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.

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.

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.

Influence of adenosine triphosphate on the isolated perfused mesenteric artery of the rabbit

1983 ◽  
Vol 61 (11) ◽  
pp. 1409-1417 ◽  
Author(s):  
V. S. R. Krishnamurty ◽  
P. J. Kadowitz
Keyword(s):  
Adenosine Triphosphate ◽  
Mesenteric Arteries ◽  
The Other ◽  
Receptor Blocker ◽  
Medium Size ◽  
Inhibitory Influence ◽  
Vasodilator Response ◽  
Other Hand ◽  
Vasoconstrictor Response ◽  
Dose Dependent

The vascular effects of adenosine triphosphate (ATP) were examined in the isolated perfused mesenteric arteries of the rabbit. Bolus injections of ATP (1 × 10−8 to 10−6 mol) induced a dose-dependent vasoconstrictor response at resting perfusion pressure, while continuous perfusion with ATP briefly elicited a vasoconstrictor response which was not maintained. Perfusion with phentolamine (2.65 × 10−6 M, an α-adrenergic receptor blocker), indomethacin (8.37 × 10−6 M, an inhibitor of cyclooxygenase), atropine (1 × 10−7 M, a muscarinic receptor blocker), and hydralazine (2 × 10−4 M, a vascular smooth muscle inhibitor) for a period of 1 h had no effect on vasoconstrictor responses to ATP. However, pretreatment with reserpine (2 mg∙kg−1∙day−1 for 2 days), an agent which depletes catecholamines, potentiated responses to ATP. On the other hand, when vascular tone was increased with an isoosmotic 60 mM K+ depolarizing Krebs bicarbonate solution, bolus injections of ATP elicited a prominent dose-dependent vasoconstriction followed by a prominent vasodilation. The degree of vasodilation but not of vasoconstriction elicited by ATP was greater in small terminal arteries with branches (<0.5 mm outside diameter (o.d.)) than in the medium size arteries (≤1 mm o.d.) without terminal branches. Both the vasoconstrictor and vasodilator responses were unaffected by a perfusion with atropine, indomethacin, or eicosatetraynoic acid (ETYA, 1 × 10−4 M) for 1 – 2 h. The vasoconstrictor responses were potentiated while the vasodilator responses were inhibited significantly by perfusion with propranolol (3 × 10−6 M) and phentolamine (2.65 × 10−6 M) together for 1 h or by pretreatment with reserpine followed by cold storage at 2 °C for 24 h. Perfusion with 8-phenyltheophylline (4 × 10−6 M (8-PT), an adenosine receptor blocker) for 1 h significantly inhibited by the vasodilator responses to bolus injections of adenosine but not to ATP. Further, ATP but not adenosine elicited a much more prominent vasodilator response on norepinephrine (NE) induced tone than on 60 mM K+. These studies suggest that ATP may induce vasoconstriction independent of activation of α-adrenergic or muscarinic receptors or enhanced synthesis of prostaglandins. This vasoconstriction is resistant to the inhibitory influence of hydralazine. On the other hand, the vasodilator response to ATP may be mediated through its interactions with released or circulating norepinephrine.

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.

Incidence de l'aération sur le traitement par compostage des sous-produits du palmier dattier contaminés parFusarium oxysporumf.sp.albedinis

2005 ◽  
Vol 51 (1) ◽  
pp. 69-77 ◽  
Author(s):  
K Chakroune ◽  
M Bouakka ◽  
A Hakkou
Keyword(s):  
Total Nitrogen ◽  
Date Palm ◽  
Dry Weight ◽  
Initial Mixture ◽  
Phoenix Dactylifera ◽  
The Other ◽  
Mineral Matter ◽  
Other Hand ◽  
Phoenix Dactylifera L ◽  
Cooling Phase

Composting of date palm (Phoenix dactylifera L.) residues contaminated with Fusarium f.sp oxysporum albedinis, causal agent of the vascular wilt (Bayoud) of the date palm, has been achieved. The effect of the aeration of the piles by manual turning has been studied. The maintenance of an adequate humidity of 60%–70%, necessary to the good progress of the composting process, required the contribution of 11.4 L of water/kg of the dried residues. The evolution of the temperatures in the three piles presents the same phases. A latency phase, followed after 2–3 d of composting by a thermophilic phase, which lasts about 24 d, where the temperature remains elevated between 50 and 70 °C. Then a cooling phase that takes about 15 d, during which the temperatures fall to values between 25 and 35 °C, near room temperature. Fusarium f.sp oxysporum albedinis is eliminated completely during the thermophilic phase of composting, and increasing frequencies of turning accelerate its disappearance to a certain extent. On the other hand, pH remained steady and relatively basic oscillating between 8.2 and 8.7. Ninety percent (90%) of the the date palm residues are composed exclusively of organic matters. The total nitrogen represents only 0.4%. The contribution of manure decreases the ratio of carbon to nitrogen (C/N) from 115 to 48 in the initial mixture. After 80 d of composting and according to the frequency of return up, there is a reduction of the granulometry of the substratum, the C/N ratio (from 29% to 44%), the organic matter (from 15% to 23%), the total volume (from 25% to 35%), and of the dry weight of the swaths (from 16% to 24%). On the other hand there is an increase in total nitrogen rate (from 20% to 40%) and in the mineral matter (from 23% to 35%).Key words: composting, palm date, Fusarium oxysporum f.sp. albedinis.

An investigation of photosynthetic sucrose production in bean leaves

1977 ◽  
Vol 55 (11) ◽  
pp. 1457-1464 ◽  
Author(s):  
S. C. Fry ◽  
R. G. S. Bidwell
Keyword(s):  
Phaseolus Vulgaris ◽  
The Other ◽  
Glyceric Acid ◽  
Cytoplasmic Fraction ◽  
Other Hand ◽  
Phosphoglyceric Acid ◽  
Detached Leaves ◽  
Chloroplast Fraction ◽  
Bean Leaves

First trifoliate leaves of wax beans. Phaseolus vulgaris, were exposed to 14CO2 in light for periods of 15 to 75 s. Leaves were frozen in liquid N2 and a chloroplast fraction was isolated nonaqueously. The chloroplast fraction contained a small amount of contaminating cytoplasm that could not be removed. Labelled photosynthetic compounds were separated from the whole leaves and from the corresponding chloroplast fractions and their radioactivity was measured.The compounds fell into two groups in their behaviour. Glyceric acid and ribulose, derived from photosynthetic 3-phosphoglyceric acid and ribulose diphosphate respectively, remained largely or exclusively in the chloroplast fraction. Labelled sucrose and serine and glycine, on the other hand, were located in the chloroplast fraction only during the first 15–30 s of 14CO2 supply, and appeared in the cytoplasmic fraction in increasing amounts thereafter. The results suggest that serine and glycine are produced in organelles in the layer of cytoplasm that closely surrounds the chloroplasts and is isolated with them in the non aqueous technique. Sucrose may also be synthesized from photosynthetic intermediates in this layer of cytoplasm. Sucrose was not formed from intermediates of the glycolate pathway in detached leaves.

THE PHOSPHORUS FRACTIONS OF BACILLUS CEREUS AND BACILLUS MEGATERIUM: II. A CORRELATION OF THE CHEMICAL WITH THE CYTOLOGICAL CHANGES OCCURRING DURING SPORE GERMINATION

1955 ◽  
Vol 1 (7) ◽  
pp. 525-548 ◽  
Author(s):  
P. C. Fitz-James
Keyword(s):  
Bacillus Cereus ◽  
Rna Synthesis ◽  
Dry Weight ◽  
Acid Synthesis ◽  
Nuclear Material ◽  
The Other ◽  
Other Hand ◽  
Soluble P ◽  
Labile P ◽  
Time Required

The oxygen uptake, the changes in the concentrations of the phosphorus (P) fractions, and the dry weights of Bacillus cereus and B. megaterium germinating in thick suspension were followed from the spore to the young vegetative cell. Parallel cytological studies were made using standard procedures of bacterial cytology. During the initial minutes of germination the dry weight of the spores fell, respiratory activity began, the concentration of cold trichloroacetic acid (TCA)-soluble P rose, and the concentration of a residual P fraction insoluble in hot TCA fell. In complete media, nucleic acid synthesis began soon after this initial activation and was accompanied by an uptake of P, a further rise in the acid-soluble P, and in the rate of respiration. The cells began to recover weight. Ribosenucleic acid (RNA) synthesis was detectable by about 10 min. after inoculation and desoxyribosenucleic acid (DNA) synthesis by 15–20 min. Following its initial rise, the rate of RNA synthesis declined and continued parallel to that of DNA for some 10 min. During this period, the uptake of P from the medium appeared to be depressed and the spores (B. cereus) changed in shape from ovoids to short rods. After this period, the RNA synthesis was steady throughout germination. The rise of DNA, on the other hand, was continuous and steady throughout, even in cultures where growth was synchronous. The nuclear material of germinating spores grew and separated in step with the continuous rise of DNA P and the increase in cell volume was of the same order as the increase in RNA P. Under crowded conditions, or in inadequate media, germinating spores and young vegetative cells of B. cereus showed a decreased RNA/DNA ratio and accumulations of labile P. Crowded cultures of B. megaterium, on the other hand, accumulated Sudan positive (fatty) granules, but no labile P. The time required for the germinating spore to duplicate its chromatin varied in different media and could, in some instances, be shortened by subculturing. Nevertheless, the product of this time of germination and the increase in RNA during the germination period approximated to a fixed value that was independent of medium, species, or cell concentration.

scholarly journals SPATIAL DISTRIBUTION OF TRACE METALS (Pb, Cr, Cu AND Zn) IN SEDIMENTS OF THE BERAU DELTA, EAST KALIMANTAN AND THEIR ACCUMULATION IN BENTHIC BIOTA

2018 ◽  
Vol 32 (2) ◽  
pp. 89-94 ◽  
Author(s):  
Z. Arifin ◽  
T. A. Koesmawati
Keyword(s):  
Spatial Distribution ◽  
Trace Metals ◽  
Dry Weight ◽  
Coastal Ecosystem ◽  
The Other ◽  
Metal Concentrations ◽  
East Kalimantan ◽  
Other Hand ◽  
Cu And Zn

Berau delta is a coastal ecosystem where man-made activities are relatively low. The present study has investigated spatial distribution of Pb, Cr, Cu and Zn in sediments and their implication to benthic biota. The result of our study showed that metal concentrations varied from undetected to 55.53 mg kg-1 for Pb and from 3.28 to 22.9 mg kg-1 for Cu, while for Cr and Zn vary from 9.65 to 64.67 mg kg-1 and 10.00 to 1,200 mg kg-1, respectively. The concentrations of Pb, Cu, Cr and Zn in Anadara sp were 7.53 ± 2.06, 4.92 ± 0.55, 1.44 ± 0.12 and 97.87 ± 9.12 mg kg-1 dry weight (dw), respectively. On the other hand, the Pb, Cr, Cu and Zn in Telescopium mauritsi were 4.49 ± 0.03, 0.87 ± 0.05, 259.0 ± 0.01 and 64.78 ± 0.01 mg kg-1 dw, respectively. In conclusion, spatial distribution of trace metals (Pb, Cu, Cr and Zn) in sediments showed that higher concentrations were found in the southern part of the delta, and the accumulation of the metals by mollusk might reflect natural concentrations in biota.

scholarly journals Storage polysaccharides in germinating yellow lupine (Lupinus luteus L.)

2014 ◽  
Vol 50 (3) ◽  
pp. 419-428 ◽  
Author(s):  
Aleksandra Hoffmannowa ◽  
Grażyna Zielińska
Keyword(s):  
Starch Synthesis ◽  
Dry Weight ◽  
The Other ◽  
Lupinus Luteus ◽  
Light Dependence ◽  
Other Hand ◽  
Yellow Lupine ◽  
Storage Polysaccharides

The yellow lupine (<em>Lupinus luteus</em> L. cv. Express) was cultured for 16 days in light or in darkness. During the first 3 days of germination starch and hemicelluloses were estimated in the seed organs, cotyledons and axis. Later the estimations were performed daily in cotyledons, shoots and roots of the cultured seedlings. Absence of starch was noted in cotyledons of airdry seeds and an abrupt starch synthesis in the first 24 hours of germination. nation. Degradation of starch, and hemicelluloses in cotyledons of the germinating yellow lupine was rapid and correlated strictly with losses in their dry weight. Similarly to starch synthesis, it showed no light dependence. On the other hand, light influenced synthesis of the studied polysaccharides in the shoot and the root of a develaping lupine seedling.

Effect of Sewage and industrial effluents on flowering behavior and yield of pea (Pisum sativum L. var. arkel)

BIBECHANA ◽  
1970 ◽  
Vol 7 ◽  
pp. 70-75
Author(s):  
Mohan Kumar Shrestha
Keyword(s):  
Pisum Sativum ◽  
Key Words ◽  
Industrial Effluents ◽  
Dry Weight ◽  
Dairy Farming ◽  
The Other ◽  
Other Hand

Municipality Sewage and effluents from Shah Udyog and Dairy Farming were taken to assess the flowering behavior and yield of pea. The effluents from Dairy Farming initiated flowering earlier than the other effluents while effluents of Shah Udyog retarded comparatively. The same trend was followed for anthesis, withering and pod appearance. Duration of anthesis was found increasing in the order: Dairy Farming, Municipality Sewage, Control and Shah Udyog respectively. On the other hand, number of seed per plant and dry weight per seed was found in decreasing order from Dairy Farming to Shah Udyog through Municipality Sewage. Key words: Effluents; Flowering; Yield; Inhibition and promotion DOI: 10.3126/bibechana.v7i0.4049BIBECHANA 7 (2011) 70-75

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