Visualization of the transport pathway in barley (Hordeum vulgare) leaves was carried out using a combination of aniline blue and a symplasmically transported fluorochrome, 5,6 carboxyfluorescein (5,6-CF). When applied to a source leaf, basipetal movement of 5,6-CF was observed after 3 h and the fluorochrome front was observed about 3-4cm away from the point of application. The fluorochrome was taken up into the symplasm of the mesophyll and was loaded into the bundle sheath cells and then subsequently the vascular parenchyma and finally into the sieve tubes. In sink leaves, acropetal movement was observed after 3 h and the fluorochrome had moved approximately 3 cm away from the point of application. Unloading of 5,6-CF occurred from all classes of longitudinal veins. Studies on solute retrieval showed that 5,6 CF-diacetate was transferred to xylem parenchyma where it was metabolized. 5,6-CF was then transferred from the xylem parenchyma to the vascular parenchyma cells, and it would appear that thick-walled sieve tubes were the first to show 5,6-CF labeling. Counterstaining with aniline blue demonstrates the presence of plasmodesmata and this suggests a potential symplasmic pathway from the mesophyll to the sieve tubes. Application of 5,6 CF-diacetate revealed a slow symplasmic pathway, which involved transfer of 5,6-CF, which was effected via plasmodesma.

Nutritional mutants of Ustilago hordel were used to demonstrate that parasexual recombination occurs within the host plant (Hordeum vulgare) prior to the production of teliospores. The nutritional mutants were also used to show that resistance of the newly-germinated seedling of H. vulgare to U. hordei and of subsequently formed tillers to infection was not correlated, and was probably not controlled by the same gene or genes. The application of gibberellic acid to H. vulgare was found to cause an increase in the overall tiller height of healthy plants by increasing the elongation of Internodal regions 0-1, 1-2, 2-3, and 3-4. There was no increased elongation of internodal regions 4-5 and 5-6. The healthy tillers of diseased plants showed no Internodal elongation when gibberellic acid was applied. Diseased tillers, which are usually shorter than healthy tillers, were also unaffected by the presence of gibberellic acid. The injection of both mating types of U. hordei into the young developing spike of a normally resistant strain of H. vulgare resulted in the production of diseased spikes. This would indicate that blockage to normal infection occurs at the time of seedling penetration, at the level of tiller primordia development, or at the time of spike primordia development. / Science, Faculty of / Botany, Department of / Graduate

High-moisture barley, preserved either anaerobically, chemically or by drying, was evaluated in a series of digestibility and nitrogen utilization trials with monogastrics and ruminants. In the first of 3 phases, high-moisture barley HMB (17% moisture) from the Peace River region was preserved in experimental silos by: (1) airtight storage, (2) alkali - 3.2 g NaOH/kg HMB (air dry basis) in a 32% w/w solution, (3) acid - 1% mixture of 60:40 acetic-propionic acids and (4) drying - 8 tonnes per hour at 82°C. After 9 months of storage, these treatments were evaluated in a digestibility trial with pigs and a nitrogen balance trial with rats. In the pigs there was no treatment effect on dry matter digestibility, but neutral detergent fibre digestibility was reduced (P < 0.001) in the dried barley. True nitrogen digestibility, with both pigs and rats, was significantly (P < 0.001) reduced by alkali treatment. In the rat trial, alkali-treated barley depressed net protein utilization (NPU) by over 20%. Differences between the non-alkali treatments were small. Digestibility studies with sheep were not carried out on these treatments due to poor palatability results. In the second phase, barley from Lacombe was harvested at 33 and 12% moisture. The HMB (33% moisture) was either stored airtight or artificially dried (ADB) to 88% DM and the field-dried barley (FDB) (12% moisture) was either stored aerobically or reconstituted (RB) to 70% DM and stored airtight. These treatments were evaluated in a nitrogen balance trial with rats and a digestibility, nitrogen-retention trial with sheep. In the rat trial, true nitrogen digestibility was highest (P < 0.001) for HMB while biological valve was higher (P < 0.001) for both of the dry treatments. NPL) tended to be the same for all treatments. In the sheep trial, dry matter digestibility of RB was improved above ADB, but organic matter digestibility of both HMB and RB were greater than that of ADB (P < 0.01). Acid detergent fibre digestibility of HMB was highest (P < 0.001) followed by FDB and RB and then ADB. There was no treatment effect for either nitrogen digestibility or nitrogen retention. Straw from both HMB and FDB was also evaluated in sheep. Apparent dry matter, organic matter and nitrogen digestibility were all significantly (P < 0.001) greater for straw from HMB. The final phase of the study was conducted with barley of an unknown origin. Dry barley was reconstituted to 30% moisture (RB) and portions were treated with 3% NaOH (NaOH-RB) or 1% and 3% anhydrous ammonia (NH3-RB) on a w/w air dry basis. These treatments were again evaluated in a nitrogen balance trial with rats and a digestibility, nitrogen-retention trial with sheep. In the rat trial, true nitrogen digestibility for NaOH-RB was approximately 20% lower than the other treatments. Biological value and NPU were also depressed below all other treatments by NaOH-RB (P < 0.001). NPU for both 1 and 3% NH₃-RB were lower (P < 0.001) than RB after most of the NH₃ was allowed to evaporate for several days. However, there appeared to be no residual effect on protein utilization after the NH₃ was removed completely from the treated barley, as NPU for both 1 and 3% NH₃-RB were not different from RB. Dry matter digestibility was improved by all alkali-treatments (P < 0.001). In the sheep trial, both apparent dry matter digestibility and organic matter digestibility were significantly (P < 0.01) better for only the 3% NH₃-RB as compared to the other treatments. Acid detergent fibre digestibility was lower for 1 and 3% NH₃-RB than RB or NaOH-RB, between which treatments there were no significant differences. NaOH treatment reduced nitrogen digestibility by approximately 20 percentage units, but nitrogen-retention was unchanged between treatments with sheep. / Land and Food Systems, Faculty of / Graduate

Soil salinity is a major abiotic stress for land plants, and multiple mechanisms of salt tolerance have evolved. Tissue tolerance is one of these mechanisms, which involves the sequestration of sodium into the vacuole to retain low cytosolic sodium concentrations. This enables the plant to maintain cellular functions, and ultimately maintain growth and yield. However, the molecular components involved in tissue tolerance remain elusive. Several candidate genes for vacuolar sodium sequestration have recently been identified by proteome analysis of vacuolar membranes purified from the salt-tolerant cereal Hordeum vulgare (barley). In this study, I aimed to characterize these candidates in more detail. I successfully cloned coding sequences for the majority of candidate genes with primers designed based on the barley reference genome sequence. During the course of this study a newer genome sequence with improved annotations was published, to which I also compared my observations. To study the candidate genes, I used the heterologous expression system Saccharomyces cerevisiae (yeast). I used several salt sensitive yeast strains (deficient in intrinsic sodium transporters) to test whether the candidate genes would affect their salt tolerance by mediating the sequestration of sodium into the yeast vacuole. I observed a reduction in growth upon expression for several of the gene candidate under salt-stress conditions. However, confocal microscopy suggests that most gene products are subject to degradation, and did not localize to the vacuolar membrane (tonoplast). Therefore, growth effects cannot be linked to protein function without further evidence. Various potential causes are discussed, including inaccuracies in the genome resource used as reference for primer design and issues inherent to the model system. Finally, I make suggestions on how to proceed to further characterize the candidate genes and hopefully identify novel sodium transporters from barley.

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Regionally-Grown barley is in demand for craft malting and brewing in Virginia. Barley lines suited to both Virginia's climate and craft brewing applications are currently under development. Free amino nitrogen (FAN) is a malt quality parameter that influences beer flavor directly and via yeast metabolism during fermentation. FAN and the individual amino acids making up FAN influence yeast health, beer color development, flavor, and flavor stability. Despite potential impacts on beer quality, individual amino acid concentrations in barley and malt are not generally measured or monitored. The objective of this project is to evaluate and assess the conversion of FAN and individual amino acid concentrations during the malting and mashing process of genetically distinct varieties. An additional objective is to evaluate their malt sensory characteristics, to understand genetic variability therein. Raw barley and malt samples were subject to low temperature aqueous extraction, and wort was produced using an isothermal hot water extract technique. FAN and amino acid composition were determined for each line for raw barley, malt and wort extracts, prepared as described. Statistical analysis revealed that these lines had significantly different changes in FAN and amino acid composition. Sensory characteristics of malt hot steep teas were evaluated by forty (N=40) panelists with brewing experience using a sorting task to group malts with similar sensory characteristics, and to assign descriptors to those groups. From the sixteen (N=16) breeding lines, five (5) distinct sensory groups were identified. Taken together, our findings will inform the selection process for barley lines for craft brewing, and add to the knowledge of the extent to which free amino acid composition varies among eastern barley lines and along the malting and mashing processes. / Master of Science in Life Sciences / Regionally-grown barley is in demand for craft malting and brewing in Virginia, and barley lines suited to both Virginia's climate and craft brewing applications are of interest. The production of beer requires high quality malt, which is defined by many parameters; one of which is free amino nitrogen (FAN), which plays a critical role in yeast nutrition and beer flavor through yeasts' metabolism and chemical reactions. FAN is a general measurement of nitrogen and its individual components (including amino acids) are rarely measured, despite their major role in beer flavor. The objective of this project was to assess the development and changes in FAN and amino acids that occur over the course of the barley supply chain – which will better inform breeders, growers, maltsters, and brewers of the raw materials they use and how they can affect their processes A second objective was to assess the flavor of newly developed barley lines and varieties, and compare them to established varieties currently being grown in Virginia through sensory evaluation methods designed to determine similarities between samples. Results from the analysis of FAN and the amino acid composition identified significant differences between varieties, and results from sensory evaluation identified 5 distinct groups with similar flavor characteristics. Taken together, these findings will help inform the selection process for barley lines for craft brewing, and add to the knowledge of the extent to which free amino acid composition varies among barley lines and along the brewing processes.

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One-irrigation barleys have been selected for performance with a pre-plant irrigation to fill the soil to field capacity to a depth of 5 feet. The barley is then grown with no additional irrigation, which simulates conditions of the North African coast. In this study, two of these barley selections were planted at four planting rates at three dates in Marana to determine optimum seeding rates. A seeding rate of 20 lbs /A resulted in greater yields than 40, 60, or 80 lbs /A when the data were combined for all planting dates.

A wheat and barley demonstration on the Bruce Church Farm, Poston, Arizona, harvested June 5, 1986, gave crop and variety performance differences under grower management conditions. The top yielding barley variety was Westbred Gustoe, 6190 lbs /acre. The leading durum varieties were Turbo and Yavaros, 7280 and 7220 lbs/acre, respectively. Durum Wheat Westbred 881 was highest in protein (15.6 %) and lowest in percentage of yellowberry. In the bread wheat varieties, yields ranged from 6740 to 6570 lbs per acre. Varieties tested were Yecora Rojo, Probred, Probrand 775, and Westbred 911, with no significant differences in yield between varieties. Yecora Rojo was highest in protein (15.8 %). While these are the results of one year, continued testing over several years is necessary to assess variety performance under grower management conditions.