Thesis (PhD.)(Plant Production))--University of Pretoria, 2008. / Includes summary. Includes bibliographical references.

Thesis (M.S.)--University of Alexandria. / Bibliography: p. 41-42.

Koo, Siu Chung Nicolas. / Thesis submitted in: November 2007. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 78-86). / Abstracts in English and Chinese. / Thesis committee --- p.i / Statement --- p.ii / Abstract --- p.iii / Chinese Abstract --- p.v / Acknowledgements --- p.vi / Abbreviations --- p.viii / Table of contents --- p.xi / List of figures --- p.xv / List of tables --- p.xvii / Chapter 1. --- General Introduction / Chapter 1.1 --- General introduction to salt tolerance in plant --- p.1 / Chapter 1.1.1 --- Adverse effecst of high salinity in plant cells / Chapter 1.1.1.1 --- Ion toxicity --- p.1 / Chapter 1.1.1.2 --- Disturbed osmotic homeostasis --- p.2 / Chapter 1.1.1.3 --- Oxidative stress --- p.3 / Chapter 1.1.2 --- Major salt tolerance strategy in plant / Chapter 1.1.2.1 --- Maintenance of ion homeostasis --- p.4 / Chapter 1.1.2.2 --- Maintaining osmotic homeostasis --- p.4 / Chapter 1.1.2.3 --- Detoxification of Reactive oxygen species --- p.4 / Chapter 1.2 --- Cytosolic Calcium signal in plant / Chapter 1.2.1 --- General introduction of calcium in plant --- p.6 / Chapter 1.2.2 --- Calcium transport in plant cell --- p.7 / Chapter 1.2.3 --- Cytosolic calcium signals in plant under abiotic stress --- p.9 / Chapter 1.2.4 --- Responding to cytosolic calcium signals --- p.12 / Chapter 1.3 --- Calcium mediated ion homeostasis in plant under salt stress / Chapter 1.3.1 --- General introduction on Calcium dependent ion channels in plant --- p.13 / Chapter 1.3.2 --- SOS family cascade in Arabidopsis --- p.13 / Chapter 1.4 --- The interaction between cytosolic calcium and reactive oxygen species in plants --- p.14 / Chapter 1.5 --- "Calcium signaling mediated by Inositol 1,4,5 triphosphate in plant" --- p.15 / Chapter 1.6 --- Study on HAL2 and its homolog in plant --- p.18 / Chapter 1.7 --- Previous studies on GmSAL1 in Prof. Lam's lab --- p.20 / Chapter 1.8 --- Hypothesis and significant of this project --- p.21 / Chapter 2 --- Materials and Methods / Chapter 2.1 --- Materials / Chapter 2.1.1 --- "Plants, bacterial strains and vectors" --- p.23 / Chapter 2.1.2 --- Chemicals and Regents --- p.25 / Chapter 2.1.3 --- Commercial kits --- p.26 / Chapter 2.1.4 --- Primers and Adaptors --- p.27 / Chapter 2.1.5 --- Equipments and facilities used --- p.27 / Chapter 2.1.6 --- "Buffer, solution, gel and medium" --- p.27 / Chapter 2.1.7 --- Software --- p.28 / Chapter 2.2 --- Methods / Chapter 2.2.1 --- Molecular Techniques / Chapter 2.2.1.1 --- Bacterial cultures for recombinant DNA and plant transformation --- p.29 / Chapter 2.2.1.2 --- Recombinant DNA techniques --- p.29 / Chapter 2.2.1.3 --- Preparation and transformation of Agrobacterium competent cells --- p.30 / Chapter 2.2.1.4 --- Gel electrophoresis --- p.31 / Chapter 2.2.1.5 --- DNA and RNA extractions --- p.32 / Chapter 2.2.1.6 --- Generation of single-stranded DIG-labeled PCR probes --- p.34 / Chapter 2.2.1.7 --- Testing the concentration of DIG-labeled probes --- p.36 / Chapter 2.2.1.8 --- Northern blot analysis --- p.36 / Chapter 2.2.1.9 --- PCR techniques --- p.37 / Chapter 2.2.1.10 --- Sequencing --- p.38 / Chapter 2.2.2 --- Plant cell culture and transformation / Chapter 2.2.2.1 --- Arabidopsis thaliana --- p.39 / Chapter 2.2.2.2 --- Nicotiana tabacum L. cv. Bright Yellow 2 (BY-2) cells --- p.39 / Chapter 2.2.3 --- Growth and treatment conditions for plants / Chapter 2.2.3.1 --- Growth and salt treatment condition of soybean samples for gene expression studies of GmSAL1 --- p.40 / Chapter 2.2.3.2 --- Root assay of GmSAL1l transgenic Arabidopsis thaliana --- p.41 / Chapter 2.2.4 --- "Cell viability, ROS detection and confocal microscopy" / Chapter 2.2.4.1 --- Cell viability assay --- p.42 / Chapter 2.2.4.2 --- Detection of intracellular contents of Na+ --- p.42 / Chapter 2.2.4.3 --- Detection of Reactive oxygen species (ROS) --- p.42 / Chapter 2.2.4.4 --- Confocal microscopy --- p.43 / Chapter 2.2.4.5 --- Images processing and analysis --- p.43 / Chapter 2.2.5 --- Statistical analysis --- p.44 / Chapter 3 --- Results / Chapter 3.1 --- GmSAL1 sequence analysis --- p.45 / Chapter 3.2 --- Expression of GmSAL1 was induced by NaCl stress --- p.49 / Chapter 3.3 --- Construction of GmSAL1 transgenic tobacco BY-2 cell line --- p.50 / Chapter 3.4 --- Ectopic expression of GmSAL1 alleviates NaCl stress in transgenic tobacco BY-2 cells --- p.52 / Chapter 3.5 --- GmSAL1 enhances vacuolar sodium compartmentalization in transgenic tobacco BY-2 cell under NaCl treatment --- p.55 / Chapter 3.6 --- GmSAL1 helps maintain cell turgidity in transgenic tobacco BY-2 cell under NaCl treatment --- p.58 / Chapter 3.7 --- GmSAL1 enhances ROS scavenging in transgenic tobacco BY-2 cell under NaCl treatment --- p.61 / Chapter 3.8 --- Effect of expressing GmSAL1 in Arabidopsis thaliana under salt stress --- p.64 / Chapter 4 --- Discussion --- p.66 / Chapter 4.1 --- Sequence analysis and enzyme activity of GmSAL1 --- p.68 / Chapter 4.2 --- Gene expression profile of GmSAL1 --- p.70 / Chapter 4.3 --- Functional analysis of GmSAL1 in transgenic tobacco BY-2 cells / Chapter 4.3.1 --- GmSAL1 protects transgenic BY-2 cells under salt treatment --- p.71 / Chapter 4.3.2 --- GmSAL1 regulates Na+ compartmentalization and ROS scavenging in transgenic BY-2 cells under NaCl treatment in a calcium dependent manner --- p.72 / Chapter 4.4 --- Functional tests of GmSAL1 transgenic A. thaliana --- p.75 / Chapter 5 --- Conclusion and perspective --- p.76 / References --- p.78 / "Appendix I: Substrate specificity and Km, Kcat values of GmSAL1 protein" --- p.87 / Appendix II: Restriction and modifying enzymes --- p.89 / Appendix II: Chemicals --- p.90 / Appendix III: Commercial kits --- p.94 / Appendix IV: Equipments and facilities used --- p.95 / "Appendix V: Buffer, solution, gel and medium formulation" --- p.96

Thesis (MScAgric)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.

Airborne hyperspectral imagery has the potential to overcome the spectral and spatial resolution limitations of multispectral satellite imagery for monitoring salinity at both regional and farm scales. In particular, saline areas that have good cover of salt tolerant plants are difficult to map with multispectral satellite imagery. Hyperspectral imagery may provide a more reliable salinity mapping method because of its potential to discriminate halophytic plant cover from non - halophytes. HyMap and CASI airborne imagery ( at 3m ground resolution ) and Hyperion satellite imagery ( at 30 resolution ) were acquired over a 140 sq km dryland agricultural area in South Australia, which exhibits severe symptoms of salinity, including extensive patches of the perennial halophytic shrub samphire ( Halosarcia pergranulata ), sea barley grass ( Hordeum marinum ) and salt encrusted pans. The HyMap and Hyperion imagery were acquired in the dry season ( March and February respectively ) to maximise soil and perennial vegetation mapping. The optimum time of year to map sea barley grass, an annual species, was investigated through spectral discrimination analysis. Multiple reflectance spectra were collected of sea barley grass and other annual grasses with an ASD Fieldspec Pro spectrometer during the September spring flush and in November during late senescence. Comparing spectra of different species in November attempted to capture the spectral differences between the late senescing sea barley grass and other annual grasses. Broad NIR and SWIR regions were identified where sea barley grass differs significantly from other species in November during late senescence. The sea barley grass was therefore shown to have the potential to be discriminated and mapped with hyperspectral imagery at this time and as a result the CASI survey was commission for November. Other salinity symptoms were characterised by collecting single field and laboratory spectra for comparison to image derived spectra in order to provide certainty about the landscape components that were to be mapped. Endmembers spectra associated with saltpans and samphire patches were extracted from the imagery using automated endmember generation procedures or selected regions of interest and used in subsequent partial unmixing. Spectral subsets were evaluated for their ability to optimise salinity maps. The saltpan spectra contained absorption features consistent with montmorillonite and gypsum. A single gypsum endmember from one image strip successfully mapped saltpans across multiple images strips using the 1750 nm absorption feature as the input to matched filter unmixing. The individual spectra of green and red samphire are dominated by photosynthetic vegetation characteristics. The spectra of green samphire, often seen with red tips, exhibit peaks in both green and red wavebands whereas the red samphire spectra only contain a significant reflectance peak in the visible red wavelength region. For samphire, Mixture Tuned Matched Filtering using image spectra, containing all wavelength regions, from known samphire patches produced the most satisfactory mapping. Output salinity maps were validated at over 100 random sites. The HyMap salinity maps produced the most accurate results compared to CASI and Hyperion. HyMap successfully mapped highly saline areas with a good cover of samphire vegetation at Point Sturt without the use of multitemporal imagery or ancillary data such as topography or PIRSA soil attribute maps. CASI and Hyperion successfully mapped saltpan, however, their samphire maps showed a poor agreement with field data. These results suggest that perennial vegetation mapping requires all three visible, NIR and SWIR wavelength regions because the SWIR region contains important spectral properties related to halophytic adaptations. Furthermore, the unconvincing results of the CASI sea barley grass maps suggests that the optimal sensor for mapping both soil and vegetation salinity symptoms are airborne sensors with high spatial and spectral resolution, that incorporate the 450 to 1450 nm wavelength range, such as HyMap. This study has demonstrated that readily available software and image analysis techniques are capable of mapping indicators of varying levels of salinity. With the ability to map symptoms across multiple image strips, airborne hyperspectral imagery has the potential for mapping larger areas covering sizeable dryland agriculture catchments, closer in extent to single satellite images. This study has illustrated the advantage of the hyperspectral imagery over traditional soil mapping based on aerial photography interpretation such as the NLWRA Salinity 2000 and the PIRSA soil landscape unit maps. The HyMap salinity maps not only improved mapping of saline areas covered with samphire but also provided salinity maps that varied spatially within saline polygons. / Thesis (Ph.D.)--School of Earth and Environmental Sciences, 2006.

Thesis (Ph. D.)--University of Adelaide, Dept. of Soil Science, 1996? / Diskette for IBM/PC in pocket on back end paper. Copies of author's previously published articles inserted. Includes bibliographical references (leaves 186-207).

Thesis (M.S.)--University of Wyoming, 2007. / Title from PDF title page (viewed on June 16, 2008). Includes bibliographical references (p. 60-62).

Spicers Creek catchment is located approximately 400 km west of Sydney in the Central West region of New South Wales, Australia. Dryland salinity has been recognised as a major environmental issue impacting soil and water resources in the Central West region of NSW for over 70 years. Due to the geological complexity of the catchment and the presence of high salt loads contained within the soils, groundwater and surface waters, the Spicers Creek catchment was identified as a large contributor of salinity to the Macquarie River catchment. Over fifty-two dryland salinity occurrences have been identified in the Spicers Creek catchment and it appears that dryland salinity is controlled by the presence of geological structures and permeability contrasts in the shallow aquifer system. Combinations of climatic, geological and agricultural factors are escalating salinity problems in the catchment. The main aim of this thesis was to identify the factors affecting salinisation processes in the Spicers Creek catchment. These include the role of geological structures, the source(s) of salts to the groundwater system and the geochemical processes influencing seepage zone development. To achieve these aims a multidisciplinary approach was untaken to understand the soils, geology, hydrogeology and hydrogeochemistry of the catchment. Investigative techniques employed in this project include the use of geophysics, soil chemistry, soil spectroscopy, hydrogeochemistry and environmental isotopes. Evaluation of high-resolution airborne magnetics data showed a major north-east to south-west trending shear zone. This structure dissects the catchment and several other minor faults were observed to be splays off this major structure. These structures were found to be conducive to groundwater flow and are influencing the groundwater chemistry in the fractured aquifer system. Two distinctive groundwater chemical types were identified in the catchment; the saline Na(Mg)-Cl-rich groundwaters associated with the fractured Oakdale Formation and the Na-HCO3-rich groundwaters associated with the intermediate groundwater system. The groundwater chemistry of other deep groundwaters in the catchment appears to be due to mixing between these end-member groundwaters within the fractured bedrock system. The spatial distribution of electrical conductivity, Cl-, Sr2+ and 87Sr/86Sr isotopic ratios showed the correlation between saline groundwaters and the location of faults. Elevated salinities were associated with the location of two crosscutting fault zones. The spatial distribution of HCO3-, K+, Li+ and ?????3CDIC highlighted the extent of Na-HCO3-rich groundwaters in the catchment and showed that these groundwaters are mixing further east than previously envisaged. These findings show that Na(Mg)-Cl-rich groundwaters are geochemically distinctive and have evolved due to extensive water-rock interaction processes within the fracture zones of the Oakdale Formation. These saline groundwaters contain elevated concentrations of trace elements such as As, V and Se, which pose a potential risk for water resources in the area. 87Sr/86Sr isotopic ratios indicated that the source of salinity to the Na(Mg)-Cl-rich groundwaters was not purely from marine or aerosol input. Salt is most likely contributed from various allochthonous and autochthonous sources. This research found that the main mechanism controlling the formation of dryland salinity seepage zones in the Spicers Creek catchment is due to the presence of geological structures. These groundwater seepage zones act as mixing zones for rainfall recharge and deeper groundwaters. The main sources of salt to the seepage zones are from deeper Na(Mg)-Cl-rich groundwaters and rainfall accession. The major importance of this research highlights the need for an integrated approach for the use of various geoscientific techniques in dryland salinity research within geologically complex environments.

Geostatistical methods were used to find efficient and accurate means for salinity assessment using regionalized random variables and limited sampling. The random variables selected, sodium absorption ratio (SAR), electrical conductivity (EC), and clay content were measured on samples taken over an area of fifteen square miles. Ordinary kriging and co-kriging were used as linear estimators. They were compared on the basis of average kriging variance and sum of squares for error between observed and estimated values. The results indicate a significant improvement in the average kriging variance and sum of squares by using co-kriging estimators. EC was used to estimate SAR because of the high correlation between them. This was not true for clay content. A saving of two-thirds of the cost and time was achieved by using electrical conductivity as an auxiliary variable to estimate sodium absorption ratio. The nonlinear estimator, disjunctive kriging, was an improvement over co-kriging in terms of the variances. More information at the estimation site is a more important consideration than when the estimator is linear. Disjunctive kriging was used to produce an estimate of the conditional probability that the value at an unsampled location is greater than an arbitrary cutoff level. This feature of disjunctive kriging aids salinity assessment and reclamation management. A solute transport model was used to show how saptially variable initial conditions influenced the amount of water required to reclaim a saline soil at each sampling point in a simulated leaching of the area. / Graduation date: 1992

Spicers Creek catchment is located approximately 400 km west of Sydney in the Central West region of New South Wales, Australia. Dryland salinity has been recognised as a major environmental issue impacting soil and water resources in the Central West region of NSW for over 70 years. Due to the geological complexity of the catchment and the presence of high salt loads contained within the soils, groundwater and surface waters, the Spicers Creek catchment was identified as a large contributor of salinity to the Macquarie River catchment. Over fifty-two dryland salinity occurrences have been identified in the Spicers Creek catchment and it appears that dryland salinity is controlled by the presence of geological structures and permeability contrasts in the shallow aquifer system. Combinations of climatic, geological and agricultural factors are escalating salinity problems in the catchment. The main aim of this thesis was to identify the factors affecting salinisation processes in the Spicers Creek catchment. These include the role of geological structures, the source(s) of salts to the groundwater system and the geochemical processes influencing seepage zone development. To achieve these aims a multidisciplinary approach was untaken to understand the soils, geology, hydrogeology and hydrogeochemistry of the catchment. Investigative techniques employed in this project include the use of geophysics, soil chemistry, soil spectroscopy, hydrogeochemistry and environmental isotopes. Evaluation of high-resolution airborne magnetics data showed a major north-east to south-west trending shear zone. This structure dissects the catchment and several other minor faults were observed to be splays off this major structure. These structures were found to be conducive to groundwater flow and are influencing the groundwater chemistry in the fractured aquifer system. Two distinctive groundwater chemical types were identified in the catchment; the saline Na(Mg)-Cl-rich groundwaters associated with the fractured Oakdale Formation and the Na-HCO3-rich groundwaters associated with the intermediate groundwater system. The groundwater chemistry of other deep groundwaters in the catchment appears to be due to mixing between these end-member groundwaters within the fractured bedrock system. The spatial distribution of electrical conductivity, Cl-, Sr2+ and 87Sr/86Sr isotopic ratios showed the correlation between saline groundwaters and the location of faults. Elevated salinities were associated with the location of two crosscutting fault zones. The spatial distribution of HCO3-, K+, Li+ and ?????3CDIC highlighted the extent of Na-HCO3-rich groundwaters in the catchment and showed that these groundwaters are mixing further east than previously envisaged. These findings show that Na(Mg)-Cl-rich groundwaters are geochemically distinctive and have evolved due to extensive water-rock interaction processes within the fracture zones of the Oakdale Formation. These saline groundwaters contain elevated concentrations of trace elements such as As, V and Se, which pose a potential risk for water resources in the area. 87Sr/86Sr isotopic ratios indicated that the source of salinity to the Na(Mg)-Cl-rich groundwaters was not purely from marine or aerosol input. Salt is most likely contributed from various allochthonous and autochthonous sources. This research found that the main mechanism controlling the formation of dryland salinity seepage zones in the Spicers Creek catchment is due to the presence of geological structures. These groundwater seepage zones act as mixing zones for rainfall recharge and deeper groundwaters. The main sources of salt to the seepage zones are from deeper Na(Mg)-Cl-rich groundwaters and rainfall accession. The major importance of this research highlights the need for an integrated approach for the use of various geoscientific techniques in dryland salinity research within geologically complex environments.