STUDIES OF NECTAR SECRETION IN EXCISED FLOWERS: I.THE INFLUENCE OF CULTURAL CONDITIONS ON QUANTITY AND COMPOSITION OF NECTAR

1956 ◽  
Vol 34 (1) ◽  
pp. 142-153 ◽  
Author(s):  
R. W. Shuel
Keyword(s):  
Metabolic Activity ◽  
Culture Medium ◽  
Dry Weight ◽  
The Other ◽  
Antirrhinum Majus ◽  
Culture Solution ◽  
Nectar Secretion ◽  
Flower Nectar ◽  
Cultural Conditions ◽  
Nectar Sugar

Nectar secretion was studied in excised flowers of snapdragon (Antirrhinum majus L.) grown in culture solution during the secretory period. The supply of sugar to the flower was regulated by varying the sugar concentration of the culture medium or the volume of medium entering the flower. Nectar sugar yield, as well as flower dry weight, was closely related to the sugar supply. Concentration of sugar in the nectar was almost identical with that of the medium, suggesting that osmotic work was not done by the nectaries. Sucrose consistently supported much higher yields of nectar than any of the other sugars tested, though many of the other sugars appeared to be assimilated as readily by the flower as sucrose. Sugar transformations occurred in nectar of flowers cultured on sucrose, glucose, fructose, maltose, lactose, galactose, mannose, and raffinose, but not in flowers supplied with xylose or sorbose. Sucrose spots were usually found in chromatograms of nectar in which transformations occurred. Despite the lack of evidence for the performance of osmotic work, the data are considered to support the recent suggestion by Frey-Wyssling that secretion results from metabolic activity in the nectary.

scholarly journals Vitrification of Crabapple, Pear, and Geum on Gellan Gum-solidified Culture Medium

HortScience ◽  
1990 ◽  
Vol 25 (12) ◽  
pp. 1648-1650 ◽  
Author(s):  
Steven R. Turner ◽  
Suman Singha
Keyword(s):  
Culture Medium ◽  
Shoot Proliferation ◽  
Dry Weight ◽  
Pyrus Communis ◽  
Gellan Gum ◽  
The Other ◽  
Ms Medium ◽  
Fresh Weight ◽  
Malus Baccata

Shoots of `Almey' crabapple [Malus baccata (L.) Borkh. × M. pumila var. niedzwetzkyana (Dieck) Schneid.], `Seckel' pear (Pyrus communis L.), and `Mrs. Bradshaw' geum (Geum quellyon Sweet.) were cultured on Murashige and Skoog (MS) medium supplemented with 8.8 μm BA and containing 0.1% to 0.4% Gelrite. Comparative shoot proliferation and vitrification were determined on Phytagar-solidified medium. Shoot proliferation, culture fresh weight, and vitrification declined in crabapple and geum with increasing Gelrite concentration. Pear proliferation and fresh weight increased with increasing Gelrite levels, but all shoots were vitrified. There were differences in the vitrification response between pear and the other two genera. The percent dry weight of vitrified cultures on Gelrite-containing media was generally higher than that of nonvitrified cultures on medium containing Phytagar. Vitrification precludes using low Gelrite concentrations for propagating these plants. Chemical name used: N-(phenylmethyl) -1H-purin-6-amine (BA).

Regenerative studies on the detached leaves of Echeveria elegans. Regeneration and growth in leaves

1973 ◽  
Vol 51 (2) ◽  
pp. 451-456 ◽  
Author(s):  
M. V. S. Raju ◽  
James E. Hines
Keyword(s):  
Metabolic Activity ◽  
Dry Weight ◽  
The Other ◽  
Inhibitory Influence ◽  
Other Hand ◽  
Detached Leaves

Detached leaves of Echeveria elegans Bgr. produce both roots and shoots. However, when their bases are severed, they tend to produce only roots. It was observed that roots had to be present on detached leaves, bases removed or not, in order to have an increase in size and also in dry weight. The growth in size was found to be due mainly to enlargement of cells, and the increase in dry weight was presumably due to maintenance of normal metabolic activity in the detached leaves. Thus detached leaves of E. elegans have a greater potential for growth than is normally realized by the leaves that are mature and still attached to the parent axis. The vigorously growing shoots seem to have an inhibitory influence on growth in the detached leaves. Roots on detached leaves, on the other hand, seem to play an important role not only in the delaying of senescence but also in reducing the inhibitory influence of shoots. Roots alone appeared to bring about "uncontrolled" enlargement of cells and consequently lesions were formed on the leaves, which finally died off. Thus growth, regeneration, and senescence in the detached leaves appear to be correlative phenomena.

scholarly journals Ação do fluoreto de sódio sobre a formação de depósitos, “in vitro”, por bactérias placogênicas

2021 ◽  
pp. 35-57
Author(s):  
Eduardo Roberto Corrêa de Barros
Keyword(s):  
Stainless Steel ◽  
Dental Caries ◽  
Sodium Fluoride ◽  
Dental Plaque ◽  
Culture Medium ◽  
External Factor ◽  
Dry Weight ◽  
The Other ◽  
Chemical Agent

The author investigated the action of sodium fluoride at the concentration of 9,2% and 1 ppm of flúor (respectively used as mouthrinses and added to water consumed by population, in dental caries prevention) "in vitro", on dental plaque forming bacteria (Streptococcus mutans, samples AHT and IB). These concentrations were selected for the present study because its application does not require previous dental prophylaxis. Thus, any possible change in the deposit formation would be the result of the action caused by the chemical agent and not by any other external factor. The developed technique was based on the determination, by dry weight of the material placed over "STICKS" of stainless steel kept inside the culture medium, where the bacteria grew. The results did not show any statistically significant changes (at the Ievel of l%) when 1 ppm of fluor was added to the cultures. On the other hand, it was noticed a reduction statistically significant (at the level of 1%), in the deposit accumulated when it was added sodium fluoride at 0.2%.

scholarly journals Haloferax mediterranei Cells as C50 Carotenoid Factories

Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 100
Author(s):  
Micaela Giani ◽  
Zaida Montero-Lobato ◽  
Inés Garbayo ◽  
Carlos Vílchez ◽  
José M. Vega ◽  
...  
Keyword(s):  
Osmotic Stress ◽  
Culture Medium ◽  
Dry Weight ◽  
Cellular Growth ◽  
The Other ◽  
Second Step ◽  
Haloferax Mediterranei ◽  
Nutritional Conditions ◽  
Deficient Medium ◽  
One Step

Haloarchaea produce C50 carotenoids such as bacterioruberin, which are of biotechnological in-terest. This study aimed to analyze the effect of different environmental and nutritional conditions on the cellular growth and dynamics of carotenoids accumulation in Haloferax mediterranei. The maximum production of carotenoids (40 µg·mL−1) was obtained during the stationary phase of growth, probably due to nutrient-limiting conditions (one-step culture). By seven days of culture, 1 mL culture produced 22.4 mg of dry weight biomass containing 0.18 % (w/w) of carotenoids. On the other hand, carbon-deficient cultures (low C/N ratio) were observed to be optimum for C50 bacterioruberin production by Hfx. mediterranei, but negatively affected the growth of cells. Thus, a two-steps process was evaluated for optimum carotenoids yield. In the first step, a nutri-ent-repleted culture medium enabled the haloarchaea to produce biomass, while in the second step, the biomass was incubated under osmotic stress and in a carbon-deficient medium. Under the conditions used, the obtained biomass contained 0.27% (w/w) of carotenoids after seven days, which accounts for 58.49 µg·mL−1 of carotenoids for a culture with turbidity 14.0.

scholarly journals Using plant tissue culture technique to evaluate of three genotypes (Triticum aestivum L.) to salinity tolerance.

2012 ◽  
Vol 6 (2) ◽  
pp. 46-51
Author(s):  
Abd A. S. ◽  
Aljibouri A. A. M. ◽  
Mahmoud S. N. ◽  
Duha M. Mejeed ◽  
Al-Hussini Z. A.
Keyword(s):  
Triticum Aestivum ◽  
Tissue Culture ◽  
Culture Medium ◽  
Dry Weight ◽  
Triticum Aestivum L ◽  
Culture Technique ◽  
The Other ◽  
Nacl Concentration ◽  
Ca Ions ◽  
Proline Concentration

he effect of five levels of sodium chloride (0.0, 0.5, 1.0, 1.5, 2) % on callus initiated from immature embryos of three genotypes of Triticum aestivum L. (I.E.Tamose 2, Rabeia, genotype 20) were investigated. Callus fresh and dry weight, cell contents of proline, carbohydrate as well as Na, Cl, K and Ca ions were used as parameters to determine the effect of NaCl on callus culture. The results showed Significant differences between genotypes in the most parameters studies significant reduction in callus fresh and dry weight as well as callus content of K, Ca ions and carbohydrate with NaCl concentration increased in the medium . On the other hand proline concentration Na and Cl ions were significant increased with NaCl concentration increased in the culture medium. Significant interactions were recorded between genotypes and salt concentration in their parameters.

Function of coprophagous beetles (Coleoptera: Scarabaeidae, Geotrupidae, Hydrophilidae) in cattle pastures inferred from pitfall trapping data

2010 ◽  
Vol 27 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Martin Šlachta ◽  
Jan Frelich ◽  
Tomáš Tonka
Keyword(s):  
Seasonal Variation ◽  
Spatial Variation ◽  
Dry Weight ◽  
Seasonal Distribution ◽  
The Other ◽  
Pitfall Trapping ◽  
Other Hand ◽  
Nested Anova ◽  
Species Groups ◽  
Dung Decomposition

Function of coprophagous beetles (Coleoptera: Scarabaeidae, Geotrupidae, Hydrophilidae) in cattle pastures inferred from pitfall trapping dataAn analysis of data on the dry weight biomass of coprophagous beetles in standardized dung (4.5 l) was conducted in order to characterize the spatial and the seasonal distribution of the beetles' biomass in cattle pastures and to elucidate their function in dung decomposition. Nested Anova with factors of farm, site (nested in farm), seasonal period and year was used to evaluate the effect of these factors on the biomass of four functional species groups: the dung dwellers ofScarabaeidae(subfamilyAphodiinae), the dung dwellers ofHydrophilidae, the small tunnellers ofScarabaeidae(subfamilyCoprinae) and the large tunnellers ofGeotrupidae. The spatial variation of biomass (between the sites and the farms) was insignificant (P>0.05) in the two dung-dweller groups and in the large-tunnellers group. On the other hand, a significant (P<0.05) seasonal variation of biomass was found in all but the large tunneller group. In dung dwellers, the spring biomass was formed mainly by two species,Aphodius prodromusandA. sphacelatus. In summer, most of the biomass was accounted for bySphaeridium lunatum, S. scarabaeoidesandA. rufipes. In the two tunneller groups,Onthophagus fracticornis, Geotrupes stercorariusandG. spinigerformed a majority of the biomass in dung.

Metamorphosen des Autors im Internet

2018 ◽  
Vol 2018 (1) ◽  
pp. 73-82
Author(s):  
Julia Genz
Keyword(s):  
Web 2.0 ◽  
Digital Media ◽  
Intrinsic Value ◽  
The Other ◽  
Cultural Conditions ◽  
Works Of Art ◽  
Periodic Schedule ◽  
Literary Authorship ◽  
The One ◽  
Death Of The Author

Digital media transform social options of access with regard to producers, recipients, and literary works of art themselves. New labels for new roles such as »prosumers « and »wreaders« attest to this. The »blogger« provides another interesting new social figure of literary authorship. Here, some old desiderata of Dadaism appear to find a belated realization. On the one hand, many web 2.0 formats of authorship amplify and widen the freedom of literary productivity while at the same time subjecting such production to a periodic schedule. In comparison to the received practices of authors and recipients many digital-cultural forms of narrating engender innovative metalepses (and also their sublation). Writing in the net for internet-publics enables the deliberate dissolution of the received autobiographical pact with the reader according to which the author’s genuine name authenticates the author’s writing. On the other hand, the digital-cultural potential of dissolving the autobiographical pact stimulates scandals of debunking and unmasking and makes questions of author-identity an issue of permanent contestation. Digital-cultural conditions of communication amplify both: the hideand- seek of authorship as well as the thwarting of this game by recipients who delight in playing detective. In effect, pace Foucault’s and Barthes’ postulates of the death of the author, the personality and biography of the author once again tend to become objects of high intrinsic value

scholarly journals Innovative Ultrasound-Assisted Approaches towards Reduction of Heavy Metals and Iodine in Macroalgal Biomass

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 649
Author(s):  
Estefanía Noriega-Fernández ◽  
Izumi Sone ◽  
Leire Astráin-Redín ◽  
Leena Prabhu ◽  
Morten Sivertsvik ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Dry Weight ◽  
The Other ◽  
Laminaria Hyperborea ◽  
Other Hand ◽  
Macroalgal Biomass ◽  
Ultrasound Assisted ◽  
I 31

The aim of this work was to evaluate the potential of ultrasound (US), alone or in combination with mild heating and/or EDTA towards reduction of As, Cd, I, and Hg content of Laminaria hyperborea. Concentrations of As, Cd, I, and Hg of 56.29, 0.596, 7340, and <0.01 mg kg−1 of dry weight, respectively, were found in L. hyperborea blades. Treatment with US at 50 °C increased approx. 2-fold the amount of As released, although did not affect significantly the content of Cd or I, as compared to control (no US) samples. Reducing the temperature to 8 °C significantly decreased the effect of US, but heating at 80 °C did not cause a significant effect as compared to treatments at 50 °C. On the other hand, treatment with 0.1 N EDTA at 50 °C enhanced the percentage of Cd released by approximately 7-fold, regardless of sonication. In the present work, the combination of US and EDTA at 50 °C for 5 min led to a significant reduction of the As (32%), Cd (52%) and I (31%) content in L. hyperborea, thus improving the product’s safety for consumers.

Soybean (Glycine max) Cultivar Response to Metribuzin in Solution Culture

Weed Science ◽  
1979 ◽  
Vol 27 (3) ◽  
pp. 278-279 ◽  
Author(s):  
W. S. Hardcastle
Keyword(s):  
Glycine Max ◽  
Dry Weight ◽  
Solution Culture ◽  
Hydroponic Culture ◽  
The Other ◽  
Top Dry Weight

Twenty-eight commercial soybean [Glycine max(L.) Merr.] cultivars of maturity classes V through VIII were evaluated for differences in response to metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one] 0.125 ppm w/w in hydroponic culture. Top dry weight (TDW) of treated ‘FFR 666’ soybeans equaled that of the cultivar check and five other cultivars were not significantly different (P = 5%). ‘Semmes' was most sensitive to the herbicide with TDW 40% of cultivar check. ‘Tracy’ and ‘Coker 156’ were not significantly different (P = 5%) from Semmes. The other cultivars tested were intermediate in response to metribuzin.

OBSERVATIONS ON AMYLOLYTIC BACTERIA: III. CULTURAL CONDITIONS INFLUENCING THE BREAKDOWN OF STARCH BY STENOTHERMOPHILIC BACTERIA BELONGING TO BACILLUS STEAROTHERMOPHILUS

1952 ◽  
Vol 30 (4) ◽  
pp. 360-370 ◽  
Author(s):  
Egon Stark ◽  
P. A. Tetrault
Keyword(s):  
Yeast Extract ◽  
Bacillus Stearothermophilus ◽  
Soluble Starch ◽  
The Other ◽  
Ph Changes ◽  
Proteose Peptone ◽  
Cultural Conditions ◽  
Initial Ph ◽  
Commercial Medium ◽  
Agar Media

Thirty-five cultures of Bacillus stearothermophilus hydrolyzed five starches under various cultural conditions. Hydrolysis occurred regardless of the type, brand, or batch of starch; regardless of the initial pH or of the subsequent pH changes of the medium. Starch in broth was better attacked than in agar media. Some cultures hydrolyzed 0.5%, but not 1% starch; others hydrolyzed easily 10% soluble starch. Length of incubation was important. Certain cultures never formed acid or sugar from starch. Dextrinization was a more reliable indication of starch hydrolysis than was the formation of acid or sugar. Soluble starch gave more consistent results in repeated experiments than did nonsoluble starches. The type of protein medium determines strongly the formation of amylase. Trypticase was the best commercial medium, yeast extract came second. The other 10 media yielded fewer amylolytic cultures. Yeast extract added to media enhanced amylase formation, except with trypticase. Tryptose, proteose-peptone, and neopeptone inhibited the growth of most cultures.

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