It has been demonstrated the technical feasibility of using seawater and other saline water for irrigation. Through the use of saline water for irrigation, highly salt-tolerant crops could greatly increase global agriculture. Brackish water and seawater from different sources are available in areas suitable for production of salt-tolerant crops. Dwarf glasswort Salicornia bigelovii Torr. (Chenopodiaceae), is a leafless, succulent, small-seeded, annual saltmarsh plant, with potential as a saline water crop. It is also a potential oilseed, forage, biomass crop, and a promising carbon sequestration plant. In the first chapter of this document we describe a study where we grew Salicornia bigelovii from seedlings, in saline, drying soils in a greenhouse experiment. The effects of drought and salinity stress were additive. Optimal growth and water use efficiency coincided at 0.35-0.53 M NaCl. The plants were tolerant of high salinity but exhibited little drought tolerance. Salicornia bigelovii plants varied little in their uptake of Na+ for osmotic adjustment, with final Na+ contents of 18% on a dry mass basis. Both growth and water use efficiency of Salicornia bigelovii were affected by salinity. Also, Na+, the primary cation involved in osmotic adjustment of this species, apparently stimulates growth by mechanisms apart from its role as an osmoticum. In the second chapter of this dissertation we developed a research study where we evaluated the production and osmotic adjustment of two S. bigelovii lines (Texas and Florida), plants were grown in pot in a green house and irrigated with water treated with three different levels of NaCl (5 ppt, 15 ppt and 30 ppt) combined with inorganic fertilizer. At the end of the experiment sixty plants from each line were measured for height, biomass, seed yield, seed size, dry matter yield, and tissue osmolarity. There was no significant difference among groups in plant height, or final biomass either in salinity irrigation treatments, or S. bigelovii lines. Tissue osmolarity differed among salinity treatments but not among S. bigelovii lines. The highest tissue osmolarity value was 1192 mM kg-1 found at the treatment 30ppt in the Florida line. Total biomass production was 12 000 kg/Ha.

Master of Science / Department of Biological and Agricultural Engineering / Stacy L. Hutchinson / The energy sector needs to transition to renewable energy to provide energy and economic security in the future (Murray & King, 2012). Liquid biofuels are an important renewable fuel in this transition because they are the preferred renewable energy source in the transportation sector (Lange, 2007), and the only renewable energy alternative for the aviation industry [International Air Transport Association (IATA), 2015]. Biofuels produced from food crops (first-generation biofuels) are being produced at an industrial scale, but they create several environmental and social conflicts (Mohr & Raman, 2013). Currently, there is a demand for the next generation of biofuels to resolve the environmental and social conflicts associated with first-generation biofuels. Salicornia, a salt tolerant oil seed crop (Panta et al., 2014), is one feedstock that might be able to resolve some of those conflicts because it can be irrigated with saline water (Warshay et al., 2017). The ability of Salicornia to tolerate saline environments suggests that it might be able to be cultivated in a hydroponic system designed to treat industrial wastewater. A hydroponic system designed to treat industrial wastewater and produce Salicornia as a biofuel feedstock could prevent some of the detrimental effects of industrial sources of saline water on terrestrial and aquatic ecosystems (Gerhart et al., 2006), and produce a feedstock that resolves some of the issues with first-generation biofuels. The first step in the development of the proposed hydroponic system is to determine if Salicornia can be cultivated with industrial wastewater in a hydroponic system. Studies were conducted with two sources of industrial wastewater, Flue Gas Desulfurization (FGD) wastewater and Cooling Tower Blowdown Water (CTBW), to determine how the composition of water affects the germination, survivability, early seedling growth, and lignocellulosic composition of Salicornia. The composition of water was shown to have no effect on seed germination and visual signs of phytotoxicity. These studies found that full strength CTBW and 20% FGD wastewater could be used to cultivate Salicornia in a hydroponic system if nutrients are added. Full strength FGD wastewater was shown to have a negative impact on seedling growth. These studies also found that Salicornia is not a good lignocellulosic biofuel feedstock because of its low lignocellulosic composition (e.g. 14.9-9.1% glucan, 13.2-6.7% xylan, 5.2-2.4% arabinan, and 9.8-6.2% lignin). However, a large percentage of the extractives content is unidentified and could have a monetary value. Additional research is needed to determine if a hydroponic system that cultivates Salicornia is able to provide any water quality treatment.

Thesis (Ph. D. - Molecular and Cellular Biology)--University of Arizona, 1986. / Includes bibliographical references (leaves 97-104).

With a global growing demand in food production, agricultural output must increase accordingly. An increased use of saline soils and brackish water would contribute to the required increase in world food production. Abiotic stresses, such as salinity and drought, are also major limiters of crop growth globally - most crops are relatively salt sensitive and are significantly affected when exposed to salt in the range of 50 to 200 mM NaCl. Genomic resources from plants that naturally thrive in highly saline environments have the potential to be valuable in the generation of salt tolerant crops; however, these resources have been largely unexplored. Salicornia bigelovii is a plant native to Mexico and the United States that grows in salt marshes and coastal regions. It can thrive in environments with salt concentrations higher than seawater. In contrast to most crops, S. bigelovii is able to accumulate very high concentrations (in the order of 1.5 M) of Na+ and Cl- in its photosynthetically active succulent shoots. Part of this tolerance is likely to include the storage of Na+ in the vacuoles of the shoots, making S. bigelovii a good model for understanding mechanisms of Na+ compartmentalization in the vacuoles and a good resource for gene discovery. In this research project, phenotypic, genomic, transcriptomic, and proteomic approaches have been used for the identification of candidate genes involved in salinity tolerance in S. bigelovii. The genomes and transcriptomes of three Salicornia species have been sequenced. This information has been used to support the characterization of the salt-induced transcriptome of S. bigelovii shoots and the salt-induced proteome of various organellar membrane enriched fractions from S. bigelovii shoots, which led to the creation of organellar membrane proteomes. Yeast spot assays at different salt concentrations revealed several proteins increasing or decreasing yeast salt tolerance. This work aims to create the basis for Salicornia research by providing a genome, transcriptomes, and organellar proteomes, contributing to salinity tolerance research overall. We identified a set of candidate genes for salinity tolerance with the aim of shedding some light on the mechanisms by which this plant thrives in highly saline environments.

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.

No description available.

The area of secondarily salinized lands is increasing at a faster rate over time. Many irrigation districts around the world are shrinking as a result of secondarily salinized soils. This is resulting in crop yield losses. Irrigation practices with low drainage are intensifying this problem. Bioremediation of salinized soils with halophytes is one of the means of reversing this process. In these studies, we tested the growth and performance of four salt tolerant halophytes to varying levels of salinity. We analyzed the salt content of the plant tissues at different salinities, in order to determine how the plants' tissues reflect the increases in salinity. It was discovered that Allenrolfea occidentalis tolerates and grows well at higher salinities than the other plants tested. Furthermore, the concentration of salt in the aerial plant tissue was high and increased further in response to the external salt concentration. Halophytes such as A. occidentalis can be used to remediate abandoned salt affected lands and their biomass can have an added economic value. On the other hand, domestication of wild halophytes for agronomic purposes represents another opportunity to address the increasingly salinized soils and shortages of freshwater around the world. In these studies, we assessed the potential for improvement of an oilseed halophyte, Salicornia bigelovii, through selective breeding. We compared plant characteristics of S. bigelovii cultivars produced in breeding programs with wild germplasm in a green house common garden experiment. We concluded that S. bigelovii has sufficient genetic diversity among wild accessions and cultivars to support a crop improvement program to introduce desirable agronomic characteristics into this wild halophyte.

Planícies hipersalinas são conhecidas em várias partes do mundo, por vezes intimamente associadas a manguezais. No Brasil são registradas do Pará a Santa Catarina, descontinuamente, por todo o litoral. Representam reservatórios de nutrientes e zonas de retração de bosques de mangue, no caso de elevação do nível médio do mar, merecendo maior atenção no que diz respeito ao manejo da zona costeira. No presente estudo, foi realizado monitoramento da salinidade da água intersticial, levantamento microtopográfico, análise granulométrica, caracterização estrutural do bosque de mangue associado e, levantamento dos dados climatológicos da região, tendo como objetivo definir os processos de formação e manutenção dos apicuns de Guaratiba. Os resultados indicam que a estrutura vegetal varia de acordo com o gradiente de inundação pelas marés, diminuindo à medida em que se afasta do corpo dágua - rio Piracão. Os valores médios de salinidade podem ser reunidos em 03 grupos distintos: interior do bosque de mangue, apicum com cobertura de Salicornia gaudichaudiana e apicum. A micro-topografia da área é variável, com pequenos canais que favorecem a colonização por A. schaueriana e elevações, onde é maior o acúmulo de sais. O clima apresentou variações interanuais, embora com presença de estações secas. A extensão dos apicuns deve-se à freqüente ocorrência de marés meteorológicas, podendo ter sido influenciada por retificações e drenagens dos pequenos rios e canais que cortam a região. / Salt flats are to be found in many different parts of the world, often associated with mangrove swamps. This is the case of the Brazilian shoreline from Pará, in the north, to Santa Catarina, in the south, although they are not continuous. They may be considered as nutrient reservoirs and as retraction zones for mangrove in the case of sea level rise and as such must be considered of great importance in the management of the coastal zone. In the present study, monitoring of the salinity of the interstitial waters was carried out over a period of two years. A micro-topographical survey, granulometric analysis, surveys of the structural characteristics of the associated mangrove areas and of the climate data of the region were included in the study with the objective to define the processes of formation and maintenance of the Sepetiba Bay salt flats. Results indicate that vegetation structure varies with the gradient of tidal inundation, decreasing landward. Interstitial water salinity measurements can be placed in three distinct groups: the mangrove grove itself, salt flat with Salicornia gaudichaudiana and salt flat. The micro-topography of the area varies considerably with small channels which favour colonization by Avicennia schaueriana and micro-mounts where the salt concentration is higher. The climate presents inter-annual variations, but always exhibiting dry seasons. The extension of salt flats is due to the frequency of meteorological tides associates with rectification and drainage of small rivers and channels which are to be found throughout the region.

Planícies hipersalinas são conhecidas em várias partes do mundo, por vezes intimamente associadas a manguezais. No Brasil são registradas do Pará a Santa Catarina, descontinuamente, por todo o litoral. Representam reservatórios de nutrientes e zonas de retração de bosques de mangue, no caso de elevação do nível médio do mar, merecendo maior atenção no que diz respeito ao manejo da zona costeira. No presente estudo, foi realizado monitoramento da salinidade da água intersticial, levantamento microtopográfico, análise granulométrica, caracterização estrutural do bosque de mangue associado e, levantamento dos dados climatológicos da região, tendo como objetivo definir os processos de formação e manutenção dos apicuns de Guaratiba. Os resultados indicam que a estrutura vegetal varia de acordo com o gradiente de inundação pelas marés, diminuindo à medida em que se afasta do corpo dágua - rio Piracão. Os valores médios de salinidade podem ser reunidos em 03 grupos distintos: interior do bosque de mangue, apicum com cobertura de Salicornia gaudichaudiana e apicum. A micro-topografia da área é variável, com pequenos canais que favorecem a colonização por A. schaueriana e elevações, onde é maior o acúmulo de sais. O clima apresentou variações interanuais, embora com presença de estações secas. A extensão dos apicuns deve-se à freqüente ocorrência de marés meteorológicas, podendo ter sido influenciada por retificações e drenagens dos pequenos rios e canais que cortam a região. / Salt flats are to be found in many different parts of the world, often associated with mangrove swamps. This is the case of the Brazilian shoreline from Pará, in the north, to Santa Catarina, in the south, although they are not continuous. They may be considered as nutrient reservoirs and as retraction zones for mangrove in the case of sea level rise and as such must be considered of great importance in the management of the coastal zone. In the present study, monitoring of the salinity of the interstitial waters was carried out over a period of two years. A micro-topographical survey, granulometric analysis, surveys of the structural characteristics of the associated mangrove areas and of the climate data of the region were included in the study with the objective to define the processes of formation and maintenance of the Sepetiba Bay salt flats. Results indicate that vegetation structure varies with the gradient of tidal inundation, decreasing landward. Interstitial water salinity measurements can be placed in three distinct groups: the mangrove grove itself, salt flat with Salicornia gaudichaudiana and salt flat. The micro-topography of the area varies considerably with small channels which favour colonization by Avicennia schaueriana and micro-mounts where the salt concentration is higher. The climate presents inter-annual variations, but always exhibiting dry seasons. The extension of salt flats is due to the frequency of meteorological tides associates with rectification and drainage of small rivers and channels which are to be found throughout the region.

Eutrophication, particularly due to nitrogen (N) and phosphorus (P) input, has been massively altered by anthropogenic activities. Thus it is important to understand the impact on salt marsh plants; however studies on salt marsh plants within Galveston Bay, Texas are limited. In this study, the effects of repeated nutrient additions in monospecific plots of Spartina alterniflora, Batis maritima¸ and Salicornia virginica as well as mixed plots of B. maritima and S. virginica were studied over 15 months. Results showed that nutrient loading led to an increase in height, biomass, growth rate and percent nitrogen (N) within all three species studied, but were species specific more than dose dependent. Nitrogen content in leaves had a positive correlation with P content in leaves but a negative correlation with carbon (C) content. Nutrient loading lead to a significant increase in total chlorophyll in the fertilized plots of S. alterniflora and S. virginica one month into the study. Nutrient addition to two succulent species, B. maritima and S. virginica in mixed plots did not reveal a distinct superior competitor within the 15 month study in terms of growth and nutrient use efficiencies; however using the maximum growth rates of the monospecific plots, the Monod model was used to determine which species would dominate at high nutrient loads. Based on height data S. alterniflora would dominate, while B. maritima would dominate according to the Monod model based on biomass.