Results 311 to 320 of about 298,868 (346)
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A Fruitful Journey: Pollen Tube Navigation from Germination to Fertilization.
Annual Review of Plant Biology, 2019In flowering plants, pollen tubes undergo tip growth to deliver two nonmotile sperm to the ovule where they fuse with an egg and central cell to achieve double fertilization.
Mark A. Johnson +2 more
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Staining Germinating Pollen and Pollen Tubes
Stain Technology, 1958Germinating pollen on stigmas and pollen tubes in styles of Antirrhinum, Brassica, Oenothera, Raphanus, Rosa, solatium and Tagetes spp. were prepared for examination as follows: The styles were fixed in ethyl alcohol-acetic acid 3:1 for 1 hr, and hydrolyzed at 60°C for 5 to 60 min (depending on the species) in 45% acetic acid.
P. B. Spicer, L. A. Dionne
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1960
In 1694, Camerarius reported that anthers play the role of male sexual organs in plants (Maheshwari, 1950). Later, AMICI observed pollen tubes travelling through the stigma and style of Portulaca oleracea and in 1830 he concluded that pollen tubes elongate and ultimately come in contact with the ovule (Maheshwari, 1950). Since then the work of numerous
I. K. Vasil, B. M. Johri
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In 1694, Camerarius reported that anthers play the role of male sexual organs in plants (Maheshwari, 1950). Later, AMICI observed pollen tubes travelling through the stigma and style of Portulaca oleracea and in 1830 he concluded that pollen tubes elongate and ultimately come in contact with the ovule (Maheshwari, 1950). Since then the work of numerous
I. K. Vasil, B. M. Johri
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Biological and therapeutic properties of bee pollen: a review.
The Journal of the Science of Food and Agriculture, 2016Natural products, including bee products, are particularly appreciated by consumers and are used for therapeutic purposes as alternative drugs. However, it is not known whether treatments with bee products are safe and how to minimise the health risks of
B. Denisow, M. Denisow-Pietrzyk
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Experientia, 1993
This review deals first with basic knowledge about pollen, especially its biology, morphology and physiology, and then discusses the connection of pollen with medical problems such as hay fever (pollinosis). The next sections cover the historical development of methods for trapping and counting airborne pollen grains to produce reliable quantitative ...
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This review deals first with basic knowledge about pollen, especially its biology, morphology and physiology, and then discusses the connection of pollen with medical problems such as hay fever (pollinosis). The next sections cover the historical development of methods for trapping and counting airborne pollen grains to produce reliable quantitative ...
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Pyrrolizidine alkaloids in pollen and pollen products
Molecular Nutrition & Food Research, 2010AbstractRecently, 1,2‐dehydropyrrolizidine alkaloid (PA) ester alkaloids, found predominantly as their N‐oxides (PANOs, pyrrolizidine N‐oxides), have been reported in both honey and in pollen obtained directly from PA plants and pollen loads collected by bees, raising the possibility of health risks for consumers of these products.
Iris Hasslauer +8 more
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Studies on pollen and pollen extracts
Journal of Allergy, 1933Abstract It has been shown that the presence of buffer salts in dextrose menstruum does not increase the potency of ragweed pollen extracts prepared with such solutions. Ragweed pollen extracts in isotonic dextrose buffered at either a slightly acid (hydrogen ion concentration 6.1) or slightly alkaline (hydrogen ion concentration 7.5) reaction have ...
Leon Unger, Marjorie B. Moore
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POLLEN PREVALENCE AND POLLEN-FREE AREAS
Journal of the American Medical Association, 1952The essential objective in atmospheric pollen research is to learn how much of what kinds of allergenic pollen are likely to be inhaled by sensitized persons at any time and in any locality. This objective may be amplified in further detail as follows: (1) to assist in the clinical evaluation, locally and generally, of known allergenic pollens, (2) to ...
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Studies on pollen and pollen extracts
Journal of Allergy, 1932Abstract Substances in pollen extracts capable of eliciting skin reactions in sensitized rabbits or in certain sensitive human beings, have been shown to be dialyzable through three different membranes, and at varied P H . The active material dialyzes more freely in solutions having a slightly acid reaction.
Hobart W. Cromwell +2 more
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Studies on pollen and pollen extracts
Journal of Allergy, 1934Abstract Protein and polysaccharide fractions of pollens have been prepared and studied with the view of determining their relative importance as allergens. The preparation of nitrogen-free pollen polysaccharides has not yet been successful. Comparative skin tests upon sensitized rabbits or upon hay fever patients gave no conclusive evidence of ...
Constance H. Seebér +3 more
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