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פותח על ידי קלירמאש פתרונות בע"מ -
Magnesium uptake by tomato plants as affected by Mg and Ca concentration in solution culture and plant age
Year:
1983
Source of publication :
Agronomy Journal
Authors :
בר-יוסף, בניהו
;
.
שוורץ, ש'
;
.
Volume :
75
Co-Authors:
Facilitators :
From page:
267
To page:
272
(
Total pages:
6
)
Abstract:

Magnesium deficiency of tomato (Lycopersicon esculentum Mill.) plants grown under glass and in the field is widespread. Deficiency may occur because of interference in Mg uptake by various cations or from diminishing rates of uptake resulting from root aging. To investigate the interrelationship of Ca and Mg uptake by tomato plants and the dependence of uptake on plant age, a solution culture study with various Mg and Ca concentrations (CMg, CCa) was conducted. From solution depletion measurements of Ca and Mg during 2 to 3‐day periods, net cation flux (Fmax) and Michaelis‐Menten uptake rate coefficients were estimated for various plant ages (18 to 21, 34 to 37, and 80 to 83 days) and solution composition. Enhanced CCa (2.5 vs. 1 meq/L) decreased Fmax and KM of Mg. This effect was attributed to stimulation by Ca of selective ion uptake (related to KM) and a competitive effect on carrier sites which reduced Fmax. Increased CMg values had no appreciable effect on Fmax of Ca but they enhanced KM, especially during early growth (18 to 21 days). The flux of Mg uptake decreased with plant age. Between Days 21 and 83, Fmax, was reduced from 68 to 17.5 µeq Mg g fresh root−1day−1, while KM values under the same conditions increased from 0.55 to 1.2 meq/L. Similar changes with time characterized the Fmax and KM values for Ca. Root and canopy growth rates were appreciably retarded at CMg of 0.05 or CCa of 0.1 meq/L, relative to those at higher Mg and Ca concentrations. At the initial appearance of deficiency symptoms, Mg and Ca concentrations in the shoots were 0.13 and 0.11%, respectively.

Note:
Related Files :
Absorption rate
canopy
Cation flux
Competitive uptake
Lycopersicon esculentum Mill
Michaelis‐Menten
roots
עוד תגיות
תוכן קשור
More details
DOI :
10.2134/agronj1983.00021962007500020026x
Article number:
0
Affiliations:
Database:
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
52821
Last updated date:
02/03/2022 17:27
Creation date:
29/12/2020 23:59
Scientific Publication
Magnesium uptake by tomato plants as affected by Mg and Ca concentration in solution culture and plant age
75
Magnesium uptake by tomato plants as affected by Mg and Ca concentration in solution culture and plant age

Magnesium deficiency of tomato (Lycopersicon esculentum Mill.) plants grown under glass and in the field is widespread. Deficiency may occur because of interference in Mg uptake by various cations or from diminishing rates of uptake resulting from root aging. To investigate the interrelationship of Ca and Mg uptake by tomato plants and the dependence of uptake on plant age, a solution culture study with various Mg and Ca concentrations (CMg, CCa) was conducted. From solution depletion measurements of Ca and Mg during 2 to 3‐day periods, net cation flux (Fmax) and Michaelis‐Menten uptake rate coefficients were estimated for various plant ages (18 to 21, 34 to 37, and 80 to 83 days) and solution composition. Enhanced CCa (2.5 vs. 1 meq/L) decreased Fmax and KM of Mg. This effect was attributed to stimulation by Ca of selective ion uptake (related to KM) and a competitive effect on carrier sites which reduced Fmax. Increased CMg values had no appreciable effect on Fmax of Ca but they enhanced KM, especially during early growth (18 to 21 days). The flux of Mg uptake decreased with plant age. Between Days 21 and 83, Fmax, was reduced from 68 to 17.5 µeq Mg g fresh root−1day−1, while KM values under the same conditions increased from 0.55 to 1.2 meq/L. Similar changes with time characterized the Fmax and KM values for Ca. Root and canopy growth rates were appreciably retarded at CMg of 0.05 or CCa of 0.1 meq/L, relative to those at higher Mg and Ca concentrations. At the initial appearance of deficiency symptoms, Mg and Ca concentrations in the shoots were 0.13 and 0.11%, respectively.

Scientific Publication
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