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.

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 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.

scholarly journals Comparative Analysis of Volatile Compounds in Flowers of Different Actinidia Species

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1675
Author(s):  
Agnieszka Stasiak ◽  
Piotr Latocha
Keyword(s):  
Volatile Compounds ◽  
Female Flower ◽  
Dioecious Plants ◽  
Male And Female ◽  
Flower Volatiles ◽  
Or Groups ◽  
Pollinating Insects ◽  
Male Flowers ◽  
Actinidia Spp ◽  
Female Flowers

Among the actinidia genus (Actinidia spp.) native to China, few species are grown commercially for their edible and healthy fruits. As they are dioecious plants, a lot of interest is paid to effective pollination and to insects as the most efficient pollinators. In this study we have concentrated on the composition of volatile compounds in male flowers of four different actinidia species (A. chinensis var. deliciosa, A. arguta, A. kolomikta and A. polygama) and on the diversity between male and female flower volatiles for the two most winter-hardy species (A. arguta and A. kolomikta) with growing commercial value. Analyses were provided using gas chromatography with mass spectrometry (GC-MS). In total, 120 compounds were found in 15 actinidia genotypes. However, the number of identified compounds varied between species. Different main compounds or groups of volatile compounds characterised flowers of every species. Smaller differences were observed between male and female flowers of the same species. Our results suggest that actinidia flowers could be attractive to pollinating insects.

scholarly journals Pseudanthium development in Calycopeplus paucifolius, with particular reference to the evolution of the cyathium in Euphorbieae (Euphorbiaceae - Malpighiales)

2008 ◽  
Vol 21 (3) ◽  
pp. 153 ◽  
Author(s):  
Gerhard Prenner ◽  
Stephen D. Hopper ◽  
Paula J. Rudall
Keyword(s):  
Female Flower ◽  
Male And Female ◽  
Early Formation ◽  
Key Innovation ◽  
Molecular Phylogenies ◽  
Male Flowers ◽  
Developmental Analysis ◽  
Female Flowers

The morphology and development of flowers and pseudanthia of Calycopeplus paucifolius are described in detail in the context of recent molecular phylogenies of the tribe Euphorbieae and a recent comparative developmental analysis of other taxa within this tribe. Calycopeplus resembles subtribes Neoguillauminiinae and Anthosteminae in some respects (dichasial formation of male flowers within male partial inflorescences, late formation of a constriction in male and female flowers and early formation of a female perianth), but resembles Dichostemma (subtribe Anthosteminae) in possessing only four male partial inflorescences. Calycopeplus and all other Euphorbieae possess only three carpels, except Dichostemma, which has four carpels per female flower. The studied species differs from the closely related Neoguillauminia cleopatra (subtribe Neoguillauminiinae) in that only four nectaries are formed, situated on the rim of the cuplike involucre (in Neoguillauminia 8–10 nectaries arise directly from the base of the pseudanthium). In contrast to all other studied Euphorbieae with trimerous gynoecia, the unpaired carpel of C. paucifolius is oriented in an upper/adaxial position (it lies in the lower/abaxial position in all other studied taxa). On the basis of these results we discuss possible pathways of cyathium evolution and the role of the cyathium as a possible key innovation within Euphorbieae. ‘Calycopeplus is as perfect an example of a connecting link as a morphologist may wish for.’ (Croizat 1937, p. 404)

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.

scholarly journals Unisexual flower initiation in the monoecious Quercus suber L., a molecular approach

2020 ◽  
Author(s):  
Rómulo Sobral ◽  
Helena Gomes Silva ◽  
Sara Laranjeira ◽  
Joana Magalhães ◽  
Luís Andrade ◽  
...  
Keyword(s):  
Female Flower ◽  
Quercus Suber ◽  
Early Summer ◽  
Cork Oak ◽  
Late Winter ◽  
Flower Initiation ◽  
Temporal Separation ◽  
Male And Female ◽  
Male Flowers ◽  
Female Flowers

AbstractSeveral plant species display a temporal separation of the male and female flower organ development to enhance outbreeding, however, little is known regarding the genetic mechanisms controlling this temporal separation. Quercus suber is a monoecious oak tree with accentuated protandry: in late winter, unisexual male flowers emerge adjacent to the swollen buds, whereas unisexual female flowers emerge in the axils of newly formed leaves formed during spring (4 to 8 weeks after male flowering). Here, phylogenetic profiling lead to the identification of cork oak homologs of key floral regulatory genes. The role of these cork oak homologs during flower development was identified with functional studies in Arabidopsis thaliana. The expression profile of flower regulators (inducers and repressors) throughout the year, in leaves and buds, suggests that the development of male and female flowers may be preceded by separated induction events. Female flowers are most likely induced during the vegetative flush occurring in spring, whereas male flowers may be induced in early summer, staying enclosed within the pre-dormant buds, but complete their development before the vegetative flush of the following year, displaying a long period of anthesis that spans the dormant period. Results portray a genetic mechanism that may explain similar reproductive habits in other tree species.

scholarly journals Unisexual flower initiation in the monoecious Quercus suber L.: a molecular approach

2020 ◽  
Vol 40 (9) ◽  
pp. 1260-1276
Author(s):  
Rómulo Sobral ◽  
Helena Gomes Silva ◽  
Sara Laranjeira ◽  
Joana Magalhães ◽  
Luís Andrade ◽  
...  
Keyword(s):  
Female Flower ◽  
Quercus Suber ◽  
Early Summer ◽  
Cork Oak ◽  
Late Winter ◽  
Flower Initiation ◽  
Temporal Separation ◽  
Male And Female ◽  
Male Flowers ◽  
Female Flowers

Abstract Several plant species display a temporal separation of the male and female flower organ development to enhance outbreeding; however, little is known regarding the genetic mechanisms controlling this temporal separation. Quercus suber is a monoecious oak tree with accentuated protandry: in late winter, unisexual male flowers emerge adjacent to the swollen buds, whereas unisexual female flowers emerge in the axils of newly formed leaves formed during spring (4–8 weeks after male flowering). Here, a phylogenetic profiling has led to the identification of cork oak homologs of key floral regulatory genes. The role of these cork oak homologs during flower development was identified with functional studies in Arabidopsis thaliana. The expression profile throughout the year of flower regulators (inducers and repressors), in leaves and buds, suggests that the development of male and female flowers may be preceded by separated induction events. Female flowers are most likely induced during the vegetative flush occurring in spring, whereas male flowers may be induced in early summer. Male flowers stay enclosed within the pre-dormant buds, but complete their development before the vegetative flush of the following year, displaying a long period of anthesis that spans the dormant period. Our results portray a genetic mechanism that may explain similar reproductive habits in other monoecious tree species.

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>

scholarly journals Use of timelapse photography to determine flower opening time and pattern in banana (Musa spp.) for efficient hand pollination

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Allan Waniale ◽  
Rony Swennen ◽  
Settumba B. Mukasa ◽  
Arthur K. Tugume ◽  
Jerome Kubiriba ◽  
...  
Keyword(s):  
Seed Set ◽  
Digital Camera ◽  
Female Flower ◽  
Time Lapse ◽  
Temporal Separation ◽  
Flower Opening ◽  
Main Challenge ◽  
Hand Pollination ◽  
Male Flowers ◽  
Female Flowers

AbstractSterility and low seed set in bananas is the main challenge to their conventional genetic improvement. The first step to seed set in a banana breeding program depends on pollination at the right time to ensure effective fertilization. This study aimed at determining bract opening time (BOT) to enhance efficient pollination and seed set in bananas. A Nikon D810 digital camera was set-up to take pictures of growing banana inflorescences at five-minute intervals and time-lapse movies were developed at a speed of 30 frames per second to allow real-time monitoring of BOT. Genotypes studied included wild banana (1), Mchare (2), Matooke (4), Matooke hybrid (1), and plantain (1). Events of bract opening initiated by bract lift for female flowers (P < 0.01) started at 16:32 h and at 18:54 h for male flowers. Start of bract rolling was at 18:51 h among female flowers (P < 0.001) and 20:48 h for male flowers. Bracts ended rolling at 02:33 h and 01:16 h for female and flowers respectively (P < 0.05). Total time of bract opening (from lift to end of rolling) for female flowers was significantly longer than that of male flowers (P < 0.001). On average, the number of bracts subtending female flowers opening increased from one on the first day, to between one and four on the fourth day. The number regressed to one bract on day eight before start of opening of bracts subtending male flowers. There was a longer opening interval between bracts subtending female and male flowers constituting spatial and temporal separation. Bract rolling increased from partial to complete rolling from proximal to the distal end of the inflorescence among female flower. On the other hand, bracts subtending male flowers completely rolled. Differences in BOT of genotypes with the same reference time of assessment may be partly responsible for variable fertility. Hand pollination time between 07:00 and 10:00 h is slightly late thus an early feasible time should be tried.

scholarly journals VviPLATZ1 is a major factor that controls female flower morphology determination in grapevine

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pat Iocco-Corena ◽  
Jamila Chaïb ◽  
Laurent Torregrosa ◽  
Don Mackenzie ◽  
Mark R. Thomas ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Vitis Vinifera ◽  
Mating System ◽  
Expression Pattern ◽  
Female Flower ◽  
Flower Morphology ◽  
Phenotype Analysis ◽  
Male Flowers ◽  
Female Flowers ◽  
Morphological Phenotype

AbstractPlant genetic sex determinants that mediate the transition to dioecy are predicted to be diverse, as this type of mating system independently evolved multiple times in angiosperms. Wild Vitis species are dioecious with individuals producing morphologically distinct female or male flowers; whereas, modern domesticated Vitis vinifera cultivars form hermaphrodite flowers capable of self-pollination. Here, we identify the VviPLATZ1 transcription factor as a key candidate female flower morphology factor that localizes to the Vitis SEX-DETERMINING REGION. The expression pattern of this gene correlates with the formation reflex stamens, a prominent morphological phenotype of female flowers. After generating CRISPR/Cas9 gene-edited alleles in a hermaphrodite genotype, phenotype analysis shows that individual homozygous lines produce flowers with reflex stamens. Taken together, our results demonstrate that loss of VviPLATZ1 function is a major factor that controls female flower morphology in Vitis.

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