scholarly journals Use of Stored Pollen to Hybridize a Mandarin Hybrid and Citrus tachibana

HortScience ◽  
1992 ◽  
Vol 27 (1) ◽  
pp. 43-44
Author(s):  
Randall P. Niedz ◽  
Michael G. Bausher ◽  
C. Jack Hearn
Keyword(s):  
Silica Gel ◽  
Glutamate Oxaloacetate Transaminase ◽  
Anhydrous Acetone ◽  
Freeze Dried ◽  
Fresh Pollen

Fresh pollen from Citrus tachibana Macf. was oven-dried (37C), freeze-dried, or placed into anhydrous acetone, and stored at -20C over silica gel. Pollen freeze-dried or stored in anhydrous acetone did not germinate 24 hours after treatment; oven-dried pollen germinated in 1 hour and was comparable to fresh pollen. Pollen that was oven-dried for 12 hours and stored for 1 year was used to pollinate a monoembryonic hybrid of `Temple' (origin unknown) × `Orlando' (C. paradisi Macf. `Duncan' ×C. reticulata Blanco `Dancy'). Glutamate-oxaloacetate transaminase (GOT) isozyme profiles verified progeny hybridity.

Determination of Aflatoxins in Animal Tissues

1981 ◽  
Vol 64 (4) ◽  
pp. 964-968
Author(s):  
Robert D Stubblefield ◽  
Odette L Shotwell
Keyword(s):  
Citric Acid ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Silica Gel ◽  
Determination Limit ◽  
Animal Tissues ◽  
Freeze Dried ◽  
Human Livers ◽  
Layer Chromatography

Abstract A method for the determination of aflatoxins in animal tissues has been developed, and applied successfully to beef, swine, chicken, and human livers, and to beef kidney, heart, spleen, muscle, and blood. Blended tissue is denatured with citric acid and extracted with dichloromethane on a wrist-action shaker. After filtration, the extract is partially purified on a silica gel column, and aflatoxins B1 and M1 are determined by 2-dimensional thin layer chromatography and densitometry. Recoveries of Bi and Mi added to meat tissues and blood were approximately 90 and 80%, respectively. The method gave results for a contaminated freeze-dried liver comparable to analyses by 3 other published meat tissue methods. The method is rapid and has a determination limit ≤0.1 ng/g. In addition, the method uses less toxic and smaller quantities of solvents and chemicals.

scholarly journals Isolation and Bioactivity Analysis of Ethyl Acetate Extract fromAcer tegmentosumUsing In Vitro Assay and On-Line Screening HPLC-ABTS+System

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Kwang Jin Lee ◽  
Na-Young Song ◽  
You Chang Oh ◽  
Won-Kyung Cho ◽  
Jin Yeul Ma
Keyword(s):  
Phenolic Compounds ◽  
Ethyl Acetate ◽  
Silica Gel ◽  
Hot Water ◽  
Assay Method ◽  
Vitro Assay ◽  
Chemical Structures ◽  
Freeze Dried ◽  
On Line

TheAcer tegmentosum(3 kg) was extracted using hot water, and the freeze-dried extract powder was partitioned successively using dichloromethane (DCM), ethyl acetate (EA), butyl alcohol (n-BuOH), and water. From the EA extract fraction (1.24 g), five phenolic compounds were isolated by the silica gel, octadecyl silica gel, and Sephadex LH-20 column chromatography. Based on spectroscopic methods such as1H-NMR,13C-NMR, and LC/MS the chemical structures of the compounds were confirmed as feniculin (1), avicularin (2), (+)-catechin (3), (−)-epicatechin (4), and 6′-O-galloyl salidroside (5). Moreover, a rapid on-line screening HPLC-ABTS+system for individual bioactivity of the EA-soluble fraction (five phenolic compounds) was developed. The results indicated that compounds1and2were first isolated from theA. tegmentosum. The anti-inflammatory activities and on-line screening HPLC-ABTS+assay method of these compounds in LPS-stimulated murine macrophages were rapid and efficient for the investigation of bioactivity ofA. tegmentosum.

Reproductive biology of Melaleuca alternifolia (Myrtaceae) 2. Incompatibility and pollen transfer in relation to the breeding system

2010 ◽  
Vol 58 (5) ◽  
pp. 384 ◽  
Author(s):  
L. Baskorowati ◽  
M. W. Moncur ◽  
S. A. Cunningham ◽  
J. C. Doran ◽  
P. J. Kanowski
Keyword(s):  
Pollen Tube ◽  
Pollen Grains ◽  
Pollen Tubes ◽  
Self Incompatibility ◽  
Melaleuca Alternifolia ◽  
Freeze Dried ◽  
Thrips Species ◽  
Fresh Pollen ◽  
Floral Visitors ◽  
Capsule Retention

The onset of stigma receptivity in Melaleuca alternifolia (Maiden & Betche) Cheel was evaluated by observing pollen-tube growth and seed set following controlled pollination. Pollen-tube numbers in the style, following controlled pollinations, increased from Day 1 to Day 6, then declining rapidly. The stigma was most receptive during Days 3–6, and still receptive at low levels as early as shortly after anthesis and as late as 10 days after pollination. The present study found that individuals of M. alternifolia differed in their degree of expression of self-incompatibility. Artificial self-pollination, with emasculation, in several families resulted in complete self-incompatibility, with no capsule retention. The microscopic observation of pollen-tube development revealed a mechanism of self-incompatibility in M. alternifolia. A self-incompatibility system operates in the style, although a few self-pollen grains are capable of germinating and producing pollen tubes. It also appears that late-acting self-incompatibility mechanisms discriminate against self-pollen tubes when they descend to the ovary. Artificial cross-pollination of selected parents produced seed with greater germination capacity and seedlings that grew faster than the corresponding open-pollinated seed and seedlings from the same parent. Freeze-dried pollen stored at −18°C maintained viability (22%) over 1 year of storage. This finding will allow greater flexibility in undertaking controlled pollinations, because stored pollen can be substituted for fresh pollen when insufficient quantities are available from new-season flowers. A wide variety of insects was observed visiting the flowers of M. alternifolia, and capsule set was high even in bags that excluded flower visitors greater than 2 mm. Thrips species seem likely to be important pollinators of this species because they are small and were abundant inside and outside of exclusion bags, although several other insect species such as bees, flies and wasps were also identified as frequent floral visitors.

scholarly journals Conservation process of water-damaged herbarium specimens at the Harvard University Herbaria

2014 ◽  
Vol 28 (1-2) ◽  
pp. 8-15
Author(s):  
Melinda Peters
Keyword(s):  
Silica Gel ◽  
Cooling System ◽  
Harvard University ◽  
Herbarium Specimens ◽  
Plant Parts ◽  
Pipe Burst ◽  
Heating And Cooling ◽  
Plastic Bags ◽  
Freeze Dried ◽  
Scientific Value

Abstract In December 2009, following an upgrade of the Harvard University Herbaria's heating and cooling system, a pipe burst in one room, resulting in the soaking of specimens in the adjacent cases. The soaked specimens were removed, and the degree of water damage was assessed. The saturated specimens were placed in plastic bags and immediately transferred to a walk-in freezer set at −20°C. Slightly wet specimens were spread out to air dry. Restoration of the frozen specimens involved tests to determine the most effective method for restoring them to usable condition. Test specimens of no scientific value were intentionally soaked, then dried using two procedures: (1) silica gel desiccation and (2) vacuum freeze drying. Freeze-dried specimens did not adhere to each other as much as did those that were dried with silica gel and was the method chosen. Upon their return, the dried specimens were sorted into groups: (1) those that were immediately ready to be returned to the collection, (2) those requiring minor repair, such as reattaching detached labels or plant parts, and (3) those requiring major repair. All specimens were annotated to indicate that they were water damaged and the method of restoration used and then they were returned to the collection.

Change of pore structure in freeze-dried silica gel during calcination

2004 ◽  
Vol 39 (3) ◽  
pp. 1037-1040 ◽  
Author(s):  
S. J. Choi ◽  
H. C. Park ◽  
R. Stevens
Keyword(s):  
Pore Structure ◽  
Silica Gel ◽  
Freeze Dried

Three-Dimensional Reconstruction Using Stereo Pairs from Serial Thick Sections

1977 ◽  
Vol 35 ◽  
pp. 562-563
Author(s):  
Robert Glaeser ◽  
Thomas Bauer ◽  
David Grano
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Serial Sections ◽  
Thin Sections ◽  
3 Dimensional ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Dimensional Reconstruction ◽  
Stereo Imagery ◽  
Whole Mounts

In transmission electron microscopy, the 3-dimensional structure of an object is usually obtained in one of two ways. For objects which can be included in one specimen, as for example with elements included in freeze- dried whole mounts and examined with a high voltage microscope, stereo pairs can be obtained which exhibit the 3-D structure of the element. For objects which can not be included in one specimen, the 3-D shape is obtained by reconstruction from serial sections. However, without stereo imagery, only detail which remains constant within the thickness of the section can be used in the reconstruction; consequently, the choice is between a low resolution reconstruction using a few thick sections and a better resolution reconstruction using many thin sections, generally a tedious chore. This paper describes an approach to 3-D reconstruction which uses stereo images of serial thick sections to reconstruct an object including detail which changes within the depth of an individual thick section.

Scanning and Transmission Microscopy of Nematocyst Batteries in Epitheliomuscular Cells of Hydra

1971 ◽  
Vol 29 ◽  
pp. 410-411 ◽  
Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Osmium Tetroxide ◽  
External Surface ◽  
Three Dimensional ◽  
Surface Structures ◽  
Transmission Microscopy ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Scanning Electron

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).

Characterization of microtubules by dark-field STEM and replication

1991 ◽  
Vol 49 ◽  
pp. 152-153
Author(s):  
S.B. Andrews ◽  
R.D. Leapman ◽  
P.E. Gallant ◽  
T.S. Reese
Keyword(s):  
Protein Interactions ◽  
Low Dose ◽  
Unit Length ◽  
Dark Field ◽  
Carbon Films ◽  
Microtubule Associated Proteins ◽  
Molecular Weights ◽  
Freeze Dried ◽  
Protein Motors ◽  
Associated Proteins

As part of a study on protein interactions involved in microtubule (MT)-based transport, we used the VG HB501 field-emission STEM to obtain low-dose dark-field mass maps of isolated, taxol-stabilized MTs and correlated these micrographs with detailed stereo images from replicas of the same MTs. This approach promises to be useful for determining how protein motors interact with MTs. MTs prepared from bovine and squid brain tubulin were purified and free from microtubule-associated proteins (MAPs). These MTs (0.1-1 mg/ml tubulin) were adsorbed to 3-nm evaporated carbon films supported over Formvar nets on 600-m copper grids. Following adsorption, the grids were washed twice in buffer and then in either distilled water or in isotonic or hypotonic ammonium acetate, blotted, and plunge-frozen in ethane/propane cryogen (ca. -185 C). After cryotransfer into the STEM, specimens were freeze-dried and recooled to ca.-160 C for low-dose (<3000 e/nm2) dark-field mapping. The molecular weights per unit length of MT were determined relative to tobacco mosaic virus standards from elastic scattering intensities. Parallel grids were freeze-dried and rotary shadowed with Pt/C at 14°.

The Effects of Drying Techniques on Clay-Rich Soil Texture

1974 ◽  
Vol 32 ◽  
pp. 466-467
Author(s):  
T. G. Naymik
Keyword(s):  
Critical Point ◽  
Liquid Nitrogen ◽  
Liquid Nitrogen Temperature ◽  
Drying Methods ◽  
Air Drying ◽  
Freeze Dried ◽  
Critical Point Drying ◽  
Set Up ◽  
The Relationship ◽  
Quartz Grains

Three techniques were incorporated for drying clay-rich specimens: air-drying, freeze-drying and critical point drying. In air-drying, the specimens were set out for several days to dry or were placed in an oven (80°F) for several hours. The freeze-dried specimens were frozen by immersion in liquid nitrogen or in isopentane at near liquid nitrogen temperature and then were immediately placed in the freeze-dry vacuum chamber. The critical point specimens were molded in agar immediately after sampling. When the agar had set up the dehydration series, water-alcohol-amyl acetate-CO2 was carried out. The objectives were to compare the fabric plasmas (clays and precipitates), fabricskeletons (quartz grains) and the relationship between them for each drying technique. The three drying methods are not only applicable to the study of treated soils, but can be incorporated into all SEM clay soil studies.

Oncornavirus assembly at the cell surface revealed in replicas of freeze-dried cells

1978 ◽  
Vol 36 (2) ◽  
pp. 354-355
Author(s):  
Anthony Demsey ◽  
Christopher W. Stackpole
Keyword(s):  
Cell Surface ◽  
Surface Membrane ◽  
Viral Origin ◽  
Intact Cells ◽  
Structural Formation ◽  
Virus Core ◽  
Freeze Dried ◽  
Cacodylate Buffer ◽  
Surface Replica ◽  
Leukemia Viruses

The murine leukemia viruses are type-C oncornaviruses, and their release from the host cell involves a “budding” process in which the newly-forming, RNA-containing virus core becomes enveloped by modified cell surface membrane. Previous studies revealed that the released virions possess a dense array of 10 nm globular projections (“knobs”) on this envelope surface, and that these knobs contain a 70, 000 MW glycoprotein (gp70) of viral origin. Taking advantage of this distinctive structural formation, we have developed a procedure for freeze-drying and replication of intact cells which reveals surface detail superior to other surface replica techniques, and sufficient to detect even early stages of virus budding by localized aggregation of these knobs on the cell surface.Briefly, cells growing in monolayer are seeded onto round glass coverslips 10-12 mm in diameter. After a period of growth, cells are fixed in situ for one hour, usually with 1% OsO4 in 0. 1 M cacodylate buffer, and rinsed in distilled water.

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