Development of the inflorescence and flower of Sagittaria cuneata

1977 ◽  
Vol 55 (9) ◽  
pp. 1087-1105 ◽  
Author(s):  
V. Singh ◽  
R. Sattler
Keyword(s):  
Male Flower ◽  
Female Flower ◽  
Point Of View ◽  
Stamen Primordia ◽  
Tunica Layer ◽  
Mature Flower ◽  
Floral Apex ◽  
Developmental Point ◽  
Floral Bud ◽  
Developmental Modification

The reproductive region of Sagittaria cuneata is basically trimerous. This trimery is exhibited in the arrangement of the bracts, sepals, petals, pairs of stamens in the male flower, and pairs of staminodia in the female flower. In the male flower after the inception of three sepal primordia, each of the three petal primordia arises with one pair of stamen primordia on an alternisepalous bulge of the floral apex, i.e., a petal–stamen (CA) primordium. Subsequent stamen primordia are formed in alternation with the six first-formed primordia. If, for convenience sake, the first six primordia are referred to as the first whorl of stamens up to four additional whorls may be produced. Depending on the size of the floral bud, the third and fourth whorls (if present) consist of two to six stamen primordia, whereas the fifth whorl (if present) contains one to five stamen primordia. Finally, primordia of pistillodes are formed in varying numbers. In the female flower the presence of CA primordia could not be as clearly established as in the male flower. However, again each petal primordium is definitely associated with a pair of antepetalous primordia. The latter primordia develop into staminodia. In alternation with the first six staminodia six additional staminodia are formed and then again in alternation many whorls of pistils (carpels). Even in the mature flower the basic trimery is reflected in the triangular shape of the globose and massive gynoecium. From a developmental point of view, the male and female flowers are primarily trimerous. The polyandric androecium and the large pleiomerous gynoecium are superimposed on the primary trimery. It appears quite possible that this developmental modification also reflects a phylogenetic derivation. This means that the pleiomerous gynoecium and androecium are not primitive but rather advanced. There is no indication of a spiral arrangement of stamens and carpels.Whereas the foliage leaves, bracts, and sepals are initiated as dorsiventral primordia, the petals, stamens, staminodia, pistils, and pistillodes arise as more or less hemispherical mounds and become dorsiventral thereafter. The vegetative apices, inflorescence apices and the floral apices have a two-layered tunica over a massive corpus. Foliage leaves, bracts, sepals, petals, stamens, staminodia, carpels, and pistillodes are initiated by periclinal divisions in the second tunica layer. In the case of the stamens and staminodia the corpus may also contribute. Ovules are initiated by periclinal divisions of the second layer of the carpel primordium.

Ontogeny of floral organs and morphology of floral apex in Phellodendron amurense (Rutaceae)

2002 ◽  
Vol 50 (5) ◽  
pp. 633 ◽  
Author(s):  
Qingyuan Zhou ◽  
Yinzheng Wang ◽  
Xiaobai Jin
Keyword(s):  
Laser Scanning ◽  
Male Flower ◽  
Female Flower ◽  
Laser Scanning Confocal Microscopy ◽  
Morphological Evidence ◽  
Phellodendron Amurense ◽  
Flower Buds ◽  
Floral Organs ◽  
Floral Apex ◽  
Female Flowers

The ontogeny of floral organs and the morphology of floral apex in the dioecious Phellodendron amurense Rupr. were investigated by light microscopy (LM), scanning electron microscopy (SEM) and laser scanning confocal microscopy (LSCM). Investigations indicated that P. amurense is hermaphroditic in its organisation and a common set of floral organs (sepals, petals, stamens and carpels) arise in all flowers during the early stages of development. Later, selective abortion of gynoecium and androecium occurs resulting in dimorphic unisexual flowers. The carpels in male flower buds become different from those in female flower buds soon after their initiation. The stamens of female flowers are not differentiated into anthers and filaments before abortion. The poorly differentiated carpel of male flowers never develops normal structures. Floral morphological evidence supports that Zanthoxylum, Tetradium and Phellodendron are related to one another in a linear sequence. LSCM revealed some interesting features on the apical meristem surface such as zonal differentiation, a triangular or sectorial cell, radiating cell files and linear rows of anticlinal cell walls fluorescing relatively brightly. The concept of carpel-enhancing meristem in the floral apex is tentatively proposed to account for the different fates of carpel development in male and female flowers in P. amurense.

Floral development of Comptonia peregrina (Myricaceae)

1974 ◽  
Vol 52 (10) ◽  
pp. 2165-2169 ◽  
Author(s):  
Alastair D. Macdonald
Keyword(s):  
Floral Development ◽  
Early Stage ◽  
Male Flower ◽  
Female Flower ◽  
Median Plane ◽  
Distal Portion ◽  
Second Order ◽  
Third Order ◽  
Floral Apex ◽  
Growth Activity

Early stages of development of the male and female flower are similar; two second-order bracts arise in the transversal plane on either side of the floral apex before the apex flattens and becomes somewhat concave because of growth activity at the flank of the apex. In the female flower, the gynoecium develops as an extension of the girdling gynoecial primordium and the two primordial stigmas each result from more rapid growth in the median plane at the distal portion of the gynoecial wall. The floral apex resumes growth to form the unitegmic ovule. Third-order lanceolate-shaped bracts develop from a meristem situated in the axil of each second-order bract. In the male flower, staminate primordia arise at three or four loci on the ridge surrounding the apex. The apex briefly resumes growth. Growth of the second-order bracts terminates at an early stage. The floral construction is compared to other myricaceous species. It is concluded that the axillary scale-like bracts of the female flower are third-order bracts; the gynoecium does not overtop the second-order axis and the female flower is not a reduced cyme; the male flower is more floral- than inflorescence-like compared to some other myricaceous species.

Floral development of Butomus umbellatus

1974 ◽  
Vol 52 (1) ◽  
pp. 223-230 ◽  
Author(s):  
V. Singh ◽  
R. Sattler
Keyword(s):  
Floral Development ◽  
Stamen Primordia ◽  
Procambial Strand ◽  
Tunica Layer ◽  
Rapid Sequence ◽  
Floral Apex ◽  
Outer Tepal ◽  
Primary Pattern

The primordia of the floral appendages appear in acropetal succession and develop in the order in which they appear. The primordia of each whorl of appendages are formed in a rapid sequence. After the inception of outer tepal primordia, the floral apex becomes triangular. On each angle, one inner tepal primordium together with the primordia of a pair of outer stamens and an inner stamen is formed. The triangularity of the floral apex might be interpreted as an indication of the formation of petal–stamen (CA) primordia as reported for Alisma and Hydrocleis. If this is the case, the primary pattern of organogenesis of the Butomus flower is trimerous and tetracyclic, i.e. one whorl of outer tepals, one complex of inner tepals and stamens, and two whorls of pistils. The floral apices have a two-layered tunica surrounding a central corpus. The initiating divisions in the formation of all floral appendages occur in the second tunica layer. In the case of stamen primordia, the outer corpus is also involved. Procambial development is acropetal. One procambial strand differentiates into each floral appendage shortly after its inception. Additional procambial strands are formed in the pedicel and the perianth and gynoecium. The relationships of Butomus to the Magnoliidae are discussed.

Floral development in the 'Symphyomyrtus group' of Eucalypts (Eucalyptus: Myrtaceae)

1991 ◽  
Vol 4 (3) ◽  
pp. 553 ◽  
Author(s):  
AN Drinnan ◽  
PY Ladiges
Keyword(s):  
Floral Development ◽  
Developmental Stages ◽  
Growth Centre ◽  
Superficial Resemblance ◽  
Stamen Primordia ◽  
Mature Flower ◽  
Floral Apex ◽  
Bud Growth ◽  
Early Developmental ◽  
Complete Interpretation

Floral development is described in selected species of informal subgenus Symphyomyrtus (Pryor and Johnson 1971). The corolline operculum in most species is equivalent to those of informal subgenera Eudesmia, Idiogenes (E. cloëziana) and Monocalyptus. It is formed by growth centre continuity, and shows characters consistent with the dorsal components of Angophora and bloodwood corolline parts. Stamen primordia form on a corolline buttress that develops into the stemonophore of the mature flower. This feature is a synapomorphy for Symphyomyrtus sens. strict., Eudesmia, Idiogenes and Monocalyptus. Eucalyptus microcoiys has the plesiomorphic conditions of four free imbricate petals that show no evidence of compound development, and stamens arising directly on the floral apex, not on a stemonophore precursor. The apparent bundling of stamens is a result of differential bud growth, and bears only a superficial resemblance to stamen groups in Eudesmia eucalypts. The corollas of E. brachyandra (informal subgenus Telocalyptus) and E. guilfoylei (Symphyomyrtus) also consist of free, simple petals, but the unavailability of early developmental stages precludes a complete interpretation of these and the remaining three species of Telocalyptus.

Ontogenetical and experimental studies of the floral apex of Portulaca grandiflora. 1. Histology of transformation of the shoot apex into the floral apex

1969 ◽  
Vol 47 (1) ◽  
pp. 133-140 ◽  
Author(s):  
Siti Raswati Soetiarto ◽  
Ernest Ball
Keyword(s):  
Shoot Apex ◽  
Experimental Studies ◽  
Floral Meristem ◽  
Vegetative Shoot ◽  
Floral Organs ◽  
Mature Flower ◽  
Floral Apex ◽  
Portulaca Grandiflora ◽  
Floral Primordia ◽  
Vegetative Shoot Apex

The vegetative apex was a low dome consisting of two layers of tunica surmounting a very small corpus. Foliar primordia originated as periclines in the flanks of T2. The transition apex became first a steep cone and then a hemisphere. All floral primordia—the two bracts, the two sepals, the several whorls of petals, the several whorls of stamens, and the carpels—originated in the manner of leaves, as periclines in T2 on the flanks of the apex. All appendages, including carpels, were therefore lateral. In the early transition, the apex had a brief stage in which there were three tunica layers, but the inner one was lost with the onset of the sepals. The bracts and the first sepal continued the normal positions of primordia for the vegetative phyllotaxy of 3/8, but with the second sepal, this phyllotaxy was lost, and petals, stamens, and carpels were produced in whorls. While leaves, bracts, sepals, and petals were produced in acropetal sequence, stamens were produced in basipetal sequence, and carpels appeared simultaneously. After carpels were formed, the rest of the floral apex underwent a brief period of expansion growth, achieving a diameter comparable to that of a shoot apex, but its substance was eventually incorporated into the carpel margins, which later produced the ovules. This agrees with the determinate nature of the floral apex. During the development of the first series of floral organs, the floral apex underwent continued increase in area, finally achieving a diameter several times that of the vegetative shoot apex. Its size and form were such that they were compared to those of some inflorescence apices. After development of the first series of floral organs, the subjacent tissues to the floral meristem underwent divisions and elongation at right angles to the axis, causing at first a flattening of the meristem, and eventually a cup-shaped form, with the carpels attached in the bottom of a bowl. The mature flower was thus perigynous, but this development arose quite differently from the perigyny as it is known from ontogenetic studies in the Rosaceae.

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.

Effects of gibberellic acid on DNA synthesis and histology in the shoot apex of Helianthus annum during the transition to flowering

1975 ◽  
Vol 53 (22) ◽  
pp. 2650-2659 ◽  
Author(s):  
Haviva D. Langenauer ◽  
Dan Atsmon ◽  
Tova Arzee
Keyword(s):  
Gibberellic Acid ◽  
Central Zone ◽  
Hormonal Treatment ◽  
Synthetic Activity ◽  
Basal Cells ◽  
Tunica Layer ◽  
Floral Apex ◽  
Number Of Leaves ◽  
And Control ◽  
Transition To Flowering

Transition to flowering is described in gibberellic acid (GA) - treated and control plants of Helianthus annuus. Hormonal treatment accelerates reproductive development without reducing the number of leaves developed before flowering. Studies of [3H]thymidine incorporation in the apex show that a non-synthesizing summital group of cells, the central zone, is present in the vegetative as well as the transitional apex. During transition to the floral apex the size of the central zone is gradually diminished, as its peripheral and basal cells undergo synthetic activity and the apex develops a domed shape. In GA-treated shoots the order is changed so that development of a dome precedes activity in the central zone. Cells of the second tunica layer of the central zone are the last to incorporate thymidine. They are conspicuously enlarged and distinct before development of the inflorescence. It is suggested that this layer has a specialized role in flowering.

scholarly journals Adolesence and Family Crises

1968 ◽  
Vol 13 (2) ◽  
pp. 125-133 ◽  
Author(s):  
Donald G. Langsley ◽  
Robert H. Fairbairn ◽  
Carol D. Deyoung
Keyword(s):  
Family Member ◽  
Point Of View ◽  
Tension Reduction ◽  
Therapy Approach ◽  
Family Crisis ◽  
The Family ◽  
Adaptive Solution ◽  
Developmental Point ◽  
The Individual

Like the individual, the family may be better understood from a developmental point of view. It has different tasks and problems at various stages of its existence. The family with adolescent children faces a change in composition (loss of children and the responsibility of helping these children become adults). This threat may produce a family crisis and individual members may react to the specific conflicts in a manner which depends on their previous problems. The family member who becomes a ‘patient’ may be the teenager or a parent. A family crisis therapy approach permits tension reduction within the group, improves functioning on the part of the ‘patient’ and permits the family to work out a more adaptive solution.

scholarly journals Growth Analysis of Watermelon Plants Grown with Mulches and Rowcovers

1995 ◽  
Vol 120 (6) ◽  
pp. 1001-1009 ◽  
Author(s):  
Nader Soltani ◽  
J. LaMar Anderson ◽  
Alvin R. Hamson
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Growth Analysis ◽  
Citrullus Lanatus ◽  
Total Yield ◽  
Carbon Dioxide Concentration ◽  
Male Flower ◽  
Female Flower ◽  
Plastic Mulch ◽  
Area Index

`Crimson Sweet' watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] plants were grown with various mulches and rowcovers and analyzed for relative growth rate (RGR), net assimilation rate (NAR), specific leaf area (SLA), leaf area index (LAI), and crop growth rate (CGR). Spunbonded polyester fabric (SB-PF) and perforated polyethylene film (PCP) rowcovers generally showed greater mean RGR, SLA and CGR than spunbonded polypropylene polyamide net (SB-PP), black plus clear combination plastic mulch and black plastic mulch alone. Plants on mulches and under rowcovers showed significant increases in RGR, NAR, and SLA over plants grown in bare soil. Carbon dioxide concentration inside the transplanting mulch holes was nearly twice the ambient CO, concentration. Growth analysis of sampled watermelon plants during early stages of development under various treatments was predictive of crop yield. Plants under SB-PF and PCP rowcovers produced the earliest fruit and the greatest total yield. An asymmetrical curvilinear model for watermelon growth and development based on cardinal temperatures was developed. The model uses hourly averaged temperatures to predict growth and phenological development of `Crimson Sweet' watermelon plants grown with and without rowcovers. Early vegetative growth correlated well with accumulated heat units. Results indicate a consistent heat unit requirement for the `Crimson Sweet' watermelon plants to reach first male flower, first female flower and first harvest in uncovered plants and plants under rowcovers. Greater variability was observed in predicting date of first harvest than first bloom.

EFFECT OF EARLY FEEDING OF SOLID FOODS ON NUTRITIVE INTAKE OF INFANTS

PEDIATRICS ◽  
1966 ◽  
Vol 38 (5) ◽  
pp. 879-885
Author(s):  
Helen A. Guthrie
Keyword(s):  
National Research Council ◽  
Point Of View ◽  
Caloric Content ◽  
Early Feeding ◽  
Cereal Products ◽  
Early Introduction ◽  
Solid Foods ◽  
Developmental Point ◽  
The Cost ◽  
Current Emphasis

The early introduction of solid foods to the diet of bottle-fed infants living in a college town causes some significant changes in the nutritive content of the diet but does not increase the adequacy of the diet before 3 months as evaluated by allowances recommended for infants by the National Research Council. Diets containing solid foods provide significantly more iron and thiamine, two of the nutrients used to enrich infant cereal products. Most of the infants were receiving nutritional supplements of vitamin A and D in spite of the fact that their diets were adequate in these nutrients. The need for a supplement of ascorbic acid was evident for some infants. The feeding of solid foods apparently had no effect on the sleeping pattern of the infants as evidenced by the number of feedings, nor did it increase the cost of the food itself. It did, however, increase the time and effort involved for the mother. Since there was no increase in the caloric content of the diet, the solid foods must have replaced milk rather then to have supplemented it, a fact confirmed by the observations of many mothers. At least 10% of the infants experienced some form of allergic reaction to solid foods. All of the infants in the study had been introduced to solid foods by 9 weeks, 2 to 4 weeks prior to the age at which the American Academy of Pediatrics suggests that there is a rational basis from a nutritional and developmental point of view to begin supplementing the diet. Although there was no evidence of adverse reactions other then allergies to the pattern of early feeding observed in this group, there was no evidence to indicate that the infant benefitted from a nutritional standpoint. Lack of evidence of benefits and an accumulating body of information on hazards from the early introduction of solid foods suggest a re-examination of current emphasis on the early supplementation of the milk diet in infants.

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