scholarly journals Differences in the structure of pollen in the ‘Senga Sengana’ and ‘Selva’ cultivars of Fragaria × ananasa

2020 ◽  
Vol 75 (4) ◽  
Author(s):  
IZABELA BORKOWSKA ◽  
MARCIN DOMACIUK ◽  
MARIA BERNAT
Keyword(s):  
Electron Microscope ◽  
Pollen Grains ◽  
Optical Microscope ◽  
Pollen Grain ◽  
Fragaria Ananassa ◽  
Arable Crops ◽  
Fertile Pollen ◽  
Rosaceae Family ◽  
Fresh Pollen ◽  
Scanning Electron

The strawberry belongs to one of the youngest species of arable crops. The study aimed to analyze pollen's structure in the ‘Senga Sengana’ and ‘Selva’ cultivars of Fragaria × ananassa. The strawberry is a dicotyledonous plant from the Rosaceae family. The article presents research carried out on Fragaria × ananassa cv. ‘Senga Sengana’ and ‘Selva’ collected during flowering. Pollen mor-phology was examined using a scanning electron microscope and a traditional optical microscope. The results showed that fresh pollen outnumbered dead pollen, confirming that the ‘Senga Sengana’ culti-var produces larger amounts of fertile pollen. Mature ‘Senga Sengana’ pollen grains are characterized by a specific sculpture of the exine walls. The analysis of Selva pollen grains revealed substantial changes in the structure of the sporoderm during its maturation. It becomes thicker and, as the size of the pollen grain increases, the exine layer becomes more elaborate.

scholarly journals Palyno-morphology of Hedera L. (The ivy genus, araliaceae) and their systematics implications

Genetika ◽  
2021 ◽  
Vol 53 (2) ◽  
pp. 851-865
Author(s):  
Fahimeh Fallah ◽  
Farrokh Ghahremaninejad
Keyword(s):  
Grain Size ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Hedera Helix ◽  
Transmission Electron ◽  
Pollen Grain Size ◽  
The Relationship ◽  
Scanning Electron

The palynomorphological characteristics of 5 species belonging to Hedera of the Araliaceae family were studied in detail. These plant species were collected from various phytogeographical regions of Iran and Hungary. The palynological investigation was accomplished using Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM). Pollen grains of the species are reticulate, prolate, sub-prolate, tricolporate, isopolar, radially symmetrical, and monad. The largest pollen grain was in the Hedera colchica species (72.24?1.6 ?m) and the smallest pollen grain was in Hedera helix (28.63?2.1 ?m). The research carried out by the TEM showed that the species were different in terms of exine thickness, tectum thickness, foot layer thickness, the diameter and length of the Columella, the thickness and shape of the Caput, the tectum to foot layer )T/F( ratio, the absence or presence of the Endexine and the thickness of the Intine layers. The main purpose of this study was the importance of the relationship between pollen grain size and the number of chromosomes and ploidy level in Hedera species.

scholarly journals Pollen morphology of Plantago species native to Poland and their taxonomic implications

2011 ◽  
Vol 73 (4) ◽  
pp. 315-325 ◽  
Author(s):  
Małgorzata Klimko ◽  
Krystyna Idzikowska ◽  
Mariola Truchan ◽  
Anna Kreft
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscope ◽  
Pollen Morphology ◽  
Pore Diameter ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Prolate Spheroidal ◽  
Taxonomic Implications ◽  
Scanning Electron

Pollen grains of 9 species of the genus <em>Plantago</em> (Plantaginaceae), including 8 taxa native to Poland, were observed under a light microscope and a scanning electron microscope. Descriptions of grain sculpture are illustrated only SEM micrographs. The studied pollen grains were medium-sized or small, spherical or prolate spheroidal. Their sculpture was always verrucate with granulation. In the studied taxa, internal apertures had the form of pores. Their number ranged from (4)5-9(14). The pores were scattered on the surface of pollen grains. Identification features of individual taxa include: presence or absence of an annulus around each pore, annulus structure, ornamentation of the pollen grain and operculum, type of aperture membrane, number of internal pores, and pore diameter. We suggest that two new pollen grain types, characteristic of <em>P. intermedia</em> and <em>P. arenaria</em>, should be distinguished, and that <em>P. alpina</em> should be assigned to the <em>P. coronopus</em> type.

scholarly journals Morphology of pollen grains of 25 species of Salix (Salicaceae) of the Asian part of Russia according to electron microscopy

2019 ◽  
pp. 94-101 ◽  
Author(s):  
A. A. Petruk
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Pollen Grains ◽  
Grain Morphology ◽  
Polar Axis ◽  
Pollen Grain ◽  
Equatorial Diameter ◽  
Different Shapes ◽  
Pollen Grain Morphology ◽  
Scanning Electron

This is a study of pollen grain morphology of 25 species of the genus Salix L. (Salicaceae) from of the Asian part of Russia was carried out with the use of scanning electron microscope. All species had 3-colpate pollen grains. The length of the polar axis varied from 14 to 30 mkm, the length of the equatorial diameter - from 9.5 to 17.4 mkm. This study has shown the different shapes of the pollen grains, such as the elliptic, broadly and narrowly elliptic.

scholarly journals Pollinic characterization of Raulinoa echinata R. S. Cowan (Rutaceae), Dyckia brevifolia Baker and Dyckia ibiramensis Reitz (Bromeliaceae), reophyte and saxicolous endemic species of river Itajaí-Açu, Santa Catarina, Brazil

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Denise Monique Dubet da Silva Mouga ◽  
Bruna Tereza Possamai ◽  
Enderlei Dec ◽  
Sílvio Murilo Cristóvão Da Silva
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Endemic Species ◽  
Pollen Grains ◽  
Bilateral Symmetry ◽  
Radial Symmetry ◽  
Medium Size ◽  
Fresh Pollen ◽  
Scanning Electron

Aiming to contribute with elements about the reproduction of the reophytes Raulinoa echinata, Dyckia brevifolia and Dyckia ibiramensis as well as to support their taxonomic definition,  their pollinic characterization was carried out. Fresh pollen grains were prepared by acetolysis. Observations occurred on a light microscope and a scanning electron microscope. Measures were done of the polar (P) and equatorial diameters (E) and thickness of the exine and are expressed as means in micrometers. R. echinata: monad; radial symmetry; medium size; P=49,07±3,33; E=33,95±3,94; prolate (ratio P / E); ambitus subtriangular; 3-aperturated with long colpi and lalongate endoapertures; exine striated with  thickness 1.54 ± 0,32. Dyckia brevifolia: monad; bilateral symmetry; medium size; P=25,16 ± 3,02; E=43,16±3,50 x 28,12±3,26; ambitus elliptical; monoaperturated with one long sulcus; exine reticulate with thickness 1,66 ± 0,31. D. ibiramensis: monad; bilateral symmetry; medium size; P=29,54±3,17; E=42,36±3,60 x 28,43±3,38; ambitus elliptical; monoaperturated with one long sulcus; exine reticulate with thickness 1,73 ± 0,28. Data obtained can allow to verify hydrophily for the three species as well as suggest Raulinoa proximity with Metrodorea and Esenbeckia (both Pilocarpinae) and confirm D. brevifolia e D. ibiramensis to Pitcairnioideae. 

Organoclay-reinforced polyethersulfone-modified epoxy-based hybrid nanocomposites

2011 ◽  
Vol 23 (7) ◽  
pp. 526-534 ◽  
Author(s):  
Yang Wang ◽  
Boming Zhang ◽  
Jinrui Ye
Keyword(s):  
Electron Microscopy ◽  
Fracture Toughness ◽  
Electron Microscope ◽  
Optical Microscope ◽  
Mechanical Analysis ◽  
Hybrid Nanocomposites ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Modified Epoxy ◽  
Scanning Electron

Hybrid nanocomposites were successfully prepared by the incorporation of polyethersulfone (PES) and organoclay into epoxy resin. They had higher fracture toughness than the prepared PES/epoxy blend and organoclay/epoxy nanocomposites. The microstructures of the hybrid nanocomposites were studied. They were comprised of homogeneous PES/epoxy semi-interpenetrating network (semi-IPN) matrices and organoclay micro-agglomerates made up of tactoid-like regions composed of ordered exfoliated organoclay with various orientations. The former was confirmed with dynamic mechanical analysis, scanning electron microscopy and transmission electron microscopy, while the latter was successfully observed with X-ray diffraction measurements, optical microscope, scanning electron microscope and transmission electron microscope. The improvement of their fracture toughness was due to the synergistic toughening effect of the PES and the organoclay and related to their microstructures.

Effect of Casting Overheat and Rolling Temperature on Morphology of Sulfide in 30MnVS Steel

2012 ◽  
Vol 457-458 ◽  
pp. 270-273
Author(s):  
Yi You Tu ◽  
Guo Zhong Li
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Continuous Casting ◽  
Optical Microscope ◽  
Rolling Temperature ◽  
Ferrite Content ◽  
Continuous Casting Slab ◽  
Intragranular Ferrite ◽  
Sulfide Segregation ◽  
Scanning Electron

Effect of superheat and initial rolling temperature on the morphology and distribution of sulfide in non quenched and tempered free cutting steel 30MnVS has been studied by optical microscope and scanning electron microscope. Results show that proper superheat and initial rolling temperature can turn rod-shaped sulfide into massive or globular sulfide，to alleviate sulfide segregation and pro-eutectoid ferrite distribution along the boundary of pearlite clusters in 30MnVS , increase the intragranular ferrite content and optimize the structure of continuous casting slab.

Analysis of an Axle Failure under Torsional Load

2016 ◽  
Vol 850 ◽  
pp. 101-106 ◽  
Author(s):  
Shu Mei Li ◽  
Jian Jun Yang ◽  
Wei Dong Zhang ◽  
August Chang ◽  
Cai Xia Zhang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Failure Mechanism ◽  
Field Testing ◽  
Optical Microscope ◽  
Fatigue Lifetime ◽  
Torsional Load ◽  
Torsional Fatigue ◽  
Secondary Cracks ◽  
Scanning Electron

Premature fracture of an axle under torsional load occurred after a tracked military tank had experienced field testing for only 80 kilometers. Visual metallographic examinations were performed with optical microscope (OM) and scanning electron microscope (SEM). The investigation demonstrates that the premature fracture is caused by metallurgical problems inside the axle where the primary and secondary cracks originate, propagate, and eventually result in final catastrophic rupture through torsional fatigue. The failure mechanism is summarized and improvement of the fatigue lifetime for the axle is recommended.

scholarly journals Características palinológicas de las araliáceas de México

2017 ◽  
pp. 117 ◽  
Author(s):  
Victoria Sosa
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscope ◽  
Pollen Grains ◽  
Point Of View ◽  
Generic Level ◽  
Dichotomous Key ◽  
Pollen Characters ◽  
Scanning Electron

This work studies 17 species of mexican Araliaceae from the palynological point of view belonging to the genera Aralia, Dendropanax, Didymopanax, Redera, Oreopanax y Sciadodendron . All the pollen descriptions are presented at the generic level. The grains were studied based in scanning electron microscope and light microscope. It includes a dichotomous key for the genera grains. The results showed few differences between the pollen grains of the genera although some exine characters are important. Redera and Didymopanax presented an exine semi-tectate and the rest of the genera had tectate-perforate grains. This paper compared also some pollen characters with morphological ones, finding pollen characters considered primitive correlated with characters of primitive Araliaceae groups .

Investigation on the Microstructure Hardness for the Hot Compressed Duplex Steel

2022 ◽  
Vol 905 ◽  
pp. 30-37
Author(s):  
Shu Lan Zhang ◽  
Xiao Dan Zhang ◽  
Hai Feng Xu ◽  
Chang Wang
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Optical Microscope ◽  
Ferrite Phase ◽  
Ferrite Formation ◽  
Average Hardness ◽  
Duplex Steel ◽  
Quench Temperature ◽  
Fluctuation Range ◽  
Scanning Electron

Effect of microstructure size and type on the hardness for the duplex steel were disclosed by using of optical microscope (OM), scanning electron microscope (SEM) and nanoindenter for the samples hot compressed under different temperature with reduction of 10%, 30%, 50% and 70%. OM and SEM were used to measure the average martensite lamellar width, space and indenter morphology. nanoindenter test characterized the microstructure hardness for the samples under different process. Experiment results show that martensite hardness for the sample hot compressed at 950°C has larger diversity than that of sample hot compressed at 1200°C. The martensite hardness fluctuation range for the sample compressed at 950°C is almost from about 7GPa to 12GPa, while, for the sample compressed at 1200°C, the fluctuation range is basically from about 9GPa to 12GPa. However, the average hardness for the samples hot compressed at 950°C is comparably smaller, which is related with lower quench temperature. The larger martensite hardness fluctuation is mainly related with induced ferrite formation and finer martensite lamellar width. For the ferrite phase, the hardness fluctuation range is lower.

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