scholarly journals Flowering, nectar secretion, and structure of the nectary in the flowers of Acer pseudoplatanus L.

2019 ◽  
Vol 72 (3) ◽  
Author(s):  
Marta Dmitruk
Keyword(s):  
Single Layer ◽  
Epidermal Cells ◽  
Average Weight ◽  
Outer Diameter ◽  
Acer Pseudoplatanus ◽  
Average Depth ◽  
Nectar Secretion ◽  
Parenchyma Cells ◽  
Circular Layer ◽  
Scanning Electron

Flowering and nectar release in <em>Acer pseudoplatanus</em> were investigated between 2011 and 2013. The micromorphology of the floral and nectary elements was observed using a scanning electron microscope and the anatomy of nectaries was examined by light microscopy. The inflorescence of the sycamore was found to contain flowers, which were functionally male or functionally female. The life-span of the former was on average 5 days, whereas the latter lived on average 4 days. Both types of <em>A. pseudoplatanus</em> flowers had yellow-green nectaries with a similar structure. The nectary tissue formed an elliptical or circular layer located on the receptacle surface between the petals and the pistil. The filament bases were located within the nectary recesses but were not fused with this organ. The nectary margins were slightly undulated. The outer diameter of the nectary was in 3.0–3.25 mm and the thickness of the nectary tissue was in the range of 532–1,023 μm. The nectary of the sycamore flower comprised a single layer of epidermal cells and several layers of secretory parenchyma cells. The average depth of epidermal cells was 16.8 μm. The stomata, which were involved in the secretion process, were arranged unevenly on the nectary surface and were surrounded by six–eight epidermal cells. Visible droplets of nectar accumulated on the nectary surface and thus they were easily accessible to insects. The average weight of nectar from 10 flowers was 16.54 mg (range: 11.0–23.75 mg) and the content of sugars in the nectar was found to be in the range of 23.5–50%, with an average of 37.3%. The calculated weight of sugars in the nectar from 10 flowers was on average 6.11 mg and so the average sugar yield from one sycamore tree was estimated to be 0.65 kg.

scholarly journals Morphological characters of the flowers and the structure of the nectaries of Acer platanoides L.

2012 ◽  
Vol 64 (3) ◽  
pp. 19-28 ◽  
Author(s):  
Elżbieta Weryszko-Chmielewska ◽  
Aneta Sulborska
Keyword(s):  
Morphological Characters ◽  
Outer Diameter ◽  
Vascular Bundles ◽  
Acer Platanoides ◽  
Nectar Production ◽  
Male And Female ◽  
Energy Material ◽  
Parenchyma Cells ◽  
Good Exposure ◽  
Scanning Electron

The micromorphology of the nectaries and of other elements of the flower was examined by scanning electron microscopy (SEM). The anatomy of the nectaries was determined using light microscopy (LM). The inflorescences of <i>A. platanoides</i> comprise flowers included in two categories: functionally male and female. Nectaries of similar structure are found in both types of these flowers. The nectary gland located on the surface of the receptacle belongs to interstaminal nectaries. It has the form of a fleshy ring situated between the petals and the pistil. The bases of the staminal filaments are located in the depressions of the nectary. The outer diameter of the nectary reaches ca. 5 mm, while the thickness of this gland's tissues is 400-700 μm. In the epidermis of the nectary gland, there are numerous, evenly distributed stomata through which nectar release occurs. The stomata function asynchronously. In some stomata, we could observe nectar drops flowing out and a layer of this secretion around the stomata. The secretory parenchyma of the nectary is composed of several layers of thick-walled cells, whereas the ends of the vascular bundles with xylem and phloem elements are situated in the subglandular parenchyma. Chloroplasts are found both in the epidermal cells and in the glandular parenchyma cells and photosynthesis can take place in them due to the nectary's good exposure to light. The presence of starch grains was found in the chloroplasts; they can be energy material for nectar production.

scholarly journals Structure of nectaries of Malus sylvestris (L.) Mill.

2012 ◽  
Vol 59 (1) ◽  
pp. 41-48
Author(s):  
Agata Konarska
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Middle Part ◽  
Epidermal Cells ◽  
Secretory Cells ◽  
Floral Nectary ◽  
Malus Sylvestris ◽  
Parenchyma Cells ◽  
Nectariferous Tissue ◽  
Scanning Electron

The structure of floral nectary of <i>Malus sylvestris</i> was examined using light and scanning electron microscopy. Nectaries in <i>M. sylvestris</i> flowers were situated on the adaxial surface of the receptacle, between the style and the base of filaments. The middle part of the nectary was covered epidermal cells with striated cuticle. The remaining part of the nectary was covered with smooth cuticle. Open and modified nectarostomata were situated at the same level as epidermal cells. The nectariferous tissue was formed by densely packed small parenchyma cells (secretory cells) with dark protoplasts.

scholarly journals Flowering pattern, the structure of nectary surface and nectar secretion in two varieties of Ocimum basilicum L.

2012 ◽  
Vol 60 (1) ◽  
pp. 55-65 ◽  
Author(s):  
Mirosława Chwil
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Pollen Grains ◽  
Ocimum Basilicum ◽  
Epidermal Cells ◽  
Nectar Secretion ◽  
Upper Lip ◽  
Flowering Pattern ◽  
Convex Part ◽  
Scanning Electron

The studies conducted in the years 2003-2004 covered two varieties of <i>Ocimum basilicum</i> L.: var. <i>purpurascens</i> Benth. and var. <i>lactucaefolium</i> I. The flower lifetime, daily flowering pattern, morphology of pollen grains and the abundance of nectar secretion of flowers were compared. The surface of the nectaries of <i>O. basilicum</i> var. <i>lactucaefolium</i> was observed using scanning electron microscopy (SEM). The automorphic nectaries of basil formed the following parts: a flat part from the side of the upper lip and a convex part with three protrusions on the opposite side. On the top of two outer protrusions, stomatal areas were located, responsible for nectar secretion. The stomata occurred at the level of other epidermal cells. On the average, nectar contained 42% of sugars. The sugar yield of flowers of var. <i>lactucaefolium</i> was 36% higher than this feature in var. <i>purpurascens</i>. In terms of their size, the pollen grains were rated as medium-sized. Their viability ranged 88-96%. The shape of the pollen grains was described as oblate and suboblate.

scholarly journals Numerical Analysis of Bearing Capacity of a Ring Footing on Geogrid Reinforced Sand

Buildings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 68
Author(s):  
Haidar Hosamo ◽  
Iyad Sliteen ◽  
Songxiong Ding
Keyword(s):  
Numerical Analysis ◽  
Bearing Capacity ◽  
Double Layer ◽  
Practical Importance ◽  
Single Layer ◽  
Outer Diameter ◽  
Storage Container ◽  
Reinforced Sand ◽  
Oil Storage ◽  
Ring Footing

A ring footing is found to be of practical importance in supporting symmetrical constructions for example silos, oil storage container etc. In the present paper, numerical analysis was carried out with explicit code FLAC3D 7.0 to investigate bearing capacity of a ring footing on geogrid reinforced sand. Effects of the ratio n of its inner/outer diameter (Di/D) of a ring footing, an optimum depth to lay the geogrid layer were examined. It was found that an intersection zone was developed in soil under inner-side (aisle) of ring footing, contributing to its bearing capacity. Substantial increase of bearing capacities could be realized if ratio n of a ring footing was around 0.6. Numerical results also showed that, bearing capacity of a ring footing could increase significantly if a single-layer geogrid was laid at a proper depth under the footing. Similar contribution was found if a double-layer geogrid was implemented. However, such increases appeared to be rather limited if a triple-layer geogrid or a four-layer geogrid was used. A double-layer geogrid was recommended to increase the bearing capacity of a ring footing; the depth to lay this double-layer geogrid was also discussed.

scholarly journals Variations and abnormalities of stamen morphologies in cornelian cherry (Cornus mas L.) cultivars

2009 ◽  
Vol 36 (No. 3) ◽  
pp. 109-116 ◽  
Author(s):  
C. Mert ◽  
A. Soylu
Keyword(s):  
Surface Morphology ◽  
Pollen Grain ◽  
Epidermal Cells ◽  
Filament Length ◽  
Cornelian Cherry ◽  
Floral Organs ◽  
Cornus Mas ◽  
Scanning Electron

: Stamen morphologies of six cornelian cherry cultivars (Degirmendere, Erkenci Degirmendere, İri Bardak, Yuvarlak Bardak, Uzun Memeli, and Bugur) (<I>Cornus mas</I> L.) were evaluated using scanning electron, light and stereo microscopes. Flowers of cornelian cherry cultivars generally had four stamens, but a few of them had three or five stamens. Abnormal and normal stamens were found together in the cultivars examined. Percentages of abnormal stamens among the cultivars ranged from 12% to 22%. Various types of stamen abnormalities were identified in the cultivars such as variations in filament length, abnormalities in anther structure, fusion of stamen to other floral organs. Pollen grain numbers per anther varied between 1,380 and 4,240 among the cultivars. Abnormal anther surface morphology in the cultivars consisted of uneven and swollen epidermal cells. Anther dimensions varied between 624.00 and 1,001.25 &mu;m in length and 460.50 and 745.50 &mu;m in width. Anthers of all the cultivars had subprolate and prolate type of shapes.

scholarly journals Breeding biology of coppersmith barbet, Megalaima haemacephala (Müller, 1776)

2013 ◽  
Vol 31 ◽  
pp. 31-34
Author(s):  
Noor Jahan Sarker ◽  
M Firoj Jaman ◽  
Shariar Mustafa ◽  
Md Saidur Rahman
Keyword(s):  
Incubation Period ◽  
Breeding Season ◽  
Breeding Success ◽  
Brood Size ◽  
Botanical Garden ◽  
Egg Laying ◽  
Breeding Biology ◽  
Average Weight ◽  
Average Height ◽  
Average Depth

Breeding biology of the Coppersmith barbet, Megalaima haemacephala (Müller, 1776) was carried out between February, 2006 and January, 2007 at Sharawardy Uddyan, Ramna Park, Curzon Hall and National Botanical Garden. The breeding season started from December and ended in June. In total 20 nests were observed, of which 10 nests were studied in details in four study areas. The coppersmith barbet mostly preferred to make holes on the branches of koroi (Albizzia procera) for nesting. Egg laying started on 15th February in the study areas. Average height of nests from the ground was 9.7m and average depth and diameter of the holes was 29.20cm and 4.46cm respectively. New holes were constructed yearly or the old one was reused. Both the sexes took part in incubation of eggs, brooding and feeding to the nestlings. A total of 30 eggs were laid in 10 nests. Clutch size varied from 2 – 4 eggs (average: 3 eggs). Among them, 20 (66.67%) eggs were hatched and the rest 10 (33.33%) were unhatched and lost. Average incubation period was 14 days. The male and the female incubated the eggs for an average of 27.44 minutes/ hours and 32.56 minutes/ hours, respectively. Average number of nestlings (brood size) per nest was 2. Out of 20 nestlings, 16 left their nests successively. The breeding success was 53.33% in relation to the number of eggs laid and 80% in relation to nestlings hatched. The average weight of eggs and nestlings was 3.59g and 9.33g, respectively. The main causes of loss of the eggs and nestlings were human interference, predation and ectoparasitic infections. Insects and fruits were fed to the nestlings by their parents.DOI: http://dx.doi.org/10.3329/ujzru.v31i0.15397Univ. j. zool. Rajshahi Univ. Vol. 31, 2012 pp. 31-34 

scholarly journals Seed morphology and histology of some Paronychia taxa (Caryophyllaceae) from Turkey

1970 ◽  
Vol 38 (2) ◽  
pp. 171-176 ◽  
Author(s):  
Ayse Kaplan ◽  
Hatice Çölgeçen ◽  
H Nurhan Büyükkartal
Keyword(s):  
Key Words ◽  
Seed Morphology ◽  
Epidermal Cells ◽  
Surface Structures ◽  
Dichotomous Key ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

Seed morphology and histology of 12 taxa (nine species, two subspecies, one variety) of Paronychia Miller (Caryophyllaceae) by light and scanning electron microscopes revealed that seeds are laterally compressed, reniform, and hilums are linear. Testa surface structures are alveolate-scalariform, colliculate, reticulate-alveolate, rugose and ruminate. Differences in cuticle and papillae properties of epidermal cells have been observed. A dichotomous key has been developed for Paronychia agryloba Stapf, P. angorensis Chaudri, P. arabica (L.) DC. subsp. euphratica Chaudri, P. carica Chaudri, P. cataonica Chaudri, P. condensata Chaudri, P. davisii Chaudri, P. dudleyi Chaudri, P. galatica Chaudri, P. kurdica Boiss subsp. kurdica var. kurdica, P. kurdica Boiss subsp. montis-munzur Chaudri and P. mughlaei Chaudri.   Key words: Paronychia; Caryophyllaceae; Seed morphology; Seed histology; Turkey DOI: 10.3329/bjb.v38i2.5142 Bangladesh J. Bot. 38(2): 171-176, 2009 (December)  

Silica in Woody Stems

1974 ◽  
Vol 22 (2) ◽  
pp. 211 ◽  
Author(s):  
G Scurfield ◽  
CA Anderson ◽  
ER Segnit
Keyword(s):  
The Other ◽  
X Ray Diffraction ◽  
Xylem Parenchyma ◽  
X Ray ◽  
Woody Perennial ◽  
Internal Surfaces ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
Ray Parenchyma Cells ◽  
Scanning Electron

Scanning electron microscopy has been used to examine silica isolated by chemical means from the wood of 32 species of woody perennial. The silica consists of aggregate grains lying free in the lumina or in ray and xylem parenchyma cells in 24 of the species. It occurs as dense silica in the other species, filling the lumina or lining the internal surfaces of vessels (and fibres) in all cases except Gynotroches axillaris where it is deposited in ray parenchyma cells. Infrared spectra and X-ray diffraction diagrams, obtained for specimens of both sorts of silica, are indistinguishable from those for amorphous silica. Aggregate grain and dense silicas are also alike in that their differential thermal analysis curves show a rather broad endothermic peak between 175° and 205°C. The results are discussed in relation to possible modes of deposition of the two sorts of silica and the tendency for silica in ray parenchyma cells to be associated with polyphenols.

Efficient synthesis of carbon nanotubes with improved surface area by low-temperature solvothermal route from dichlorobenzene

2013 ◽  
Vol 67 (11) ◽  
Author(s):  
Gantigaiah Krishnamurthy ◽  
Sarika Agarwal
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Carbon Source ◽  
Surface Area ◽  
Heating Temperature ◽  
Outer Diameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

AbstractThe synthesis of well-aggregated carbon nanotubes in the form of bundles was achieved by the catalytic reduction of 1,2-dichlorobenzene by a solvothermal approach. The use of 1,2-dichlorobenzene as a carbon source yielded a comparably good percentage of carbon nanotubes in the range of 60–70 %, at a low reaction temperature of 200°C. The products obtained were analysed by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy techniques. The X-ray diffraction studies implied the presence of pure, crystalline, and well-ordered carbon nanotubes. The scanning electron and transmission electron microscopic images revealed the surface morphology, dimensions and the bundled form of the tubes. These micrographs showed the presence of multi-walled carbon nanotubes with an outer diameter of 30–55 nm, inner diameter of 15–30 nm, and lengths of several hundreds of nanometers. Brunauer-Emmett-Teller-based N2 gas adsorption studies were performed to determine the surface area and pore volume of the carbon nanotubes. These carbon nanotubes exhibit a better surface area of 385.30 m2 g−1. In addition, the effects of heating temperature, heating time, amount of catalyst and amount of carbon source on the product yield were investigated.

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