Flower development in Amelanchier alnifolia (Maloideae)

1991 ◽  
Vol 69 (4) ◽  
pp. 844-857 ◽  
Author(s):  
Taylor A. Steeves ◽  
Margaret W. Steeves ◽  
A. Randall Olson
Keyword(s):  
Key Words ◽  
Flower Development ◽  
Floral Development ◽  
Floral Meristem ◽  
Amelanchier Alnifolia ◽  
Inferior Ovary ◽  
Postgenital Fusion

The development of the flower of Amelanchier alnifolia from initiation to the onset of anthesis is described. Sepals are formed sequentially, but interprimordial zonal growth results in the initiation of the hypanthium. Petals and stamens arise in whorls around the floral meristem as the hypanthium extends. They show neither coalescence nor adnation and do not appear to contribute to the development of the hypanthium. Gynoecial primordia arise individually, give rise to the styles and stigmas, and are joined basally by zonal growth to produce the roof of the ovary. The wall of the inferior ovary is interpreted as a gynoecial hypanthium. It is difficult to determine the extent to which the gynoecial primordia contribute to the development of the ovary. They do not give rise to most of its structure but may be responsible for the initiation of the ovules. There is evidence of postgenital fusion of the septal margins as they converge in the centre of the ovary. The timing of events in floral development is recorded for the locality of the study. The observations are discussed in relation to current theories concerning the nature of the inferior ovary. Key words: Amelanchier, flower, development, inferior ovary, hypanthium.

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.

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 induction and maintenance of flowering in Impatiens

Development ◽  
1997 ◽  
Vol 124 (17) ◽  
pp. 3343-3351 ◽  
Author(s):  
S. Pouteau ◽  
D. Nicholls ◽  
F. Tooke ◽  
E. Coen ◽  
N. Battey
Keyword(s):  
Transcriptional Activation ◽  
Flower Development ◽  
Vegetative Growth ◽  
Floral Development ◽  
Floral Meristem ◽  
Additional Function ◽  
Axillary Meristems ◽  
Meristem Identity ◽  
Floral Characters ◽  
Inductive Signal

The mechanisms that establish the floral meristem are now becoming clearer, but the way in which flowering is maintained is less well understood. Impatiens balsamina provides a unique opportunity to address this question because reversion to vegetative growth can be obtained in a predictable way by transferring plants from inductive to non-inductive conditions. Following increasing amounts of induction, reversion takes place at progressively later stages of flower development. Partial flower induction and defoliation experiments show that a floral signal is produced in the cotyledon in response to inductive conditions and that this signal progressively diminishes after transfer to non-inductive conditions, during reversion. Therefore reversion in Impatiens is most likely due to the failure of leaves to become permanent sources of inductive signal in addition to the lack of meristem commitment to flowering. Analysis of the expression of the Impatiens homologues of the meristem identity genes floricaula and squamosa indicates that a change in floricaula transcription is not associated with the establishment or maintenance of the floral meristem in this species. Squamosa transcription is associated with floral development and petal initiation, and is maintained in existing petal or petaloid primordia even after the meristem has reverted. However, it is not expressed in the reverted meristem, in which leaves are initiated in whorled phyllotaxis and without axillary meristems, both characteristics usually associated with the floral meristem. These observations show that squamosa expression is not needed for the maintenance of these floral characters. The requirement for the production of the floral signal in the leaf during the process of flower development may reflect an additional function separate to that of squamosa activation; alternatively the signal may be required to ensure continued transcriptional activation in the meristem.

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.

scholarly journals SlGT11 Controls Floral Organ Patterning and Floral Determinacy in Tomato

2020 ◽  
Author(s):  
Liling Yang ◽  
Shilian Qi ◽  
Arfa touqeer ◽  
Haiyang Li ◽  
Xiaolan Zhang ◽  
...  
Keyword(s):  
Floral Development ◽  
Bulked Segregant Analysis ◽  
Floral Organ ◽  
Fruit Production ◽  
Floral Meristem ◽  
Rnai Silencing ◽  
The Third ◽  
Spatiotemporal Expression ◽  
Higher Temperature ◽  
Floral Determinacy

Abstract Background: Flower development directly affects fruit production in tomato. Despite the framework mediated by ABC genes have been established in Arabidopsis, the spatiotemporal precision of floral development in tomato has not been well examined.Results: Here, we analyzed a novel tomato stamenless like flower (slf) mutant in which the development of stamens and carpels is disturbed, with carpelloid structure formed in the third whorl and ectopic formation of floral and shoot apical meristem in the fourth whorl. Using bulked segregant analysis (BSA), we assigned the causal mutation to the gene Solanum lycopersicum GT11 (SlGT11) that encodes a transcription factor belonging to Trihelix gene family. SlGT11 is expressed in the early stages of the flower and the expression becomes more specific to the primordium position corresponding to stamens and carpels in later stages of the floral development. Further RNAi silencing of SlGT11 verifies the defective phenotypes of the slf mutant. The carpelloid stamen in slf mutant indicates that SlGT11 is required for B-function activity in the third whorl. The failed termination of floral meristem and the occurrence of floral reversion in slf indicate that part of the C-function requires SlGT11 activity in the fourth whorl. Furthermore, we find that at higher temperature, the defects of slf mutant are substantially enhanced, with petals transformed into sepals, all stamens disappeared, and the frequency of ectopic shoot/floral meristem in fourth whorl increased, indicating that SlGT11 functions in the development of the three inner floral whorls. Consistent with the observed phenotypes, it was found that B, C and an E-type MADS-box genes were in part down regulated in slf mutants.Conclusions: Together with the spatiotemporal expression pattern, we suggest that SlGT11 functions in floral organ patterning and maintenance of floral determinacy in tomato.

scholarly journals Transcriptomic Identification of Floral Transition and Development-Associated Genes in Styrax japonicus

Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 10
Author(s):  
Wei Li ◽  
Zhengzhao Xu ◽  
Cuiping Zhang ◽  
Xinqiang Jiang ◽  
Kuiling Wang
Keyword(s):  
Gene Expression ◽  
Protein Kinase ◽  
Flower Development ◽  
Floral Development ◽  
Differentially Expressed ◽  
Cdna Libraries ◽  
Expression Data ◽  
Kegg Database ◽  
Pathway Enrichment ◽  
Gene Expression Dynamics

Styrax japonicus (S. japonicus) is an important flowering tree species in temperate regions, and it is regarded as a nectariferous plant. However, there have been few studies to date analyzing floral development in this species. In order to understand gene expression dynamics during S. japonicus flower development, we; therefore, prepared cDNA libraries from three distinct stages of S. japonicus. Illumina sequencing generated 31,471 differentially expressed unigenes during flower development. We additionally conducted pathway enrichment analyses using the GO and KEGG database in order to assess the functions of genes differentially expressed during different stages of the floral development process, revealing these genes to be associated with pathways including phytohormone signaling, Transcription factor, protein kinase, and circadian rhythms. In total, 4828 TF genes, 8402 protein kinase genes, and 78 DEGs related to hormone pathways were identified in flower development stages. Six genes were selected for confirmation of expression levels using quantitative real-time PCR. The gene expression data presented herein represent the most comprehensive dataset available regarding the flowering of S. japonicus, thus offering a reference for future studies of the flowering of this and other Styracaceae species.

Floral development in three species of Acacia (Leguminosae, Mimosoideae)

2007 ◽  
Vol 55 (1) ◽  
pp. 30 ◽  
Author(s):  
Sandra Luz Gómez-Acevedo ◽  
Susana Magallón ◽  
Lourdes Rico-Arce
Keyword(s):  
Floral Development ◽  
Complete Sequence ◽  
Developmental Pathways ◽  
Flower Formation ◽  
Acacia Berlandieri ◽  
Postgenital Fusion

The complete sequence of floral development in three species of Acacia was analysed. These species were sampled from each of the three Acacia subgenera. The species were Acacia berlandieri Benth. (subg. Aculeiferum), A. pennatula (Schltdl. & Cham.) Benth. (subg. Acacia) and A. saligna (Labill.) H.L.Wendl. (subg. Phyllodineae). The aim of the study was to determine whether the different subgenera share developmental pathways during flower formation. This study showed that development in the genus Acacia is heterogeneous. Each species studied showed different inception patterns of the calyx and androecium, whereas the inception patterns of the corolla and gynoecium were similar. These differences of inception in the calyx are not necessarily constant within each subgenus. Nevertheless, each subgenus was differentiated on the basis of inception patterns of the androecium, and other features such as the presence or absence of congenital or postgenital fusion in the calyx and corolla, and the time of differentiation of calyx and corolla tubes and the style.

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.

scholarly journals Structural Analysis of Reproductive Development in Staminate Flowers of Laurus nobilis L.

2012 ◽  
Vol 4 (1) ◽  
pp. 31-43 ◽  
Author(s):  
Özlem AYTÜRK ◽  
Meral ÜNAL
Keyword(s):  
Flower Development ◽  
Pollen Grains ◽  
Female Flower ◽  
Sem Analysis ◽  
Floral Meristem ◽  
Anther Wall ◽  
Laurus Nobilis ◽  
Initial Development ◽  
Mother Cells ◽  
Pollen Sacs

Male (staminat) flower development, being separated in 8 phases, was investigated in Laurus nobilis (Lauraceae) through the usage of histological sections and scanning electron microscopy (SEM) analysis. Flower development starts when apical meristem differentiates, followed by the conversion of this structure to floral meristem. Initial development phases comprise incidents similar to the ones of the female flower. 4 tepals and 8-10 stamens primordia develop through floral meristem in turn. In early stages of the development, sexual dimorphism occurs when the carpel primordium arrests. Filaments carry 2 nectaries in stamens which arise in 3 whorls. Anther wall consists of epidermis, endothecium, 2 or 3 middle layers and a single-layered glandular tapetum. Anthers are bisporangiate. Meiotic division is regular in pollen mother cells, and pollen grains do not contain aperture. Beside the pollen scattered individually within the pollen sacs, groups which contain some pollen tied to each other are rarely observed, as well. Pollen grains seldom germinate within microsporangium. Anthers are opened with 2 valves which widen from the base through the top. Accumulation of polysaccharides, lipids and proteins were identified by histochemical methods in stamens. These organic substances are greater within and around the vascular bundle compared to other tissues.

scholarly journals SlGT11 controls floral organ patterning and floral determinacy in tomato

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Liling Yang ◽  
Shilian Qi ◽  
Arfa Touqeer ◽  
Haiyang Li ◽  
Xiaolan Zhang ◽  
...  
Keyword(s):  
Floral Development ◽  
Bulked Segregant Analysis ◽  
Floral Organ ◽  
Fruit Production ◽  
Floral Meristem ◽  
Rnai Silencing ◽  
The Third ◽  
Spatiotemporal Expression ◽  
Higher Temperature ◽  
Floral Determinacy

Abstract Background Flower development directly affects fruit production in tomato. Despite the framework mediated by ABC genes have been established in Arabidopsis, the spatiotemporal precision of floral development in tomato has not been well examined. Results Here, we analyzed a novel tomato stamenless like flower (slf) mutant in which the development of stamens and carpels is disturbed, with carpelloid structure formed in the third whorl and ectopic formation of floral and shoot apical meristem in the fourth whorl. Using bulked segregant analysis (BSA), we assigned the causal mutation to the gene Solanum lycopersicum GT11 (SlGT11) that encodes a transcription factor belonging to Trihelix gene family. SlGT11 is expressed in the early stages of the flower and the expression becomes more specific to the primordium position corresponding to stamens and carpels in later stages of the floral development. Further RNAi silencing of SlGT11 verifies the defective phenotypes of the slf mutant. The carpelloid stamen in slf mutant indicates that SlGT11 is required for B-function activity in the third whorl. The failed termination of floral meristem and the occurrence of floral reversion in slf indicate that part of the C-function requires SlGT11 activity in the fourth whorl. Furthermore, we find that at higher temperature, the defects of slf mutant are substantially enhanced, with petals transformed into sepals, all stamens disappeared, and the frequency of ectopic shoot/floral meristem in fourth whorl increased, indicating that SlGT11 functions in the development of the three inner floral whorls. Consistent with the observed phenotypes, it was found that B, C and an E-type MADS-box genes were in part down regulated in slf mutants. Conclusions Together with the spatiotemporal expression pattern, we suggest that SlGT11 functions in floral organ patterning and maintenance of floral determinacy in tomato.

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