Search Results

You are looking at 51 - 60 of 860 items for :

  • All content x
Clear All

1 102 Hartmond, U., Schaesberg, N. V., Graham, J. H. and Syvertsen, J. P. (1987): Salinity and flooding stress effects on mycorrhizal and non-mycorrhizal citrus rootstock

Restricted access

-Kazi, A. 2000b. Identification of four bread cultivars tolerant to salinity following sea-water field evaluations as varietal candidates for Baja California, México. Annu. Wheat Newsl. 46 :90–91. Mujeeb-Kazi A

Restricted access

Abd-El Baki, G. K., Siefritz, F., Man, H. M., Weiner, H., Kaldenhoff, R., Kaiser, W. M. (2000) Nitrate reductase in Zea mays L. under salinity. Plant Cell Environ. 23 , 515

Restricted access

.-K., Bohnert, H. J. (2000) Plant cellular and molecular responses to high salinity. Annu. Rev. Plant Physiol. Plant Mol. Biol. 51 , 463–499. Bohnert H. J. Plant cellular and molecular

Restricted access

Abstract  

An establishéd electrodeposition method for separating americium and plutonium from highly saline used-fuel-leaching solutions has been extended to the determination of Np and U in saline groundwaters. The interference of major ionic species in groundwater on the yield was investigated using three groundwaters of varying salinity (ionic strength I=1.37, 0.0748 and 0.0253 mol/l). High average yields (>92%), and good reproducibility were obtained for Np and U electroplated from solutions with ionic strength less than 0.1. The greatest interferences from individual ions were caused by Mg2+ and HCO 3 .

Restricted access

The statistical analysis of salinity data from samples collected yearly from genetic soil horizons of 69 points of the Hungarian Soil Information and Monitoring System between 1992 and 2000 showed changes in time. There is a strong atmospheric control over the groundwater level and the resulting soil salinity. Weak statistical association was established between either the pattern of yearly soil salinity changes in the second (10-20 cm) and third (30-40 cm) genetic horizon and the groundwater observation stations or the soil types. In the area of Kecskemét there was a tendency of decreasing soil salinity patterns, while around Békéscsaba a tendency of increasing soil salinity patterns, as illustrated by the correspondence biplot. Regarding soil types, the solonetzic meadow soil showed a tendency of increasing salinity. It was concluded that the statistical analyses of the monitored data must be carefully planned in order to provide the optimal background data as independent data from all those available to accompany the monitored soil data as dependent variable.

Restricted access

On brief exposure of Azolla fronds to salinity stress, a significant decrease in photosynthetic pigment like chlorophyll and carotenoid with a decrease in ascorbate and glutathione content was observed. Lipid peroxidation increases with doses of NaCl stress resulting a greater membrane damage supported by increase in superoxide radical. However, increase in activities of superoxide dismutase, catalase, guaiacol peroxidase and glutathione reductase showed the development of biochemical defence mechanism against free radicals generated during exposure to short-term salinity stress. K+ ion was found to be decreased with increasing NaCl concentration, with a decrease in relative water content. An increase in fresh mass was observed, with a significant increase in dry mass suggested a development of salt tolerance in Azolla exposed to short-term salinity stress.

Restricted access

The distribution of phytoplankton at different salinities in the eastern Niger Delta of Nigeria was investigated. The paper aims to contribute to the dearth of salinity-based distribution of organisms as well as phytoplankton studies in the region. A total of 64 taxa of phytoplankton were identified and classified into four divisions of Bacillariophyta (49 taxa), Chlorophyta (7 taxa), Cyanophyta (4 taxa) and Dinophyta (4 taxa). Salinity was found to produce floristical gradients. Three assemblages of phytoplankton were recognized which were those found at low narrow salinity range, those occurring at wide salinity zone and those with high narrow salinity range. Phytoplankton found in narrow salinity range were predominantly chlorophytes, while those occurring at high and narrow salinity were dinoflagellates and some diatoms.

Restricted access

Abstract  

Viscoelastic properties of κ-carrageenan in saline solution at various concentrations and pH were investigated by dynamic rheological techniques, viscosity, elasticity measurements, and IR spectrometry. The viscosity and elasticity at low concentrations of κ-carrageenan do not depend on pH, confirming that κ-carrageenan is in a disordered conformation. At 0.7% κ-carrageenan, the disordered confirmation transforms into an ordered helical confirmation with the possibility of weak-type gel formation. The transformation is also confirmed by dynamic measurements of loss and storage moduli. Furthermore, at this concentration, the viscosity and elasticity are highly dependent on pH. At higher concentrations of NaCl (0.5 M) at some pHs, we observed that storage moduli is greater than loss moduli for the entire frequency region. Hence, there is a possibility of structure transformation from weak-type gel to a somewhat intermediate gel. The lowest viscosity and elasticity were obtained at extreme pH, confirming that there are structural changes occurring at these pHs due to hydrolysis. This is confirmed by IR data.

Restricted access

Hordeum spontaneum (wild barley) is a good gene source to improve salt tolerance in barley because it rapidly hybridizes and recombines with barley cultivars. Proteomics can assist in identifying proteins associated with a certain environmental or developmental signal. We employed a proteomic approach to understand the mechanisms of plant responses to salinity in a salt tolerant accession of H. spontaneum. At the 4-leaf stage, wild barley plants were exposed to 0 (control treatment) or 300 mM NaCl (salt treatment). The salt treatment lasted 3 weeks. Total proteins of leaf 4 were extracted and separated by two-dimensional gel electrophoresis. More than 500 protein spots were reproducibly detected. Of these, 29 spots showed significant differences between salt treatment and control. Using MALDI-TOF-TOF MS, we identified 29 cellular proteins, which represented 16 different proteins. These were classified into six categories and a group with unknown biological function. The proteins identified were involved in many different cellular functions. Three spots were identified as unknown proteins; searching in the NCBI database revealed that there was a 71% match with clathrin assembly protein putative [Ricinus communis], a 67% match with actin binding protein [Zea mays], and a 66% match with phosphatidylinositol kinase [Arabidopsis thaliana]. Other proteins identified included ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), oxygen-evolving enhancer protein (OEE), photosystem II reaction centerWprotein (Psbw), ribosomal proteins, chloroplast RNA binding protein (ChRBP), superoxide dismutase (SOD), malate dehydrogenase (MDH), thioredoxin h (Trx), nucleoside diphosphate kinase (NDPK), profilin, translationally-controlled tumor protein (TCTP), polyamine oxidase (PAO) and universal stress protein family (USP).

Restricted access