Induction of nucellar embryogenesis in nucellar tissue of Citrus aurantifolia for their clonal multiplication

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Manjula Singh ◽  
S.P. Paliwal ◽  
Shailendra Singh
Keyword(s):  
Malt Extract ◽  
Clonal Multiplication ◽  
Citrus Aurantifolia ◽  
Globular Embryos ◽  
Ex Vitro Growth ◽  
Nucellar Tissue ◽  
Intermediate Response ◽  
Well Differentiated ◽  
Pass Through ◽  
Further Development

Citrus aurantifolia (lime) has been selected as explant for nucellar embryogenesis. Nucellus is a non-vascularized tissue being true-to-type same as mother plant, meristematic cells have no plasmodesmata connection, no virus can pass through nucellus, thus it seems to be a good material for production of virus freeplantlet.Putrescine at 0.25 or 0.5 mg1-1 and anapthaleneacetic acid at 0.10 mg1-1 supplemented to nutrient formulation were most effective in alleviating cotyledonary proliferation and fasciation while promoting embryo-to-embryo proliferation producing numerous whitish globular embryos were formed. For further development of globular embryos to well-differentiated cotyledonary embryos, additional presence of 2-isopentenyladenine at concentrations of 0.10 or 0.25 mg 1-1 was essential, contrary to incorporation of 0.10 or 0.25 mg 1-1 6benzylaminopurine, which promoted excessive proliferation of cotyledonary structures and their fasciation while zeatin at the same concentrations produced intermediate response. In the optimum treatment containing 0.25 mg l-1 putrescine, 0.10 mg 1-1 isopentenyladenine, 0.10 mg 1-1 indole-3-acetic acid and 100 mg l-1 malt extract, an average 10 well-developed embryos per culture were formed, besides some abnormal cotyledonary structures. Well-developed embryos measuring ca. 2 cm. in length (leaving the root) germinated 100% into plantlets, during 60 days, in the additional presence of amino acid supplement comprising, 5 mg 1-1 each of L-arginine, L-asparagine, L-histidine, L-cysteine, L-lysine and 10 mg l-1 L-glutamine. Such plantlets nurtured in a different medium attained a height of ca. 4 cm in 45 days before they were taken out for ex vitro growth. There was 100% transplant success and the plants grew normally.

Somatic embryogenesis in tissue cultures of Podophyllum hexandrum

1990 ◽  
Vol 68 (3) ◽  
pp. 487-491 ◽  
Author(s):  
N. Arumugam ◽  
Sant S. Bhojwani
Keyword(s):  
Somatic Embryogenesis ◽  
Somatic Embryos ◽  
Basal Medium ◽  
Podophyllum Hexandrum ◽  
Zygotic Embryos ◽  
Tissue Cultures ◽  
Globular Embryos ◽  
Further Development ◽  
Sucrose Level

In vitro multiplication of Podophyllum hexandrum Royle (Podophyllaceae) via somatic embryogenesis is reported. The callus derived from zygotic embryos on Murashige and Skoog medium containing 2 μM BA and 0.5μM IAA differentiated globular embryos. On this medium the globular embryos continued to multiply but failed to mature. Further development of the embryos occurred if the sucrose level in the basal medium was raised to 6% or the medium was supplemented with 1–10 μM NAA. Light and temperatures higher than 25 °C suppressed embryogenesis. Embryogenic potential of the callus has been maintained for over 20 months through subcultures. The somatic embryos developed into plantlets on the basal medium. Key words: endangered species, podophyllotoxin, Podophyllum, somatic embryogenesis.

The Oxford Handbook of Dynamic Capabilities

2015 ◽  
Keyword(s):  
Dynamic Capabilities ◽  
Deep Understanding ◽  
Capabilities Approach ◽  
Publication Date ◽  
Strategic Decisions ◽  
Business Decision ◽  
Big Picture ◽  
Impossible Task ◽  
Pass Through ◽  
Further Development

This handbook is currently in development, with individual articles publishing online in advance of print publication. At this time, we cannot add information about unpublished articles in this handbook, however the table of contents will continue to grow as additional articles pass through the review process and are added to the site. Please note that the online publication date for this handbook is the date that the first article in the title was published online. For more information, please read the site FAQs. In order to make quality strategic decisions, managers need a deep understanding of industry dynamics and enterprise capabilities. In this book, we present a conceptual framework that will help executives lead their organizations in highly competitive global markets. For some, it will change frames of reference and accepted priorities in terms of what’s important for the enterprise to build, own, and manage. Management theory is young and fragmented, and generally not much of a guide for executives, except around certain narrow issues. The framework presented in this volume can be helpful with the big-picture issues. To be useful, a theoretical framework must be flexible enough to provide guidance in a variety of situations. However, the theory must not be so general that it fails to speak to practical management problems. Another useful attribute is parsimony, so that an overwhelming number of variables don’t render analysis an impossible task. This book includes a number of essays about the Dynamic Capabilities Framework (Teece et al., 1990, 1997; Teece, 2007), which increasingly provides an intellectual infrastructure for both theoretical and applied analyses of strategic management and other issues facing business decision makers. Since 2006, articles concerning dynamic capabilities have been published in business and management journals at a rate of more than 100 per year (Di Stefano et al., 2010). And an increasing number of these articles contain new empirical research validating the Dynamic Capabilities approach to competitive advantage. A broad panoply of scholars and executives are contributing to the further development of this framework. This book summarizes and integrates many of these contributions, and this introduction will introduce some of the major themes of the chapters that follow.

Results with a Multi Stage System of Filtration Employing a Cyclone

2009 ◽  
Vol 630 ◽  
pp. 147-154
Author(s):  
John H. Courtenay ◽  
Frank Reusch
Keyword(s):  
Liquid Metal ◽  
Ceramic Foam ◽  
Grain Refiner ◽  
Foam Filter ◽  
Multi Stage ◽  
Stage System ◽  
Pass Through ◽  
Further Development ◽  
Final Chamber ◽  
Industrial Prototype

The development of a new prototype multi stage filter was described at TMS 2008 in which a ceramic foam filter was applied in a first chamber operating in cake mode; grain refiner added in a second chamber and a cyclone deployed in a final chamber to ensure removal of any oxides or agglomerates arising from the grain refiner addition or release events from the foam filter. The first industrial prototype was installed at Trimet Aluminium at Essen in Germany and demonstrated that liquid metal could pass through the cyclone successfully without excessive turbulence or splash. The further development of the prototype based on new water modeling work is described.

scholarly journals A potential microbial control for fireweed (Epilobium angustifolium)

2005 ◽  
Vol 75 (1) ◽  
pp. 19-33 ◽  
Author(s):  
R.S. Winder ◽  
A.K. Watson
Keyword(s):  
Microbial Control ◽  
Pathogenic Fungi ◽  
Field Trials ◽  
Control Agent ◽  
Malt Extract ◽  
Promising Candidate ◽  
Test Species ◽  
Epilobium Angustifolium ◽  
Screening Assays ◽  
Further Development

Diseased fireweed (Epilobium angustifolium) plants were collected in Quebec and organisms isolated from these plants were evaluated as potential biocontrol agents. Thirteen pathogenic fungi were isolated and three of these (Colletotrichum dematium, Seimatosporium kriegerianum, and Alternaria alternata) were virulent in initial screening assays. C. dematium was selected for further study because it was the most virulent pathogen, causing large necrotic lesions on leaves and stems of infected plants. Inoculum production was optimized on modified malt extract agar and the virulence enhanced by suppression of the conidial matrix with tannic acid and the addition of extracts of Aloe saponaria. The fungus was pathogenic to fireweed and E. lanceolatum, while other test species were very resistant or immune. Measurements of conidial and appressorial dimensions and its restricted host range support the hypothesis that the isolate may be an unreported form-species. Application of formulated conidia consistently provided 100% mortality of 7-wk-old inoculated fireweed rosettes within 48 h using 109 conidia m-2, from 10- to 15-d-old inoculum, and a 18- to 24-h dew period. Virulence was diminished in older plants. In field trials, growth of inoculated rosettes was reduced by 33%. These results suggest that C. dematium is a promising candidate for further development as a control agent for seedling fireweed in silviculture.

scholarly journals A comparison of three programming languages for a full-fledged next-generation sequencing tool

2019 ◽  
Author(s):  
Costanza Pascal ◽  
Herzeel Charlotte ◽  
Verachtert Wilfried
Keyword(s):  
Programming Languages ◽  
Main Memory ◽  
Complex Task ◽  
Sequencing Data ◽  
Runtime Performance ◽  
Pass Through ◽  
Reference Counting ◽  
The One ◽  
Further Development ◽  
Generation Sequencing

AbstractBackgroundelPrep is an established multi-threaded framework for preparing SAM and BAM files in sequencing pipelines. To achieve good performance, its software architecture makes only a single pass through a SAM/BAM file for multiple preparation steps, and keeps sequencing data as much as possible in main memory. Similar to other SAM/BAM tools, management of heap memory is a complex task in elPrep, and it became a serious productivity bottleneck in its original implementation language during recent further development of elPrep. We therefore investigated three alternative programming languages: Go and Java using a concurrent, parallel garbage collector on the one hand, and C++17 using reference counting on the other hand for handling large amounts of heap objects. We reimplemented elPrep in all three languages and benchmarked their runtime performance and memory use.ResultsThe Go implementation performs best, yielding the best balance between runtime performance and memory use. While the Java benchmarks report a somewhat faster runtime than the Go benchmarks, the memory use of the Java runs is significantly higher. The C++17 benchmarks run significantly slower than both Go and Java, while using somewhat more memory than the Go runs. Our analysis shows that concurrent, parallel garbage collection is better at managing a large heap of objects than reference counting in our case.ConclusionsBased on our benchmark results, we selected Go as our new implementation language for elPrep, and recommend considering Go as a good candidate for developing other bioinformatics tools for processing SAM/BAM data as well.

Instrumentation for detecting channelling radiation in the high-voltage electron microscope

1983 ◽  
Vol 41 ◽  
pp. 318-319
Author(s):  
J. H. Butler ◽  
C. J. Humphreys
Keyword(s):  
Monochromatic Light ◽  
Incident Beam ◽  
Laboratory Frame ◽  
Relativistic Electrons ◽  
Voltage Electron ◽  
Dipole Emission ◽  
Sinusoidal Oscillations ◽  
Pass Through ◽  
Incident Beam Energy ◽  
Increasing Function

Electromagnetic radiation is emitted when fast (relativistic) electrons pass through crystal targets which are oriented in a preferential (channelling) direction with respect to the incident beam. In the classical sense, the electrons perform sinusoidal oscillations as they propagate through the crystal (as illustrated in Fig. 1 for the case of planar channelling). When viewed in the electron rest frame, this motion, a result of successive Bragg reflections, gives rise to familiar dipole emission. In the laboratory frame, the radiation is seen to be of a higher energy (because of the Doppler shift) and is also compressed into a narrower cone of emission (due to the relativistic “searchlight” effect). The energy and yield of this monochromatic light is a continuously increasing function of the incident beam energy and, for beam energies of 1 MeV and higher, it occurs in the x-ray and γ-ray regions of the spectrum. Consequently, much interest has been expressed in regard to the use of this phenomenon as the basis for fabricating a coherent, tunable radiation source.

Radiation Damage, Contrast and Statistics in High Resolution Biological Electron Microscopy

1970 ◽  
Vol 28 ◽  
pp. 260-261
Author(s):  
Robert M. Glaeser
Keyword(s):  
High Resolution ◽  
Particle Flux ◽  
Unit Area ◽  
Signal To Noise ◽  
Resolution Image ◽  
High Resolution Image ◽  
Pass Through ◽  
Counting Statistics ◽  
The Relationship ◽  
Picture Element

It is well known that a large flux of electrons must pass through a specimen in order to obtain a high resolution image while a smaller particle flux is satisfactory for a low resolution image. The minimum particle flux that is required depends upon the contrast in the image and the signal-to-noise (S/N) ratio at which the data are considered acceptable. For a given S/N associated with statistical fluxtuations, the relationship between contrast and “counting statistics” is s131_eqn1, where C = contrast; r2 is the area of a picture element corresponding to the resolution, r; N is the number of electrons incident per unit area of the specimen; f is the fraction of electrons that contribute to formation of the image, relative to the total number of electrons incident upon the object.

Application of TEM to Deformation, Wear, and Fracture of Ceramics

1974 ◽  
Vol 32 ◽  
pp. 472-473
Author(s):  
B. J. Hockey
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Brittle Materials ◽  
High Temperature Strength ◽  
Wide Range ◽  
Corrosive Environments ◽  
Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

Ultrastructure of NPC/HK1 cells heterotransplanted in athymic nude mice

1982 ◽  
Vol 40 ◽  
pp. 236-237
Author(s):  
E.C. Chew ◽  
C.L. Li ◽  
D.P. Huang ◽  
H.C. Ho ◽  
L.S. Mak ◽  
...  
Keyword(s):  
Cell Line ◽  
Nude Mice ◽  
Biopsy Specimen ◽  
Epithelial Cell Line ◽  
Present Communication ◽  
Recurrent Tumour ◽  
Athymic Nude Mice ◽  
Cell Line Establishment ◽  
Fine Structures ◽  
Well Differentiated

An epithelial cell line, NPC/HK1, has recently been established from a biopsy specimen of a recurrent tumour of the nasopharynx which was histologically diagnosed as a moderately to well differentiated squamous cell carcinoma. A definite decrease in the amount of tonofilaments and desmosomes in the NPC/HK1 cells during the cell line establishment was observed. The present communication reports on the fine structures of the NPC/HK1 cells heterotraneplanted in athymic nude mice.

An Established Epithelial Cell Line (NPC/HK1) from a Nasopharyngeal Carcinoma - II. A Sem Study

1982 ◽  
Vol 40 ◽  
pp. 224-225
Author(s):  
Li C.L. ◽  
Chew E.C. ◽  
Huang D.P. ◽  
Ho H.C. ◽  
Mak L.S. ◽  
...  
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Epithelial Cell ◽  
Surface Morphology ◽  
Cell Line ◽  
Epithelial Cell Line ◽  
Present Communication ◽  
Cells In Culture ◽  
Sem Study ◽  
Well Differentiated

An epithelial cell line, NPC/HK1, has recently been successfully established from a nasopharyngeal carcinoma of the moderately to well differentiated squamous type. The present communication reports on the surface morphology of the NPC/HK1 cells in culture.

Sign in / Sign up

Export Citation Format

Share Document