[en] Under inappropriate environments, plants responses by changing their metabolisms to maintain homeostasis that acclimation abilities are different among species and varieties. Saline tolerance tomato is an alternative way to overcome saline soil condition of some areas in Thailand. This study aims to select one or some saline tolerance tomato varieties from mostly used commercial ones. Six tomato variety seeds (Pethlanna, Puangphaka, Seeda, Beefeater, Seeda chompoo and TE VF 1-3-4) were grown by tissue culture technique in MS medium and MS medium supplied with 0, 5, 10, 25 and 50 mM NaCl. The Puangphaka variety was selected since it could grow in all tests NaCl concentrations with best germination time compared to the others cultivar seeds and exhibited 80-90% growth compared to control group. The seedlings were further cultivated in the same medium for 7, 14 and 21 days before they were conducted to determine stem and root superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities as well as amount of chlorophyll. It was found that the SOD, CAT and GPx exhibited increase and decrease trends nearly the same pattern in salinity responses but with different activity levels. Inhibition of nutrient uptake could also be seen from the results. The maximum activities were 5, 0.18, 0.08, 2 and 3 U/mg protein for stem SOD, stem CAT, root CAT, stem GPx and root GPx, respectively. Furthermore, the chlorophyll A and B levels were decrease slightly except for the 21 days plants which presented considerable decrease. (author)

[en] To investigate the effect of equilibrating time on phosphate adsorption and desorption on saline sodic soils a study was carried using three soil series from Dera Ismail Khan (Pakistan) district, namely Zindani, Tikken and Gishkori. These soils are alkaline calcareous in nature with greater Electrical Conductivity (EC) and Sodium Adsorption Ratio (SAR) values which classify them as saline sodic soils. The equilibrating time for the adsorption study was 8, 12, 16, 20, 24, 48 and 72 hours for two levels (5 mg L/sup -1/ and 100 mg L/sup -1/). For desorption study 1, 2, 3, 4 and 5 hours after 24 hours for low and high dilution. Adsorption and desorption isotherms of phosphate were developed for these soils. The Gishkori soil showed the greatest rate of adsorption as compared with the other two soils. Applying Langmuir and Freundlich models to P adsorption data revealed that Freundlich equation (R2 = 0.99) showed a better fit over the Langmuir equation (R2 =0. 97) in the three soils. The desorption curves varied similarly from each other. The amount of P adsorbed was different from that released back to the soil solution. The amount of adsorption increased with the time. Statistical analysis showed that the rate of adsorption for both 5 and 100 mg P L/sup -1/ was significantly different at P<0.05 at 16 and 20 hours and at P<0.01 beyond 20 hours. However, the rate of desorption was not significantly influenced by the equilibrating time as compared with the theoretical values of the three series. As the P - desorption curve did not coincide the P - adsorption curve, hence the availability of P to plant was adversely affected on its application. (author)

[en] Soil salinization is a serious environmental menace that reduces the development, growth and yield of most of the plants. Growing halophyte crops such as quinoa (Chenopodium quinoa Willd.) is a promising way of productive utilization of saline soils. The present study was conducted during 2018-19, in which we investigated the comparative salt tolerance potential of two genotypes of quinoa (Puno and A1) on the basis of growth, ionic and physiological attributes. Five-week-old seedlings of both genotypes were exposed to different levels of salinity (0, 100, 200 and 400 mM NaCl) developed in Hoagland’s nutrient solution. Results revealed that root and shoot growth, chlorophyll contents, membrane stability and relative water content remained unchanged at lower level of NaCl (100 mM). However, these attributes decreased significantly at higher level of NaCl (400 mM). The Na/sup +/ concentrations increased, whereas K+ concentrations and the ratio of K/sup +/: Na/sup +/ showed an inverse relation to the increasing salinity levels. The comparison of both genotypes indicated that physiological attributes and plant biomass were higher in A1 than Puno due to less uptake of Na+ ions and higher K/sup +/: Na/sup +/ ratio. Therefore, A1 is more suitable genotype than Puno to be grown on saline soils in arid regions of Pakistan. (author)

[en] Melilotus officinalis L. (Fabaceae) is an important forage plant that has high contents of both protein and digestible fiber. In the present study, the effects of calcium chloride (0, 10 and 20 mM Ca2+) on M. officinalis germination and seedling growth under various levels of NaCl stress (0, 50, 100, 150 and 200 mM Na+) were investigated. The percentage germination was 66.67 % at salt levels ≤ 150 mM. Moreover, salt tolerance was greater in the seedlings than at germination level. An optimal Ca2+ concentration of 10 mM protected M. officinalis against salt stress, particularly in terms of germination and recovery germination under high salt conditions. In addition, 10 mM Ca2+ significantly enhanced the water content of early seedlings, as well as having a beneficial visual effect. The relative growth rate, biomass, and water content of underground parts and resource allocation of above ground parts also increased significantly with addition of 10mM Ca2+. Moreover, 10mM Ca2+ had a stronger effect on seedling growth than 20mM Ca2+, suggesting that excessive Ca2+ combined with high salt concentrations imposes additional stress. Overall, these findings suggest that an optimal Ca2+ concentration of 10 mM contributes to seedling establishment during germination and growth. Appropriate application of exogenous Ca2+ could therefore help to improve salt tolerance in forage plants such as M. officinalis and those growing in saline-alkaline soil, so long as the optimal calcium level is applied. (author)

[en] In the present study, MODFLOW-MT3D groundwater model was employed to perform numerical experimentation to develop design and operational parameters for SW (skinning wells) based on hydrogeology and groundwater salinity conditions of Chag Doab, Punjab, Pakistan. Numerical experimentation resulted in: (i) a I-strainer SW with discharge of 141/s (litres per second) and penetration of 30% resulted in more saltwater up coning at 8 hours/day well operation compared to that occurred at 4 hours/day operation; (ii) a I-strainer well with penetration of 30% and operation of 8 hours/day caused higher saltwater up coning at 141/s discharge compared to that at 91/s discharge; (iii) a 4-strainer well with penetration of 30% and operation of 8 hours/day also caused more saltwater up coning at 141/s well discharge compared to that at 91/s discharge. Similar trend was found for a 8-strainer well; and (iv) 1- or 4- or 8-strainerwell with 30-60% penetration, 9-141/s discharge and 4-8 hours/day operation could provide pumped groundwater of salinity less than 1000 ppm. Considering hydro-chemical performance and costs of wells, a 4-strainer well with 30% penetration, 9-14l/s is charge and 4-8 hours/day operation is recommended to skim groundwater of salinity less than 1000 ppm in Chaj Doab of Punjab, Pakistan. (author)

[en] Salicylic acid (SA) is a plant signaling molecule, which regulates various metabolic processes and involves in eliciting specific responses against abiotic/biotic stresses. Present study investigated the effect of SA on seed germination and seedling growth of salt stressed wheat. Wheat seeds were primed with water and two concentrations of SA (0.5 and 1.0 mM) for 12 h. For In-vitro experiment, seeds were soaked in 0, 50 and 100 mM NaCl solutions and seed germination and seedling growth parameters were studied. Primed seeds (both 0.5 and 1.0 mM SA) significantly improved seed germination, rate of germination, total chlorophyll, soluble sugars, proteins and phenolic content, as compared to non-primed and hydro-primed controls. For greenhouse experiment, hydro-primed (control) and SA primed (0.5 and 1.0 mM) seeds were grown in plastic pots and irrigated with 0 and 100 mM NaCl for 4 weeks. Plants emerged from SA primed seeds showed better response to salinity in which higher contents of photosynthetic pigments, soluble sugars, proteins and phenols contributed to enhanced growth and biomass production, as compare to control plants. Seed priming with 1.0 mM SA was found most effective to protect plants from damaging effects of salinity as compare to hydro-priming and 0.5 mM SA priming. Therefore, it is suggested that the priming of seeds with 1.0 mM SA can be adopted as a strategy to enhance wheat growth especially in salt affected soils. (author)

[en] The study observed a complex of figures and graphics that reveal the progressive pollution in the pumping wells. Also, it is made a detailed and current review of the underground physics-chemistry evolution, which results justify the importance of finding a real solution to the degradations problem of the aquifers in Santiago del Estero. for that reason, it is strictly necessary to build a total of eleven wells in the recharges zone, so five of them will be diggings 70 m in the gravel wedge (aquifer II) and six wells of 150 m of depth in the margins of the river Dulce. On the other hand, the studies carried out in the area indicate that all the wells will obtain water directly from the river to a direct recharge, so 81% of its flow will be absorb from the river and the rest, 19 % would be taken from the aquifer. This reason will avoid the progressive advance of the saline wedge and there wont harm the chemical quality of the recharge area. The batteries of the wells will supply 1.500.000 L/hour to the interconnected system on the top most potable conditions. (Author) 14 refs.

[en] The driving mechanism of thermohaline circulation is still a controversial topic in physical oceanography. Classic theory is based on Stommel's two-box model under buoyancy constraint. Recently, Guan and Huang proposed a new viewpoint in the framework of energy constraint with a two-box model. We extend it to a three-box model, including the effect of wind-driven circulation. Using this simple model, we further study how ocean mixing impacts on thermohaline circulation under the energy constraint. (geophysics, astronomy, and astrophysics)

[en] The paper describes the extent of salinity in the Indus Plain and mentions some of the methods employed for reclaiming the salt-affected soils. The rationale of a biological approach consisting of introduction of a plant succession on calcareous saline-sodic soils has been described, and has given encouraging results in the preliminary experiments carried out by the authors

[en] Soil salinity can limit plant growth and productivity. The cultivation of tolerant varieties is convenient and cost-effective for making good use of the saline soils. The sweet sorghum plant has a high tolerance for saline alkaline soils. The KF1210-3 and KF1210-4 early-maturity mutants of sweet sorghum were obtained via carbon ion irradiation. The study assesses the productivity of three sweet sorghum cultivars (KF1210-3, KF1210-4, and KFJT-CK) which were grown in intermediate (4.6 dS m^-1) and high (11.9 dS m^-1) soil salinity. The sweet sorghum grown in the soil salinity of 4.6 dS m^-1 produced 50.00-57.30 % greater fresh weight than that in the soil salinity of 11.9 dS m^-1, while the difference was not as obvious among the dry biomass of the three sweet sorghum cultivars. Moreover, the Brix degree of the sweet sorghum grown in the soil salinity of 11.9 dS m^-1 was greater than that grown in the soil salinity of 4.6 dS m^-1. The heavy ion irradiation experiment is of great significance in screening plant mutants, improving environmental conditions, and assessing the productivity. This process, in turn, aids in the understanding of the effects of the biochemical and physiological mechanisms of salt stress. (authors)