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1
Kalifa, Ali. "Salt stress, and phosphorus absorption by potato plants cv. 'Russet Burbank'." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq29727.pdf.
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Attumi, Al-Arbe. "Effect of salt stress on phosphorus and sodium absorptions by soybean plants." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=20242.
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The radiotracer methodology was combined with the Hoagland solution culture of growing soybean in a greenhouse to investigate the absorptions of phosphorus (P), calcium (Ca), and sodium (Na) as a function of salinity. Salt stress was varied by using zero to 120 mM NaCl. The research was initiated because of a need to increase soybean production in the saline soils of the semi-arid regions of the world. Although P absorption increased with time at each concentration of NaCl, increasing its concentrations ([NaCl]) to 120 mM reduced P uptake considerably. The addition of inorganic P (Pi) to the salt medium improved P absorption significantly (P < 0.0001) in stem, petiole, and roots. Polynomial regressions showed the relationship between 22Na activity and [NaCl] for leaves and petiole to be cubic (R2 = 1) while in the stem a quadratic relationship prevailed. A maximum of P and Na absorption was observed at 40 mM NaCl. The relationship between 32P activity and increasing [NaCl] was linear for the roots (a positive slope) and the stem (a negative slope). 45Ca and 32P dual labelling part of the experiments failed to produce results because an unexpectedly high degree of tissue quenching which prevented from obtaining the minimum counting requirements for separation. Shoot fresh and dry weights decreased linearly with increasing [NaCl] as did the root fresh and dry weights. Leaf chlorophyll content during the last week of the final harvest showed a linear relationship with time. Chlorophyll increased with time linearly when the growth medium contained zero and 40 mM NaCl; whereas a negative slope was obtained for 80 and 120 mM NaCl. It seems that P fertilization of the soil could ameliorate the salt effect. 22 Na uptake results indicated that there is a mechanism for exclusion of Na from soybean plant parts.
3
Zhou, Maoqian 1961. "Nitrogen fixation by alfalfa as affected by salt stress and nitrogen levels." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277231.
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The growth and Nitrogen fixation by one low salt tolerant alfalfa (Medicago sativa L.) and two germination salt tolerant selections inoculated with were investigated at two salt levels (0, -0.6 Mpa) and two N rates (1, 5ppm) using a system which automatically recirculates a nutrient solution. The high level of salinity (-0.6 Mpa osmotic potential of culture solution) resulted in substantial reduction in the N fixation percentage and total fixed N. The effect of salinity was more pronounced for later cuttings than for the earlier cutting. The N fixation percentages were substantially decreased by increasing N level and the reduction was enhanced by time. The N treatment levels did not exhibit a significant effect on total fixed N. Cultivars did not differ in either growth or N fixation. However, the interaction of N and salinity significantly decreased the percentage and amount of N fixation.
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McKimmie, Timothy Irving 1948. "CHARACTERIZATION OF SALT TOLERANCE IN ALFALFA (MEDICAGO SATIVA L.)." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/276348.
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El-Sheikh, Medhat. "Studies on the cellular and molecular basis of salt resistance in a halotolerant Arabidopsis thaliana cell line." Thesis, University of Glasgow, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274256.
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Alm, David Michael. "Comparison and interaction of heat and salt stress in cultured tobacco cells." Virtual Press, 1986. http://liblink.bsu.edu/uhtbin/catkey/445616.
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Cultured tobacco cells (Nicotiana tabacum L., cv Wisconsin-38) were subjected to temporary sub-lethal heat and salt shock treatments to determine the effects of these treatments on various physiological parameters after subsequent lethal heat or salt stresses. Tobacco cells developed a tolerance to a non-permissive temperature stress (54C for 14 min) when pretreated with heat shock of 38C for 2h but not when pretreated at 42C for 2h. Cells pretreated at 38 (2h) exhibited less than 30% normal growth when the 54C stress came immediately after the 38C treatment. Tolerance to the 54C stress developed with increased interval between shock and stress with cells exhibiting 95% normal regrowth when the 54C stress was administered 8h after the 38C shock. The developement of heat tolerance was inhibited if heat shock was done in the presence of a non-injuring level of EGTA (.0.5mM). Cells treated with EGTA during heat shock grew normally at 23C but not after a 54C heat stress. EDTA (0.5mM) had little effect on the acquisition of tolerance to heat stress.Wisconsin-38 cells developed a tolerance to a non-permissive salt stress (2% NaCl for 16h) when pretreated at a lower salt level (1.2% NaCl) for 3h. Cells heat shocked at 38C exhibited increased tolerance of the lethal salt stress up to 8h. Conversely, cells heat shocked at 42C exhibited immediate tolerance to lethal salt stress and this tolerance decayed over eight hours. The heat shock-induced acquisition of salt tolerance was inhibited by both EGTA and EDTA.Proteins synthesized during heat and salt stress treatments were labeled with [35S]-methionine and/or [3H]-leucine and separated using Sodium dodecylsulfate polyacrylamide gel electrophoresis. Fluorographic analysis of the gels indicate that a number of proteins are produced in response to heat shock. Similar analysis of proteins from salt shocked cells indicates that no salt shock proteins are produced in response to a brief low-level sodium chloride shock.
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LEDBETTER, CRAIG ALLEN. "HERITABILITY OF SALT TOLERANCE DURING GERMINATION AND EMERGENCE IN SHORT STAPLE COTTON (GOSSYPIUM HIRSUTUM L.)." Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/183961.
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Soil salinity is a serious problem for farmers in irrigated agriculture. Soil salts cause reduced stands and yields because of toxic ion and osmotic problems for surviving seedlings. The tolerance to sodium chloride during germination and emergence was studied in three commercial cultivars of short staple cotton (Gossypium hirsutum L.). It is this stage of the life cycle that cotton is most sensitive to salts in the soil solution. The objectives of this study were to increase the tolerance to sodium chloride during germination and emergence and to determine the narrow sense heritability of this factor. Parental cultivars initially demonstrated 15% emergence at -1.2 MPa NaCl. Surviving salt tolerant plants were planted in the field and seeds from these plants were used as the germplasm for the next cycle of salt tolerance selection. Experiments were conducted to determine the relative salt tolerance of all plants at -1.2, -1.4, -1.6, and -1.8 MPa NaCl. Emergence of salt tolerant accessions from the first cycle of selection ranged from 3.1 to 25.8% in the first relative salt tolerance experiment. The average emergence of all accessions taken over all four salinity levels was 8.9% for first cycle plants. After a second cycle of selection for salt tolerance, the average emergence percentage increased to 13.0% over the four salinity levels. Emergence ranged from 0.7 to 32.6% in the second relative salt tolerance experiment. Narrow sense heritability of sodium chloride tolerance during germination and emergence was estimated at 0.38 using data from the first and second relative salt tolerance experiments.
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Slail, Nabeel Younis 1963. "INFLUENCE OF SODIUM-CHLORIDE ON TRANSPIRATION AND PLANT GROWTH OF TWO TOMATO CULTIVARS." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276516.
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Seedlings were grown at five salinity levels in Hoagland's solution for 4 weeks. Transpiration, leaf diffusive resistance, leaf temperature and plant growth of the tomato (Lycopersicon esculentum Mill.) cultivars 'VF 145B' and 'VF 10' were examined at different levels of NaCl ranging from 0 to -12 bars. Salinity-reduced transpiration increased leaf diffusive resistance and increased leaf temperature for both cultivars. Shoot length, root length, shoot and root weight and leaf area were all lower for the two cultivars at increasing salinity levels. However, the two cultivars responded differently to salinity, with VF 10 showing better growth at the control and the -4 bar treatment than VF 145 B. At -9 and -12 bar treatment, the reverse was true. Selection of tomato for salt resistance should not be based on vigorous growth at non-saline conditions because different genes may control the salt tolerance ability of the plants at high salinity levels.
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Robinson, David Lowell 1955. "RECURRENT SELECTION FOR GERMINATION SALT TOLERANCE IN ALFALFA (SALINITY, FORAGES, BREEDING)." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/277015.
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Andrade, Maria Isabel. "PHYSIOLOGY OF SALT TOLERANCE IN GUAR, CYAMOPSIS TETRAGONOLOBA (L.) TAUB." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275416.
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Al-Rawahy, Salim Ali. "Nitrogen uptake, growth rate and yield of tomatoes under saline conditions." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184894.
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Results of two studies are reported here, a greenhouse study and a field study. In the greenhouse study, dry matter yield and nitrogen (total and 15N) uptake of leaves, stems and roots of tomato plants (Lycopersicum esculentum Mill., cv. Columbia) subjected to saline stress by NaCl were studied. The integrated effects of responses of these tissues to salinity on the whole plant basis and levels of Na⁺, Cl⁻ and K⁺ accumulation in these tissues were also studied. The treatments consisted of low (control, 0.3 bar), medium (4.3 bars), and high (8.3 bars) salinity. The saline treatments were prepared by adding NaCl to nutrient solution in sand culture. The plants were 80 days old at the start of the treatments and each was in a pot containing 1.8 kg of quartz sand. The ¹⁵N was provided to plants by adding K¹⁵NO₃ to the pots and the 15N treatment continued with the saline treatments up to 30 days. The plants were harvested at each 5-day interval during the treatment period. Dry matter production and nitrogen (total and ¹⁵N) uptake were significantly lower for saline treatments as compared with the control. Differences in dry matter production and ¹⁵N uptake on whole plant basis appeared in the latter part of the treatment period between the two saline treatments. For most of the parameters studied, the leaves were found to be affected most by salinity, the roots were intermediate in their response and the stems were the least affected by salinity. The effect of salinity on the studied parameters were attributed to osmotic effects and specific ion effects of Na⁺ and/or Cl⁻. A field study with two cultivars--Columbia and Pearson was conducted at the Safford Agricultural Center. Three N treatments were used: 0 kg N/ha, 84 kg N/ha and 168 kg N/ha and two treatments consisting of two water sources--river water with an EC of 1.15 dS/m and more saline well water of EC of 2.21 dS/m. Columbia had a significantly higher yield of tomatoes than Pearson for both water types. The N treatments had no effect on tomato yield apparently due to high residual N remaining in the field from the previous crop. Commercially acceptable fresh market yields were approached with both varieties and waters in spite of moderate salinity and sodium under heavy textural soil conditions, high temperatures and the presence of certain diseases in the area.
12
Wang, Ding Xiang. "Interaction between the effects of sodium chloride and high temperature on the vegetative growth of tomato (Lycopersicon esculentum Mill.)." Title page, contents and summary only, 1993. http://web4.library.adelaide.edu.au/theses/09PH/09phw2456.pdf.
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Rasmussen, Scott Lynn 1958. "The effects of salinity stress on the development of Pythium blight of Agrostis palustris." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276627.
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Salinity stress predisposed Penncross creeping bentgrass to cottony blight caused by P. aphanidermatum. Studies were conducted on the effects of salinity on the mycelial growth of P. aphanidermatum and on the growth of Penncross bentgrass. Mycelial growth increased significantly up to Ec levels of 7.1 ds/m when compared to mycelial growth at the control Ec levels of 0.5 ds/m. Plant growth was reduced to 50% of the control at Ec levels of 4.3 ds/m. 3-month-old Penncross bentgrass plants were inoculated and incubated at two differing temperatures. At 32 C, all plants died within 3 days regardless of salinity treatment. Rates of plant death were greatest at salinity levels over 2.8 ds/m. At 27 C, plants irrigated with water at Ec levels from 4.3 to 7.1 ds/m showed complete necrosis within 5 days, while treatments irrigated with tap water showed no disease symptoms.
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Al-Bahrany, Abdulaziz Maatook 1960. "Physiological and biochemical responses of short staple cotton (Gossypium hirsutum L.) to salt stress." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184634.
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Three cotton (Gossypium hirsutum L.) germplasms (DP62, 84027, and 84033) were used to investigate the physiology of salt tolerance. Lines 84027 and 84033 were developed from the parental line DP62 and showed superior vigor under varying NaCl conditions (0.5 to 2.0 M) during germination and emergence. Proline levels increased in the leaves of all germplasms in response to increasing salinity. Varietal differences in proline levels did not reflect their variation in salt tolerance. Several physiological characteristics were also evaluated under non-saline condition in the greenhouse. There were no significant differences among germplasm sources for all parameters measured. However, salinity reduced transpiration rate, increased leaf diffusive resistance and leaf temperature for all lines. Ribosomal-RNA levels in all germplasms were evaluated after seeds were stressed for 24 hrs in various concentrations of NaCl and then germinated under normal conditions for 72 hrs. Ribosomal-RNA levels were inversely related to salt concentrations. Line 84033 followed by line 84027 had highest ribosomal-RNA content than the parental line DP62 when averaged over the four salt concentrations. Sodium content (ppm/g FW) and Cl⁻ content (ppm/g FW) were evaluated in microsomal and cell walls fractions as well as a cytoplasmic fraction which consisted of vacuoles, mitochondria, and plastids. The Cl⁻ ion exhibited a greater consistency in a concentration shift from one fraction to another as a function of time than did the Na⁺ ion. As a result, there may be a correlation between the drop in ribosomal-RNA and the amount of Cl⁻ in the microsomal fraction. Other parameters measured in the germinating seed were soluble protein (globulin), insoluble proteins (prolamin and glutelin) and fiber percentage. Variations within the germplasms were shown to exist. This study shows that even among lines that have been selected for salt tolerance from a single variety, the possibility exists that each of these lines may have a different mechanism to cope with salt stress.
15
Weeks, Jon Randall 1949. "The growth and water relations of a coastal halophyte, Salicornia bigelovii." Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/191114.
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The succulent, annual euhalophyte, Salicornia bigelovii was grown in 1, 10, 35, 45 and 60 ppt Instant Ocean. This range represents approximately 1/35 to nearly twice the salinity of seawater. The plants in the 4 highest salinities had common final dry weights and seed yields of about 60 and 11 g, respectively, while the 1 ppt plants had 28 and nearly 5 g, respectively. The water relations data reflected the growth and seed production of the plants. The plants in the 4 higher salinities had water potentials sufficient to generate large import gradients and osmotic potentials which contributed to substantial turgors. The 1 ppt plants had a gradient like the rest, but a very low turgor of 0.11 MPa which was barely 23% of that of the lowest of the other treatments. Higher salinities resulted in slightly greater organic and inorganic osmotica contents. Overall, these results suggest a relatively fixed genetic response to a wide range of salinities, as well as an inability to function well at very low salinities. No plant grown at 0 ppt was ever able to reproduce. Therefore, this plant is an obligate halophyte. Experiments in the plant's native coastal estuary indicated meristem water potentials fluctuate with the tides, although they remain about 1.5 MPa below the corresponding soil water potentials. The plants occupy a discrete elevational range throughout the estuary, spending about 1/3 of their daylight hours submerged, and apparently never see dryness. Phenotype differences in the estuary suggest that, within the habitat, pacing and consequent resource domination may be important parameters affecting plant size and possibly fitness. Nitrogen, which is characteristically rare in this and other estuaries, may be critical in this regard. The plants produce large quantities of glycine-betaine, which may be for simultaneous osmoticum use and nitrogen storage. Most roots occur in the first 3 inches of soil. A mechanism is proposed, based on highly efficient compartmentation at the cellular level and the shuttling of organic osmoticum across the tonoplast, by which the tidally based cyclical water potentials could be explained.
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Zheng, Liansheng 1955. "Gene expression in two different genotypes of alfalfa under salt stressed and unstressed conditions." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276936.
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Gene expression in two different genotypes of alfalfa, salt-tolerant and salt-sensitive, was examined by studying differences in protein products coded for by poly(A+) RNA isolated from shoot and root tissue. Plants were grown in hydroponics under unstressed or salt-stressed conditions. Two salinity levels (low salt: 30 mM NaCl and 6 mM CaCl2 and high salt: 133 mM NaCl and 27 mM CaCl2) and one unstressed control were applied. The salt-tolerant genotype showed higher biomass accumulation than the salt-sensitive genotype under both control and salt-stressed conditions. The difference in biomass accumulation between the two genotypes was greatest at the highest salt level. The effect of salt stress on gene expression was studied via in vitro translation of poly (A+) RNA with (35S) -methionine. The labeling pattern was similar in all treatments when analyzed by one dimensional SDS-PAGE. However, a two dimensional analysis (isoelectric focusing followed by SDS-PAGE) showed that salt-stress induced a number of new proteins and repressed several others.
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Cepeda, Jose de los Angeles 1955. "Nitrogen fixation by alfalfa as affected by osmotic potentials and measured by nitrogen-15 techniques." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276591.
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One low salt tolerant alfalfa (Medicago sativa L.) cultivar and two germination salt tolerant alfalfa selections were compared for growth and N fixation at four salinity levels (0, -0.3, -0.6 and -1.2 Mpa). In the first experiment a Hoagland's solution at 5 ppm-N was used; in the second experiment the solution had a 1 ppm-N concentration and supplemental light was used. No significant differences were found among the cultivars. This provides additional support that germination salt tolerance is not necessarily related to salt tolerance for growth. Nitrogen fixed to the first harvest was 61, 48, 49, and 27% of the total shoot N for plants in the control, -0.3, -0.6, and -1.2 Mpa solutions, respectively. At the second harvest, N fixation percentages were 94, 89, 80, and 57% for the corresponding salinity levels which showed significant reduction in N fixation at -0.3 Mpa. The evaluation of N fixation was by 15N techniques.
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Poteet, David Charles 1953. "Biochemical and physiological adaptations of alfalfa to germination stresses imposed by sodium-chloride." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277063.
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Nine cycles of recurrent selection for germination salt tolerance in alfalfa (Medicago sativa L.) were compared with their parental cultivar, 'Mesa-Sirsa'. Test seeds were produced in the same season and locale. Cycle 9 and Mesa-Sirsa showed 90% and 2.5% germination, respectively, in a -1.7 MPa NaCl medium. Cycle 8 germinated more vigorously compared to Mesa-Sirsa in stressed and non-stressed environments. Selection also enhanced germination speed and radicle length. Fresh seed and one year old seed showed similar percent germination. Scarification decreased germination in a saline solution. Mesa-Sirsa and Cycle 8 displayed the same pattern of water uptake in a salt solution. Salinity decreased water uptake in Cycle 8 and Mesa-Sirsa compared to the control. Cycle 8 and Mesa-Sirsa contained 7% galactomannan and 3.2% stachyose. Galactomannan was not an important factor in seed salt tolerance. Seed protein content was stable throughout the cycles of selection. Selection for germination salt tolerance in alfalfa significantly affected the percentage of seed amino acids.
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El, Mghadmi Z. Y. "Effect of environmental stresses and growing medium amendment with 'Zander' on growth of Acacia saligna under saline conditions." Thesis, Coventry University, 2011. http://curve.coventry.ac.uk/open/items/5727ee90-f827-485e-93d9-94a9b5456f43/1.
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In Libya salinization of land and ground water is a key problem. A. saligna is one species that offers potential for growth under these conditions. Experiments were undertaken to accelerate the germination of Acacia seeds, and various pre-treatment methods were assayed. Boiling water treatment, mechanical scarification and acid improved germination and germination rate. Sowing A. saligna seeds at 30 mm depth gave greatest seedling growth from large and medium seeds whereas 20 mm was more suitable for small seeds. This study aimed to improve the establishment of Acacia saligna irrigated with saline water, plants were grown for seven weeks under greenhouse or field conditions in (Libya) either sand or soil salinized with varying applications of NaCl. Irrigation with NaCl significantly decreased plant survival and growth and concentration of Ca, Na, K, Fe and P ions in plants with 0.5 M or 1.0 M NaCl. The experiments were repeated using a naturally occurring soil amendment called ‘Zander’. Seeds of A. saligna were grown for seven weeks in both greenhouse and field trials as before but with the addition of Zander and NaCl. Zander improved plant survival and growth with salinity and increased the elements in plants (Ca, Na, K, Fe and P). Field experiments were conducted to assess the effects of saline irrigation with 1.0 M NaCl and extra water added to 0% or 10% Zander on survival and growth, consequently, seedling growth significantly decreased with increase in soil salinity. Survival and growth increased with increase in extra water. The additional irrigation water caused an increase in the uptake of Ca++ and increased the Ca++/Na+ and K+/Na+ ratio. Zander did not appear to reduce net uptake of Na+ and its transport to shoot tissues. Mg++, P, K+ and Ca++ content significantly decreased in plants in response to salinity. Possible mechanisms to avoid Na+ toxicity in A. saligna in response to salinity included increasing the supply of Ca++. Extra Ca++ applied into the medium with and without salt increased survival and growth even in the absence of Zander. Calcium increased uptake of Ca++ and increased Ca++/Na+ and K+/Na+ ratio.
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Collins, R. P. "The role of calcium and potassium in salinity tolerance in Brassica rapa L. cv. RCBr seed." Thesis, Coventry University, 2012. http://curve.coventry.ac.uk/open/items/e0d653ff-7d6b-4827-9467-dc8bcb6ff621/1.
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The possibility of manipulating calcium (Ca2+) and potassium (K+) levels in seeds of Brassica rapa by altering parent plant nutrition and investigating the potential for increased salinity tolerance during germination, given that considerable amounts of literature imply that greater amounts of available exogenous Ca2+ and K+ can ameliorate the effects of salinity on both whole plant growth and germination, was evaluated. The investigation consisted of four growth trials. Two preliminary growth trials suggested that seed ion manipulation was possible without affecting the overall growth and vigour of the plant. After developing suitable high and low Ca2+ and K+ nutrient solutions for growth, a trial was carried out in a growth room and greenhouse, with various substrates and the seed of a certain size category was collected for subsequent ion and salinity tolerance analysis. Seed Ca2+ and K+ was significantly affected by growth substrate and nutrient solution and data showed that a significant negative regression relationship existed between seed Ca2+, K+ and Ca2+ + K+ levels and salinity tolerance. Further experimentation using hydroponic culture attempted to remove any possible effects of substrate and also to compare size categories of seed with a view to elucidating localisation of Ca2+ and K+. Seed Ca2+ was found to be significantly altered by nutrient solution in the two different sizes tested and higher Ca2+ nutrient solution was found to increase salinity tolerance in daughter seed. One significant negative regression correlation between salinity tolerance and seed K+ concentration existed in smaller seed, but disregarding seed size in a regression analysis of seed ion content and salinity tolerance, a significant negative relationship existed between seed Ca2+, K+ and Ca2++ K+. The results, especially in terms of Ca2+ nutrition, contradict much previous research that suggests increased salinity tolerance at germination can arise with the increased presence of Ca2+ and/or K+. Salinity tolerance was greater in seeds of larger size across all nutritional treatments and the smaller size range exhibited increased Ca2+ and K+ per μg seed. Ca2+ concentration in smaller seeds with greater surface area:volume ratios provided a clue to the potential localisation of Ca2+. Cross sectional staining showed that a greater proportion of seed Ca2+ may reside in the coat. This was confirmed by analysis which showed an approximate 50% split of total extractable seed Ca2+, regardless of size, between coat and embryo within a seed; the majority of which, per μg, resides in the coat. Further work looked at the relative solubility of the Ca2+ and K+ in these tissues and whole seed to look at the potential bioavailability of Ca2+ during germination from various parts of the seed. Most water soluble Ca2+ exists in the embryo and most insoluble Ca2+ exists in the coat, but coat Ca2+ was found to be ionically exchangeable and therefore bioavailable. K+ appeared mostly water soluble in embryo and coat. In line with previous whole plant research in this species, most Ca2+ is readily water soluble or ionically exchangeable in form and the possible negative effects of how increasing bioavailable Ca2+ may reduce salinity tolerance was discussed.
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Lawson, Inez Ilicia. "Invertebrate Community Composition Across Inundation Regimes and Its Potential to Reduce Plant Stress." PDXScholar, 2017. https://pdxscholar.library.pdx.edu/open_access_etds/3891.
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Appreciation of the ecological and economic values associated with healthy salt marshes has led to a recent rise in the number of marshes that are being targeted for restoration by dike removal. The success of restoration is often measured by the return of marsh plants, though this overlooks a key component of salt marshes, that of the invertebrate community within marsh sediments. To evaluate the short-term recovery of these invertebrates, sediment cores were collected across an elevational gradient in a recent dike removal marsh, one and two years post removal, and a nearby reference marsh. Abundance, richness and diversity as well as morphospecies community composition were compared across treatment groups (Reference, Removal) and elevation zone (High Marsh, Low Marsh). Morphospecies richness, abundance and diversity were significantly higher in Low Marsh samples than in High Marsh samples, though no statistically significant differences were found across treatments of the same elevation (e.g., Reference Low Marsh versus Removal Low Marsh). Pair-wise ANOSIM results found significant differences between community compositions across treatments, specifically Reference Low Marsh and Removal Low Marsh.
The marsh edge, the lowest point of vascular plant growth before transitioning to tide flats, is considered a high stress environment for emergent vegetation. Plant establishment and survival in this low elevation zone is limited by the tolerance to inundation duration and frequency and anoxic sediments. Bioturbation and burrowing by macroinvertebrates increases the surface area exposed to surface water for gas exchange, increasing the depth of the redox potential discontinuity layer. Crabs that make stable, maintained burrows have been shown to increase oxygen penetration into sediment, improving plant productivity. Such crabs are not found in salt marshes of the Pacific Northwest of North America. However, other burrowing invertebrates may have a positive impact on plant health in these areas by reducing abiotic stress due to anoxic sediments, thereby allowing plants to establish and survive lower in the intertidal zone. To assess this potential relationship, study plots of Distichlis spicata were selected at equivalent elevations at the lowest point of plant establishment at the marsh edge. Focal plant rhizomes were severed from upland ramets and assigned an invertebrate abundance treatment based on a visual burrow count surrounding each plant (9 cm diameter). Focal plants were visited monthly from July to September 2016, plant health variables of chlorophyll content and chlorophyll fluorescence (photosynthetic efficiency), and sediment ORP readings were collected. Plant survivorship was significantly higher in plots with invertebrates, 96% of plants in 'With Invertebrate' plots and 50% of plants in 'No Invertebrates' plots survived the duration of the study. Plant health (chlorophyll content and chlorophyll fluorescence) generally increased with increased invertebrate presence though, not statistically significant. There may be potential for improved plant productivity and resilience to plants at the marsh edge due to invertebrate burrowing activity. This benefit could help mitigate projected losses in plant productivity due to sea level rise, though more research is needed to investigate the mechanism by which these invertebrates confer a health benefit to plants at the marsh edge.
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Goertz, Steven Harvey. "Salt tolerance of tepary (Phaseolus acutifolius Gray) and navy (P. vulgaris L.) beans at several developmental stages." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184646.
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Two accessions of tepary (phaseolus acutifolius Gray var. latifolius) and navy (P. vulgaris L. 'Fleetwood') beans were studied for salt tolerance at several• developmental stages. Genotypes were germinated at 0.0 through -2.5 MPa NaCl at 25°C and 35°C for nine days. Tepary accessions had higher germination percentages and rates than navy for ≤ - 2.0 MPa at 250C and ≤ - 1.5 MPa at 35°C. Fresh weights of root plus hypocotyl decreased severely with the first increment of NaCl (-0.5 MPa) for all genotypes. Fresh weight of navy was reduced more at 35°C than at 25°C. Genotypes were stressed in vermiculite-filled trays with 0.0 through -1.5 MPa NaCl for 14 days. Final growth stage and rates of emergence were reduced at salinities ~ -0.6 MPa NaCl, and were higher in tepary than navy at -1.2 MPa. Tepary beans tended to maintain higher water and osmotic potentials, and at -0.9 MPa had less reduction in leaf area than navy beans. Fresh weights, dry weights and root:shoot ratios declined in all genotypes with increasing salinities. Plants grown hydroponically were stressed with -0.10, -0.25, and -0.50 MPa NaCl during either vegetative or reproductive stages. Navy had equal or greater fresh and dry weights of leaf, stem, and pods at -0.10 MPa, but tepary beans had equal or greater weights at the highest salinity relative to navy. Tepary had the greatest pod weight with -0.50 MPa NaCl applied during the reproductive stage. Carbon exchange rates (CER) were lower in navy than one or both tepary beans at some sampling times. Tepary beans tended to have higher leaf water and osmotic potentials than did navy. Transpiration and stomatal resistance values were similar in all genotypes, while leaf temperatures were different in white tepary versus navy. Tepary beans yielded higher than navy when grown in low and high salinity fields. Transpiration rates, leaf water and osmotic potentials, and CERs were similar or higher, while stomatal resistance and leaf temperatures were similar or lower in tepary than in navy. Plant height and stand count also were measured. Tepary was more salt tolerant than navy, exhibiting greater tolerance to NaCl at every growth stage.
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Alislail, Nabeel Yonnis. "Influence of sodium chloride on tepary (Phaseolus acutifolius Gray) and navy (Phaseolus vulgaris L) beans." Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/184985.
Full textAbstract:
Shoot and root fresh and dry weight, shoot length, leaf area, leaf area index and relative growth rate of 14 day old tepary bean (Phaseolus acutifolis Gray) and navy bean (Phaseolus vulgaris L.) seedlings were reduced following treatment with NaCl solution exhibiting osmotic potential of either -0.25, 0.50, and -0.75 MPa. Salinity reduced the growth of navy bean more than tepary bean. The physiological basis of the adaptive response of tepary bean seedlings to salt stress was explored by determining the water and osmotic potentials, relative water content, free amino acid and sugar concentrations, distribution and levels of inorganic ions within the seedlings and ATPase activity of the root plasma membrane. Salinity led to an osmotic adjustment in the leaves and the proximal part of the root of tepary bean. Turgor remained almost constant whereas osmotic and water potential and relative water content declined following the salt treatments. The osmotic adjustment of the leaves and proximal part of the roots was -1.7 MPa and -1.2 MPa, respectively, in seedlings treated with -0.75 MPa NaCl solution. Free amino acids and sugars increased under salinity stress in both species but they increased more in the tepary bean. Glucose was the most abundant free sugar. The nonstructural carbon solutes contributed -0.15 MPa to the seedling's osmotic adjustment whereas Na, Cl, K and Ca ion levels contributed -0.85 MPa. However, the levels of these solutes were not large enough to account for the total osmotic adjustment observed in the salt treated seedlings. This study shows that tepary bean has specific strategies to overcome the impact of salinity through osmotic adjustment and exclusion of Na and Cl ions from the stems and leaves by retaining these ions in the proximal part of root and stem base. (Abstract shortened with permission of author.)
24
Badenhorst, Petrus Cornelius. "Identification of molecular markers for Thinopyrum distichum chromosomes contributing to salt tolerance." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51794.
Full textAbstract:
Thesis (MSc.)--University of Stellenbosch, 2000.ENGLISH ABSTRACT: The detrimental effect of soil salinity on crop production is a growmg problem worldwide (Tanji, 1990b). The degree to which plants can tolerate high concentrations of salt in their rooting medium is under genetic control with different genetic and physiological mechanisms contributing to salt tolerance at different developmental stages (Epstein & Rains, 1987). Only limited variation exists for salt tolerance in the cultivated cereals. This has prompted attempts to select tolerant progeny following hybridisation of cultivated species and wild, salt-tolerant species. Thinopyrum distichum, an indigenous wheatgrass that is naturally adapted to saline environments (McGuire & Dvorak, 1981), was crossed with triticale (x Triticosecale) in an attempt to transfer its salt tolerance and other hardiness characteristics (Marais & Marais, 1998). The aims of this study were to (i) identify Thinopyrum chromosomes carrying genes for salt tolerance and to identify molecular markers for these chromosomes, (ii) identify a number of diverse monosomic and disomie addition plants. Bulked segregant analysis (BSA), in combination with AFLP, RAPD and DAF marker analysis was implemented to screen for polymorphisms associated with salt tolerance. Five putative AFLP markers and two RAPD markers were detected using bulks composed of salt tolerant plants and bulks composed of salt sensitive plants. The distribution of the markers in these bulks suggests that more than one Thinopyrum chromosome carry genes for salt tolerance. Salt tolerant monosomic and disomie addition plants were characterised for AFLP, RAPD and DAF polymorphisms in an attempt to find markers associated with the chromosome(s) conditioning salt tolerance. One salt tolerant monosomic and one disomie addition plant was identified. One AFLP and two RAPD markers were identified for the Thinopyrum chromosome( s) present in the monosomic addition plant, while three AFLP and three RAPD markers were identified for the disomie addition plant. An attempt was also made to identify diverse chromosome addition plants having complete or near complete triticale genomes plus an additional random Thinopyrum chromosome. Plants with 2n = 43 /44 were identified and characterised for molecular markers (AFLP and RAPD). Cluster analysis was used to group the putative monosomic or disomie addition plants according to the specific Thinopyrum chromosomes they retained. Seventeen AFLP and RAPD markers could be used to group the 24 putative addition plants into six broadly similar groups with different additional Thinopyrum chromosomes. While the members of each group are likely to carry the same additional Thinopyrum chromosomes, this may not necessarily be the case as the interpretation of the marker results is complicated by heterogeneity among plants with regard to the triticale background chromosomes they possess. It is also likely that chromosome translocations occurred during backerossing which may further complicate data. Nonetheless, it is now possible to select disomie addition plants from each group that are likely to represent different Thinopyrum chromosomes. The data will also be useful in future attempts to find further addition plants carrying the remaining Thinopyrum chromosomes.
AFRIKAANSE OPSOMMING: Die skadelike effek van grond versouting op gewasproduksie neem wêreldwyd toe (Tanji, 1990b). Die mate waartoe plante hoë konsentrasies sout in die wortelstelsel kan hanteer is onder genetiese beheer en verskillende genetiese en fisiologiese meganismes dra by tot die soutverdraagsaamheid tydens verskillende ontwikkelingstadia (Epstein & Rains, 1987). Slegs beperkte variasie bestaan vir soutverdraagsaamheid in verboude grane. Dit het aanleiding gegee tot pogings om soutverdraagsame nageslag te selekteer na hibridisasie van verboude spesies en wilde, soutverdraagsame spesies. Thinopyrum distichum, 'n inheemse koringgras, wat aangepas is by brak omgewings (McGuire & Dvorak, 1981), is met korog (x Triticosecale) gekruis in 'n poging om die gene vir soutverdraagsaamheid en ander gehardheidseienskappe oor te dra (Marais & Marais, 1998). Die oogmerke van hierdie studie was om (i) Thinopyrum chromosome te identifiseer wat gene bevat vir soutverdraagsaamheid en molekulêre merkers te vind vir hierdie chromosome, (ii) 'n aantal diverse monosomiese en disomiese addisieplante te identifiseer. Bulksegregaatanalise (BSA), gekombineer met AFLP-, RAPD- en DAF-merkeranalise, is gebruik om polimorfismes geassosieerd met soutverdraagsaamheid op te spoor. Vyf moontlike AFLPmerkers en twee RAPD-merkers is geïdentifiseer met gebruik van bulks bestaande uit soutverdraagsame plante en bulks bestaande uit soutgevoelige plante. Die verspreiding van die merkers in soutverdraagsame bulks dui daarop dat meer as een Thinopyrum chromosoom bydra tot soutverdraagsaamheid. Soutverdraagsame, monosomiese en disomiese addisieplante is gekarakteriseer vir AFLP- en RAPD-polimorfismes in 'n verdere poging om merkers te vind vir chromosome betrokke by soutverdraagsaamheid. Een soutverdraagsame monosomiese en een disomiese addisieplant is geïdentifiseer. Een AFLP- en twee RAPD-merkers is geïdentifiseer vir die Thinopyrum chromosoom(e) teenwoordig in die monosomiese addisieplant, terwyl drie AFLP- en drie RAPDmerkers geïdentifiseer is vir die disomiese addisieplant. 'n Poging is ook gemaak om diverse addisieplante te identifiseer met 'n volledige koroggenoom plus 'n addisionele Thinopyrum chromosoom. Plante met 2n = 43 / 44 is geïdentifiseer en gekarakteriseer met molekulêre merkers (AFLP en RAPD). Tros-analise is gebruik om die vermoedelik monosomiese of disomiese addisieplante te groepeer volgens die spesifieke Thinopyrum chromosome wat hulle behou het. Sewentien AFLP- en RAPD-merkers is gebruik om die 24 vermoedelike addisieplante in 6 groepe met verskillende Thinopyrum chromosome te groepeer. Alhoewel dit voorkom of die verskillende plante in 'n groep dieselfde addisionele Thinopyrum chromosoom het, is dit nie noodwendig die geval nie aangesien die interpretasie van die merkers bemoeilik word deur die heterogeniteit tussen die plante wat betref die agtergrond korogchromosome wat hulle besit. Dit is ook moontlik dat chromosoom herrangskikkings plaasgevind het gedurende die terugkruisings, wat die data verder kan bemoeilik. Nietemin, dit is nou moontlik om disomiese addisies te selekteer uit elke groep wat moontlik verskillende Thinopyrum chromosome bevat. Die data kan ook gebruik word om in die toekoms verdere addisieplante te identifiseer wat die oorblywende Thinopyrum chromosome bevat.
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Thomson, Danielle, and n/a. "Arsenic and Selected Elements in Marine Photosynthetic Organisms,South-East Coast, NSW, Australia." University of Canberra. Resource, Environmental and Heritage Sciences, 2006. http://erl.canberra.edu.au./public/adt-AUC20070521.120826.
Full textAbstract:
The cycling of arsenic in the marine photosynthetic plants and algae was examined by
analysing total arsenic concentrations and arsenic species in selected marine photosynthetic
organisms from the south-east coast, NSW, Australia. A range of elements required for
metabolism in photosynthetic organisms were also analysed to determine if any relationship
between these elements and arsenic concentrations occurred. Organisms were selected from salt marsh and mangrove ecosystems, marine inter-tidal and estuarine environments, and two
species of marine phytoplankton cultured, to represent the different marine environments that
primary producers inhabit. Organisms selected were compared to species within their own
environment and then a comparison made between the varying ecosystems.
In the salt marsh and mangrove ecosystems, the leaves of four species, the mangrove
Avicennia marina, the samphire Sarcocornia quinqueflora, the seablight Suaeda australis,
and the seagrass Posidonia australis were sampled from three locations from the south-east
coast of NSW using nested sampling. Mean total arsenic concentrations (mean � sd) dry mass
for all locations were A. marina (0.38 � 0.18 �g g-1 to 1.2 � 0.7 �g g-1), S. quinqueflora
(0.13 � 0.06 �g g-1 to 0.46 � 0.22 �g g-1), S. australis (0.03 � 0.06 �g g-1 to 0.05 � 0.03 �g g-1)and P. australis (0.34 � 0.10 �g g-1 to 0.65 � 0.26 �g g-1). Arsenic concentrations were
significantly different between species and locations but were consistently low compared to
marine macroalgae species. Significant relationships between As and Fe concentrations for A. marina, S. quinqueflora and P. australis and negative relationship between As and Zn
concentrations for S. quinqueflora could partially explain arsenic concentrations in these
species. No relationship between As and P concentrations were found in this study. All
terrestrial species contained predominantly inorganic arsenic in the water extractable and
residue fractions with minor concentrations of DMA in the water-soluble fraction. P. australis
also contained dimethylated glycerol and phosphate arsenoriboses. The presence of
arsenobetaine, arsenocholine and trimethylated glycerol arsonioribose is most likely due to
the presence of epiphytes on fronds on P. australis.
In contrast, macroalgae contained higher total arsenic concentrations compared to marine
terrestrial angiosperms. Total arsenic concentrations also varied between classes of algae: red macroalgae 4.3 �g g-1 to 24.7 �g g-1, green macroalgae 8.0 �g g-1 to 11.0 �g g-1 and blue green algae 10.4 �g g-1 and 18.4 �g g-1. No significant relations were found between As
concentrations and concentrations of Fe, Co, Cu, Mn, Mo, Mg, P and Zn concentrations,
elements that are required by macroalgae for photosynthesis and growth. Distinct differences
between algal classes were found for the proportion of arsenic species present in the lipid and water-soluble fractions, with green algae having a higher proportion of As in lipids than red or estuarine algae. Acid hydrolysis of the lipid extract revealed DMA, glycerol arsenoribose and TMA based arsenolipids. Within water-soluble extracts, red and blue-green algae contained a greater proportion of arsenic as inorganic and simple methylated arsenic species compared to green algae, which contained predominantly glycerol arsenoribose. Arsenobetaine, arsenocholine and tetramethylarsonium was also present in water-soluble extracts but is not normally identified with macroalgae and is again likely due to the presence of attached epiphytes. Residue extracts contained predominantly inorganic arsenic, most likely associated with insoluble constituents of the cell.
Mean arsenic concentrations in the green microalgae Dunaliella tertiolecta were 13.3 �g g-1 to 14.5 �g g-1, which is similar to arsenic concentrations found in green macroalgae in this
study. Diatom Phaeodactylum tricornutum arsenic concentrations were 1.62 �g g-1 to
2.08 �g g-1. Varying the orthophosphate concentrations had little effect on arsenic uptake of microalgae. D. tertiolecta and P. tricornutum metabolised arsenic, forming simple methylated arsenic species and arsenic riboses. The ratio of phosphate to glycerol arsenoriboses was higher than that normally found in green macroalgae. The hydrolysed lipid fraction contained DMA arsenolipid (16-96%) with minor proportions of phosphate arsenoribose (4-23%).
D. tertiolecta at f/10 phosphate concentration, however, contained glycerol arsenoribose and
another arsenic lipid with similar retention as TMAO as well as DMA. The similarities
between arsenic species in the water-soluble hydrolysed lipids and water-soluble extracts,
especially for P. tricornutum, suggests that cells readily bind arsenic within lipids, either for membrane structure or storage, releasing arsenic species into the cytosol as degradation of lipids occurs. Inorganic arsenic was sequestered into insoluble components of the cell.
Arsenic species present in D. tertiolecta at lower phosphate concentrations (f/10) were
different to other phosphate concentrations (f/2, f/5), and require further investigation to
determine whether this is a species-specific response as a result of phosphate deficiency.
Although there are similarities in arsenic concentrations and arsenic species in marine
photosynthetic organisms, it is evident that response to environmental concentrations of
arsenic in uncontaminated environments is dependent on the mode of transfer from the
environment, the influence of other elements in arsenic uptake and the ability of the organism
to metabolise and sequester inorganic arsenic within the cell. It is not scientifically sound to generalise on arsenic metabolism in �marine plants� when species and the ecosystem in which
they exist may influence the transformation of arsenic in higher marine organisms.
There is no evidence to suggest that angiosperms produce AB as arsenic is mostly present as
inorganic As, with little or no arsenic present in the lipids. However, marine macro- and
microalgae both contain lipids with arsenic moieties that may be precursors for AB
transformation. Specifically, the presence of TMA and dimethylated arsenoribose based
arsenolipids both can transform to AB via intermediates previously identified in marine
organisms. Further identification and characterization of As containing lipids is required.
26
Alemayehu, Makonnen. "Germination and emergence salt tolerance of sorghum (Sorghum bicolor L.) as influenced by seed quality and generations." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184933.
Full textAbstract:
Artificially aged and non-aged seeds of 22 grain sorghum (Sorghum bicolor L.) F₁ hybrids and their F₂ and F₃ generations were evaluated for germination salt tolerance. Six of the hybrids, along with their F₂ and F₃ generations, were tested for emergence salt tolerance. Effects of seed production environments on germination salt tolerance were also studied using F₂ generations of 12 sorghum hybrids produced under full-season irrigation, limited irrigation, and double-cropping conditions. Germination tests were conducted in a growth chamber, on trays, while the emergence test was conducted in a greenhouse in flats filled with sand. The experiments were conducted under non-saline and saline conditions in randomized complete block designs. Artificial seed aging resulted in significant reductions in germination percentages under both non-saline and saline environments. The overall mean reduction in germination caused by seed aging was more than twice as much under salinity stress as under the non-stress conditions (48 vs. 17%), indicating differential effects of salinity on different quality seeds. Entries that appeared to be resistant to seed aging also had higher germination percentages under salinity stress. Seed production environment influenced germination performance in both non-saline and saline environments. The overall mean germination percentages of sorghum seeds produced under three different field environments were significantly different from one another. Significant differences were observed in germination and emergence percentages within F₁, F₂, and F₃ generations. Except for the F₁ entries, however, emergence index differences within the F₂ and F₃ generations were not significant. Correlations between germination and emergence percentages in the non-saline and saline treatments were generally nonsignificant. This suggests that germination and emergence responses of sorghum may vary under different salinity levels and different environments.
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Supriati, Rochmah. "The impact of salinity on root and leaf anatomy of hordeum jubatum L." Virtual Press, 1994. http://liblink.bsu.edu/uhtbin/catkey/902476.
Full textAbstract:
It had been generally accepted that salinity adversely affects the growth of plants. This study examined how the salinity level affects the growth of H. jubatum. A green house study was conducted to determine the effects of salinity levels on growth, and anatomy of root and leaf of H. jubatum. One week-old seedlings were transplanted and grown on 10-cm plastics pots filled with sand at Ball State University green house. Plants were subirrigated with hydroponic solution Dyna gro liquid 9-7-5 (NPK) and 0%, 0.5%, 1 %, and 1.5% NaCl for each treatment. The solutions were changed bi-weekly, evaporation losses were replaced daily. After aproximately 45 days, randomly chosen plants were harvested, washed, measured and weighted, to determine their growth such as: root biomass, shoot biomass, shoot height, leaf lenght, and leaf width. Slides of root and leave tissues were prepared with microtechnic standard using rotary microtome and N-butyl alcohol series. Anatomical variables measured included; root diameter, stele diameter, ratio of stele to root, thickness of leaf at mid vein, diameter of vb in mid vein, diameter of metaxylem in midvein, thickness of leaf at second lateral vein (left and right), diameter of vb at second lateral vein (left and right). The slides then were potoghraped with Olympus camera. Statistical analysis supported that salinity significantly affected the growth, morphology, and anatomy of H. jubatum.Department of Biology
28
Chen, Futai 1952. "Selection of asparagine substrate analog and sodium-chloride resistant mutants in Arabidopsis thaliana." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276860.
Full textAbstract:
The inhibitory effects of NaCl, L- and D-asparagine, and asparagine substrate analogs, beta-aspartyl hydroxamate (AAH) and albizziin, alone or in combination on Columbia Arabidopsis seed germination and seedling survival were characterized under aseptic conditions. Germination on an agar medium supplemented with inorganic nutrients was prevented by 200 mM NaCl, 20 mM L-asparagine, 60 mM D-asparagine, 1.4 mM AAH, or 8 mM albizziin. Established seedlings were generally more tolerant to these chemicals than germinating seeds. Exogenous L- and D-asparagine partly reversed the inhibitory effects of NaCl on seed germination. L-asparagine also partly reversed AAH inhibition of germination. A M2 seed bank was created from the self-pollinated progeny of ethyl methane sulfonate treated seeds. Arabidopsis mutants having increased tolerance to NaCl and AAH, but not albizziin, were successfully selected from this seed bank.
29
Zegeer, Abreeza May 1956. "Interactions between saline stress and benzyladenine on chili peppers (Capsicum annuum L.)." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277069.
Full textAbstract:
Exogenous application of BA (0, 50, 100 mg ul--1) had no significant effects on tolerance of chili peppers to salt (--0.75 MPa NaCl:CaCl₂, 3:1, w/w) as measured by vegetative and reproductive weights, numbers of reproductive structures, transpiration and total chlorophyll. When peppers were applied with microliter amounts of ¹⁴C labelled benzyladenine (BA; 44,400 dpm 1⁻¹), BA was translocated primarily acropetally from the site of application. Regardless of application site, translocated BA was ported primarily to expanding leaves, and BA was more readily absorbed by leaf as opposed to stem surfaces. Exogenous application of BA (0, 50, 100 mg ul⁻¹) had no significant effects on tolerance of chili peppers to salt (-0.75 MPa NaCl:CaCl₂, 3:1, w/w) as measured by vegetative and reproductive weights, numbers of reproductive structures, transpiration and total chlorophyll.
30
Lintnaar, Melissa. "The physiological responses of salinity stressed tomato plants to mycorrhizal infection and variation in rhizosphere carbon dioxide concentration." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/52002.
Full textAbstract:
Thesis (MSc)--Stellenbosch University, 2000.ENGLISH ABSTRACT: This investigation was undertaken to determine whether elevated concentrations of dissolved inorganic carbon (DIC) supplied to plant roots could improve plant growth and alleviate the effects of salinity stress on tomato plants infected with arbuscular mycorrhizae. Lycopersicon esculentum cv. FI44 seedlings were grown in hydroponic culture (pH 5.8) with 0 and 75 mM NaCI and with or without infection with the fungus Glomus mosseae. The root solution was aerated with ambient CO2 (360 ppm) or elevated CO2 ( 5 000 ppm) concentrations. The arbuscular and hypha I components of mycorrhizal infection as well as the percentages total infection were decreased or increased according to the variation in seasons. The plant dry weight of mycorrhizal plants was increased by 30% compared to non-mycorrhizal plants at elevated concentrations of CO2, while the dry weight was decreased by 68% at ambient CO2 concentrations. Elevated CO2 also stimulated the growth of the mycorrhizal fungus. Elevated CO2 increased the plant dry weight and stimulated fungal growth of mycorrhizal plants possibly by the provision of carbon due to the incorporation of HCO)- by PEPc. Plant roots supplied with elevated concentrations of CO2 had a decreased CO2 release rate compared to roots at ambient CO2. This decrease in CO2 release rate at elevated CO2 was due to the increased incorporation of HC03- by PEPc activity. Under conditions of salinity stress plants had a higher ratio of N03-: reduced N in the xylem sap compared to plants supplied with 0 mM NaCI. Under salinity stress conditions, more N03- was transported in the xylem stream possibly because of the production of more organic acids instead of amino acids due to low P conditions under which the plants were grown. The N03· uptake rate of plants increased at elevated concentrations of CO2 in the absence of salinity because the HCO)- could be used for the production of amino acids. In the presence of salinity, carbon was possibly used for the production of organic acids that diverted carbon away from the synthesis of amino acids. It was concluded that mycorrhizas were beneficial for plant growth under conditions of salinity stress provided that there was an additional source of carbon. Arbuscular mycorrhizal infection did not improve the nutrient uptake of hydroponically grown plants.
AFRIKAANSE OPSOMMING: In hierdie studie was die effek van verhoogde konsentrasies opgeloste anorganiese koolstof wat aan plant wortels verskaf is, getoets om te bepaal of dit die groei van plante kan verbeter asook of sout stres verlig kon word in tamatie plante wat met arbuskulêre mikorrhizas geïnfekteer was. Lycorpersicon esculentum cv. FJ44 saailinge was in water kultuur gegroei (pH 5.8) met 0 en 75 mM NaCI asook met of sonder infeksie met die fungus Glomus mosseae. Die plant wortels was bespuit met normale CO2 (360 dele per miljoen (dpm)) sowel as verhoogde CO2 (5 000 dpm) konsentrasies. Die arbuskulere en hife komponente, sowel as die persentasie infeksie was vermeerder of verminder na gelang van die verandering in seisoen. Die plant droë massa van mikorrhiza geïnfekteerde plante by verhoogde CO2 konsentrasies was verhoog met 30% in vergelyking met plante wat nie geïnfekteer was nie, terwyl die droë massa met 68% afgeneem het by gewone CO2 konsentrasies. Verhoogde CO2 konsentrasies het moontlik die plant droë massa en die groei van die fungus verbeter deur koolstof te verskaf as gevolg van die vaslegging van HCO)- deur die werking van PEP karboksilase. Plant wortels wat met verhoogde CO2 konsentrasies bespuit was, het 'n verlaagde CO2 vrystelling getoon in vergelyking met die wortels by normale CO2 vlakke. Die vermindering in CO2 vrystelling van wortels by verhoogde CO2 was die gevolg van die vaslegging van HC03- deur PEPk aktiwiteit. Onder toestande van sout stres, het plante 'n groter hoeveelheid N03- gereduseerde N in die xileemsap bevat in vergelyking met plante wat onder geen sout stres was nie, asook meer NO)- was in die xileemsap vervoer moontlik omdat meer organiese sure geproduseer was ten koste van amino sure. Dit was die moontlike gevolg omdat die plante onder lae P toestande gegroei het. Die tempo van NO.; opname was verhoog onder verhoogde CO2 konsentrasies en in die afwesigheid van sout stres omdat die HCO)- vir die produksie van amino sure gebruik was. In die teenwoordigheid van sout was koolstof moontlik gebruik om organiese sure te vervaardig wat koolstof weggeneem het van die vervaardiging van amino sure. Daar is tot die slotsom gekom dat mikorrhizas voordelig is vir die groei van plante onder toestande van sout stres mits daar 'n addisionele bron van koolstof teenwoordig is. Arbuskulere mikorrhiza infeksie het 'n geringe invloed gehad op die opname van voedingstowwe van plante wat in waterkultuur gegroei was.
31
Danon, Avihai. "Molecular events associated with halophytic growth in Lycopersicon pennellii." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184642.
Full textAbstract:
We have studied the effects of exogenous salt on whole plant and suspension culture cells of the halophytic tomato Lycopersicon pennellii. Under low salt conditions (2.9 dS/M) plants showed enhanced (halophytic) growth (107% of control). At moderate (7.5 dS/M) and high (18.5 dS/M) salt levels, salt stress reduced growth to about 78% and 40% of control respectively. Salt-induced changes in root mRNAs were analyzed via two-dimensional PAGE of cell free translation (CFT) products. We have identified 14 proteins whose levels were enhanced by exogenous salt. One of these proteins was unique to low salt induced halophytic growth. This system allowed for discrimination between proteins up-regulated at all salt levels and those up-regulated only during salt stress induced growth reduction. Ten proteins were identified whose levels were reduced by exogenous salt. Once again, one could identify a subset of proteins whose levels were reduced only under salt stressed conditions. Proteins identified in this study are candidates for roles in growth maintaining stress adaptive metabolism in L.pennellii. These data underscore the complexity of the genetic control of salt metabolism in higher plants. The effects of exogenous salt on protein synthesis and accumulation were studied in suspension cultures of L.pennellii. Two salt levels were applied to the cells. Under low salt conditions (LS, 10 mM), L.pennellii cells showed enhanced (halophytic) growth. Under high salt conditions (HS, 50 mM), the cells showed reduced (salt-stressed) growth. Changes in proteins with time were analyzed by a combination of cell free translation, in vivo labeling and total accumulated protein. In vivo labeling studies showed that the pattern of steady state protein synthesis was disrupted shortly after addition of salt. High salt induced greater disruption in the pattern. Over time, the steady state levels of most proteins shifted back towards those of the unstressed-control. However, the level of several proteins remained altered. Analysis of proteins whose levels increased with exogenous salt showed differences in the response patterns that may allow for discrimination between proteins involved in growth maintaining and stress shock responses.
32
Whittington, John. "Physiological effects of salinity on chara corallina /." Title page, contents and summary only, 1990. http://web4.library.adelaide.edu.au/theses/09PH/09phw6258.pdf.
Full text
33
Gadeh, H. M. "The effect of compost and priming on the salt tolerance of bread wheat (Triticum aestivum L. cv. S-24 and cv. Slambo) during germination and early seedling establishment." Thesis, Coventry University, 2013. http://curve.coventry.ac.uk/open/items/f0bd31e5-d16c-4435-993a-ab1ec64d7bc3/1.
Full textAbstract:
Soil salinity and the arid climate in Libya are major constraints in agriculture and predominantly in foodstuff production which are limiting wheat production and yield. The effect of pre-sowing seed treatments with 50 mM of KCl, NaCl, CaCl2, and distilled water as hydropriming on germination and early seedling growth in two wheat (Triticum aestivum L.) cultivars S-24 (tolerant) and Slambo (untested before) under 0, 100, 200 and 300 mM NaCl concentrations was examined. CaCl2 was the only priming treatment that significantly improved the germination percentage, germination rate, and mean germination time in both cultivars under almost all NaCl concentrations. Thus, priming with CaCl2 was selected for further experiments. In the greenhouse, seeds primed with 50 mM of CaCl2 also improved the emergence percentage, emergence rate, shoot and root length, and fresh and dry weight of shoots and roots of both cultivars under all NaCl concentration except at 300 mM where the emergence was completely inhibited. The response of wheat cultivars to three compost treatments including cow manure compost (CC), greenwaste compost (GC) and 50:50 mixture (mix) between them and sand at percentage inclusions of 10 and 30 % by weight under 0, 100, 200, and 300 mM of NaCl was also investigated. Among all compost treatments, 30% GC and 30% mix were the best treatment and improved almost all growth parameters under salt stress, and 30% GC was also the only treatment that had any emergence at 300 mM NaCl. 30% GC and 30% mix were selected for further experiments. The effect of the combination of the selected priming agent (CaCl2) and the best two compost treatments (30% GC and 30% mix) on the emergence and early seedling growth of both cultivars was tested. The results showed that all the treatments enhanced plant growth parameters including seedling ion uptake in both cultivars, with preference to primed seeds sown in 30% GC. The treatments had the following order of the performance of both cultivars under salt stress. Primed seeds sown in 30% GC > unprimed seeds sown in 30% GC > primed seeds sown in 30% mix > unprimed seeds sown in 30% mix. This enhancement is possibly due to the provision of Ca2+ and / or the improvement in the availability of water as both of them were improved by the application of priming and compost.
34
Hendrati, Rina Laksmi. "Developing systems to identify and deploy saline and waterlogging tolerant lines of Eucalyptus occidentalis Endl." University of Western Australia. Faculty of Natural and Agricultural Sciences, 2009. http://theses.library.uwa.edu.au/adt-WU2010.0036.
Full textAbstract:
[Truncated abstract] Eucalyptus occidentalis, a timber species from south Western Australia, is highly salt and waterlogging tolerant. Screening identified genotypes tolerant of high salt concentrations and waterlogging. Tolerance at provenance, family and individual level, and how phenotypic performance under salt and waterlogging was inherited was explored to provide a breeding population. Salt and/or waterlogged screening was carried out under controlled conditions up to extreme salt levels to determine tolerance between genotypes. This tank method was shown to produce repeatable results. Seedlings of 30 families from 9 provenances were used for screening. At low salt concentration (up to 300 mM NaCl), differentiation occurred for some traits but in general there was only a slight reduction in growth under salt, and waterlogging alone was not detrimental. At high salt concentration (550 mM) differentiation occurred among genotypes for all traits. Equivalent genotypes were also planted in field trials at three sites, two with medium (583 - 847 mm) and one with low rainfall (372 - 469 mm), in southern Western Australia. Survival was low (<53%) after 9 months due to an exceptional dry season followed by 3 months waterlogging in Kirkwood (38 - 1360 mSm-1), but was high >89% after 33 months in saline fields in Sandalwindy (96 - 976 mSm-1) and Roberts (88 - 1424 mSm-1). Some families were similarly in high rank for height under saline conditions in controlled and field trials. Height had the highest narrow-sense heritability value, especially under controlled saltwaterlogging (0.85) treatment and 20% selection enabled a gain of 8-14% under controlled conditions and in the field. Leaf production under salt was not an inherited trait. Systems were developed to hasten deployment of selected material. Extended daylength (16 h) and paclobutrazol (1 mg a.i/mm stem circumference) stimulated flowering in 2 year-old plants. Clonal propagation was possible. Grafting success varied from 0-100% depending on scion/rootstock provenances. ... There was only a slight reduction in heterozygosity from species level to provenance and family levels, and two superior genotypes maintained high diversity. v Crossing was possible using one stop pollination of cut immature styles and capsule retention varied from 0-34% and germination rate from 2-96%. Genetic distance between parents was correlated with seed set and offspring fitness. Wider genetic distances increased capsule retention, seed germination and seedling survival. Under 500 mM salt-waterlogging, offspring heights were similar when parental genetic distances were similar. High heritability value for height from ANOVA-REML parental screening was confirmed using parent-offspring regression. Screened superior genotypes, which withstood very high salt concentration, provide a breeding population for further breeding and for plantations under saline regions in low-medium rainfall areas in Western Australia and other parts of the world. These trees provide an economic return in areas where no other plants may survive and an environmental service in potentially reducing waterlogging, salinity and its spread.
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Kidd, Sarah Ann. "Ecosystem Recovery in Estuarine Wetlands of the Columbia River Estuary." PDXScholar, 2017. https://pdxscholar.library.pdx.edu/open_access_etds/3637.
Full textAbstract:
In the restoration of tidal wetland ecosystems, potential drivers of plant community development range from biotic controls (e.g. plant competition, seed dispersal) to abiotic controls (e.g. tidal flooding, salinity levels). How these controls influence the success of tidal wetland restoration are only partly understood, but have important implications for wetland habitat recovery. Specifically, the extent to which the existing native and non-native seed banks in tidally reconnected wetlands interact with these controls is not clear, yet the potential success of passive restoration methods depends upon this understanding.
For a 54-year chronosequence of eleven tidal wetland restoration sites in the Lower Columbia River of western Oregon, USA, it was hypothesized that native plant species and soil properties would show trends approaching reference levels within 3 to 20 years post-restoration and that lower elevation wetland areas within restored sites would exhibit a greater native species abundance and similarity to reference sites, compared with restored high elevation wetland areas. Results indicated that plant species richness, soil organic matter, bulk density, pH, and salinity conditions among the restoration sites reached reference wetland ranges within 3-6 years post-tidal reconnection. The mid-low marsh elevation zones (<2.5 m) recovered native plant cover within 3-6 years post-tidal reconnection, while high marsh elevation zones (>2.5 m) remained dominated by nonnative species Phalaris arundinacea and Juncus effusus subsp. effusus.
To investigate the mechanisms driving these non-native plant invasions, it was ii hypothesized that native and non-native wetland plant community distributions would be reflective both of their abundance in the seed bank and of their germination tolerance to wetland tidal flooding and salinity conditions. Using a factorial study design of three tidal conditions by three salinity levels, these hypotheses were tested in the greenhouse. Overall, non-native seeds were found to significantly outnumber native seeds in both seed banks. In the greenhouse, P. arundinacea and J. effusus were found to germinate more readily out of the seed bank under freshwater high-marsh flooding (1 hour a day) treatments as compared to oligohaline (3 ppt) mid-low marsh flooding (3-6 hours twice a day) treatments and to brackish salinity (10 ppt) treatments. Dominant native wetland species, Carex lyngbyei and Schoenoplectus lacustris, germination were not found to vary significantly among the treatments (p > 0.10).
These results indicate that the salinity and flooding gradients within these restored marshes suppress germination of the non-native species in the low-mid marsh but not in the high marsh, where they are likely able to outcompete the native species due to their dominance in the seed bank. The implications of these results for passive tidal wetland restoration efforts are that both seed bank composition and species-specific tolerances to restored tidal flooding and salinity gradients are key mechanisms driving native and nonnative plant community development and resilience.
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Ferreres, Contreras Irene. "Plant physiology and biotechnology for the study and improvement of Mediterranean japonica rice varieties." Doctoral thesis, Universitat de Barcelona, 2020. http://hdl.handle.net/10803/673999.
Full textAbstract:
Rice belongs to the Poaceae family and Oryza genus. The genus Oryza comprehends 24 species, being 22 wild and 2 cultivated. These two cultivated species correspond to Oryza sativa, originated in Asia, nowadays cultivated and consumed worldwide, and Oryza glaberrima, originated in Africa, but cultivated and consumed limitedly in West Africa, both are diploid (2n=24) (Bernis & Pamies, 2006; Wei & Huang, 2019).
Traditionally, Oryza sativa has been classified into two subspecies, indica and japonica. Molecular analyses, as well as biochemical and hybrid sterility analyses, point out at the separate domestication of Oryza rufipogon populations as the origin for these two subspecies (Garris et al., 2005; Rakshit et al., 2007; Wei et al., 2012), with a gene flow present from japonica to indica (Yang et al., 2012). Indica rice is usually long grained, less sticky and with a lower level of amylopectin than japonica rice, which is short grained and sticky. There are also phenotypical differences between these subspecies, for example, japonica plants are generally shorter, the leaves have a lighter color and shaper shape. Also, the tiller number is lower in japonica than in the indica plants (Wei & Huang,
2019).
The O. sativa plant is a semiaquatic annual monocot grass although rice can live as perineal in the tropics (McLean et al., 2013). The plant has a height that varies from 80 to 150 centimeters depending on the variety and growing conditions (Bernis & Pamies,
2006), or even less in modern varieties. Its morphology varies according to the development stage, this being the vegetative phase or the reproductive phase. The vegetative phase includes the germination, the seedling and the tillering stage. The reproductive phase comprehends panicle initiation, also called heading, and flowering stages.
As a food, rice contributes to the 20% of calories ingested worldwide (Kubo & Purevdorj,
2004), reaching half of the calories ingested daily in some areas (Counce et al., 2000). In terms of consumption, as well as production, Asia is the main continent (McLean et al.,
2013). The rice production and consumption in Europe is minor compared to Asia. Despite that, rice holds an important sociocultural role since it is one of the basic foods of the Mediterranean diet. Some regions have developed famous rice dishes, like risotto in Italy or paella in Spain. The annual rice consumption per capita in Europe is 6-18
kilograms in the southern regions, and 3.5-5.5 kilograms in the northern regions (McLean et al., 2013). The main European producer is Italy, followed by Spain. These two countries hold more than 75% of the total rice production in Europe. Rice in Europe is also of ecological importance, due to the great biodiversity that inhabits and benefits from the paddy fields. Around 70-80% of rice cultivated in Europe are japonica varieties, and the rest indica (Bernis & Pamies, 2006; Ferrero, 2007). Agriculture is the most important bioeconomy sector in Spain, with a value of 43.8 million of euros in 2015 and coping the
50.9% employment of all bioeconomy sectors (Lániez & Periago, 2016). Rice mobilized
258.766 millions of euros in Spain in 2019 (MINECO, 2019). Thus, the studies dedicated to improving different aspects of the rice production in Spain are crucial.
This thesis has made a multidisciplinary approach, from genetics to the field, in order to study Mediterranean rice varieties considering its actual applicability for the Spanish rice industry through three experimental approaches: (i) an improvement of the anther culture protocol for two Mediterranean temperate japonica varieties and two tropical japonica varieties trough the addition of additives to the media; (ii) testing the salt-tolerance of Saltol-introgressed varieties to select those that will help to fight the apple snails plague in the Ebro Delta; and (iii) a study of genetic and physicochemical aspects of the rice pearl in five Mediterranean varieties, an important feature in gastronomical terms.
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Yousfi, Salima. "Salinidad y trigo duro: Firmas isotópicas, actividad enzimática y expresión génica." Doctoral thesis, Universitat de Barcelona, 2012. http://hdl.handle.net/10803/83604.
Full textAbstract:
La salinidad y el estrés hídrico son los factores más importantes que limitan la producción de trigo duro, sobre todo en regiones áridas y semiáridas, como la región Mediterránea. El trigo duro es uno de los principales cultivos en el sur y este de la Cuenca Mediterránea, donde se cultiva frecuentemente en condiciones de secano y si es posible con riego deficitario, a menudo con agua de poca calidad, que junto a una elevada evapotranspiración, puede provocar una progresiva salinización del terreno.
En este sentido, la mejora genética de trigo duro para una mejor adaptación a estas condiciones de estrés es una de las pocas alternativas viables. El objetivo general de esta Tesis es estudiar las bases fisiológicas y moleculares de las diferencias genotípicas en crecimiento potencial y tolerancia a la salinidad y el estrés hídrico. En un primer estudio (Experimento 1) publicado en “Functional Plant Biology” se investigó qué criterio fenotípico de selección era el más adecuado para seleccionar genotipos de trigo duro que crecieran mejor en condiciones de salinidad continuada. De esta forma se determinó la importancia de los isótopos estables como criterios eficientes para seleccionar genotipos tolerantes y susceptibles a la salinidad. Posteriormente, se realizó un segundo estudio (Experimento 2) donde se evaluó el efecto de la salinidad en la composición isotópica del carbono (δ13C) y el nitrógeno (δ15N) de genotipos de trigo duro y de dos amfiploides (un tritordeo y un triticale). Este trabajo está publicado en la revista “Journal of Experimental Botany”. En este segundo ensayo, la salinidad se aplicó durante la floración y el llenado del grano durante unas pocas semanas. Los resultados de este trabajo representaron la puesta a punto del estudio del comportamiento fisiológico del trigo duro durante la fase reproductiva y bajo diferentes combinaciones de salinidad y riego. Como continuación de los dos Experimentos (1 y 2) y en vista de los resultados obtenidos en el uso de las firmas isotópicas como criterio de evaluación bajo condiciones salinas, se planteó evaluar el uso combinado de la composición isotópica del carbono (δ13C), oxígeno (δ18O) y el nitrógeno (δ15N) en materia seca para observar las respuestas genotípicas de plantas de trigo duro sometidas a diferentes combinaciones de salinidad. Como contribución original, se elaboró un modelo conceptual de las tres firmas isotópicas juntas (δ13C, δ18O, δ15N) junto con características del metabolismo nitrogenado para explicar las diferencias genotípicas en tolerancia a distintas condiciones de salinidad y estrés hídrico. También se evaluaron las características fotosintéticas en relación con las firmas isotópicas y las actividades de enzimas clave del metabolismo nitrogenado. (Trabajo Publicado en la revista “New Phytologist”). Además de los resultados anteriores obtenidos, en esta Tesis se comparó la eficiencia de las firmas isotópicas del carbono, oxígeno y nitrógeno mediante dos vías: muestras de materia seca y muestras de fracción soluble en genotipos de trigo duro para la evaluación de diferencias genotípicas en tolerancia a diferentes condiciones de salinidad y regimenes hídricos. Posteriormente se analizó la respuesta genética de plantas de trigo duro a la salinidad evaluando el nivel de transcripción de genes específicos asociados a tolerancia a salinidad y estrés hídrico, junto a otros que codifican para enzimas claves del metabolismo nitrogenado. También se han estudiado las relaciones entre estas tasas de transcripción, las diferencias genotípicas en crecimiento, firmas isotópicas y actividades de enzimas del metabolismo nitrogenado. El trabajo ha mostrado la eficacia de los isótopos estables de carbono y del nitrógeno como herramientas de evaluación de la respuesta del trigo duro frente a la salinidad.Inadequate irrigation for long term and under conditions of high evapotranspiration demand, combined with the use of poor water quality and the lack of adequate drainage frequently induces the salinization of arable land causing a significant increase in the area affected by salinity. Salinity is an environmental factor that limits in a remarkable manner the production of crops in many parts of the world, but especially in arid and semiarid regions like the Mediterranean. Under these conditions, which is often grown durum wheat improvement for tolerance to salinity under irrigation deficit may be one of the strategies to alleviate this problem. This Thesis shows that isotope compositions of carbon (δ13C), oxygen (δ18O), and nitrogen (δ15N) and the concentration of nitrogen in dry matter are potentially and effective criteria for discriminating between different growing conditions and between genotypes tolerant or susceptible to salt. Furthermore, the results of this study reflect the importance of nitrogen metabolism in tolerance to salinity. Additionally, this thesis develops a model relating genotypic tolerance to different conditions of salinity and drought with the signatures of the three isotopes (C, O, N), together with photosynthetic and transpiration exchanges and parameters key of nitrogen metabolism such as nitrogen concentration and activities of the glutamine synthetase and nitrate reductase. Finally, we study the relationship between the expression of genes potentially key in the tolerance to salinity and drought and genotypic variability in response to different combinations of these stresses.
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Martin, Katherine Clare. "Interactive effects of salinity and nutrients on mangrove physiology : implications for mangrove forest structure and function." Phd thesis, 2007. http://hdl.handle.net/1885/149911.
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Christian, Rochelle. "The distribution of two sympatric mangrove species and interactive effects of salinity and irradiance." Phd thesis, 1999. http://hdl.handle.net/1885/147188.
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Preston, Christopher. "Structure and function of photosynthetic membranes from salt-tolerant plants." Phd thesis, 1987. http://hdl.handle.net/1885/142181.
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Sweby, Deborah Lee. "Effects of nitrogen nutrition on salt stressed Nicotiana tabacum var. Samsum in vitro." Thesis, 1992. http://hdl.handle.net/10413/8128.
Full textAbstract:
The responses of Nicotiana tabacum L. var. Samsun to alterations in the nitrogen
(N) supply under saline conditions in vitro were monitored. The aim was to test the
hypothesis that nitrate-nitrogen supplementation to salt stressed plants alleviates the
deleterious effects of salt on plant growth.
Due to its capacity to be maintained under stringent environmental conditions, in
vitro shoot cultures were chosen as the system of study. Nicotiana tabacum plantlets
regenerated from callus in vitro were excised and rooted on solid MS culture
medium containing a range of concentrations of NaCI (0 - 180 mM) and N (0 - 120
mM, as NO3--N, NH4+-N or a combination). A variety of parameters of root and
shoot growth, nutrient utilisation and nitrogen metabolism were assessed over a 35 d
period. Plant growth on 40 mM NO3--N + 20 mM NH4+-N (standard MS nutrients) was
inhibited by the presence of salt, with root growth being more adversely affected by
salt than stem growth. Root emergence was delayed from 6 d (0 mM NaCI) to 15 d
(180 mM NaCI). Similar suppression of growth for all parameters, except root mass
and leaf chlorophyll content, was observed when NaCI was replaced with mannitol
at equivalent osmolalities. Root mass and leaf chlorophyll were significantly
improved in plantlets supplied with mannitol. The time of root emergence was
unaffected by mannitol supply, with all roots emerging after 10 d in culture. Plantlet
growth on NH4+-N only (0 - 60 mM) was severely inhibited, even in the absence of
NaCI, and was inferior to growth on NO3--N. Nitrate additions to salt stressed
plantlets could not match growth in control (0 mM NaCI) plantlets. When plantlets
were cultured on NO3--N only (0 mM, 30 mM, 60 mM, 120 mM), the increase in
nitrate supply up to 60 mM resulted in a small improvement in growth on 90 mM
NaCI, but had almost no effect on growth at 180 mM NaCl. A nitrate supply of 120
mM led to growth inhibition in all parameters, even in the absence of NaCl.
Plantlet growth on isosmotic concentrations of mannitol in the presence of 0 - 120
mM NO3--N essentially mimicked that of NaCI, except for leaf chlorophyll content
which was improved on mannitol at all NO3-·N levels.
Nitrate uptake (measured as depletion from growth medium) by plantlets grown on
0 - 180 mM NaCI was positively correlated to availability of nitrate but negatively
correlated to NaCI supply. Similar results were obtained for a mannitol supply
except nitrate uptake was enhanced significantly on mannitol compared to NaCl.
Sodium and chloride uptake appeared unaffected by nitrate concentration. Leaf
protein content responded favourably to an increase in the NO3--N supply up to 60
mM and, in particular, appeared to be stimulated in the presence of 180 mM NaCl.
Nitrate reductase (NR) activity was found to be inhibited drastically by salt and
NO3--N supplementation to the salt medium had no effect on enzyme activity.
A reduction in leaf total RNA content was recorded with an increase in NaCI
concentration from 0 - 180 mM. A positive response to an increase in the NO3--N
supply from 30 mM to 60 mM was detected in the presence of NaCl. Attempts were
made to assess the levels of mRNA for NR in response to the various NaCl and N
regimes. The plasmid pBMCI02010 containing a NR cDNA insert was isolated and
purified and used in both radioactive and non-radioactive RNA slot blot
hybridisation procedures. However, due to problems of non-specific binding of the
probe, no quantification of the levels of NR mRNA in response to the various
treatments could be made. Nitrate supplementation to plantlets of Nicotiana tabacum growing in vitro did not
appear to ameliorate the effects of salinity stress, such that growth of plantlets in the
presence of NaCI was always inferior to that in the absence of NaCl. As a large
portion of growth inhibition was found in this study to be a result of osmotic rather
than ionic effects of salt, it is questioned whether a nitrate supply would have an
ameliorating effect on plant growth under field conditions.Thesis (M.Sc.)-University of Natal, Durban, 1992.
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Aswathappa, Nanjappa. "Salt tolerance of casuarinas with special reference to ion regulation." Phd thesis, 1987. http://hdl.handle.net/1885/140684.
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"Cloning and identification of salt inducible genes in arabidopsis thaliana." 2000. http://library.cuhk.edu.hk/record=b5890290.
Full textAbstract:
Chan Yee-kwan.Thesis (M.Phil.)--Chinese University of Hong Kong, 2000.
Includes bibliographical references (leaves 108-131).
Abstracts in English and Chinese.
Thesis Committee --- p.i
Abstract --- p.ii
Acknowledgments --- p.v
General Abbreviations --- p.vii
Abbreviation for Chemicals --- p.x
Table of Contents --- p.xi
List of Figures --- p.xiv
List of Tables --- p.xv
Chapter 1. --- Literature Review
Chapter 1.1 --- Salinity as a global problem --- p.1
Chapter 1.2 --- Salinity and agriculture --- p.2
Chapter 1.3 --- Plant adaptation to salinity --- p.4
Chapter 1.3.1 --- Salt secretion --- p.6
Chapter 1.3.2 --- Ion transport --- p.8
Chapter 1.3.2.1 --- Role of H+-ATPase in salt tolerance --- p.8
Chapter 1.3.2.2 --- Potassium and sodium uptake --- p.13
Chapter 1.3.2.3 --- Sodium efflux --- p.15
Chapter 1.3.3 --- Osmotic adjustment --- p.20
Chapter 1.3.3.1 --- Accumulation of mannitol --- p.21
Chapter 1.3.3.2 --- Accumulation of proline --- p.23
Chapter 1.3.3.3 --- Accumulation of glycinebetaine --- p.23
Chapter 2. --- Materials and Methods
Chapter 2.1 --- Plant materials and growth conditions --- p.26
Chapter 2.1.1 --- Surface sterilization of Arabidopsis seeds --- p.26
Chapter 2.1.2 --- Determination of sub-lethal inhibitory doses of sodium --- p.27
Chapter 2.1.3 --- Growth conditions of Arabidopsis seeds for total RNA extraction --- p.27
Chapter 2.1.4 --- NaCl dosage tests --- p.28
Chapter 2.1.5 --- Expression kinetic tests --- p.28
Chapter 2.2 --- Isolation of total RNAs --- p.28
Chapter 2.3 --- Isolation of genes differentially expressed in NaCl concentration by RAP-PCR --- p.30
Chapter 2.3.1 --- RNA fingerprinting by RAP-PCR --- p.30
Chapter 2.3.2 --- PCR reamplificatin of RAP products --- p.31
Chapter 2.3.3 --- Cloning of differentially expressed genes --- p.33
Chapter 2.3.3.1 --- Ligation of inserts into pCR-Script vector and transformation --- p.33
Chapter 2.3.3.2 --- Ligation of inserts into pBluescript II KS (+) T-vector and transformation --- p.36
Chapter 2.3.3.3 --- Screening of recombinant plasmids --- p.37
Chapter 2.4 --- Sequencing of differentially expressed genes --- p.39
Chapter 2.4.1 --- DNA cycle sequencing --- p.39
Chapter 2.5 --- Northern blot hybridization of NaCl inducible genes --- p.40
Chapter 2.5.1 --- RNA fractionation by formaldehyde gel electrophoresis --- p.40
Chapter 2.5.2 --- Northern blotting --- p.41
Chapter 2.5.3 --- Preparation of single-stranded DIG-labeled PCR probes --- p.41
Chapter 2.5.3.1 --- Isolation of Total RNA --- p.41
Chapter 2.5.3.2 --- Primer design --- p.42
Chapter 2.5.3.3 --- PCR amplification of single-stranded DIG PCR probes --- p.43
Chapter 2.5.4 --- Hybridization --- p.45
Chapter 2.5.5 --- Stringency washes --- p.46
Chapter 2.5.6 --- Chemiluminescent detection --- p.46
Chapter 3. --- Results
Chapter 3.1 --- Determination of sub-lethal inhibitory doses of sodium --- p.48
Chapter 3.2 --- Isolation of total RNA from A. thaliana treated with sodium chloride --- p.48
Chapter 3.3 --- Isolation of genes differentially expressed in sodium concentration by RNA arbitrarily primed polymerase chain reaction RAP-PCR --- p.52
Chapter 3.3.1 --- Differential cDNA fragments identified by RAP-PCR --- p.52
Chapter 3.3.2 --- PCR reamplification of RAP products --- p.52
Chapter 3.3.3 --- Cloning of selected RAP-fragments --- p.62
Chapter 3.4 --- Nucleotide sequence analysis of selected RAP PCR clones --- p.65
Chapter 3.5 --- Expression pattern analysis of salt inducible genes by northern blot hybridization --- p.75
Chapter 3.5.1 --- Preparation of single-stranded digoxigenin (DIG)-labeled probes --- p.75
Chapter 3.5.2 --- Dosage response of NaCl inducible genes --- p.79
Chapter 3.5.3 --- Expression kinetics of NaCl inducible genes --- p.80
Chapter 4. --- Discussion
Chapter 4.1 --- Isolation of RAP-PCR targets --- p.93
Chapter 4.2 --- Expression of NaCl inducible P450 genes --- p.94
Chapter 4.2.1 --- Cytochrome P450 CYP73A5 --- p.97
Chapter 4.2.2 --- Cytochrome P450 CYP83A1 --- p.98
Chapter 4.3 --- NaCl induction gene related to post-transcriptional activities --- p.99
Chapter 4.3.1 --- Glycine-rich RNA binding protein (BAC F3F19) --- p.100
Chapter 4.3.2 --- Chloroplast signal recognition particle (54CP) --- p.103
Chapter 4.4 --- Conclusion --- p.106
References --- p.108
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Batista, Ana Isabel Lillebo. "The effect of salt marshes plants on the nutrient dynamics in the Mondego estuary (Portugal)." Doctoral thesis, 2001. http://hdl.handle.net/10316/2147.
Full textAbstract:
Tese de doutoramento em Biologia (Ecologia) apresentada à Fac. de Ciências e Tecnologia de CoimbraO estuário do Mondego tem uma importância regional considerável, acrescida do facto de se encontrar sob forte pressão ambiental o que se traduz no processo de eutrofização no seu braço sul. Tendo em conta que perturbações no ciclo de nutrientes podem induzir alterações na produtividade e composição específica do sistema, o alvo deste estudo foram as áreas mais representativas e menos estudadas do braço sul do estuário do Mondego: os sapais de Spartina maritima e de Scirpus maritimus, considerando a dinâmica de populações e o seu efeito na dinâmica de nutrientes neste sistema. No braço sul do estuário do Mondego, os sapais de Scirpus maritimus ocorrem nas áreas mais a montante, enquanto que os sapais de Spartina maritima estendem-se pelas áreas mais a jusante, acompanhando o gradiente de salinidade. Adicionalmente, resultados experimentais demonstraram que a variação sazonal da salinidade poderá ser o factor condicionante do ciclo de vida de Scirpus maritimus no estuário do Mondego. Considerando a importância das plantas de sapal nos processos biogeoquímicos, os nossos dados de campo sugerem que as trocas entre o sedimento e as poças intertidais, que se formam na baixa-mar, são maiores nos sapais de S. maritima comparativamente aos sapais de S. maritimus, sendo específico para cada espécie. Um estudo comparativo, em ciclos de 24 horas, focando a variação sazonal do fluxo de nutrientes entre poças intertidais sem coberto vegetal, formadas em sedimento vasoso e arenoso, e poças também formadas em sedimento vasoso, mas cobertas por Spartina maritima, demonstraram que embora o teor de matéria orgânica no sedimento reflicta a disponibilidade de nutrientes, a dinâmica diária e sazonal de S. maritima influencia claramente o fluxo de amónia e de fósforo, em especial no Verão e durante o dia. Adicionalmente, parece-nos bastante plausível que este processo seja muito relevante na exportação de fósforo inorgânico dissolvido para águas costeiras e desta forma exercer um controlo na produção primária e no processo de eutrofização. Nos estuários, uma complexa actividade biológica, envolvendo diversos níveis fauna, promove a circulação de nutrientes no sistema. De forma a melhor compreender a contribuição parcial da macrofauna, meiofauna e microfauna, na degradação do material vegetal e nas trocas entre estes detritos, coluna de água e sedimento, foram realizadas duas experiências laboratoriais. Estas experiências, com vista a avaliar a importância dos diferentes níveis de fauna na degradação de Spartina maritima e de Scirpus maritimus, demonstraram que, embora a actividade bacteriana seja a maior responsável, a presença de meiofauna e de macrofauna aceleram significativamente o processo.
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Wang, Ding Xiang. "Interaction between the effects of sodium chloride and high temperature on the vegetative growth of tomato (Lycopersicon esculentum Mill.) / by Ding Xiang Wang." Thesis, 1993. http://hdl.handle.net/2440/21452.
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Soares, Bruno Miguel Ribeiro. "Effect of halophilic bacteria from Aveiro salt pans in the attenuation of saline stress in plants." Master's thesis, 2018. http://hdl.handle.net/10773/25368.
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Soil salinization is a globally growing problem, and several approaches have been proposed to mitigate its effects on the productivity of plants of economic interest. The use of halophilic or halotolerant bacteria as plant growth promoters is one of the strategies recommended for the mitigation of salt stress. However, halotolerant bacteria isolated from the rhizosphere of halophyte plants are the most commonly used inoculum. The objective of this work was to evaluate the potential of halophilic bacteria, isolated from a salt pan, in the attenuation of saline stress Lactuca sativa, used as a model crop glycophyte. A collection of strains isolated from Santiago da Fonte saltpans (Aveiro) representing the genera Bacillus, Halobacillus, Idiomarina and Marinobacter, was analyzed for some characteristics considered as advantageous in the colonization and promotion of growth of host plants. The production of extracellular enzymes in presence of 0, 20 and 100 NaCl, as well as the ability to solubilize phosphate and produce 1-aminocyclopropane-1-carboxylate deaminase were tested. H. locisalis and I. seosinesis, considered as more interesting in terms of plant growth promoting traits, were tested separately and together as inoculum in lettuce seeds. A factorial experimental design was applied to test the effect of inoculation and salinity of the irrigation water on the efficiency of seed germination and plant growth. Germination efficiency was strongly affected by salinity and no significant effects of inoculation were observed. The germination efficiency was lower at 10 NaCl than at salinity 0 and the weight of the plants was significantly lower in the plants inoculated with the consortium of isolates than in the uninoculated plants. Plants inoculated with the consortium and grown at salinity 10 had lower water content. When used separately, H. locisalis or I. seosinesis caused an increase in leaf size in plants cultivated in salinity, in relation to the inoculated control. Inoculation did not cause a significant effect on chlorophyll fluorescence. Although no evidence of attenuation of saline stress by inoculation was detected, H. locisalis inoculum showed a positive effect on the growth of plants in non-saline conditions, indicating a potential as a growth promoting bacterium of plants of agricultural interest.A salinização dos solos é um problema crescente a nível global e têm sido várias as abordagens propostas para atenuar os seus efeitos na produtividade de plantas de interesse económico. O uso de bactérias halófilas ou halotolerantes como promotoras do crescimento de plantas, é uma das estratégias preconizadas para a mitigação do stresse salino. No entanto, são normalmente usadas como inóculo bactérias halotolerantes isoladas da rizosfera de plantas halófitas. O objetivo deste trabalho foi avaliar o potencial de bactérias halófilas, isoladas de uma marinha de sal, na atenuação do stresse salino em Lactuca sativa, usada como modelo de glicófita de interesse agrícola. Uma coleção de estirpes isoladas da marinha de Santiago da Fonte (Aveiro) representando os géneros Bacillus, Halobacillus, Idiomarina e Marinobacter, foi analisada quanto a algumas caraterísticas consideradas como vantajosas na colonização e promoção do crescimento de plantas. Testou-se a produção de enzimas extracelulares em salinidades 0, 20 e 100 de NaCl bem como a capacidade para solubilizar fosfato e produzir ácido 1-aminociclopropano-1-carboxilato desaminase. H. locisalis e I. seosinesis, considerados como mais interessantes face às características promotoras do crescimento, foram testados separadamente e em conjunto, como inóculo em sementes de alface. Foi aplicado um desenho experimental fatorial para testar o efeito da inoculação e da salinidade da água de irrigação sobre a eficiência de germinação das sementes e crescimento das plantas. A eficiência de germinação foi fortemente afetada pela salinidade não tendo sido observados efeitos significativos de nenhum dos inóculos testados. Na condição de salinidade 10, a eficiência de germinação foi mais baixa do que com salinidade 0 e o peso das plantas foi significativamente menor nas plantas inoculadas com o consórcio de isolados do que nas plantas não inoculadas. As plantas inoculadas com o consórcio e cultivadas na salinidade 10 apresentaram menor teor de água. As plantas inoculadas separadamente com H. locisalis ou com I. seosinesis cultivadas em salinidade 0, revelaram um aumento do tamanho das folhas relativamente ao controle não inoculado. Embora não tenham sido encontradas evidências de atenuação do stresse salino, o inóculo H. locisalis apresentou um efeito positivo no crescimento das plantas em condições não-salinas, o que demonstra um potencial como bactéria promotora do crescimento de plantas de interesse agrícola.
Projeto nº 029736 - Programa Operacional Regional do Centro (02/SAICT/2017).
Mestrado em Ecologia Aplicada
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