Floral sex ratios in scrub oak (Quercus ilicifolia) vary with microtopography and stem height

1990 ◽  
Vol 68 (6) ◽  
pp. 1364-1368 ◽  
Author(s):  
Marcelo A. Aizen ◽  
Alejandra Kenigsten
Keyword(s):  
Sex Ratios ◽  
Scrub Oak ◽  
Size Dependent ◽  
Female Function ◽  
Dependent Relationship ◽  
Quercus Ilicifolia ◽  
Allocation Patterns ◽  
Male Flowers ◽  
Short Stems ◽  
Female Flowers

We measured floral sex ratios (number of male inflorescences:number of female flowers) and height of stems (= ramets) of monoecious scrub oak (Quercus ilicifolia) growing along a topographic gradient on the slope of a 20 m deep depression. Stems lower in the gradient experienced increasingly severe conditions in terms of a shorter growing season and a higher incidence of killing frosts. At the top of the gradient, floral sex ratios of tall stems were male biased; however, sex allocation patterns at the bottom showed no such size-dependent relationship. With decreasing elevation (greater stress), the production of male flowers declined more rapidly than that of female flowers. Tall stems reduced overall resource allocation to flower production proportionately more with decreasing elevation than did short stems, but this reduction was again more marked in the male flowering function than in the female. These differential patterns of sex investment explain, at least in part, the variation in size-related gender relationships along this gradient. The more stressful environmental conditions prevailing at the bottom of the depression and the relative costs of the male and prezygotic female function may combine to produce these flowering patterns.

scholarly journals Size-dependent sex allocation in Solanum lycocarpum St. Hil. (Solanaceae)

2022 ◽  
Vol 82 ◽  
Author(s):  
F. F. Coelho ◽  
A. G. Damasceno ◽  
A. Fávaro ◽  
G. S. Teodoro ◽  
L. P. Langsdorff
Keyword(s):  
Resource Allocation ◽  
Sex Allocation ◽  
Plant Size ◽  
Male And Female ◽  
Size Dependent ◽  
Female Function ◽  
Plant Group ◽  
Optimal Resource ◽  
Sex Allocation Theory ◽  
Male Flowers

Abstract Resource allocation to reproduction can change depending on size, as predicted by the size-dependent sex allocation. This theory is based on the fact that small individuals will invest in the allocation of sex with lower cost of production, usually male gender. In plants, there are some andromonoecy species, presence of hermaphrodite and male flowers in the same individual. Andromonoecy provides a strategy to optimally allocate resources to male and female function, evolving a reproductive energy-saving strategy. Thus, our objective was to investigate the size-dependent sex allocation in Solanum lycocarpum St. Hil. We tested the hypothesis that plants with larger size will invest in the production of hermaphrodite flowers, because higher individuals have greater availability of resources to invest in more complex structures involving greater energy expenditure. The studied species was S. lycocarpum, an andromonoecious species. From June 2016 to March 2017 the data were collected in 38 individuals, divided in two groups: the larger plant group (n=18; height=3-5 m) and the smaller plant group (n=20; height=1-2 m).Our data show that there was effect of plant size on the flower production and the sexual gender allocation. The larger plants showed more flowers and higher production of hermaphrodite flowers. Furthermore, in the flower scale, we observed allometric relationship among the flower’s traits with proportional investments in biomass, anther size and gynoecium size. Our results are in agreement with size-dependent sex allocation theory and andromonoecy hypothesis related to mechanisms for optimal resource allocation to male and female function.

Resource allocation and floral sex ratios in Zizania aquatica

1984 ◽  
Vol 62 (4) ◽  
pp. 799-805 ◽  
Author(s):  
Mary F. Willson ◽  
Kurt P. Ruppel
Keyword(s):  
Biomass Allocation ◽  
Wild Rice ◽  
Reproductive Effort ◽  
Plant Biomass ◽  
Sex Ratios ◽  
Total Biomass ◽  
Female Function ◽  
Zizania Aquatica ◽  
Maternal Function ◽  
Female Flowers

Reproductive effort (RE) in Zizania aquatica (wild rice) averaged about 11% of total biomass except in extremely large plants, in which RE was about 17%. Plant biomass of wild rice was correlated positively with the numbers of male and female flowers produced. The average number of flowers per inflorescence varied markedly among stands and at different times in several lakes in northwestern Minnesota. Floral sex ratios of individuals (and of stands) consistently favored males, but the estimated allocation of biomass to female function (including seeds) consistently exceeded male allocation. Average flora sex ratios of individuals differed among stands and zones within stands, and very often declined steadily on successively produced inflorescences. The observed variation in biomass allocation to each gender and the consistent marked excess of biomass allocation to maternal function do not fit simple expectations of nearly equal expenditures in chiefly outcrossing cosexual plants nor of relatively high male allocation in wind-pollinated plants.

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>

A new species of Smilax (Smilacaceae) from Yunnan, China

Phytotaxa ◽  
2016 ◽  
Vol 275 (2) ◽  
pp. 159 ◽  
Author(s):  
XIN-JIE JIN ◽  
YAO CHEN ◽  
JOONGKU LEE ◽  
Zhechen Qi ◽  
LuXian Liu ◽  
...  
Keyword(s):  
New Species ◽  
Species Delimitation ◽  
Flower Morphology ◽  
Evolutionary Transition ◽  
Ideal Model ◽  
Floral Trait ◽  
Evolution And Development ◽  
Male Flowers ◽  
A New Species ◽  
Female Flowers

A new species, Smilax hirtellicaulis (Smilacaceae), from southwestern China is described and illustrated. The new species differs from all known Smilax species in its unique tepals, i.e., basally connate in male flowers but separate in female flowers. Phylogenetic analysis supports its species delimitation, and suggests a sister position to the clade of Smilax sect. Heterosmilax which have flowers with connate tepals. Their closest phylogenetic relationship and resembled flower morphology may represent an evolutionary transition from separate to united tepals in Smilax. It thus provides us an ideal model for studying the evolution and development of such an innovative floral trait.

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