tunica layer
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2020 ◽  
Vol 38 (1) ◽  
pp. 69
Author(s):  
Rifky Rizkiantino ◽  
Ridzki M.F. Binol

A wild-captive male Jenkins' whipray was found dead in a quarantine tank with a clinical sign before death in the form of decreased appetite for a week. The treatment history was oral administration of enrofloxacin antibiotic tablets. The therapy period lasts for ten days. The last treatment was the administration of Hepavit® (liver extract) and intramuscular injection of enrofloxacin antibiotic. One day before the death, blood was collected and then examined for the hematocrit and some parameters of chemical blood. The results of blood examination were found a decrease in blood urea nitrogen (BUN), alkaline phosphatase (ALP), and alanine aminotransferase (ALT) levels, increased glucose level, decreased total protein and albumin levels, and increased globulin level. Anatomical pathology examination was found lesions on the tail, around the eyes, and claspers. Hemorrhagic lesions were found in the mucous layer of the esophagus, stomach, and spiral colon. The blood clot was found under the tunica layer of testicular organs. The liver is damaged by showing a non-homogeneous coloration, organ thickening, congestion, and fragile consistency. Based on the results of the blood examination and was supported by the results of the anatomical pathology examination after death, it is suspected that the fish died due to the condition of septicemia infection during the previous few weeks.


2014 ◽  
Vol 49 (1-2) ◽  
pp. 21-31
Author(s):  
Zygmunt Hejnowicz ◽  
Wiesław Włoch

The vegetative phase of development of the main shoot apex lasts over 5 plastochrons after germination. The endosperm has a sufficient store of nutrition for this period. At the beginning of this phase the apex has a one-layer tunica. The cells of the latter divide above the level of bulge formation for leaf primordia, exclusively anticlinally, although somewhat lower within the leaf bulge periclinal divisions may occur. The cells immediately under the first tunica layer in the apical part grow tangentially to the surface. These cells divide only anticlinally forming gradually the second tunica layer. In the course of the entire phase the shape of the meristeanatic caulis from the tip to the 4th frustum remains unchanged.


2003 ◽  
Vol 81 (1) ◽  
pp. 28-39 ◽  
Author(s):  
Usher Posluszny ◽  
P Barry Tomlinson

Amborella has woody axes whose development is intrinsically plagiotropic and determinate. The tree habit is achieved through overtopping of older axes by basally produced younger axes, as in Mangenot's model. Inflorescence units, which are produced in the axils of distal leaves, may be described as extended cymes, each branch ending in a flower. Basal bracteoles have a decussate arrangement, which is modified to an alternate phyllotaxis distally. Flowers produce one or more additional bracteoles with a rapid transition to the spiral phyllotaxis of the broad overlapping tepals. In this transition the initially conical floral apex becomes invaginated to form a floral cup, with subsequent appendages appearing on its inner margin. The floral apex then forms the flat base of the cup but retains a discrete single tunica layer. The receptacular bowl is deepened and narrowed by the basal meristem of each appendage, the last formed floral organs usually consuming the floral meristem. Sexual parts are more numerous in male than female flowers, accounting for their size difference, but primordia of stamens and carpels are initially very similar. Floral symmetry is largely a consequence of close packing of appendages within the floral cup. In its initial stages of development the flower does not conform to any conventional floral model in angiosperms and is better regarded as highly specialized rather than ancestral in its synorganization. This is not unexpected in a lineage of such long independent evolution.Key words: Amborella, basal angiosperm, development, inflorescence, primitive flower.


1989 ◽  
Vol 67 (7) ◽  
pp. 1985-1997 ◽  
Author(s):  
Marie-France Turlier ◽  
Josiane Alabouvette

The scheme of floral morphogenesis is based on a histocytological analysis of organogenesis. Several points are emphasized: (i) the activity of the meristem during the development of inflorescence, the receptacle, and the placenta is always brought about by the iterative activity of the corpus initials, generating six superposed levels, each of them producing a type of lateral appendage: bract, calyx, corolla, stamens, carpels, and ovarian partitions; (ii) the evolution of cauline components is described: the corpus is responsible for the organogenesis of part of the corolla, the stamens, and the placenta; the second tunica layer is responsible for the calyx, the other part of the corolla, the carpels and reproductive cells, the protoderm of transmitting tissue, and the stigma; (iii) the calyx, corolla, and gynoecium are trifacial, while the stamens are pentafacial and the placenta is axial; (iv) there is no fusion: the calyx, corolla, and gynoecial tubes arise as an extension of the initiation started on separate sites; the corollo-staminal tube results from the elongation of the lower part of the corolla and of the base of the stamen filaments under the zone of interpetalous-corolla initiation; an anticlinal growth, joining face to face, produces the filling of the style. Thus, during flower morphogenesis, organogenous, histogenous, and differentiation patterns begin in well defined places, at given times.


1977 ◽  
Vol 55 (9) ◽  
pp. 1106-1120 ◽  
Author(s):  
V. Singh ◽  
R. Sattler

The primordia of the floral appendages are initiated in an acropetal succession. Members of the same whorl appear nearly simultaneously. The gynoecial whorl and the two staminal whorls are trimerous, whereas the perianth consists only of two anteriolateral tepals. However, the posterior (adaxial) tepal may be present as an extremely reduced buttress whose growth becomes arrested immediately after its inception. If this somewhat questionable tepal rudiment is included we have a perfectly trimerous and tetracyclic flower with alternation of successive whorls. Subtending bracts of the flowers are completely missing in all developmental stages. While the tepal primordia are dorsiventral from their inception, the stamen and pistil (carpel) primordia originate as hemispherical mounds which become dorsiventral in subsequent stages of development. Each pistil (carpel) primordium becomes horseshoe shaped. As the margins grow up and contact they fuse postgenitally. No cross zone is formed. Placentation is submarginal. In A. natans eight ovules are formed and in A. undulatus only two arise; all ovules are bitegmic. The floral apices have a two-layered tunica up to the stage of pistil formation. The inception of all floral appendages (including the ovules) occurs by periclinal cell division in the second tunica layer. The third layer (corpus) may contribute to the formation of the stamens and pistils. Each appendage primordium receives only one procambial strand which begins to differentiate after the inception of the primordium. The questionable rudimentary tepal buttress lacks a procambial strand. Apparently it does not reach the developmental stage at which procambial induction occurs. From the point of view of floral development, the two species of Aponogeton differ drastically from members of the Alismatales studied so far. Among the Helobiae, the Aponogetonaceae appear to be most closely related to the Scheuchzeriaceae and the Juncaginaceae (Triglochinaceae).


1977 ◽  
Vol 55 (9) ◽  
pp. 1087-1105 ◽  
Author(s):  
V. Singh ◽  
R. Sattler

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.


1975 ◽  
Vol 53 (22) ◽  
pp. 2650-2659 ◽  
Author(s):  
Haviva D. Langenauer ◽  
Dan Atsmon ◽  
Tova Arzee

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.


1974 ◽  
Vol 52 (1) ◽  
pp. 223-230 ◽  
Author(s):  
V. Singh ◽  
R. Sattler

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.


1973 ◽  
Vol 51 (9) ◽  
pp. 1611-1617 ◽  
Author(s):  
G. S. Hicks

Floral buds of Nicotiana tabacum were fixed, sectioned, and stained by routine procedures, then analyzed microscopically. Initiation and emergence of all four classes of floral organs involved periclinal division in the second tunica layer (T2) and division of corpus cells. The extent of periclinal T2 divisions was different in different organs. Plasmolysis of tunica and corpus cells was observed at organ sites. The results generally parallel those of other studies.


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