Effect of salinity level on uptake and distribution of chloride, sodium and potassium ions in citrus plants

1983 ◽  
Vol 34 (2) ◽  
pp. 145 ◽  
Author(s):  
RR Walker ◽  
TJ Douglas
Keyword(s):  
Marked Reduction ◽  
Shoot Growth ◽  
Potassium Ions ◽  
Citrus Reticulata ◽  
Salt Treatment ◽  
Rangpur Lime ◽  
Upper Limit ◽  
Induced Changes ◽  
Sodium And Potassium ◽  
Chloride Concentrations

Seedlings of the Citrus rootstocks Rangpur lime (Citrus reticulata var. austera hybrid?), Kharna khatta (C. karna Raf.) and Etrog citron (C. medica L.), were grown in a porous medium under glasshouse conditions and irrigated with 0, 25, 50 or 100 mM NaCl for 6 weeks. Chloride concentrations in roots of all three rootstocks were increased by salt treatment. Increasing the level of salinity from 25 to 100 mM NaCl did not increase further the chloride concentrations in roots of any rootstock, implying an upper limit to the extent of chloride loading in roots. The upper limit appeared to be similar for all rootstocks. Differences between the rootstocks were found in chloride concentrations in leaves and to a lesser extent in stems, emphasizing pronounced rootstock differences in root to shoot transport of chloride, i.e. in their ability for chloride exclusion. This ability increased in the order: Etrog citron, Kharna khatta, and Rangpur lime. Root, stem and leaf sodium concentrations increased with salt treatment, but a concurrent reduction in potassium concentrations with salt treatment occurred only in roots and stems. Shoot growth of Etrog citron and Kharna khatta plants was reduced significantly by 50 mM NaCl, but growth of Rangpur lime plants showed a marked reduction only at 100 mM NaCl. Shoot-growth and salt-induced changes in the concentrations of chloride, sodium and potassium in leaves and roots of each rootstock were unaffected by sodium to calcium ratios in the range 6.25 : 1 to 25 : 1 for plants treated with 50 mM NaCl, and in the range 12.5 : 1 to 50 : 1 for plants treated with 100 mM NaCl. Shoot growth and ion uptake patterns

Uptake and distribution of chloride, sodium and potassium ions in salt-treated citrus plants

1983 ◽  
Vol 34 (2) ◽  
pp. 133 ◽  
Author(s):  
AM Grieve ◽  
RR Walker
Keyword(s):  
Sweet Orange ◽  
Poncirus Trifoliata ◽  
Potassium Ions ◽  
Citrus Reticulata ◽  
Rangpur Lime ◽  
Rough Lemon ◽  
Young Leaves ◽  
Chloride Accumulation ◽  
Sodium And Potassium ◽  
Cleopatra Mandarin

Seedlings of a range of citrus rootstocks were grown under glasshouse conditions and supplied with dilute nutrient solution containing either 0 or 50 mM NaCl. The partitioning of accumulated chloride and sodium into and within the major organs was compared between plants of Rangpur lime (Citrus reticulata var. austera hybrid?), Trifoliata (Poncirus trifoliata) and sweet orange (C. sinensis). Rootstocks differed in their leaf and stem chloride and sodium concentrations, but there was little or no difference between the rootstocks in root chloride and sodium concentrations. The lowest leaf chloride and sodium concentrations were found in the top region of shoots of all rootstocks. The different patterns of accumulation of chloride and sodium found in the three rootstocks were consistent with the existence of apparently separate mechanisms which operate to limit the transport of these two ions from the roots into the young leaves of citrus plants. The chloride excluding ability of 10 rootstocks and two hybrids was also compared and assessed in relation to rootstock vigour. Sampling from the middle leaves on salt-treated plants enabled a distinction to be made between rootstocks in their chloride accumulation properties. Cleopatra mandarin (C. reticulata), Rangpur lime, Macrophylla (C. macrophylla) and Appleby smooth Seville (C. paradisi x C. sinensis) accumulated significantly less chloride than did Trifoliata and rough lemon (C. jambhiri). Differences in chloride accumulation properties between rootstocks were unrelated to rootstock vigour.

Photosynthetic Responses of the Citrus Varieties Rangpur Lime and Etrog Citron to Salt Treatment

1982 ◽  
Vol 9 (6) ◽  
pp. 783 ◽  
Author(s):  
RR Walker ◽  
E Torokfalvy ◽  
WJS Downton
Keyword(s):  
Photosynthetic Capacity ◽  
Citrus Reticulata ◽  
Photosynthetic Response ◽  
Salt Treatment ◽  
Rangpur Lime ◽  
Mature Leaves ◽  
Salt Exclusion ◽  
Photosynthetic Responses ◽  
Citrus Varieties ◽  
Chloride Concentrations

Seedlings of Rangpur lime (Citrus reticulata var. austera hyb.?) and Etrog citron (C. medica L.), which differ markedly in ability for salt exclusion (i.e. the ability to restrict the uptake and/or transport of salt between roots and shoots), were grown under glasshouse conditions and supplied with dilute nutrient solution containing either 0 or 50 mM NaCl. Photosynthetic response to salt treatment and subsequent recovery were followed for 105 days for Etrog citron and for 119 days for Rangpur lime. Photosynthesis in mature leaves of both varieties was progressively reduced by salt treatment irrespective of ability for salt exclusion. The photosynthetic decline in each case was related to increases in stomatal and internal resistances. The reduction in photosynthetic capacity in Etrog citron leaves was associated with high leaf chloride concentrations while in Rangpur lime, a salt excluder, it could be related to a loss of leaf turgor. Leaf sodium concentrations were not markedly increased by salt treatment in either variety. Cessation of salt treatment led to a progressive recovery of photosynthesis for both varieties accompanied by a reduction in both stomatal and internal resistances. Recovery in Etrog citron leaves occurred despite little change in leaf chloride concentrations. These leaves tolerated up to 350 mM chloride (leaf water basis) under glasshouse conditions without sustaining a permanent reduction in photosynthetic capacity.

Uptake and distribution of chloride, sodium and potassium ions and growth of salt-treated pistachio plants

1987 ◽  
Vol 38 (2) ◽  
pp. 383 ◽  
Author(s):  
RR Walker ◽  
E Torokfalvy ◽  
MH Behboudian
Keyword(s):  
Growth Rates ◽  
Potassium Ions ◽  
Salt Treatment ◽  
Tissue Water ◽  
Relative Growth ◽  
Matter Production ◽  
Salinity Levels ◽  
Sodium And Potassium ◽  
Chloride Concentrations ◽  
Scion Cultivar

Plant growth rates and rates of uptake and root to shoot transport of chloride and sodium were compared between seedlings of the rootstock Pistacia atlantica Desf. and a scion cultivar P. Vera L. cv. Kerman treated with 30 mM NaCl for 63 days. Uptake and distribution of chloride, sodium and potassium ions were then investigated in P. atlantica and in another rootstock P. terebinthus L. subjected to periods of increasing salinity, commencing with 30 mM chloride and 18 mM sodium, and then increasing sequentially by these amounts every 3 weeks to reach a maximum of 150 mM chloride and 90 mM sodium. Shoot growth rates of P. Vera and P. atlantica were not affected by treatment with 30 mM NaCl. Rates of uptake and root to shoot transport of chloride were similar between the two species. However, the rates of uptake and root to shoot transport of sodium by P. atlantica were approximately 2-fold and 4-fold higher, respectively, than in P. vera. The chloride and sodium accumulated in the shoots of both species was diluted by growth, with the result that there was no marked increase in leaf and stem chloride and sodium concentrations in either species with time. After 63 days of salt-treatment, mean leaf chloride concentrations were less in P. atlantica, which had a higher relative growth rate and a higher shoot to root ratio than P. vera. Mean leaf sodium concentrations were higher in P. atlantica, reflecting the greater rate of root to shoot transport of sodium by this species. Sequentially increasing salinities up to a maximum of 150 mM chloride and 90 mM sodium had no significant effect on the dry matter production of P. atlantica and P. terebinthus. Laminae chloride concentrations of both species increased as the level of salinity was increased. Sodium concentrations in laminae of P. terebinthus showed a small but significant increase during treatment with the two highest salinity levels. Chloride concentrations on a tissue water basis were highest in laminae and petioles of salt-treated plants, whereas sodium concentrations were highest in roots, especially the proximal root, indicating retention of sodium in the lower part of the plant.

scholarly journals Response of Nagpur mandarin (Citrus reticulata Blanco) to high density planting systems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. S. Ladaniya ◽  
R. A. Marathe ◽  
A. A. Murkute ◽  
A. D. Huchche ◽  
A. K. Das ◽  
...  
Keyword(s):  
Plant Density ◽  
High Density ◽  
Citrus Reticulata ◽  
Plant Canopy ◽  
Area Index ◽  
Rangpur Lime ◽  
Net Returns ◽  
Area Basis ◽  
Crop Harvest ◽  
Major Nutrients

AbstractHigh density planting system i.e. accommodating a higher number of plants than routine in a given area is an innovative agro-technology to increase yield and thereby early net returns. Due to conventional wide spacing plantation in Nagpur mandarin (Citrus reticulata Blanco), the land remains unutilized as the plant canopy gradually increases over the years. In the present study, Nagpur mandarin (Citrus reticulata Blanco) budded on Rangpur lime rootstock was evaluated under six different planting spacings. It was observed that the organic carbon (1.10–1.82%) and major nutrients viz. N (309–430 kg ha−1), P (20–54 kg ha−1) and K (291–810 kg ha−1) increased vis-à-vis plant density and was highest under 2 × 2 m spacing. Plants were tallest at 2 × 2 m spacing with the higher PAR interception (88.2) and the lowest leaf area index (1.09). Fruit yield on area basis, under 2 × 2 m spacing was 26, 7.1, 4.6 times more as compared to conventional plantation during the first, second and third year, respectively. At fifth year of crop harvest, the highest B:C ratio (6.36) was recorded in 6 × 3 m followed by 4 × 2 m and 2 × 2 m.

Sodium and Potassium Fluxes in the Abdominal Nerve Cord of the Cockroach, Periplaneta Americana L

1961 ◽  
Vol 38 (2) ◽  
pp. 315-322
Author(s):  
J. E. TREHERNE
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Nerve Cord ◽  
Periplaneta Americana ◽  
Unit Area ◽  
Potassium Ions ◽  
Sodium Ions ◽  
Nerve Sheath ◽  
The Central Nervous System ◽  
Sodium And Potassium

1. The influx of sodium and potassium ions into the central nervous system of Periplaneta americana has been studied by measuring the increase in radioactivity within the abdominal nerve cord following the injection of 24NA and 42K. into the haemolymph. 2. The calculated influx of sodium ions was approximately 320 mM./l. of nerve cord water/hr. and of potassium ions was 312 mM./l. of nerve cord water/hr. These values are very approximately equivalent to an influx per unit area of nerve cord surface of 13.9 x 10-2 M cm. -2 sec.-1 for sodium and 13.5 x 10-12 M cm. -2 sec.-1 for potassium ions. 3. The relatively rapid influxes of these ions are discussed in relation to the postulated function of the nerve sheath as a diffusion barrier. It is suggested that a dynamic steady state rather than a static impermeability must exist across the sheath surrounding the central nervous system in this insect.

Tetanic hyperpolarization of single medullated nerve fibers in sodium and lithium

1976 ◽  
Vol 231 (4) ◽  
pp. 1033-1038 ◽  
Author(s):  
GM Schoepfle
Keyword(s):  
Steady State ◽  
Interspike Interval ◽  
Nerve Fibers ◽  
Repetitive Stimulation ◽  
Time Dependent ◽  
Potassium Ions ◽  
Current Densities ◽  
Medullated Nerve Fiber ◽  
Sodium And Potassium ◽  
Stimulation Of

Repetitive stimulation of a single medullated nerve fiber of Xenopus yields a succession of postspike voltage-time curves which are nearly coincident until attainment of a voltage that corresponds to that of the maximum attained by the normal postspike undershoot. Initially the interspike potential returns toward a resting level after this brief phase of hyperpolarization. However, as tetanization proceeds, a pattern of hyperpolarization develops with the result that, in the tetanic steady state, there exists a progressive hyperpolarization throughout each interspike interval. Extent of postspike hyperpolarization in terms of a deviation deltaVm from the resting level of membrane potential is approximated by the variation deltaVm = delta[MNa + MK]/[GNa + GK] where MNa and MK are current densities associated with active pumping of sodium and potassium ions and GNa and GK are corresponding time-dependent leak conductances. Tetanic hyperpolarization is reversibly abolished by cyanide and by exposure to lithium Ringer. Eventual reappearance of tetanic hyperpolarization in the presence of lithium Ringer suggests lithium pumping.

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