The floral development of Monococcus echinophorus (Phytolaccaceae)

1997 ◽  
Vol 75 (11) ◽  
pp. 1941-1950 ◽  
Author(s):  
P. F. Vanvinckenroye ◽  
L. P. Ronse Decraene ◽  
E. F. Smets
Keyword(s):  
Electron Microscope ◽  
Floral Development ◽  
Variable Number ◽  
Monotypic Genus ◽  
Floral Ontogeny ◽  
Short Style ◽  
Close Relationship ◽  
Median Position ◽  
Relationship Of ◽  
Scanning Electron

The floral ontogeny of the monotypic genus Monococcus (Phytolaccaceae) is investigated with the scanning electron microscope. Flowers arise on pendent racemes and are preceded by a bract and two bracteoles arising successively. In both staminate and pistillate flowers four sepals are incepted in diagonal position. In the staminate flowers four alternisepalous stamens are initiated successively. Further stamen inception occurs centrifugally and runs concomitant with peripheral growth of the receptacle. This centrifugal stamen initiation is interpreted phylogenetically as a secondary increase and is expressed by the appearance of four triplets. Initiation of a variable number of outermost stamens (0–8) occurs mostly in the latero-abaxial region of the flower. In staminate flowers there is no trace of a gynoecium. In pistillate flowers a gynoecium primordium arises centrally and grows into a monocarpellate structure. Later, hooked bristles arise on the carpel flanks while a short style is produced bearing a distal tangle of long hairs. A close relationship of Monococcus with Petiveria is confirmed; similarities include the median position of the prophylls, the diagonal position of four sepals, the sequential inception of four alternisepalous stamens, and the fruits with adaptations for exozoochory. Key words: androecium, floral ontogeny, Monococcus, Phytolaccaceae, Rivinoideae.

scholarly journals Taxonomic significance of spermoderm pattern in Cucurbitaceae

2013 ◽  
Vol 20 (1) ◽  
pp. 61-65
Author(s):  
M. Ajmal Ali ◽  
Fahad M.A. Al-Hemaid ◽  
Arun K. Pandey ◽  
Joongku Lee
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Cucumis Melo ◽  
Taxonomic Significance ◽  
Citrullus Colocynthis ◽  
Benincasa Hispida ◽  
The Family ◽  
Plant Taxon ◽  
Relationship Of ◽  
Scanning Electron

Studies on spermoderm using scanning electron microscope (SEM) were undertaken in 12 taxa under 11 genera of the family Cucurbitaceae sampled from India, China and Korea. The spermoderm pattern in the studied taxa varies from rugulate, reticulate to colliculate type. The spermoderm shows rugulate type in Benincasa hispida and Sicyos angulatus; reticulate type in Citrullus colocynthis, Cucumis melo var. agrestis, Diplocyclos palmatus, Hemsleya longivillosa, Luffa echinata, Momordica charantia, M. cymbalaria, Schizopepon bryoniifolius, and Trichosanthes cucumerina; and colliculate type  in Gynostemma laxiflorum. The present study clearly reveals that the testa features greatly varies across the genera which can be used as micromorphological markers for identification as well as character states for deducing relationship of the taxa within the family.DOI: http://dx.doi.org/10.3329/bjpt.v20i1.15465Bangladesh J. Plant Taxon. 20(1): 61-65, 2013 (June)

FLORAL DEVELOPMENT OF EREMURUS ALTAICUS (LILIACEAE)

1994 ◽  
Vol 42 (3) ◽  
pp. 227-233 ◽  
Author(s):  
Rina Kamenetsky ◽  
Madina Akhmetova
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Floral Development ◽  
Floral Bract ◽  
Cut Flower ◽  
Flower Production ◽  
Scanning Electron

Morphogenesis of the monocarpic shoot and fiorai development of Eremurus altaicas (Pall.) Stev. from Kazakhstan was examined by Scanning Electron Microscope (SEM). The lifespan of the monocarpic shoot is about 18 months. Differentiation of the inflorescence starts in June and proceeds in the acropetal direction until the end of the following February. Each flower arises in the axil of a flower bract. Differentiation of stamens and perianth lobes occurs first from common primordia, followed by the formation of the gynoecium. One of the perianth lobes develops first opposite the floral bract in whose axil the flower is located. Cultivation of the Eremurus species for winter cut flower production could be achieved by delaying flowering so that it occurs during the following winter, instead of during May/June.

Ultrastructure of conidiogenesis in Scopulariopsis brevicaulis

1971 ◽  
Vol 49 (5) ◽  
pp. 745-755 ◽  
Author(s):  
Garry T. Cole ◽  
H. C. Aldrich
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Scopulariopsis Brevicaulis ◽  
Freeze Etching ◽  
Cytological Changes ◽  
Relationship Of ◽  
The Relationship ◽  
Fungi Imperfecti ◽  
Scanning Electron

An ultrastructural study of conidia and conidiogenous cells of Scopulariopsis brevicaulis (Sacc.) Bain. in various stages of development is presented using transmission and scanning electron microscope and freeze-etching techniques. Septa between both fertile and vegetative cells are examined. The development of the double septum is outlined and mechanisms are suggested to explain conidium secession. Cytological changes which occur in the developing conidium initial are illustrated and their possible association with wall synthesis and deposition is noted. Change in the orientation of rodlets occurs on the walls of frozen-etched conidia at different stages of formation. The relationship of this phenomenon to conidium development is discussed. Description of the nature of wall relations during conidium ontogeny is stressed because of its importance in a classification of Fungi Imperfecti based on developmental characters of the reproductive cells. A diagrammatic interpretation of the sequence of formation of wall layers of the developing conidium is presented.

Systematic relevance of the pollen morphology for the Rondeletia complex (Cinchonoideae, Rubiaceae)

2020 ◽  
Vol 194 (3) ◽  
pp. 290-307
Author(s):  
Alejandro Torres-Montúfar ◽  
Elia Ramírez-Arriaga ◽  
Enrique Martínez-Hernández ◽  
Helga Ochoterena
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Pollen Morphology ◽  
Morphological Characters ◽  
Palynological Data ◽  
Molecular Studies ◽  
Close Relationship ◽  
Relationship Of ◽  
Scanning Electron

Abstract Seventeen morphologically related genera have been considered as the Rondeletia complex, traditionally in Rondeletieae. Molecular studies agree that this is a polyphyletic group and some genera have been transferred to Guettardeae. Nevertheless, no solid morphological characters support this hypothesis. Our aim is to explore pollen morphology to see if this source of characters has systematic value. Our study uses light and scanning electron microscopy for 30 species of both tribes representing 14 genera. The most important characters are polar outline, endoaperture type and nexine discontinuities. Our results do not permit diagnosis of tribes, but they show that the genera formerly included in the Rondeletia complex, but now placed in Guettardeae, have nexine discontinuities in polar areas: endofissures (Rogiera) or endocracks (Arachnothryx complex: Arachnothryx-Gonzalagunia-Javorkaea-Renistipula). Palynological data also confirm a close relationship of Rondeletia with Stevensia, corroborating their synonymy, and of Arachnothryx with Gonzalagunia-Javorkaea-Renistipula, providing evidence of their close relationship. We conclude that pollen is a useful source of characters for supporting main lineages, but further research is still necessary for other genera, including Blepharidium, Machaonia, Mazaea and additional Rondeletia spp.

Floral development of the Ornithocephalus clade (Oncidiinae, Orchidaceae): the origin of the tabula infrastigmatica, gynostemium appendices and labellar callus

2020 ◽  
Author(s):  
Carla A Royer ◽  
A L V Toscano de Brito ◽  
Thomas Stützel ◽  
Eric C Smidt ◽  
Elaine L P Nunes
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Floral Development ◽  
Developmental Stages ◽  
Complex Structures ◽  
Scanning Electron ◽  
Single Organ

Abstract The Ornithocephalus clade comprises small epiphytes distributed in 12 genera and c. 120 species. Their flowers have complex structures, the homologies of which are difficult to interpret. Through ontogenetic studies, we identified the origins of the tabula infrastigmatica, floral appendages located in the gynostemium and the labellar callus. Using a scanning electron microscope (SEM), we analysed flowers at various developmental stages from representatives of three genera: Ornithocephalus (two species), Phymatidium (two species) and Zygostates (three species). The tabula infrastigmatica of Phymatidium results from the fusion of the lateral carpels and staminodes, with different degrees of synorganization across species and can be considered a plesiomorphic characteristic within the clade. Contradicting hypotheses of a staminodial origin, the auricles present in this genus derive from the gynostemium. In Zygostates, the lateral appendices derive from staminodes and can show different development degrees, whereas in Ornithocephaus that character has been lost. We corroborate the view that the labellum is a single organ derived from the median petal and the labellar callus is derived from it.

scholarly journals Hermaphroditism in the rubber tree Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell. Arg. - II

1998 ◽  
Vol 21 (4) ◽  
pp. 523-526 ◽  
Author(s):  
Silvia Marina Cuco ◽  
Gerhard Bandel
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Hevea Brasiliensis ◽  
Floral Development ◽  
Rubber Tree ◽  
Sterile Male ◽  
Scanning Electron Microscope Analysis ◽  
Electron Microscope Analysis ◽  
And Bisexual ◽  
Scanning Electron

Flowers of three Hevea brasiliensis clones, RRIM 527, RRIM 600 and GT 1, were analyzed under stereomicroscope and scanning electron microscope, aiming to observe hermaphroditism rates. Results showed 71.49% hermaphrodite flowers, 29.83% of which exhibited incompletely developed, residual anthers. The scanning electron microscope analysis did not detect differences in anther epidermis of male and bisexual flowers of RRIM 600 and RRIM 527. In GT 1 clone (sterile male), the anther epidermis was already weak at the beginning of floral development and completely wrinkled at the end of maturation. Consequently, the anthers were empty by this stage.

Metaxonchium toroense n. sp. (Nematoda, Dorylaimida, Belondiridae) from Costa Rica, with the first molecular study of a representative of the genus

2017 ◽  
Vol 93 (1) ◽  
pp. 100-108 ◽  
Author(s):  
I. Varela-Benavides ◽  
R. Peña-Santiago
Keyword(s):  
New Species ◽  
Costa Rica ◽  
Molecular Study ◽  
Natural Habitats ◽  
Molecular Analyses ◽  
Close Relationship ◽  
Relationship Of ◽  
Genital Branch ◽  
General Size ◽  
Scanning Electron

AbstractThe new species Metaxonchium toroense n. sp. from natural habitats of Costa Rica is described, including light microscopy (LM), scanning electron microscopy (SEM) and molecular (D2–D3 28S rDNA) analyses. The new species is characterized by its general size, the dimensions and appearance of its lip region, the length of the odontostyle and its fusiform aspect, the length of the neck and its pharyngeal expansion, the reduction of the anterior genital branch to a very short uterine sac without any rudiment of ovary or oviduct, tripartite and non-echinophor posterior uterus, the somewhat posterior vulva position, the length and shape of the caudal region, and the absence of males. Molecular analyses, the first to be performed on a Metaxonchium species, show a close relationship of the new species with representatives of the genera Axonchoides and Syncheilaxonchium.

scholarly journals Floral development and vascularization help to explain merism evolution inPaepalanthus(Eriocaulaceae, Poales)

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2811 ◽  
Author(s):  
Arthur de Lima Silva ◽  
Marcelo Trovó ◽  
Alessandra Ike Coan
Keyword(s):  
Floral Development ◽  
Staminate Flower ◽  
Vascular Bundles ◽  
Infrageneric Classification ◽  
Electron Microscopies ◽  
Short Style ◽  
Outer Whorl ◽  
Close Relationship ◽  
Evolutionary Context ◽  
Lateral Petal

BackgroundFlowers in Eriocaulaceae, a monocot family that is highly diversified in Brazil, are generally trimerous, but dimerous flowers occur inPaepalanthusand a few other genera. The floral merism in an evolutionary context, however, is unclear.Paepalanthusencompasses significant morphological variation leading to a still unresolved infrageneric classification. Ontogenetic comparative studies of infrageneric groups inPaepalanthusand in Eriocaulaceae are lacking, albeit necessary to establish evolution of characters such as floral merism and their role as putative synapomorphies.MethodsWe studied the floral development and vascularization of eight species ofPaepalanthusthat belong to distinct clades in which dimery occurs, using light and scanning electron microscopies.ResultsFloral ontogeny in dimerousPaepalanthusshows lateral sepals emerging simultaneously and late-developing petals. The outer whorl of stamens is absent in all flowers examined here. The inner whorl of stamens becomes functional in staminate flowers and is reduced to staminodes in the pistillate ones. In pistillate flowers, vascular bundles reach the staminodes. Ovary vascularization shows ventral bundles in a commissural position reaching the synascidiate portion of the carpels. Three gynoecial patterns are described for the studied species: (1) gynoecium with a short style, two nectariferous branches and two long stigmatic branches, in most species; (2) gynoecium with a long style, two nectariferous branches and two short stigmatic branches, inP. echinoides; and (3) gynoecium with long style, absent nectariferous branches and two short stigmatic branches, inP. scleranthus.DiscussionFloral development of the studied species corroborates the hypothesis that the sepals of dimerous flowers ofPaepalanthuscorrespond to the lateral sepals of trimerous flowers. The position and vascularization of floral parts also show that, during dimery evolution inPaepalanthus, a flower sector comprising the adaxial median sepal, a lateral petal, a lateral stamen and the adaxial median carpel was lost. In the staminate flower, the outer whorl of staminodes, previously reported by different authors, is correctly described as the apical portion of the petals and the pistillodes are reinterpreted as carpellodes. The occurrence of fused stigmatic branches and protected nectariferous carpellodes substantiates a close relationship betweenP.sect.ConodiscusandP.subg.Thelxinoë. Free stigmatic branches and exposed carpellodes substantiate a close relationship betweenP. sect.Diphyomene,P. sect.EriocaulopsisandP. ser.Dimeri. Furthermore, the loss of nectariferous branches may have occurred later than the fusion of stigmatic branches in the clade that groupsP. subg.ThelxinoëandP. sect.Conodiscus.

Evaluation of the interface between calcified bone and metal implants

1991 ◽  
Vol 49 ◽  
pp. 32-33
Author(s):  
K. E. Krizan ◽  
D. H. Han ◽  
R. L. Ettinger ◽  
G. F. Koorbusch ◽  
J. D. Spivey
Keyword(s):  
Electron Microscope ◽  
Soft Tissue ◽  
Alveolar Bone ◽  
Porous Hydroxyapatite ◽  
Metal Implants ◽  
Immediate Placement ◽  
Relationship Of ◽  
Endosteal Implants ◽  
The Relationship ◽  
Scanning Electron

In recent years oral endosteal implants have been placed in healed extraction sites but it has been suggested that osseointegration may not occur. This study places IMZ implants1 in fresh extraction sites with and without two biological graft materials: porous hydroxyapatite granules (HA) and polytetrafluorethylene (PTFE) membranes. The purpose of this study was to investigate the influence of immediate placement of implants on osseointegration. This presentation uses the scanning electron microscope (SEM) to evaluate the relationship of implant to bone. In addition, the effect of these two graft materials on bone regeneration and prevention of soft tissue (ST) ingrowth was examined. Under anesthesia three adult mongrel dogs had premolars extracted bilaterally from the mandible. Using the IMZ system six implant sites were prepared, five implants placed in alveolar bone and the sixth site was a no implant control. A total of fifteen implants were placed in the area between the canine and first molar of the three animals.

scholarly journals Redescription of Lemuricola (Madoxyuris) bauchoti (Nematoda, Oxyuridae) from Lemur catta in Madagascar

2010 ◽  
Vol 55 (3) ◽  
Author(s):  
María Rosario Robles ◽  
James Loudon ◽  
John Kinsella ◽  
Mandala Hunter-Ishikawa ◽  
David Miller ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Host Species ◽  
Host Record ◽  
Lemur Catta ◽  
New Host ◽  
New Host Record ◽  
Close Relationship ◽  
Single Host ◽  
Scanning Electron

AbstractLemuricola (Madoxyuris) bauchoti Chabaud, Brygoo et Petter, 1965 is redescribed from material collected from the ring-tailed lemur, Lemur catta, from the Beza Mahafaly Special Reserve in Madagascar using the scanning electron microscope. This is a new host record and the first oxyurid reported from the ring-tailed lemur. Previously, records of each species of the subgenus Madoxyuris have been restricted to a single host species, but the close relationship between these nematodes and their Strepsirrhini hosts will only be proven when additional records fill in the gaps in their distribution.

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