The hypothesis that inoculation of transplants with vesicular-arbuscular mycorrhizal (VAM) fungi before planting into saline soils would alleviate salt effects on growth and productivity was tested on lettuce (Lactuca sativa L.) and onion (Allium cepa L.). A secondary hypothesis was that the fungi isolated from a saline soil would be more effective than those from a nonsaline soil. VAM inocula from a high-and a low-salt soil were trap-cultured, their propagules quantified, adjusted, and added to a pasteurized growth medium in which seeds germinated and seedlings grew for a few weeks. These seedlings, once colonized by VAM fungi, were transplanted into saline soil. Seedlings were exposed to high concentrations of NaCl at the time of transplant; in this respect, our technique aimed to simulate conditions of high salinity prevalent in soils affected by NaCl. Preinoculated lettuce and onion transplants grown for 10 weeks had increased shoot biomass compared with nonVAM plants at all salinity (NaCl) levels tested. Leaves of VAM lettuce at the highest salt level were significantly greener than those of the nonVAM lettuce. NonVAM onions were stunted due to available P deficiency in the soil, but inoculation with VAM fungi alleviated P deficiency and salinity effects except at the highest salinity level; nevertheless, VAM onions were significantly larger at all salinity levels. Increasing the level of available P by weekly applications to nonVAM plants partially alleviated the salinity effects on onion growth. VAM fungi from the saline soil site were not more effective in ameliorating the reduction on plant growth caused by salt than those from the nonsaline site. Colonization of roots and length of soil hyphae produced by the test fungi decreased with increasing salt. Results indicate that preinoculation of transplants with VAM fungi can effectively alleviate deleterious effects of saline soils on crop productivity. / Graduation date: 2000

Two studies on potential approaches for processing low-salt, low-fat (LSLF) bologna were completed. In study 1, the effects of three factors, namely salt type (sea salt vs. regular NaCl), NaCl concentration (0.75%, 1.00%, 1.25% and 2.00%) and holding of stuffed batter before cooking (cooked immediately (CI) vs. delayed cooking (DC)), on the quality of LSLF bologna were investigated. There was no difference between salt type for most of the parameters measured. The holding factor significantly improved the water holding capacity (WHC) and texture of bologna samples containing 0.75% NaCl, as shown by lower (p<0.05) expressible moisture. However, holding factor did not affect WHC and instrumental texture of samples with 1.00%, 1.25% or 2.00% NaCl. A NaCl level by hold effect (p<0.05) was observed for texture profile analysis (TPA) in which there was significant improvement in the texture of samples containing 0.75% NaCl that were subjected to DC, but no effect at other NaCl levels. Panelists were able to detect the positive effect (p<0.05) of DC on the texture of samples with 0.75% or 1.00% NaCl. This study showed that DC is effective in improving the texture of bologna samples with extremely low NaCl (0.75%) content. The biggest challenge in this first study was the difficult sample handling experienced during slicing. Since bologna is commonly sold as thin slices, the bologna must be firm enough for ease of slicing. The second study focused on improving bologna firmness by the addition of microbial transglutaminase (MTG), known for its functionality as a protein cross-linker, and of flaxseed meal (FSM), known for its excellent water holding capacity. The physico-chemical and sensory characteristics of 12 treatment combinations (0, 0.15% and 0.30% MTG; 0, 0.5%, 1.0% and 1.5% FSM) were determined. In general, results showed that MTG significantly improved the textural quality of bologna, but resulted in a higher purge loss during storage of vacuum packaged slices. On the other hand, FSM significantly reduced the expressible moisture content and purge loss of the product. In terms of product colour, MTG had no effect but FSM when added to the formulation at level as low as 0.5%, affected the colour as determined by both instrumental and sensory evaluation. The overall results of the project indicated that texture in LSLF bologna is not a major issue, since processing conditions and combinations of ingredients can be manipulated to improve texture. The biggest challenge, however, is in the area of flavour – improving the flavour of low-salt processed meats warrants further research.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

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Identification of salt- resistant tree species and genotypes is needed for rehabilitation of lands affected by salinity in Mexico. This dissertation consists of four studies for analyzing the responses of Pinus leiophylla seedlings to salt. In the first study, resistance to salt stress was studied in six-month-old seedlings from eight different sources of seed collected from the areas with contrasting precipitation levels. Plants from the xeric areas were shorter and had smaller stem diameters but were less sensitive to salt stress and recovered faster from salt injury compared with the plants from mesic sites, suggesting that morphological and physiological adaptations to drought were helpful with salt stress resistance. In the second study, fascicle needle production and tissue ion accumulation were examined in NaCl-treated three-month-old seedlings from two populations of the xeric origin and two populations from the mesic areas. Seedlings from the xeric population of San Felipe developed fewer fascicles and had shorter needles compared with seedlings from the remaining three populations. NaCl treatment delayed the emergence of fascicles and reduced the fascicle needle production and needle length. However, the extent of needle injury and ion accumulation in shoots were lower in the San Felipe seedlings compared with the other studied populations. In the third study, the effects of branch pruning and seedling size on total transpiration and accumulation of Na+ and Cl- in tissues were examined. Total plant transpiration, as affected by plant size and branch pruning, was correlated with Na+ and Cl- needle concentrations and needle necrosis. Branch pruning reduced ion accumulation in the shoots and needle necrosis levels in short seedlings but not in the tall seedlings. In the fourth study, sprouting and physiological responses of 16 month-old-seedling to salt were examined. NaCl treatment concentrations of 100, 150, and 200 mM reduced gas exchange and root hydraulic conductance, caused needle injury and triggered sprouting of adventitious shoots. Sprouting from the upper parts of the main stem and lateral branches was three times greater with 100 and 150 mM NaCl compared with 200 mM NaCl treatment but, at the base of the stem, sprout numbers were similar for all NaCl treatments.

Heterocyclic organic and organometallic compounds (i.e. polypyrrole), and their derivatives, have been of great interest for conductive polymers due to their novel properties and environmental stability as compared to their non-aromatic analogs (i.e. polyacetylene). Our current interest focus upon the potential role of metal ligand bound pyridazines as the next generation of electronic devices that utilize the metal ligands bound to organics as the semiconducting material. Pyridazine is a 6-membered aromatic ring with two adjacent nitrogen atoms. These are promising candidates for a variety of materials and commercial applications; but they are difficult to get a metal ligand to fuse to the aromatic ring. Our recent efforts focused in attaching Rhenium and Manganese ligands/substituents (process in which is called doping) that would cause oxidation to occur to our polymer making it a p-type polymer. Since p-type polymers charge carriers leave a vacancy that does not delocalize completely. This vacancy (known as a hole) or a radical cation that only partially delocalizes over several monomeric units causing them to be structurally deformed. This deformed structure is at a higher energy than that of an undoped polymer. Typical carriers in organic semiconductors are holes and electrons in a π-orbital. So when these molecules of π-conjugated systems have a π-bond overlap (or π- stacking), electrons can move via these π-electron clouds overlapping thus causing an electrical current. Our worked focused on the synthesis of pyridazines and their organometallic rhenium complexes and polymer research. Several aryl-substituted 5,6-fused pyridazines have been synthesized but none have been documented until this study. The main goal of the research was to fully characterize the general synthesis of furan containing organometallic complexes, [M(CO)3{η5-1,2-C5H3(CC4H3ON)(CC4H3ON)}] (M = Re or Mn) (4B). We successfully characterized the ability to attach a metal organic ligand to pyridazine though IR and NMR. However, when attempts were made to recrystallize our product, we yielded an orange-brown, block like crystal of 1,2- C5H3(CC4H3ONH)(CC4H3ON) (5) in which our metal ligand group fell off and we were left with pyridazine and inorganics. Though, we successfully got an X-ray characterization and electronic studies of compound 5 which are reported herein.

Thesis (M.S. - Agricultural Economics)--University of Arizona. / Includes bibliographical references (leaves 122-123).

Thesis (D.Sc.)--University of Adelaide, Dept. of Geology and Geophysics, 2002. / "April 2002" Includes bibliographical references and list of the publications and papers submitted.