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.

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.

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.

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.

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.

Impact of an Open Trellis on Canopy Growth, Light Interception, Yield, and Leaf Physiology of Red Raspberry (Rubus idaeus)

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 468b-468
Author(s):  
Stephen F. Klauer ◽  
J. Scott Cameron ◽  
Chuhe Chen
Keyword(s):  
Leaf Area ◽  
Total Nitrogen ◽  
Dry Weight ◽  
Light Interception ◽  
Rubus Idaeus ◽  
Above Ground Biomass ◽  
Red Raspberry ◽  
Leaf Physiology ◽  
Total Dry Weight ◽  
Upper Third

After promising results were obtained with an open-style split trellis (two top wires) in its initial year, two new trials were established in 1997 in northwest (Lynden) and southwest (Woodland) Washington. For the split trellis, actual yields were 33% (machine-picked 1/2 season) and 17% (hand-picked) greater, respectively, for the two locations compared to the conventional trellis (one top wire). In Woodland, canes from the split trellis had 33% more berries, 55% more laterals, 69% more leaves, and 25% greater leaf area compared with the conventional trellis. Greatest enhancement of these components was in the upper third of the canopy. Laterals were also shorter in this area of the split canopy, but there was no difference in average total length of lateral/cane between trellis types. Total dry weight/cane was 22% greater in the split trellis, but component partitioning/cane was consistent between the two systems with fruit + laterals (43%) having the greatest above-ground biomass, followed by the stem (30% to 33%) and the leaves (21% to 22%). Measurement of canopy width, circumference, and light interception showed that the split-trellis canopy filled in more quickly, and was larger from preanthesis through postharvest. Light interception near the top of the split canopy was 30% greater 1 month before harvest with 98% interception near the top and middle of that canopy. There was no difference between the trellis types in leaf CO2 assimilation, spectra, or fluorescence through the fruiting season, or in total nitrogen of postharvest primocane leaves.

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.

SOLUBLE SUGAR CHANGES OCCURRING DURING COLD HARDENING OF SPRING WHEAT, FALL RYE AND ALFALFA

1983 ◽  
Vol 63 (2) ◽  
pp. 415-420 ◽  
Author(s):  
D. G. GREEN
Keyword(s):  
Spring Wheat ◽  
Soluble Sugar ◽  
Soluble Sugars ◽  
Dry Weight ◽  
Weight Basis ◽  
Cold Hardening ◽  
Spring Type

Alfa, a relatively nonhardy alfalfa cultivar continued to accumulate, on a dry weight basis, fructose, α- and β-D-glucose, sucrose and maltose during the latter stages of cold hardening. Rambler, a hardier alfalfa cultivar conversely showed a decrease for these soluble sugars with hardening. Frontier rye, a very hardy winter habit cereal showed decreases in these soluble sugars plus melibiose during the same hardening period. These results support the hypothesis that hardy cereals and alfalfa undergo a decrease in soluble sugars with hardening, while less hardy cereals and alfalfa continue to increase in content of soluble sugars. Manitou wheat appeared not to fit this hypothesis and showed the decreased soluble sugars usually associated with hardy cultivars. Although Manitou is a spring type wheat, one of its parents, Thatcher, does contain gene(s) for the winter habit.Key words: Sugar, cold hardening, wheat, rye, alfalfa

scholarly journals THE MOLECULAR WEIGHT OF RHODOPSIN AND THE NATURE OF THE RHODOPSIN-DIGITONIN COMPLEX

1954 ◽  
Vol 37 (3) ◽  
pp. 381-399 ◽  
Author(s):  
Ruth Hubbard
Keyword(s):  
Molecular Weight ◽  
Single Molecule ◽  
Extinction Coefficient ◽  
Dry Weight ◽  
Weight Basis ◽  
Sedimentation Behavior ◽  
A Value ◽  
Wet Weight ◽  
Single Boundary ◽  
Stoichiometric Complex

The sedimentation behavior of aqueous solutions of digitonin and of cattle rhodopsin in digitonin has been examined in the ultracentrifuge. In confirmation of earlier work, digitonin was found to sediment as a micelle (D-1) with an s20 of about 6.35 Svedberg units, and containing at least 60 molecules. The rhodopsin solutions sediment as a stoichiometric complex of rhodopsin with digitonin (RD-1) with an s20 of about 9.77 Svedberg units. The s20 of the RD-1 micelle is constant between pH 6.3 and 9.6, and in the presence of excess digitonin. RD-1 travels as a single boundary also in the electrophoresis apparatus at pH 8.5, and on filter paper at pH 8.0. The molecular weight of the RD-1 micelle lies between 260,000 and 290,000. Of this, only about 40,000 gm. are due to rhodopsin; the rest is digitonin (180 to 200 moles). Comparison of the relative concentrations of RD-1 and retinene in solutions of rhodopsin-digitonin shows that RD-1 contains only one retinene equivalent. It can therefore contain only one molecule of rhodopsin with a molecular weight of about 40,000. Cattle rhodopsin therefore contains only one chromophore consisting of a single molecule of retinene. It is likely that frog rhodopsin has a similar molecular weight and also contains only one chromophore per molecule. The molar extinction coefficient of rhodopsin is therefore identical with the extinction coefficient per mole of retinene (40,600 cm.2 per mole) and the E(1 per cent, 1 cm., 500 mµ) has a value of about 10. Rhodopsin constitutes about 14 per cent of the dry weight, and 3.7 per cent of the wet weight of cattle outer limbs. This corresponds to about 4.2 x 106 molecules of rhodopsin per outer limb. The rhodopsin content of frog outer limbs is considerably higher: about 35 per cent of the dry weight, and 10 per cent of the wet weight, corresponding to about 2.1 x 109 molecules per outer limb. Thus the frog outer limb contains about five hundred times as much rhodopsin as the cattle outer limb. But the relative volumes of these structures are such that the ratio of concentrations is only about 2.5 to 1 on a weight basis. Rhodopsin accounts for at least one-fifth of the total protein of the cattle outer limb; for the frog, this value must be higher. The extinction (K500) along its axis is about 0.037 cm.2 for the cattle outer limb, and about 0.50 cm.2 for the frog outer limb.

Influence of Temperature and Water Activity on Aflatoxin Production by Aspergillus flavus in Cowpea (Vigna unguiculata) Seeds and Meal

1985 ◽  
Vol 48 (12) ◽  
pp. 1040-1043 ◽  
Author(s):  
P. E. KOEHLER ◽  
L. R. BEUCHAT ◽  
M. S. CHHINNAN
Keyword(s):  
Heat Treatment ◽  
Water Activity ◽  
Aspergillus Flavus ◽  
Vigna Unguiculata ◽  
Dry Weight ◽  
Aflatoxin Production ◽  
Weight Basis ◽  
Influence Of Temperature

Experiments were done to determine the influence of temperature (21, 30 and 37°C) and aw (0.76 to 0.98) on aflatoxin production by Aspergillus flavus on cowpea (Vigna unguiculata) seeds, meal and meal supplemented with onion. Larger quantities of aflatoxin were produced at 21 and 30°C than at 37°C. The highest amount of aflatoxin (2777 μg/20 g, dry weight basis) was observed in meal containing onion at aw 0.98 after 20 d of incubation at 21°C. A level of 870 |μg/20 g was detected in seeds at aw 0.95 after 14 d of incubation at 30°C. Meal at aw 0.96 supported production of 551 μg of aflatoxin per 20 g after 20 d at 30° C. Temperature had little influence on the optimal aw for aflatoxin production in cowpea meal. However, an increase in temperature resulted in a decreased optimal aw for aflatoxin production on whole cowpeas. When known quantities of aflatoxin were added to cowpea meal which was subsequently steamed for 5 min, only 29% was extractable using a variety of procedures, indicating that the toxin may be bound in some manner to cowpea constituents as a result of heat treatment.

Sign in / Sign up

Export Citation Format

Share Document