Simultaneous Determinations of Phosphorus, Potassium, Calcium, and Magnesium in Wet Digestion Solutions of Plant Tissue by AutoAnalyzer

Author(s):  
Joseph E. Steckel ◽  
Roy L. Flannery
1960 ◽  
Vol 40 (4) ◽  
pp. 589-595 ◽  
Author(s):  
G. M. Ward ◽  
H. B. Heeney

Thirteen Canadian laboratories collaborated in a 2-year study of methods of analysis of plant tissue. The investigation has shown that the flame photometric procedure for potassium and a modification of the chelatometric method using EDTA for calcium and magnesium give the most consistent and reproducible results. Further research is necessary before the flame photometer can be used for the reliable determination of calcium and magnesium.


1981 ◽  
Vol 38 (1) ◽  
pp. 327-344
Author(s):  
I.P. Oliveira ◽  
E. Malavolta

Seven cultivars of Phaseolus vulgaris L. were grown in nutrient solution in the presence and absence of aluminum. Da ta obtained herewith allowed for the following conclusions to be drawn: (1) plant height, root lenght and total dry weight decreased with increase of aluminum levels in the nutrient solution; (2) aluminum concentration in plant tissue increased with higher levels of aluminum in the substrate; decreases pf calcium and magnesium concentration in the dry matter in the presence of higher aluminum concentration in the nutrient solution were observed.


1967 ◽  
Vol 50 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Mary Heckman

Abstract Seventeen laboratories collaborated in the study of analysis of feeds for calcium, magnesium, zinc, manganese, iron, and copper by atomic absorption spectrophotometry. Six feeds and one mineral mixture were analyzed; both dry ashing and wet digestion were used to prepare samples. Three feeds were in the form of solutions to eliminate sample preparation as a variable. Strontium and lanthanum were added to the feed to eliminate phosphorus interference and results were compared. Results indicate that the method is suitable for calcium and magnesium. Further work is needed on the determination of zinc, manganese, iron, and copper.


Author(s):  
Russell L. Steere ◽  
Eric F. Erbe

It has been assumed by many involved in freeze-etch or freeze-fracture studies that it would be useless to etch specimens which were cryoprotected by more than 15% glycerol. We presumed that the amount of cryoprotective material exposed at the surface would serve as a contaminating layer and prevent the visualization of fine details. Recent unexpected freeze-etch results indicated that it would be useful to compare complementary replicas in which one-half of the frozen-fractured specimen would be shadowed and replicated immediately after fracturing whereas the complement would be etched at -98°C for 1 to 10 minutes before being shadowed and replicated.Standard complementary replica holders (Steere, 1973) with hinges removed were used for this study. Specimens consisting of unfixed virus-infected plant tissue infiltrated with 0.05 M phosphate buffer or distilled water were used without cryoprotectant. Some were permitted to settle through gradients to the desired concentrations of different cryoprotectants.


Author(s):  
R. D. Sjolund ◽  
C. Y. Shih

The differentiation of phloem in plant tissue cultures offers a unique opportunity to study the development and structure of sieve elements in a manner that avoids the injury responses associated with the processing of similar elements in intact plants. Short segments of sieve elements formed in tissue cultures can be fixed intact while the longer strands occuring in whole plants must be cut into shorter lengths before processing. While iyuch controversy surrounds the question of phloem function in tissue cultures , sieve elements formed in these cultured cells are structurally similar to those of Intact plants. We are particullarly Interested In the structure of the plasma membrane and the peripheral ER in these cells because of their possible role in the energy-dependent active transport of sucrose into the sieve elements.


Planta Medica ◽  
2013 ◽  
Vol 79 (05) ◽  
Author(s):  
M Mujeeb ◽  
M Amir ◽  
AS Nadeem ◽  
M Aqil ◽  
AK Najmi ◽  
...  

1964 ◽  
Vol 12 (01) ◽  
pp. 179-200 ◽  
Author(s):  
Torstein Hovig

SummaryThe effect of calcium and magnesium on the aggregation of rabbit blood platelets in vitro was studied, with the following results:1. Platelet aggregation induced by ADP or collagen could be prevented by EGTA or EDTA. The aggregating effect was restored by recalcification. The effect was also restored by addition of magnesium in EDTA-PRP, but not in EGTA-PRP unless a surplus of calcium was present.2. Calcium remained in concentrations of the order of 0.15–0.25 mM after dialysis or cation exchange of plasma. Aggregation of washed platelets resuspended in such plasma could not be produced with ADP or collagen, unless the calcium concentration was increased or that magnesium was added.3. The adhesiveness of blood platelets to collagen was reduced in EGTA-PRP and EDTA-PRP. Release of ADP from platelets influenced by collagen could not be demonstrated either in EGTA-PRP (presence of magnesium) or in EDTA-PRP.4. It is concluded that calcium is a necessary factor both for the reaction leading to release of ADP and for the the aggregation produced by ADP.5. Thrombin induced aggregation of washed platelets suspended in tris-buffered saline in the presence of calcium. No effect of magnesium could be observed unless small quantities of calcium were present.


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