Floral structure and development in the dioecious Australian endemic Lomandra longifolia (Lomandraceae)

2008 ◽  
Vol 56 (8) ◽  
pp. 666 ◽  
Author(s):  
Nabil M. Ahmad ◽  
Peter M. Martin ◽  
John M. Vella
Keyword(s):  
Floral Development ◽  
Cytological Analysis ◽  
Floral Structure ◽  
Male And Female ◽  
Pistil Abortion ◽  
Stamen Arrest ◽  
Male Flowers ◽  
Mother Cells ◽  
Female Flowers ◽  
Scanning Electron

The micromorphology and histology of the development of male and female flowers of the dioecious Australian endemic species Lomandra longifolia Labill. was studied by means of scanning electron microscopy and light microscopy of entire and sectioned material. Although mature flowers are functionally unisexual, in the early stages of development pistillate and staminate flowers are identical and apparently bisexual. In a sequential fashion, six perianth parts are initiated within two alternating whorls, the sepals first and the petals second; six stamens are initiated in two alternating whorls of three stamens each, the first opposite the sepals and the second opposite the petals; and last, a central gynoecium is initiated. Following initiation, the two flower types diverge developmentally when the stamens become bilobed. In male flowers, cytological analysis of the slowly growing abortive pistil shows that megasporogenesis does not occur. Pistil abortion happens before meiosis whereas the stamens continue to develop until maturity and dehiscence. In female flowers, stamen arrest occurs before the onset of meiosis in microspore mother cells, after which the pistil continues its development through megasporogenesis and megagametogenesis. In all, 14 stages of floral development of both male and female flowers have been designated. Stages 1–6 of the two flower types were common to both sexes.

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.

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.

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 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>

Cucumis anguria (West Indian gherkin).

2021 ◽  
Author(s):  
Julissa Rojas-Sandoval
Keyword(s):  
Pollen Grains ◽  
Growing Season ◽  
Low Fertility ◽  
Annual Rainfall ◽  
Editorial Committee ◽  
Male And Female ◽  
Tropical Plants ◽  
Wide Range ◽  
Male Flowers ◽  
Female Flowers

Abstract Genetics: The chromosome number reported for Cucumis anguria is 2n=24 (Ramachandran and Narayan, 1990; Flora of North America Editorial Committee, 2020). Reproductive Biology: Cucumis anguria is a monoecious species, with individual male and female flowers appearing on both plants, that depends of pollinators to transfer pollen grains in order to produce fruits. Although self-fertile, a degree of outcrossing results from insect pollination. Zagorcheva (1988) has suggested that C. anguria may also be a facultative apomict. The flowering season is of about 55-58 days. Male flowers appear before female flowers and both male and female flowers remain open for one day (from 7:30 am to 4:00 pm). The relationship between male and female flowers is on average 5.5 male flowers for each female flower. The greater number of male flowers compared to female flowers produces a greater flow of pollen in the crop and ensures pollination. Flowers are visited and pollinated by insects. In a study in Brazil, the most important visitor was Apis mellifera (72% of all visits) followed by native bees from the genera Plebeia sp. (16.7%), Exomalopsis sp. (8.3%) and Melissodes sp. (2.8%). Flowers are also visited by butterflies (Malerbo-Souza et al., 2020). Physiology and Phenology: Cucumis anguria is an annual species. Early growth is upright, followed by branching at the base to produce several trailing stems. Within its native distribution range, this species germinates in a few days during the summer rains when night temperatures are above 12°C and the soil is sufficiently wet. When plants are about 2-3 m length, they start to develop flowers. Fruits are often produced within 60 days after germination. Plants may produce up to 50 fruits per stem. Fruits remain attached to the withered annual stems long after these have died back at the end of the growing season (Wilkins-Ellert, 2004). Photoperiod is important and longer days coupled with higher temperatures confines plants to the production of male flowers. Shorter days and a drop in temperature stimulate the production of female flowers. Fruiting occurs within 60 days of planting and fruit are produced continuously, with as many as 50 fruits per plant produced during the growing season (Wilkins-Ellert, 2004). Environmental Requirements: Cucumis anguria prefers to grow in tropical and subtropical climates. It grows best in areas with mean annual temperatures ranging from 15°C to 28°C (tolerates 8°C-35°C) and mean annual rainfall between 800 mm-1000 mm (tolerates 300 mm-1700 mm). It is well adapted to soils with low fertility and is adapted to grow in a wide range of soil types, including Kalahari sands (regosols), red clays and black cotton soils (vertisols) with pH in the range 6-7.5 (tolerates 5.5 - 8.3), but it grows best on well drained sandy soils (Fernandes, 2011). This species is sensitive to cold and does not tolerate frost (Wilkins-Ellert, 2004; Useful Tropical Plants, 2020).

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.

scholarly journals Transcriptome-based analysis of the hormone regulation mechanism of gender differentiation in Juglans mandshurica Maxim

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12328
Author(s):  
Baiting Qin ◽  
Xiujun Lu ◽  
Xiaomei Sun ◽  
Jianguo Cui ◽  
Jifeng Deng ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Female Flower ◽  
Negative Regulator ◽  
Regulation Mechanism ◽  
Juglans Mandshurica ◽  
Flower Buds ◽  
Male And Female ◽  
Gender Differentiation ◽  
Male Flowers ◽  
Female Flowers

Juglans mandshurica Maxim is a hermaphroditic plant belonging to the genus Juglans in the family Juglandaceae. The pollination period of female flowers is different from the loose powder period of male flowers on the same tree. In several trees, female flowers bloom first, whereas in others, male flowers bloom first. In this study, male and female flower buds of J. mandshurica at the physiological differentiation stage were used. Illumina-based transcriptome sequencing was performed, and the quality of the sequencing results was evaluated and analyzed. A total of 138,138 unigenes with an average length of 788 bp were obtained. There were 8,116 differentially expressed genes (DEGs); 2,840 genes were upregulated, and 5,276 genes were downregulated. The DEGs were classified by Gene Ontology and analyzed by Kyoto Encyclopedia of Genes and Genomes. The signal transduction factors involved in phytohormone synthesis were selected. The results displayed that ARF and SAUR were expressed differently in the auxin signaling pathway. Additionally, DELLA protein (a negative regulator of gibberellin), the cytokinin synthesis pathway, and A-ARR were downregulated. On April 2nd, the contents of IAA, GA, CTK, ETH and SA in male and female flower buds of two types of J. mandshurica were opposite, and there were obvious genes regulating gender differentiation. Overall, we found that the sex differentiation of J. mandshurica was related to various hormone signal transduction pathways, and hormone signal transduction plays a leading role in regulation.

Morphological and anatomical development in the Vitaceae. II. Floral development in Vitis riparia

1988 ◽  
Vol 66 (7) ◽  
pp. 1334-1351 ◽  
Author(s):  
Jean M. Gerrath ◽  
Usher Posluszny
Keyword(s):  
Fourth Order ◽  
Floral Development ◽  
Vitis Riparia ◽  
Stamen Primordia ◽  
Male Flowers ◽  
Female Flowers

The anatomy, morphology, and ontogeny of the flowers of Vitis riparia are presented in this paper. The inflorescence is initiated as an uncommitted primordium, which in turn initiates a bract and then bifurcates to form inner and outer "arms." Both of the arms initiate inflorescence branches, first in a decussate pattern, then in a 2/5 phyllotactic spiral. These branches may initiate pairs of lateral primordia until a series of third- or fourth-order cymose inflorescence branches is initiated. Floral development begins when the calyx is initiated as three primordia, which first merge by meristem extension and then grow out to form an indistinctly five-toothed ring. The petals and stamens arise as five common primordia, alternating with the sepals. They divide into separate petal and stamen primordia. The gynoecium arises as a ring primordium. Two septae are initiated on the inner walls of the ring and grow together to form a two-loculed ovary. Two ovules arise from each septum. In male flowers the ovules form but do not mature, and the stigma and style fail to develop. The pollen is tricolporate. In female flowers the ovules are bitegmic and anatropous, the style is short, and the stigma is discoid or two parted. The pollen lacks furrows and pores. The yellowish disc arises from the base of the gynoecium and is more prominent in male flowers. The fruit is a one- to four-seeded bluish purple berry.

scholarly journals Sexual dimorphism in floral scents of the neotropical orchid Catasetum arietinum and its possible ecological and evolutionary significance

AoB Plants ◽  
2020 ◽  
Vol 12 (4) ◽  
Author(s):  
Katharina Brandt ◽  
Isabel Cristina Machado ◽  
Daniela Maria do Amaral Ferraz Navarro ◽  
Stefan Dötterl ◽  
Manfred Ayasse ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Chemical Composition ◽  
Floral Scent ◽  
Evolutionary Significance ◽  
Male And Female ◽  
Floral Scents ◽  
First Case ◽  
Male Flowers ◽  
Euglossine Bee ◽  
Female Flowers

Abstract Dioecy in angiosperms is often associated with sexual dimorphism in floral traits other than the sexual organs. Species of the neotropical orchid genus Catasetum produce unisexual flowers characterized by a remarkable morphological sexual dimorphism. Catasetum species emit strong floral perfumes that act as both signal and reward for male euglossine bee pollinators. Although the role of floral perfumes of Catasetum in attracting euglossine pollinators is well investigated, little is known about whether perfumes differ between floral sexes and, if they do, whether this chemical dimorphism influences the pollination ecology of the plants. Taking Catasetum arietinum as a model species, our aim was to observe the behaviour of pollinators on male and female flowers and to compare scent properties (i.e. chemical composition, total amount and temporal fluctuation) of male and female flowers. Floral scent samples were collected by using dynamic headspace methods and were analysed via gas chromatography coupled with mass spectroscopy (GC-MS). Catasetum arietinum is pollinated by males of two Euglossa species (i.e. E. nanomelanotricha and E. securigera). Bees approached male and female inflorescences of C. arietinum in similar proportions but landed significantly more often and spent more time on female flowers, which emitted more scent than male flowers. Furthermore, the amount of scent emitted varied across the different times of sampling, corresponding to the pattern of the diel foraging activity of pollinating bees on male and female flowers. The chemical composition of scents differed significantly between sexes. The two major compounds (Z)-methyl-p-methoxycinnamate and (E)-geranyl geraniol contributed most to this difference. This is the first case of sexual dimorphism reported in orchid floral perfumes. We discuss the influence of sex-specific floral scents on the behaviour of euglossine pollinators and offer new insights into the ecological and evolutionary significance of divergence in floral scents among dioecious plants.

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