariaceae. Sepals emerge successively in a median position and are followed by two alternating pairs of petals. Four stamen primordia are formed in a diagonal position. They are promptly followed by two lateral, slightly externally inserted primordia. In Dicentra and Corydalis the stamens arise on two crescent-shaped protuberances. In Hypecoum, four diagonal androecial primordia fuse into two median staminal complexes. The gynoecium emerges as a girdling primordium with four growth centers. Different interpretations of the androecium are discussed. It is demonstrated that the androecium in the Fumariaceae consists basically of two whorls: an outer whorl of four alternipetalous stamens and an inner whorl of two lateral stamens superposed to the outer petals. The monothecal nature of the alternipetalous stamens and the fusion of the stamens in two triplets is probably caused by a spatial median compression of the flower bud. The androecium of Hypecoum is the result of interprimordial growth between the pairs of monothecal stamens, and the androecium of Pteridophyllum arises through the loss of the two lateral stamens superposed to the outer petals. Key words: Fumariaceae, floral development, androecium, stamen whorls.

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.

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.

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.

Floral development of Rosa setigera

1993 ◽  
Vol 71 (1) ◽  
pp. 74-86 ◽  
Author(s):  
James R. Kemp ◽  
Usher Posluszny ◽  
Jean M. Gerrath ◽  
Peter G. Kevan
Keyword(s):  
Key Words ◽  
Floral Development ◽  
Functional Approach ◽  
Floral Meristem ◽  
Cryptic Dioecy ◽  
Congenital Fusion ◽  
Postgenital Fusion

The development of the flower of Rosa setigera from initiation to the onset of anthesis is described. Rosa setigera is the only known member of the genus Rosa to exhibit dioecy. Flowers of functionally staminate (male) and functionally carpellate (female) plants appear identical, a condition referred to as cryptic dioecy. Discrete sepals and petals are formed on the floral meristem. As the hypanthium forms, stamens are initiated in alternating whorls on the wall of the hypanthium and continue to develop as the hypanthium extends. Carpel primordia arise individually on the remainder of the floral meristem and show neither adnation to the hypanthial wall nor coalescence to one another as they give rise to the styles and stigmas that are exserted above the hypanthium lip. The only observable fusion in this species appears to be the postgenital fusion of the margins of the carpel primordia to form the enclosed locule. Although historically the hypanthium has been variously interpreted as either axial and (or) appendicular in nature, resulting from congenital fusion of sepals, petals, and stamens, this paper uses a more realistic, testable and functional approach to the development of the hypanthium that is in keeping with current concepts such as process morphology. Key words: Rosa setigera, dioecy, floral development, fusion, hypanthium.

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.

Effects of nitrogen addition on the population dynamics and flowering of Pulsatilla vernalis

1993 ◽  
Vol 71 (5) ◽  
pp. 732-736 ◽  
Author(s):  
Olle Kellner
Keyword(s):  
Population Dynamics ◽  
Key Words ◽  
Nitrogen Addition ◽  
Permanent Plots ◽  
Flower Buds ◽  
Flower Bud ◽  
Bud Formation ◽  
Single Fertilization ◽  
Flower Bud Formation ◽  
And Control

A population of Pulsatilla vernalis (L.) Mill, was studied in permanent plots for 8 years. Half the plots were fertilized with ammonium nitrate (15 g N/m2) at the start of the study. Mortality and natality in the ramet population were very low in both fertilized and control treatments. In contrast, there was a considerable between-year turnover of shoots within ramets in both treatments. The number of shoots increased threefold after fertilization and then gradually decreased to the original level. Flower-bud formation in unfertilized plots was lower in warm and dry years than in cooler, wetter ones. In fertilized plots, flower-bud formation was higher after fertilization irrespective of the climate at the time. The proportion of flower buds grazed was higher in fertilized plots. Even though the species is confined to nitrogen-poor habitats, a single fertilization did not adversely affect its performance. Key words: Pulsatilla vernalis, population dynamics, nitrogen, weather, forestry.

scholarly journals MADS-box genes are involved in floral development and evolution.

2001 ◽  
Vol 48 (2) ◽  
pp. 351-358 ◽  
Author(s):  
H Saedler ◽  
A Becker ◽  
K U Winter ◽  
C Kirchner ◽  
G Theissen
Keyword(s):  
Floral Development ◽  
Higher Plants ◽  
Control Cell ◽  
Floral Organ ◽  
Reproductive Organs ◽  
Mads Box ◽  
Mads Box Genes ◽  
Flower Bud ◽  
Organ Identity ◽  
Eukaryotic Organisms

MADS-box genes encode transcription factors in all eukaryotic organisms thus far studied. Plant MADS-box proteins contain a DNA-binding (M), an intervening (I), a Keratin-like (K) and a C-terminal C-domain, thus plant MADS-box proteins are of the MIKC type. In higher plants most of the well-characterized genes are involved in floral development. They control the transition from vegetative to generative growth and determine inflorescence meristem identity. They specify floral organ identity as outlined in the ABC model of floral development. Moreover, in Antirrhinum majus the MADS-box gene products DEF/GLO and PLE control cell proliferation in the developing flower bud. In this species the DEF/GLO and the SQUA proteins form a ternary complex which determines the overall "Bauplan" of the flower. Phylogenetic reconstructions of MADS-box sequences obtained from ferns, gymnosperms and higher eudicots reveal that, although ferns possess already MIKC type genes, these are not orthologous to the well characterized MADS-box genes from gymnosperms or angiosperms. Putative orthologs of floral homeotic B- and C-function genes have been identified in different gymnosperms suggesting that these genes evolved some 300-400 million years ago. Both gymnosperms and angiosperms also contain a hitherto unknown sister clade of the B-genes, which we termed Bsister. A novel hypothesis will be described suggesting that B and Bsister might be involved in sex determination of male and female reproductive organs, respectively.

scholarly journals Development and Abortion of Flowers in Capsicum annuum Exposed to High Temperatures

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 476A-476
Author(s):  
Ami N. Erickson ◽  
Albert H. Markhart
Keyword(s):  
Growth Rate ◽  
High Temperature ◽  
Capsicum Annuum ◽  
High Temperatures ◽  
Floral Development ◽  
Leaf Growth ◽  
Flower Initiation ◽  
Treatment Rate ◽  
Flower Bud ◽  
Stage Of Development

Reduction of floral number in Capsicum annuum has been observed during growth at high temperature. To determine whether decreased flower production or increased flower abscission is a direct response to high temperatures or a response to water stress induced by high temperatures, we compared flowers and fruit produced and flowers aborted to leaf growth rate, osmotic potential, stomatal conductance, and chlorophyll fluorescence of two cultivars. To determine the stage(s) of floral development that are most sensitive to high temperatures, flower buds were wax-embedded and examined at each stage of development during heat treatment. Rate of floral development also was examined. At first visible floral bud initiation, plants were transferred to each of three controlled environment growth chambers with set temperatures and vapor pressure deficits (VPD) of 25°C, 1.1 kPa; 33°C, 1.1 kPa; and 33°C, 2.1 kPa. Flower bud production and leaf growth rate were not significantly affected by high temperatures. Pepper fruit set, however, was inhibited at 33°C at either VPD. Preliminary water relations data suggested that water potentials were more negative under high temperature conditions. Differences in leaf fluorescence were statistically significant for temperature treatments, but not for VPD. Temperature is the primary factor in the decrease of fruit production in pepper. Decreased production is due to flower abortion and not to decreased flower initiation or plant growth.

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]

Comparison of two air temperature based models for predicting phenophase occurrence in Persian lilacs (Syringa chinensis) cultivar Red Rothomagensis

1990 ◽  
Vol 68 (5) ◽  
pp. 1113-1116 ◽  
Author(s):  
Gary W. Moorman ◽  
James L. Rosenberger ◽  
Leslie A. Gladstone
Keyword(s):  
Mathematical Models ◽  
Key Words ◽  
Growth Model ◽  
Air Temperature ◽  
Growing Degree Days ◽  
Bud Break ◽  
Degree Days ◽  
Flower Bud ◽  
Phenological Data ◽  
Vegetative Bud

Phenological data collected for 9–11 years from genetically uniform Persian lilacs (Syringa chinensis L.) cultivar Red Rothomagensis were analyzed to determine whether the number of days elapsed between vegetative bud break and flower bud break is correlated with either the accumulated growing degree-days or the average daily temperature. The lack of statistically significant correlations between these variables suggests these mathematical models cannot accurately predict the onset of flower bud break for this cultivar. Key words: degree-days, growth model, phenology.

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