Control of sprout growth in the potato. Effect of humidity and water supply

1984 ◽  
Vol 62 (10) ◽  
pp. 2140-2145 ◽  
Author(s):  
Gordon I. McIntyre ◽  
William A. Quick
Keyword(s):  
Water Supply ◽  
Water Content ◽  
Significant Interaction ◽  
Growth Response ◽  
Dry Weight ◽  
Weight Basis ◽  
Potato Tubers ◽  
Factors Affecting ◽  
External Water ◽  
Sprout Growth

The growth of apical sprouts of potato tubers, var. Norland, kept in darkness at 15 °C, was significantly increased either by increasing the relative humidity (RH) from approximately 40 to 100% or by supplying water to the basal cut end of the tubers. These two treatments showed a significant interaction, the response to the external water supply being considerably greater at the higher RH. The growth response was closely correlated with increases in the dry weight and the water content of the sprouts, expressed on either a sprout or dry weight basis. The high RH plus water treatment also eliminated the inhibition of sprout growth by light, the length of the sprouts in this treatment being almost 160% greater than in the light at low RH and 60% greater than in the dark. These results are consistent with the hypothesis that when the tuber has no external supply of water, the growth of the sprouts is determined primarily by their water content, and thus by the effect and interaction of factors affecting the supply of water from the tuber and its rate of loss from the sprouts by transpiration.

Some physiological responses of Verticillium albo-atrum to zinc

1973 ◽  
Vol 51 (1) ◽  
pp. 57-59 ◽  
Author(s):  
G. O. Throneberry
Keyword(s):  
Oxygen Uptake ◽  
Total Nitrogen ◽  
Growth Response ◽  
Zinc Concentration ◽  
Physiological Responses ◽  
Dry Weight ◽  
Weight Basis ◽  
Optimum Growth ◽  
Nitrate Sources ◽  
Verticillium Albo Atrum

Zinc markedly stimulated growth of Verticillium albo-atrum R. & B. in Czapek-Dox broth shake cultures. Minimum zinc concentration producing optimum growth response was 0.15 to 0.2 μg/ml. On a dry weight basis added zinc resulted in increased total nitrogen content and oxygen uptake. Oxygen uptake per unit total nitrogen was essentially unaffected. Cells from 5- and particularly 7-day-old zinc-free cultures showed less response to zinc than did those from 3- and 10-day-old cultures. Zinc response was greatest with L-alanine as the nitrogen source as compared with nitrate, urea, and ammonium nitrate sources.

scholarly journals Some moisture relations of colloids. II.—Further observations on the evaporation of water from clay and wool

1923 ◽  
Vol 103 (723) ◽  
pp. 664-675 ◽  
Keyword(s):  
Water Content ◽  
Variable Temperature ◽  
Dry Weight ◽  
Vertical Axis ◽  
Weight Basis ◽  
Wool Fabric ◽  
Rate Of Evaporation ◽  
Straight Lines ◽  
Rate Of Movement

In two earlier paper, the results of a study of the rate of evaporation of water from soil, sand and a wool fabric were described and discussed. It was shown that, when the rate of evaporation is plotted against the water content (on a dry weight basis), the curve obtained is made up of three straight lines cutting one another sharply, so that there are points on the curve at which there are sudden changes of direction. The factors determining the shape of the curve were discussed and it was suggested that variable temperature of the drying mass, and two others, due to capillarity, viz., the diminishing rate of movement of water from the interior of the material to the surface as the larger capillary spaces become empty, or as the water wedges between the soil grains get progressively smaller. It was shown that, with the materials mentioned above, the first sloping portion of the rate curves could be accurately expressed by the equation – dw / dt – A = kw in which A is the intercept cut off from the vertical axis when the curve is extrapolated to W = 0. With wool, the curve, on extrapolation, passed through the origin, in which case A = 0.

Salt Tolerance Is Not Associated With the Sodium Accumulation of Two Maize Hybrids

1994 ◽  
Vol 21 (5) ◽  
pp. 675 ◽  
Author(s):  
GR Cramer ◽  
GJ Alberico ◽  
C Schmidt
Keyword(s):  
Salt Tolerance ◽  
Ion Transport ◽  
Growth Response ◽  
Dry Weight ◽  
Weight Basis ◽  
Ion Concentration ◽  
Na Transport ◽  
Maize Hybrids ◽  
Sodium Accumulation ◽  
Ion Concentrations

In this report, we test the hypothesis that Na+ accumulation in the shoot in maize is negatively correlated with salt tolerance. Salt tolerance is defined as a percentage of the control on a dry weight basis. Two hybrids (Pioneer hybrid 3578 and Pioneer hybrid 3772) differing widely in Na+ accumulation were compared. Plants were treated with two types of salinity for 15 days (80 mol m-3 NaCl or 80 mol m-3 NaCl plus 8.75 mol m-3 CaCl2). Ion concentrations (Na+, K+, Ca2+ and Cl-) were measured in the roots, stalks, sheaths and leaves of plants harvested every third day. Ion concentrations were significantly affected by the treatments. Na+ and Cl- concentrations increased with salinity treatments; K+ and Ca2+ concentrations decreased. Supplemental Ca2+ increased Ca2+ and decreased Na+ concentrations. Hybrid 3772 maintained very low Na+ concentrations in the shoots, whereas 3578 did not. The largest distinction between the hybrids was in the ability to transport Na+ to the shoot; hybrid 3578 transported Na+ at twice the rate of hybrid 3772. In general, ion transport to the shoot appeared to be a function of root ion concentration. This model could account for the effects of NaCl salinity and supplemental Ca2+ on ion transport, although Na+ transport was complicated by an apparent reabsorption mechanism in the root and mesocotyl. The lack of correlation of Na+ accumulation in the shoot and other ion parameters with growth indicated that the mineral nutrition of the plants was not correlated with salt tolerance. It was concluded that the growth response of maize to salinity was primarily affected by osmotic factors.

PHYSIOLOGICAL AND BIOCHEMICAL STUDIES IN PLANT METABOLISM: VI. THE EFFECT OF ONTOGENY ON THE PHYSIOLOGICAL HETEROGENEITY IN THE FIRST LEAF OF WHEAT

1952 ◽  
Vol 30 (5) ◽  
pp. 558-570 ◽  
Author(s):  
D. W. A. Roberts
Keyword(s):  
Water Content ◽  
Respiration Rate ◽  
Dry Weight ◽  
Weight Basis ◽  
Plant Metabolism ◽  
Mature Leaves ◽  
Biochemical Studies ◽  
Physiological And Biochemical ◽  
Physiological Heterogeneity ◽  
Very High

The respiration rate, R.Q., and the water content of each of the developing quarters of the first leaf of Khapli wheat have been measured at different ages and found to change as the tissue ages. In general the respiration rate declines as the tissue ages. The R.Q. is usually close to unity except in the basal quarter around the fifth day. The water content of the quarters tends to decline as the mature leaves become older. In the basal quarter of four- and five-day-old leaves the oxygen uptake appears to reach its peak when calculated on a dry weight basis. In the five-day-old leaves the rate of water uptake is very high and the R.Q. very low. These properties are thought to be correlated with the phase of elongation which is occurring in this quarter at that stage.

Influence of Nitrogen and Humidity on Rhizome Bud Growth and Glyphosate Translocation in Quackgrass (Agropyron repens)

Weed Science ◽  
1982 ◽  
Vol 30 (6) ◽  
pp. 655-660 ◽  
Author(s):  
Gordon I. McIntyre ◽  
Andrew I. Hsiao
Keyword(s):  
Apical Dominance ◽  
Growth Response ◽  
Dry Weight ◽  
Nitrogen Supply ◽  
Weight Basis ◽  
High Humidity ◽  
Apical Node ◽  
Bud Growth ◽  
Rhizome Bud ◽  
Agropyron Repens

When buds on the rhizome of quackgrass [Agropyron repens(L.) Beauv.] were released from apical dominance either by increasing the nitrogen supply to the parent shoot (from 5.25 to 210 ppm) or by raising the humidity around the rhizome (from 55 to 100%), the growth response of the buds was closely correlated with their uptake of foliar-applied14C-labeled glyphosate [N-(phosphonomethyl] glycine]. The14C level in the buds, expressed on a dry-weight basis, was greatest in the youngest, most rapidly growing bud at the apical node and decreased in successively older buds along the rhizome. A similar gradient was shown by the14C content of the associated rhizome nodes. The high-humidity treatment also increased the total amount of14C that was translocated into the rhizome, whereas increasing the nitrogen supply, while promoting14C uptake by the buds, markedly reduced the amount in the rhizome nodes and in other parts of the plant. This nitrogen-induced reduction in translocation was associated with a reduction of about 30% in uptake of the herbicide by the treated leaves.

Characterization of frozen hydrated biological specimens by low-loss EELS

1992 ◽  
Vol 50 (2) ◽  
pp. 1572-1573
Author(s):  
Songquan Sun ◽  
Richard D. Leapman
Keyword(s):  
Water Content ◽  
Direct Method ◽  
Internal Standard ◽  
Dry Weight ◽  
Dark Field ◽  
Protein Solutions ◽  
Subcellular Compartment ◽  
Differential Shrinkage ◽  
Electron Energy Loss

Analyses of ultrathin cryosections are generally performed after freeze-drying because the presence of water renders the specimens highly susceptible to radiation damage. The water content of a subcellular compartment is an important quantity that must be known, for example, to convert the dry weight concentrations of ions to the physiologically more relevant molar concentrations. Water content can be determined indirectly from dark-field mass measurements provided that there is no differential shrinkage between compartments and that there exists a suitable internal standard. The potential advantage of a more direct method for measuring water has led us to explore the use of electron energy loss spectroscopy (EELS) for characterizing biological specimens in their frozen hydrated state.We have obtained preliminary EELS measurements from pure amorphous ice and from cryosectioned frozen protein solutions. The specimens were cryotransfered into a VG-HB501 field-emission STEM equipped with a 666 Gatan parallel-detection spectrometer and analyzed at approximately −160 C.

STEM measurement of subcellular water distributions

1993 ◽  
Vol 51 ◽  
pp. 568-569
Author(s):  
R.D. Leapman ◽  
S.Q. Sun ◽  
S-L. Shi ◽  
R.A. Buchanan ◽  
S.B. Andrews
Keyword(s):  
Water Content ◽  
Internal Standard ◽  
Dry Weight ◽  
Dry Mass ◽  
Scanning Transmission Electron Microscope ◽  
Dark Field ◽  
Bulk Water ◽  
Inelastic Electron ◽  
Scanning Transmission ◽  
Annular Dark Field

Recent advances in rapid-freezing and cryosectioning techniques coupled with use of the quantitative signals available in the scanning transmission electron microscope (STEM) can provide us with new methods for determining the water distributions of subcellular compartments. The water content is an important physiological quantity that reflects how fluid and electrolytes are regulated in the cell; it is also required to convert dry weight concentrations of ions obtained from x-ray microanalysis into the more relevant molar ionic concentrations. Here we compare the information about water concentrations from both elastic (annular dark-field) and inelastic (electron energy loss) scattering measurements.In order to utilize the elastic signal it is first necessary to increase contrast by removing the water from the cryosection. After dehydration the tissue can be digitally imaged under low-dose conditions, in the same way that STEM mass mapping of macromolecules is performed. The resulting pixel intensities are then converted into dry mass fractions by using an internal standard, e.g., the mean intensity of the whole image may be taken as representative of the bulk water content of the tissue.

ERRORS ASSOCIATED WITH HERBAGE DISSECTION ANALYSES 2. Problems of species identification

1976 ◽  
pp. 213-225
Author(s):  
I.M. Ritchie ◽  
C.C. Boswell ◽  
A.M. Badland
Keyword(s):  
New Zealand ◽  
Dry Weight ◽  
Analytical Tool ◽  
Species Level ◽  
Weight Basis ◽  
Plant Identification ◽  
Leaf Fragment ◽  
Research Division ◽  
Or Groups ◽  
Botanical Analysis

HERBACE DISSECTION is the process in which samples of herbage cut from trials are separated by hand into component species. Heavy reliance is placed on herbage dissection as an analytical tool ,in New Zealand, and in the four botanical analysis laboratories in the Research Division of the Ministry of Agriculture and Fisheries about 20 000 samples are analysed each year. In the laboratory a representative subsample is taken by a rigorous quartering procedure until approximately 400 pieces of herbage remain. Each leaf fragment is then identified to species level or groups of these as appropriate. The fractions are then dried and the composition calculated on a percentage dry weight basis. The accuracy of the analyses of these laboratories has been monitored by a system of interchanging herbage dissection samples between them. From this, the need to separate subsampling errors from problems of plant identification was, appreciated and some of this work is described here.

Polycyclic Aromatic Hydrocarbons (PAHs) in Sediments of the Brisbane River (Australia) – Preliminary Results

1989 ◽  
Vol 21 (2) ◽  
pp. 161-165 ◽  
Author(s):  
S. I. Kayal ◽  
D. W. Connell
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
River Estuary ◽  
Dry Weight ◽  
Weight Basis ◽  
Sediment Samples ◽  
Preliminary Results ◽  
Treated Sewage ◽  
Polycyclic Aromatic ◽  
Petroleum Refineries

Results of the analysis of twenty-three composite sediment samples revealed that PAHs are widely distributed in the Brisbane River estuary. Mean concentrations for individual compounds, on a dry weight basis, ranged from 0.03 µg/g for dibenz [ah] anthracene to 2.34 µg/g for fluoranthene. Observed PAH assemblages were rich in compounds having pyrolytic origins. However, the presence of petroleum derived compounds was indicative of the importance of petroleum as a PAH source in the estuary. Petroleum refineries, a coal loading terminal and a major treated sewage outfall located at the mouth were not indicated as major contributing sources of PAH pollution in the estuary.

Mineral nutrition, dinitrogen fixation, and growth of Alnuscrispa and Alnusglutinosa

1985 ◽  
Vol 15 (5) ◽  
pp. 855-861 ◽  
Author(s):  
G. Prégent ◽  
C. Camiré
Keyword(s):  
Mineral Nutrition ◽  
Dry Weight ◽  
Optimal Growth ◽  
Maximum Growth ◽  
Dinitrogen Fixation ◽  
Weight Basis ◽  
Critical Levels ◽  
N Status

Invitro cultures of Alnuscrispa (Ait.) Pursh and Alnusglutinosa (L.) Gaertn. were used to estimate critical foliage levels of selected nutrients for optimal growth and dinitrogen (N2) fixation. For A. crispa to obtain 90% of maximum growth and N2 fixation, foliar levels of 0.12% P, 0.13% Mg, <0.31% K, and <0.04% Ca on a dry weight basis were needed. For A. glutinosa, the critical levels were 0.138% P, 0.10% Mg, 0.29% Ca, and ~0.20% K. From all the deficiencies observed, P had the more pronounced effects on N status of both species.

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