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

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.

1983 ◽  
Vol 34 (2) ◽  
pp. 145 ◽  
Author(s):  
RR Walker ◽  
TJ Douglas

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


1979 ◽  
Vol 15 (1) ◽  
pp. 73-79 ◽  
Author(s):  
R. C. Hawkins ◽  
P. J. M. Cooper

SUMMARYMaize was grown from three batches of seed, with mean 1000-grain weights of 225, 432 and 649 g. Initial plant size was larger when grown from large seed, but development rates were similar for all three sizes and relative growth rates were similar during the early stages. Relative differences in plant size became smaller as the crop matured. Crop growth rates during the linear phase of dry matter production were the same, and there were no significant yield differences. Comparisons of leaf and spikelet initiation, and individual leaf size are also reported.


1996 ◽  
Vol 26 (9) ◽  
pp. 1556-1568 ◽  
Author(s):  
Thimmappa S. Anekonda ◽  
Richard S. Criddle ◽  
Lee D. Hansen ◽  
Mike Bacca

Seventeen Eucalyptus species and 30 rapid-growing Eucalyptuscamaldulensis trees (referred to as plus trees), growing in a plantation were studied to examine relationships among measured plant growth and respiratory parameters, geographical origins, and growth climate. The respiratory parameters measured at two different temperatures by isothermal calorimetry were metabolic heat rate, rate of CO2 production, and the ratio of heat rate to CO2 rate. Metabolic heat rate was also measured as a continuous function of temperature by differential scanning calorimetry in the range of 10 to 40 °C. Tree growth was measured as rates of height and stem volume growth. The values of respiratory and growth variables of Eucalyptus species are significantly correlated with latitude and altitude of origin of their seed sources. The maximum metabolic heat rate, the temperature of the maximum heat rate, the temperature coefficients of metabolic rate, and the temperatures at which the slopes of Arrhenius plots change are all genetically determined parameters that vary both within and among species. Measurement of growth rate–respiration rate–temperature relationships guide understanding of why relative growth rates of Eucalyptus species and individual genotypes differ with climate, making it possible to identify genotypes best suited for rapid growth in different climates. The temperature dependence of respiration rates is an important factor determining relative growth rates of eucalypts in different climates. To achieve optimum biomass production the temperature dependence of individual plants must be matched to growth climate.


1967 ◽  
Vol 69 (3) ◽  
pp. 305-315 ◽  
Author(s):  
J. E. Jackson

Growth analysis of cotton crops sown in the Sudan Gezira at monthly intervals between August and May revealed a marked seasonal pattern of growth. Irrespective of plant age and fruiting state growth of non-senescent plants was slowest during the cool winter months. Relative growth rates of young plants were highest in August, September and early October due to the high specific leaf areas and fairly high net assimilation rates found then. They were lowest when minimum temperatures were lowest. Net assimilation rates were also lowest in the coolest months, probably as a result of restricted growth. High temperatures in the spring reduced fruiting. It is concluded that low minimum temperatures and high evaporation rates are both associated with slow growth, and play a large part in determining the characteristic decline of growth rates of cotton sown at the usual date in August.I wish to thank the Chief of the Research Division, Ministry of Agriculture, Sudan, for permission to publish this paper and to record my gratitude to the team of field and laboratory assistants, especially Salih Saad and Hassan Osman, who helped in the work.


1961 ◽  
Vol 38 (2) ◽  
pp. 315-322
Author(s):  
J. E. TREHERNE

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.


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