Développement de l'inflorescence et des fleurs du Philodendron acutatum Schott (Araceae)

1996 ◽  
Vol 74 (6) ◽  
pp. 909-918 ◽  
Author(s):  
Chafika Boubes ◽  
Denis Barabé
Keyword(s):  
Flower Development ◽  
Distal Part ◽  
Chemical Processes ◽  
Bisexual Flower ◽  
Male Flowers ◽  
Morphogenetic Gradient ◽  
Female Flowers

The inflorescence of Philodendron acutatum possesses female flowers in the inferior part and male flowers in the distal part. The male flowers possess from three to six stamens, rarely seven to nine. The female flowers possess a multilocular ovary comprising from 8 to 12 locules. Each locule corresponds to a closed carpel. The stylar canals remain separate up to the upper part of the gynoecium. In this inflorescence, one observes an intermediary zone comprising bisexual flowers with fused or free carpels and stamens, inserted in the same whorl. Generally, the portion of the bisexual flower facing the male zone is formed by stamens, and that facing the female zone is formed by an incomplete gynoecium comprising few carpels. The separation between the two parts of a bisexual flower is generally clear; however, in rare cases, a stamen appears between two carpels, or a carpel between two stamens. Nevertheless, in all cases, the different flower parts are inserted on the same whorl. The presence of bisexual flowers corresponds probably to a morphogenetic gradient at the level of the overall inflorescence. The genes controlling the expression of flower sex are probably governed by chemical processes that act at the level of the overall inflorescence. Keywords: morphogenesis, gradient, flower, development, inflorescence.

Developmental morphology of normal and atypical flowers of Philodendron insigne (Araceae): a new case of homeosis

2002 ◽  
Vol 80 (11) ◽  
pp. 1160-1172 ◽  
Author(s):  
Denis Barabé ◽  
Christian Lacroix ◽  
Bernard Jeune
Keyword(s):  
Flower Development ◽  
Distal Portion ◽  
Sterile Male ◽  
Developmental Morphology ◽  
Bisexual Flower ◽  
Male And Female ◽  
Male Flowers ◽  
Morphogenetic Gradient ◽  
Female Flowers ◽  
Scanning Electron

The early stages of development of the inflorescence of Philodendron insigne were examined using scanning electron microscopy. Pistillate flowers are initiated on the lower portion of the inflorescence and staminate flowers are initiated on the distal portion. The male flowers have three to five stamens. The female flowers have a multilocular ovary consisting of three to five locules. A transition zone consisting of sterile male flowers and atypical bisexual flowers with fused or free carpels and staminodes is located between the male and female floral zones. Generally, the portion of the bisexual flower facing the male zone forms stamens, and the portion facing the female zone develops one or two carpels. In P. insigne, the incomplete separation of staminodes from the gynoecial portion of the whorl shows that the staminodes and carpels belong to the same whorl. The atypical bisexual flowers of P. insigne are believed to be a case of homeosis where carpels have been replaced by sterile stamens on the same whorl. However, there is no regularity in the number of organs involved in the homeotic transformation taking place in atypical bisexual flowers. The presence of atypical bisexual flowers may correspond to a morphogenetic gradient at the level of the inflorescence as a whole.Key words: flower, development, gradient, inflorescence.

Organogénie florale des genres Culcasia et Cercestis (Araceae)

1996 ◽  
Vol 74 (6) ◽  
pp. 898-908 ◽  
Author(s):  
Denis Barabé ◽  
Charles Bertrand
Keyword(s):  
Flower Development ◽  
Floral Development ◽  
Intermediate Zone ◽  
The Other ◽  
Other Hand ◽  
Unisexual Flowers ◽  
Male Flowers ◽  
Morphogenetic Gradient ◽  
Female Flowers

The floral development of Culcasia saxatilis, Culcasia tenuifolia, and Cercestis stigmaticus has been analyzed. These two genera possess unisexual flowers without perianth. In these species, the cylindrical inflorescence carry male flowers in the upper part and female flowers in the lower part. In C. tenuifolia, the separation between the female zone and the male zone is very sharp. There is no intermediate zone. In C. saxatilis and C. stigmaticus, we may observe rudimentary bisexual flowers between the two zones. In this intermediate zone, flowers located near the male zone possess male appendages more developped than those located near the female zone. On the other hand, the flowers located near the female zone possess female appendages more developped than those located near the male zone. The results suggest the existence of a morphogenetic gradient in the inflorescence of some species of Araceae. Keywords: morphogenesis, gradient, flower, development, inflorescence.

The game of numbers in homeotic flowers of Philodendron (Araceae)

2004 ◽  
Vol 82 (10) ◽  
pp. 1459-1467 ◽  
Author(s):  
Denis Barabé ◽  
Christian Lacroix ◽  
Bernard Jeune
Keyword(s):  
Quantitative Relationship ◽  
Distal Portion ◽  
The Other ◽  
Sterile Male ◽  
Homeotic Transformation ◽  
Bisexual Flower ◽  
Position Information ◽  
Male Flowers ◽  
Female Flowers ◽  
Organ Replacement

In Philodendron, pistillate flowers are initiated on the proximal portion of the inflorescence and staminate flowers are initiated on the distal portion. Between the staminate and pistillate flowers, there is a transition zone consisting of sterile male flowers adjacent to the male zone and a row of atypical bisexual flowers between the sterile male zone and the female zone. The portion of the atypical bisexual flower facing the male zone forms stamens, and the portion facing the female zone develops into an incomplete gynoecium with few carpels. The atypical bisexual flowers of Philodendron are believed to be a case of homeosis where carpels are replaced by sterile stamens on the same whorl. In Philodendron melinonii Brongniart ex Regel, Philodendron pedatum (Hooker) Kunth, Philodendron squamiferum Poeppig., and Philodendron solimoesense A.C. Smith, there is a significant quantitative relationship between the number of carpels and the number of staminodes involved in the homeotic transformation in atypical bisexual flowers. On the other hand, such a significant correlation does not exist in Philodendron fragrantissimum (Hooker) Kunth and Philodendron insigne Schott, and Philodendron callosum K. Krause. There is a one to one organ replacement in homeotic flowers in both P. pedatum and P. squamiferum whereas, in P. solimoesense, an average of 2.56 staminodes replace one carpel. The average number of organs developing on an atypical bisexual flower and the number of organs involved in a homeotic transformation appear to be two independent phenomena. The number of carpels in female flowers is correlated with the maximum total number of appendages (carpels and staminodes) that can develop in atypical bisexual flowers.Key words: development, inflorescence, gradient, position, information.

scholarly journals Developmental basis for flower sex determination and effects of cytokinin on sex determination in Plukenetia volubilis (Euphorbiaceae)

2020 ◽  
Vol 33 (1) ◽  
pp. 21-34 ◽  
Author(s):  
Yan Luo ◽  
Bang-Zhen Pan ◽  
Lu Li ◽  
Chen-Xuan Yang ◽  
Zeng-Fu Xu
Keyword(s):  
Sex Determination ◽  
Flower Development ◽  
Early Stage ◽  
Male Flower ◽  
Flower Initiation ◽  
Exogenous Application ◽  
Plukenetia Volubilis ◽  
Sacha Inchi ◽  
Male Flowers ◽  
Female Flowers

Key message Cytokinin might be an important factor to regulate floral sex at the very early stage of flower development in sacha inchi. Abstract Sacha inchi (Plukenetia volubilis, Euphorbiaceae) is characterized by having female and male flowers in a thyrse with particular differences. The mechanisms involved in the development of unisexual flowers are very poorly understood. In this study, the inflorescence and flower development of P. volubilis were investigated using light microscopy and scanning electron microscopy. We also investigated the effects of cytokinin on flower sex determination by exogenous application of 6-benzyladenine (BA) in P. volubilis. The floral development of P. volubilis was divided into eight stages, and the first morphological divergence between the male and female flowers was found to occur at stage 3. Both female and male flowers can be structurally distinguished by differences in the shape and size of the flower apex after sepal primordia initiation. There are no traces of gynoecia in male flowers or of androecia in female flowers. Exogenous application of BA effectively induced gynoecium primordia initiation and female flower development, especially at the early flower developmental stages. We propose that flower sex is determined earlier and probably occurs before flower initiation, either prior to or at inflorescence development due to the difference in the position of the female and male primordia in the inflorescence and in the time of the female and male primordia being initiated. The influence of cytokinin on female primordia during flower development in P. volubilis strongly suggests a feminization role for cytokinin in sex determination. These results indicate that cytokinin could modify the fate of the apical meristem of male flower and promote the formation of carpel primordia in P. volubilis.

scholarly journals The Dynamics of Flower Development in Castanea Sativa Mill.

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1538
Author(s):  
Ana Teresa Alhinho ◽  
Miguel Jesus Nunes Ramos ◽  
Sofia Alves ◽  
Margarida Rocheta ◽  
Leonor Morais-Cecílio ◽  
...  
Keyword(s):  
Flower Development ◽  
Molecular Mechanisms ◽  
Castanea Sativa ◽  
Male And Female ◽  
Sweet Chestnut ◽  
Chestnut Tree ◽  
Abcde Model ◽  
Organ Identity ◽  
Castanea Sativa Mill ◽  
Female Flowers

The sweet chestnut tree (Castanea sativa Mill.) is one of the most significant Mediterranean tree species, being an important natural resource for the wood and fruit industries. It is a monoecious species, presenting unisexual male catkins and bisexual catkins, with the latter having distinct male and female flowers. Despite the importance of the sweet chestnut tree, little is known regarding the molecular mechanisms involved in the determination of sexual organ identity. Thus, the study of how the different flowers of C. sativa develop is fundamental to understand the reproductive success of this species and the impact of flower phenology on its productivity. In this study, a C. sativa de novo transcriptome was assembled and the homologous genes to those of the ABCDE model for floral organ identity were identified. Expression analysis showed that the C. sativa B- and C-class genes are differentially expressed in the male flowers and female flowers. Yeast two-hybrid analysis also suggested that changes in the canonical ABCDE protein–protein interactions may underlie the mechanisms necessary to the development of separate male and female flowers, as reported for the monoecious Fagaceae Quercus suber. The results here depicted constitute a step towards the understanding of the molecular mechanisms involved in unisexual flower development in C. sativa, also suggesting that the ABCDE model for flower organ identity may be molecularly conserved in the predominantly monoecious Fagaceae family.

Studies in the Alismataceae. XI. Development of the inflorescence and flowers of Wiesneria triandra (Dalzell) Micheli

2000 ◽  
Vol 77 (11) ◽  
pp. 1569-1579
Author(s):  
W A Charlton
Keyword(s):  
Shoot Development ◽  
Annual Plant ◽  
Foliage Leaf ◽  
The Family ◽  
Unisexual Flowers ◽  
Male Flowers ◽  
Female Flowers

Wiesneria triandra (Dalzell) Micheli is an unusual annual plant of the Alismataceae with spike-like inflorescences bearing unisexual flowers. Shoot development follows the sympodial pattern of other Alismataceae, but the cycle is so condensed that initiation of each foliage leaf is followed by inflorescence formation. The plant develops a tufted habit by the formation of an unusual accesory bud adjacent to each inflorescence. Male flowers have three sepals, three petals, three stamens, and usually three carpellodes; female flowers have a similar perianth, three staminodes, and three or more carpels. Up to the first three carpels, floral parts are arranged in alternating trimerous whorls. Additional carpels may occur above and between those of the first whorl. The androecium is particularly unusual for the Alismataceae since it has conventional alternation of stamens with petals rather than the antipetalous pairs of stamens commonly perceived in the family, but the phylogenetic postion of Wiesneria within the family (as revealed by other studies) indicates that the apparently conventional androecium of Wiesneria represents a derived state rather than a primitive one. The unisexual flowers also represent a derived state.

Pollination ecology of Monstera obliqua (Araceae) in French Guiana

2007 ◽  
Vol 23 (5) ◽  
pp. 607-610 ◽  
Author(s):  
Mathieu Chouteau ◽  
Melanie McClure ◽  
Marc Gibernau
Keyword(s):  
French Guiana ◽  
Pollination Ecology ◽  
Lower Portion ◽  
Floral Rewards ◽  
Pollination Mechanisms ◽  
Unisexual Flowers ◽  
Male Flowers ◽  
Female Flowers

Data on pollination ecology of Araceae are still scarce and most concern species belonging to the subfamily Aroideae (García-Robledo et al. 2004, Gibernau 2003, Ivancic et al. 2004, 2005; Maia & Schlindwein 2006). In this subfamily, inflorescences consist of unisexual flowers: female flowers are located in the lower portion and the male flowers are in the upper portion of the inflorescence (Mayo et al. 1997). In the documented neotropical Aroideae, pollinators are nocturnal beetles and pollination mechanisms take place within a floral chamber during a short flowering cycle (generally 24–48 h) with floral rewards (sterile flowers rich in proteins and/or lipids) for the beetle pollinators, the secretion of resin to secure pollen on the pollinator, and the production of heat and odours (Chouteau et al. 2007, García-Robledo et al. 2004, Gibernau & Barabé 2002, Gibernau et al. 1999, 2000, 2003; Maia & Schlindwein 2006, Young 1986).

Differential nectar production between male and female flowers in a wild cucurbit: Cucurbita maxima ssp. andreana (Cucurbitaceae)

2002 ◽  
Vol 80 (11) ◽  
pp. 1203-1208 ◽  
Author(s):  
Lorena Ashworth ◽  
Leonardo Galetto
Keyword(s):  
Reproductive Output ◽  
Male Flower ◽  
Female Flower ◽  
Cucurbita Maxima ◽  
Nectar Production ◽  
Male And Female ◽  
Nectar Sugar Composition ◽  
Nectar Sugar ◽  
Male Flowers ◽  
Female Flowers

In dioecious and monoecious plants that depend on animal vectors for reproduction, pollinators have to be attracted to male and female flowers for pollination to be effective. In the monoecious Cucurbita maxima ssp. andreana, male flowers are produced in greater quantity, are spatially more exposed to pollinators and offer pollen in addition to nectar as floral rewards. Nectar traits were compared between male and female flowers to determine any differences in the characteristics of the main reward offered to pollinators. Nectar chemical composition and sugar proportions were similar between flower types. Total nectar sugar production per female flower was threefold higher than per male flower, and nectar removal did not have any effect on total nectar production in both flower morphs. Pollinators reduced nectar standing crops to similar and very scarce amounts in both flower types. Results indicate indirectly that pollinators are consuming more nectar from female flowers, suggesting that the higher nectar production in female flowers may be a reward-based strategy to achieve the high female reproductive output observed in this species.Key words: Cucurbitaceae, Cucurbita maxima ssp. andreana, nectar production, nectar sugar composition, removal effects, standing crop.

scholarly journals The Effects of Silver Nitrate Applications on the Flower Quantity of Cucumbers (Cucumis sativus L.)

2011 ◽  
Vol 39 (1) ◽  
pp. 139 ◽  
Author(s):  
Deniz KARAKAYA ◽  
Hüseyin PADEM
Keyword(s):  
Silver Nitrate ◽  
Cucumis Sativus ◽  
Male Flower ◽  
Flower Formation ◽  
Cucumis Sativus L ◽  
Male Flowers ◽  
Female Flowers

This study was conducted to investigate the effects of silver nitrate (AgNO3) on the flower quantity of cucumbers. The seeds used in this study, which was carried out in a plastic greenhouse, in the Gazi village of Antalya Province (Turkey) the during spring and autumn 2005 breeding periods, were ‘Mostar F1’ (designated as ‘GND1’) and ‘Vesco Seeds Beith Alpha F1 (26.50 F1)’, designated as ‘GND2’ and those are the types having common production. The silver nitrate application was performed by the method of spraying on the growth tips of plants and 0, 250, 500, 750, and 1000 ppm silver nitrate doses were administered. The research was conducted with 4 repetitions having 5 plants in each repetition according to the Random Parcel Trial Pattern. In order to determine the effects of the applications, the effects of a number of female flowers and male flowers on generative characteristics of planting periods (spring and fall) were identified and the results were statistically evaluated. According to the results obtained in this research, AgNO3 has led to the formation of male flowers (no male flower formation in control), has increased the number of male flowers, and has led to a decrease in the number of female flowers. The increase in the number of male flowers varied according to the periods (in ‘GND2’).

scholarly journals Pollen load and distribution on the body of Elaeidobius kamerunicus Faust. (Coleoptera: Curculionidae) within oil palm plantations

2020 ◽  
Vol 17 (2) ◽  
pp. 81
Author(s):  
Van Basten Tambunan ◽  
Bandung Sahari ◽  
Damayanti Buchori ◽  
Purnama Hidayat
Keyword(s):  
Oil Palm ◽  
The Body ◽  
Body Parts ◽  
Pollen Load ◽  
Male And Female ◽  
Male Flowers ◽  
Pollen Distribution ◽  
Male To Female ◽  
Female Flowers ◽  
Elaeidobius Kamerunicus

<p>The African oil palm weevil,<strong> </strong><em>Elaeidobius kamerunicus</em> is an effective pollinator of oil palm. Each individual palm produces exclusively male or female inflorescence so that the success of pollination depends on the ability of the pollinator to transfer pollen from male to female flowers. The objective of this research was to study the amount of pollen carried by <em>E. kamerunicus</em> between male and female inflorescences (pollen load) and the amount of pollen carried on each part of the weevil’s body (pollen distribution). Fifty each of male and female  <em>E. kamerunicus</em> individuals were collected from male and female flowers on trees in 3 locations: Siantar (North Sumatra), Dramaga (West Java), and Morowali (Central Sulawesi). Data on pollen load and pollen distribution on the weevil’s body were analyzed using <em>ImageJ</em> software. Results show that <em>E. kamerunicus</em> individuals collected more pollen from male flowers than from female flowers. In addition, male insects carried more pollen on their bodies than female insects. Pollen distribution on weevil body parts was highest on the elytra, followed by the thorax, abdomen, legs, and head respectively.</p>

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