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.

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.

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.

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).

Flowering and fruit set in lychee (Litchi chinensis Sonn.) in subtropical Queensland

1992 ◽  
Vol 32 (1) ◽  
pp. 105 ◽  
Author(s):  
CM Menzel ◽  
DR Simpson
Keyword(s):  
Flower Development ◽  
Fruit Set ◽  
The Other ◽  
Litchi Chinensis ◽  
Panicle Development ◽  
Maximum Temperatures ◽  
The Times ◽  
Female Flowers

The pattern of panicle and flower development of lychee (Litchi chinensis Sonn.) trees was studied in subtropical Queensland (lat. 27�S.). The cultivars studied were Tai So at 3 sites, Bengal at 4 sites, Kwai May Pink at 2 sites, Salathiel at 3 sites, and Wai Chee at 2 sites. Tai So was the earliest cultivar, with panicle emergence in late May and flower anthesis in mid September. The other cultivars were 5-7 weeks later. Tai So had a longer period of flower anthesis than the other cultivars (4 weeks v. 1-3 weeks). Cultivars Tai So and Bengal generally had longer panicles than cvv. Kwai May Pink, Salathiel and Wai Chee (17-32 v. 10-14 cm), and more flowers per panicle (1800-3400 v. 400-900). Similarly, the number of fruit per panicle ranged from 7-33/panicle 2-3 weeks after the end of flowering, to 4-22/panicle at harvest. The proportion of female flowers setting fruit ranged from 2.1 to 19.5%. Similar estimates for fruit carried to harvest ranged from 0.8 to 6.8%. Variations in the times of panicle emergence, panicle development, and anthesis among the cultivars in relation to seasonal progressions in temperature affected the number of fruit set. The number of fruit set per panicle increased as the number of female flowers per panicle increased. Higher numbers of female flowers were associated with maximum temperatures during flower development of 18�C, with lower numbers at 23�C. Higher maximum temperatures during anthesis (30�C v. 24�C) increased the proportion of female flowers setting fruit.

Comparative morphology and ontogenetic patterns of Bdallophytum species (Cytinaceae, Malvales): insight into the biology of an endoparasitic genus

Botany ◽  
2020 ◽  
Author(s):  
Sandra Rios-Carrasco ◽  
SONIA VÁZQUEZ-SANTANA
Keyword(s):  
New World ◽  
Floral Development ◽  
Developmental Stages ◽  
Comparative Morphology ◽  
The Family ◽  
Unisexual Flowers ◽  
Male Flowers ◽  
And Bisexual ◽  
Early Developmental ◽  
Insight Into

Cytinaceae are root endoparasitic plants with only three genera. Their biology is largely unknown, and most knowledge of the family is based on the Old World genus, Cytinus. Here, we studied all three species of the New World Bdallophytum from Mexico. We describe their morphoanatomy, floral development, and embryology, highlighting the unique traits of Bdallophytum compared with two other genera of the family and members of Malvales. Both B. americanum and B. andrieuxii are dioecious, while B. oxylepis is gynomonoecious. The floral size and the number of floral organs vary within and among species, which appears common in Cytinaceae. The flowers of Bdallophytum exhibit synorganization in sexual organs, a synandrium in male flowers, and a gynostemium in bisexual flowers of B. oxylepis. Unisexual and bisexual flowers are zygomorphic at the early developmental stages. The unisexual flowers become actinomorphic in later development, while the bisexual flowers of B. oxylepis remain zygomorphic. The androecium of Bdallophytum has key traits shared with some Malvales, such as the fused filaments in Malvaceae and Sarcolaenaceae and the connective appendage shared with Dipterocarpaceae. Our results suggest that a unitegmic ovule is a unique trait for Bdallophytum. This is proposed here as a putative synapomorphy for Bdallophytum.

Pengaruh Beberapa Konsentrasi Hyrasil Terhadap Pembungaan Tanaman Melon (Cucumis melo L.)

Agrotek ◽  
2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Liz Yanti Andriyani
Keyword(s):  
Experimental Design ◽  
Sea Level ◽  
Cucumis Melo ◽  
Block Design ◽  
The Other ◽  
Experimental Station ◽  
Randomized Complete Block Design ◽  
Male Flowers ◽  
Cucumis Melo L ◽  
Female Flowers

<em>The objective of the experiment was to observe the best Hydrasil� concentration to the flowering of �melon� to increase the yield of melon </em>(<em>Cucumis melo</em> L.)<em> . The experiment was conducted at Jambi University experimental station, which is located in an altitude of ��35 m above the sea level.� The experimental� design was randomized complete block design with 4 replications and 6 treatment levels of Hydrasil concentration, ie. : H<sub>0 =� </sub>none� Hydrasil treatment, H<sub>1 =� </sub>100 ppm� Hydrasil, H<sub>2 =� </sub>200 ppm�� Hydrasil, H<sub>3 =� </sub>300 ppm� Hydrasil, H<sub>4 =� </sub>400 ppm� Hydrasil, H<sub>5 =� </sub>500 ppm� Hydrasil. The results� showed that Hydrasil concentration� significantly affected number of female �flowers and number of male� flowers per plant. �Hydrasil concentration at� 200 ppm�� gave �more� number of female �flowers �per plant and� less �number of male �flowers per plant than the other treatments.</em>

Biology of Australian seagrasses: Floral development and morphology in Amphibolis (Cymodoceaceae)

1982 ◽  
Vol 30 (3) ◽  
pp. 251 ◽  
Author(s):  
CA McConchie ◽  
SC Ducker ◽  
RB Knox
Keyword(s):  
Floral Development ◽  
Female Flower ◽  
Floral Meristem ◽  
Ovary Wall ◽  
Male And Female ◽  
Mature Flower ◽  
Male Flowers ◽  
Lateral Branches ◽  
Floral Vasculature ◽  
Female Flowers

Floral development of male and female flowers in Amphibolis antarctica and A. griffithii was followed from the initiation of the floral meristem to the mature flower. In A. antarctica the flowers form on lateral branches, while in A. griffithii they may also develop terminally on an upright branch from the rhizome. A. griffithii and. to a lesser extent, A. antarctica, show sympodial branching from the floral axis. The female flower develops from a pair of primordia; in A. griffithii these primordia each develop three stigmas, which in A. antarctica subsequently may form secondary branches. The. ovary wall bears the initials of the future grappling apparatus, comprising four comb initials in A. grijjjthii and a further inner set of horns in A. antarctica. The female flowers of Amphibolis are unique amongst the members of the Cymodoceaceae in being subtended by a bract or perianth, similar to the male flowers. Differences between the floral vasculature and intravaginal squamulae are presented for both species.

scholarly journals Flower Development in Cassava Is Feminized by Cytokinin, While Proliferation Is Stimulated by Anti-Ethylene and Pruning: Transcriptome Responses

2021 ◽  
Vol 12 ◽  
Author(s):  
Deborah Oluwasanya ◽  
Olayemisi Esan ◽  
Peter T. Hyde ◽  
Peter Kulakow ◽  
Tim L. Setter
Keyword(s):  
Flower Development ◽  
Fruit Set ◽  
Floral Development ◽  
Apical Region ◽  
Hormone Signaling ◽  
Treatment Combination ◽  
Flower Production ◽  
Additive Increase ◽  
Male Flowers ◽  
The Tropics

Cassava, a tropical storage-root crop, is a major source of food security for millions in the tropics. Cassava breeding, however, is hindered by the poor development of flowers and a low ratio of female flowers to male flowers. To advance the understanding of the mechanistic factors regulating cassava flowering, combinations of plant growth regulators (PGRs) and pruning treatments were examined for their effectiveness in improving flower production and fruit set in field conditions. Pruning the fork-type branches, which arise at the shoot apex immediately below newly formed inflorescences, stimulated inflorescence and floral development. The anti-ethylene PGR silver thiosulfate (STS) also increased flower abundance. Both pruning and STS increased flower numbers while having minimal influence on sex ratios. In contrast, the cytokinin benzyladenine (BA) feminized flowers without increasing flower abundance. Combining pruning and STS treatments led to an additive increase in flower abundance; with the addition of BA, over 80% of flowers were females. This three-way treatment combination of pruning+STS+BA also led to an increase in fruit number. Transcriptomic analysis of gene expression in tissues of the apical region and developing inflorescence revealed that the enhancement of flower development by STS+BA was accompanied by downregulation of several genes associated with repression of flowering, including homologs of TEMPRANILLO1 (TEM1), GA receptor GID1b, and ABA signaling genes ABI1 and PP2CA. We conclude that flower-enhancing treatments with pruning, STS, and BA create widespread changes in the network of hormone signaling and regulatory factors beyond ethylene and cytokinin.

Pollination of northeastern North American Spiranthes (Orchidaceae)

1983 ◽  
Vol 61 (4) ◽  
pp. 1080-1093 ◽  
Author(s):  
Paul M. Catling
Keyword(s):  
North American ◽  
Cell Elongation ◽  
The Other ◽  
Lower Side ◽  
Terminal Portion ◽  
Stigmatic Surface ◽  
Male Flowers ◽  
Halictine Bees ◽  
Cross Fertilization ◽  
Female Flowers

Most northeastern North American Spiranthes are adapted to pollination by long-tongued bees (e.g., Bombus spp. and Megachilidae). The salient features of this adaptation are (i) a long, flat viscidium which attaches the pollinia readily to the flat rigid galea of the insect's proboscis, (ii) the nectar secreted into the base of the floral tube, (iii) the flowers are protandrous and sequential beginning at the base. In contrast, Spiranthes lucida apparently is pollinated largely by halictine bees. It differs from other northeastern taxa of Spiranthes in (i) having an oval viscidium which attaches the pollinia to the clypeus below the antennae, (ii) having the nectar available on the under side of the column behind the stigmatic surface, and (iii) in lacking protandry. In the characteristically Bombus-pollinated taxa, protandry is accomplished by a change in the position of the terminal portion of the column with respect to the lip, apparently due to cell elongation in both the column and the lip. The present investigation documents protandry in S. cernua var. cernua, S. lacera var. lacera, S. lacera var. gracilis, S. laciniata, S. magnicamporum, S. ochroleuca, S. romanzoffiana, S. tuberosa, and S. vernalis. Bees moving up the spike from the older female flowers to the younger male flowers act initially as pollen donors and later as pollen receivers; thus cross-fertilization is enhanced. Halictines occasionally act as pollinators of characteristically Bombus-pollinated taxa by visiting the flowers upside down so that the pollinia are inconspicuously attached to the lower side of the prementum. Data presently available for northeastern North American Spiranthes fail to establish pollinator specificity as significant in speciation except perhaps with respect to the separation of S. lucida from the other 14 northeastern taxa.

Sign in / Sign up

Export Citation Format

Share Document