Thesis (M.S.) in Resource Economics and Policy--University of Maine, 2001. / Includes vita. Advisory Committee: James D. Leiby, Assoc. Prof. of Resource Economics and Policy, Advisor; Mario F. Teisl, Asst. Prof. of Resource Economics and Policy; Kathleen P. Bell, Asst. Prof. of Resource Economics and Policy. Includes bibliographical references (leaves : 52-53).

Orientador: Jose Tadeu Jorge / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-09T04:04:28Z (GMT). No. of bitstreams: 1 Fujii_ArmandoKazuo_D.pdf: 2309726 bytes, checksum: cd86459b9e2cc372e4775ae338181364 (MD5) Previous issue date: 2007 / Resumo: O principal objetivo deste trabalho é a obtenção de sementes de canola com menor redução de germinação, devido às injúrias térmicas, durante a secagem. Foi aplicado o método de acondicionamento hermético de sementes de canola em embalagens de alumínio imersas em banho-maria a 50, 60 e 70ºC para determinar o modelo matemático da redução de germinação (SIGMA) de acordo com as condições de umidade e temperatura de secagem. O modelo é baseado na dispersão de mortes de sementes acondicionadas a condições constantes de umidade e temperatura, durante determinado período de tempo. Os valores experimentais de SIGMA foram obtidos através dos resultados de germinação durante o acondicionamento hermético que validaram o modelo proposto, com elevado coeficiente de correlação. Esses valores de SIGMA foram inseridos em um programa de secagem disponível em linguagem FORTRAN, que fornece os valores estimados de germinação simulando-se a secagem sob condições conhecidas. Sementes de canola a 21% de umidade foram submetidas à secagem sob três temperaturas: 51, 61 e 67ºC para validar o modelo matemático de simulação, de acordo com as condições de umidade e temperatura dos grãos durante o processo de secagem. Temperaturas maiores resultaram em maiores perdas de germinação, principalmente a 61 e 67°C, sendo que a 51°C, a mudança da declividade não é tão visível. O modelo utilizado representa bem os dados experimentais e são compatíveis com os dados das referências bibliográficas. O modelo representou significativamente os experimentos de secagem processados a 61 e 67ºC, sendo que a 51ºC, a germinação experimental apresentou valores acima dos valores estimados, o que não inviabiliza a análise dos resultados. Este trabalho fornece subsídios para definir o período necessário para efetuar a secagem visando preservar a germinação das sementes / Abstract: The main objective of this research work is to study of the reduction of germination loss in canola seeds after drying. The experimental procedure based on hermetic storage was used to determine the mathematical model of the germination reduction (SIGMA) for the actual drying conditions. The procedure consists in storing canola seeds hermetically in aluminum pouches, and immersed in water-bath at temperatures of 50°C, 60°C and 70°C, for a range of time periods, and the germination were determined. These data were used to determinate the experimental values of SIGMA function resulted from the multiple regression, presenting high correlation coefficient, and the parameters of this model were applied for the model of equation for canola seeds. This model was included in an existing drying simulation program. Canola seeds, with 21% of moisture content, were dried at 51°C, 61°C and 67 ºC, to validate the mathematical model of simulation, as function of the drying conditions. Higher drying temperatures resulted in higher losses of viability, however, the germination losses were slight lower for 61°C and 67°C. For drying at 51°C, the slope of the canola seeds were not perceptible. The values of germination of canola seeds during drying at 51°C, were higher than estimated germination at the same conditions, however this is not bad, because the simulation presents lower output than the actual germination. Drying temperature of 61°C and 67°C presented high correlation between the experimental points and the drying model. This publication present results to define the time for the drying process to preserve the seed germination / Doutorado / Tecnologia Pós-Colheita / Doutor em Engenharia Agrícola

Silo bags are a recently-developed temporary grain storage system that is becoming more widely used in Western Canada without any scientific information about the effect of changing conditions over time on seed quality. The main goal of this study was to examine the conditions that would allow safe storage of canola in these bags in the Canadian Prairie provinces. Canola at three different moisture contents (m.c.) 8.9, 10.5 and 14.4% (wet basis), which represent dry, straight and damp classifications, were stored in silo bags for 40 weeks and seed germination, free fatty acid value (FAV), and moisture content of canola were analysed every 2 weeks along with carbon dioxide concentrations of intergranular air and temperature of canola. For dry grade canola, the germination was maintained above 90%, and FAV stayed within 1.5 times the initial value. However, the germination of damp canola dropped to below 80%, and FAV doubled its initial value within 8 weeks of storage. Another study was conducted for two storage years (2011-12 and 2013-14) to determine the changes in grain quality over time while storing 12% moisture content canola seeds in silo bags. The germination of canola seeds at most parts of the silo bags stayed above a safe level up to the end of the winter season. At the top layer of the silo bags, germination of canola seeds decreased to below 30% and FAV increased more than 2-fold of initial values during summer storage. A polynomial regression model was developed using field data to predict CO2 concentration inside a silo bag with canola. The coefficient of determination of this regression model was 0.76 and had a root mean square error (RMSE) value of 0.196. The standardized coefficients indicated that initial moisture content was 3.9 times more important than storage temperature for CO2 prediction. Permeability to CO2 and O2 of the silo bag material was determined using a specially designed testing unit and the permeability of silo bag material to CO2 was 21.61 ±1.50×10-6 m3 m d-1m-2atm-1, and for O2 was 1.95 ± 0.36×10-6, m3 m d-1m-2atm-1 at room temperature. / May 2016

Indian mustard (Brassica juncea L.) has recently been identified as a potential and profitable alternative oilseed crop in the grain growing regions of Australia. To date, no research has been reported on adaptation of mustard in water limited Mediterranean-type environments in south Western Australia. Experiments presented in this thesis were undertaken to study adaptation of mustard in the Mediterranean-type environments in south Western Australia, with the hypothesis that mustard would be better adapted to these environments due to its reputation for drought tolerance. Experiments were conducted with three main aims. Firstly, to identify the effects of genotype, environment (times of sowing/seasons/sites) and genotype x environment interaction on the phenology, growth, dry matter production, seed yield, oil and protein contents of mustard and canola. Secondly, to identify phenological, morphological and physiological characters responsible for adaptation and yield improvement of mustard in these environments. Thirdly, to study the response of mustard to soil moisture deficits, especially in the post-flowering period, in comparison to canola. Adaptation of six mustard breeding lines/cultivars varying in maturity, height and oil quality and three canola cultivars varying in maturity were tested at a medium rainfall site (Northam) in the 1999 growing season. These genotypes were sown at four times after the break of the season and their phenology, growth, morphology, dry matter production and partitioning, radiation absorption, seed yield and its components, and seed oil and protein concentrations were measured. Adaptation of mustard to short season, low rainfall areas was tested, in the 2000 and 2001 growing seasons, at three sites (Merredin. Mullewa and Newdegate), by sowing seven genotypes of mustard and canola at three times after the break of the season. / Seed yield, oil and protein concentrations were measured at all three sites and detailed measurements of phenology, morphology, dry matter production and partitioning, radiation absorption, seed yield and its components, and seed oil and protein concentrations were taken only at Merredin. The effects of post-flowering soil moisture stress on mustard and canola was studied in detail using rainout shelters at Merredin in the 2001 growing season. Measurements of water use, leaf water potential, osmotic potential, osmotic adjustment, relative water content, and leaf diffusive conductance were taken together with morphology, dry matter production and partitioning, radiation absorption, seed yield and its components, and seed oil and protein concentration. Mustard produced seed yields similar to canola at a medium rainfall site at Northam in south Western Australia. Early sowing (May) was more suitable for mid and late maturing genotypes and mid sowing (early June) was optimum for early maturing genotypes at this site. Dry matter production and seed yield was highest in early sowing due to balanced pre-anthesis and post-anthesis development of the crop and its ability to avoid terminal drought. Very late sowing (after July) significantly reduced the dry matter production, seed yield and oil concentration of mustard and canola due to poor establishment, reduced post-anthesis duration, soil moisture and high temperature stresses which occurred at the end of the season. Mustard did not produce significantly higher dry matter and seed yield compared to canola at the medium rainfall site, Northam. Seed yield and oil concentration of mustard and canola in low rainfall environments (Merredin, Mullcwa and Newdegate) were higher when sown early in the season (May). Longer growing duration and post-anthesis duration were favourable for higher yields. / Higher rainfall during the post-anthesis phase, warmer pre-anthesis phase and cooler post-anthesis phase were associated with higher seed yield in these environments. As shown by the Principal Component Analysis and the Finlay Wilkinson Analysis, adaptation of mustard genotypes to low rainfall environments was better compared to canola genotypes. Mustard genotypes, 887.1.6.1, 82 No 2298 demonstrated their general adaptability by producing the highest mean seed yield across all environments and showing average phenotypic stability across all environments. The low yielding canola genotype, Oscar was best adapted to high yielding environments and showed below average phenotypic stability. Low yielding mustard genotypes, JM 25 and JM 33 were best adapted to low yielding environments and showed above average phenotypic stability. Early flowering and developmental plasticity had a significant contribution to yield potential and its stability. All mustard genotypes were more tolerant to soil moisture and high temperature stresses and exhibited early vigour compared to canola varieties. Mustards produced significantly higher dry matter compared to canola under soil moisture and high temperature stresses. Yield reduction due to late sowing VI was greater in canola compared to mustards. Greater dry matter production of mustards under severe soil moisture stress was related to their higher water use and radiation use, which in turn was related to their superior osmotic adjustment. / Osmotic adjustment improved dry matter production in mustards as it allowed stomata to remain partially open at progressively lower leaf water potentials and maintained higher stomatal conductance, maintained leaf area and reduced the rate of leaf senescence by increasing both avoidance and tolerance of dehydration and thereby increased radiation use, increased water use by stomatal adjustment, and increased soil moisture uptake by producing deeper roots. Mustard exhibited many agronomic advantages over canola, such as vigorous seedling growth, quick ground covering ability, early vigour, and the feasibility of direct harvesting due to non-shattering pods. Despite all these advantages currently available mustard genotypes do not have the ability to out yield canola due to their lower efficiency of conversion of dry matter to seeds, as indicated by lower harvest indices, and inferior yield component structure. Further breeding in mustard is required to modify its morphology and yield component structure. Mustard plants with more pods and pods with more seeds would produce higher yields. Shorter, compact plant stature and reduced branching would improve harvest index in mustard. Furthermore, development of mustard genotypes with high oil quality and concentration similar to canola would improve its market value as an oil seed crop.

Antioxidant compounds were extracted from canola meal by subcritical water extraction (SWE), hot water (80°C) extraction and ethanolic (95%) extraction. The highest extract yields were obtained with SWE at 160°C, and the lowest with ethanolic extraction (SWE 160°C > SWE sequential > SWE 135°C > SWE 110°C = hot water extraction > ethanolic extraction). Ethanolic extracts exhibited the highest total phenolics contents and Trolox equivalent antioxidant capacity (TEAC) values on a per gram of extract basis, and hot water extracts, the lowest (ethanolic extraction > SWE 110°C > SWE 160°C > hot water extraction). Extraction pressure (3.44-6.89 MPa) had no effect on the yields, total phenolics contents or TEAC values of extracts from SWE. The use of buffered water (pH 2-8) for SWE increased extract yield but had adverse effects on the total phenolics contents and TEAC values of extracts. No increase in efficacy of SWE at 110 or 160°C was observed at extraction times longer than 25-30 min. The total phenolics contents and antioxidant capacities of extracts were assessed by the total phenolics assay, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method, TEAC method, the β-carotene-linoleic acid (linoleate) model system, the reducing power assay and the stripped oil model system. Ethanolic extracts exhibited the highest total phenolic contents and antioxidant capacities on a per gram of extract basis. Subcritical water extraction at 160°C exhibited the highest total phenolic contents and antioxidant capacities on a per gram of meal basis. Results from the total phenolics assay and the antioxidant capacity assays were significantly correlated, with the exception of those from the stripped oil model system.

Seed vigor, although not well understood, is a key critical component for yield and is in part due to a well establishment and vigorous stand of canola (<i>Brassica napus</i>) seedling under less than ideal conditions in Western Canada. My objective was to determine what constitutes vigor by studying the response of a black seed line and a yellow seed line imbibed at 8 ºC in either water, saline or osmotic solutions, abscisic acid (ABA), ABA biosynthesis inhibitor, gibberellin (GA4+7), inhibitor of GA biosynthesis and a germination promoter, fusicoccin. Also tested was the effect of seed coat (testa) on seed germination rate and percent germination. Previous studies have established that seed vigor is in part hormonal controlled and genetically controlled. In our study, gene expression was investigated by using transcriptome analysis and hormonal analysis was used to quantitate the changes in hormones and their metabolites during germination. <p> Both the black and the yellow canola seed lines were very sensitive to increasing concentrations of saline and osmotic solutions; however, at the same osmotic potential, osmotic solutions were more inhibitory. The yellow seed line was more sensitive to these conditions than the black seed line. As expected, ABA delayed seed germination, whereas GA4+7 enhanced seed germination and GA4+7 partially overcame the inhibitory effect of ABA. The seed coat was a major factor affecting the germination rate of the yellow seed line; however, GA4+7 overcame the inhibitory effect of the seed coat, whereas ABA exacerbated it. Fusicoccin was more stimulatory to germination than GA4+7; however, unlike GA4+7, it was unable to overcome the inhibitory effect of paclobutrazol, a GA biosynthesis inhibitor. Fluridone, an ABA biosynthesis inhibitor, was unable to overcome the inhibitory effects of a saline solution suggesting that the inhibitory effect was not due to elevated ABA levels. Ethylene, a stimulator of germination, did not appear to be involved in the germination of these two lines. Controlled deterioration at 35 ºC, 85% RH was either partially or completely overcome by exogenous GA4+7. This study demonstrates that the role of hormones, salinity and seed coat on the germination of canola seed under low temperature environmental conditions. <p>During germination, ABA declined while GA4 increased. Higher ABA was found in un-germinated seeds compared to germinated seeds. GA4+7 was lower in seeds imbibed in the saline solution compared to seeds imbibed in water. Un-germinated seeds imbibed in ABA had lower GA4+7 compared to un-germinated seeds imbibed in water; however, the contents of GA4+7 were similar for germinated seeds imbibed in either water or ABA. Phaseic acid (PA) and dihydrophaseic acid (DPA) increased in seeds imbibed in either water, the saline solution or ABA, while they decreased in seeds imbibed in GA4+7. In addition, we found that ABA inhibited GA4 biosynthesis, whereas, GA had no effect on ABA biosynthesis, but altered the ABA catabolic pathway. <p> Gene expression profiles revealed that there are significant differences between un-germinated and germinated seeds. Seeds imbibed in water, GA4+7, a saline solution or ABA had different gene profiles. LEA genes, hormone-related genes, hydrolase-related genes and specific seed germination-related genes were identified and their expression profiles were finely associated with seed germination performance.

Antioxidant compounds were extracted from canola meal by subcritical water extraction (SWE), hot water (80°C) extraction and ethanolic (95%) extraction. The highest extract yields were obtained with SWE at 160°C, and the lowest with ethanolic extraction (SWE 160°C > SWE sequential > SWE 135°C > SWE 110°C = hot water extraction > ethanolic extraction). Ethanolic extracts exhibited the highest total phenolics contents and Trolox equivalent antioxidant capacity (TEAC) values on a per gram of extract basis, and hot water extracts, the lowest (ethanolic extraction > SWE 110°C > SWE 160°C > hot water extraction). Extraction pressure (3.44-6.89 MPa) had no effect on the yields, total phenolics contents or TEAC values of extracts from SWE. The use of buffered water (pH 2-8) for SWE increased extract yield but had adverse effects on the total phenolics contents and TEAC values of extracts. No increase in efficacy of SWE at 110 or 160°C was observed at extraction times longer than 25-30 min. The total phenolics contents and antioxidant capacities of extracts were assessed by the total phenolics assay, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method, TEAC method, the β-carotene-linoleic acid (linoleate) model system, the reducing power assay and the stripped oil model system. Ethanolic extracts exhibited the highest total phenolic contents and antioxidant capacities on a per gram of extract basis. Subcritical water extraction at 160°C exhibited the highest total phenolic contents and antioxidant capacities on a per gram of meal basis. Results from the total phenolics assay and the antioxidant capacity assays were significantly correlated, with the exception of those from the stripped oil model system.

Seed vigor, although not well understood, is a key critical component for yield and is in part due to a well establishment and vigorous stand of canola (<i>Brassica napus</i>) seedling under less than ideal conditions in Western Canada. My objective was to determine what constitutes vigor by studying the response of a black seed line and a yellow seed line imbibed at 8 ºC in either water, saline or osmotic solutions, abscisic acid (ABA), ABA biosynthesis inhibitor, gibberellin (GA4+7), inhibitor of GA biosynthesis and a germination promoter, fusicoccin. Also tested was the effect of seed coat (testa) on seed germination rate and percent germination. Previous studies have established that seed vigor is in part hormonal controlled and genetically controlled. In our study, gene expression was investigated by using transcriptome analysis and hormonal analysis was used to quantitate the changes in hormones and their metabolites during germination. <p> Both the black and the yellow canola seed lines were very sensitive to increasing concentrations of saline and osmotic solutions; however, at the same osmotic potential, osmotic solutions were more inhibitory. The yellow seed line was more sensitive to these conditions than the black seed line. As expected, ABA delayed seed germination, whereas GA4+7 enhanced seed germination and GA4+7 partially overcame the inhibitory effect of ABA. The seed coat was a major factor affecting the germination rate of the yellow seed line; however, GA4+7 overcame the inhibitory effect of the seed coat, whereas ABA exacerbated it. Fusicoccin was more stimulatory to germination than GA4+7; however, unlike GA4+7, it was unable to overcome the inhibitory effect of paclobutrazol, a GA biosynthesis inhibitor. Fluridone, an ABA biosynthesis inhibitor, was unable to overcome the inhibitory effects of a saline solution suggesting that the inhibitory effect was not due to elevated ABA levels. Ethylene, a stimulator of germination, did not appear to be involved in the germination of these two lines. Controlled deterioration at 35 ºC, 85% RH was either partially or completely overcome by exogenous GA4+7. This study demonstrates that the role of hormones, salinity and seed coat on the germination of canola seed under low temperature environmental conditions. <p>During germination, ABA declined while GA4 increased. Higher ABA was found in un-germinated seeds compared to germinated seeds. GA4+7 was lower in seeds imbibed in the saline solution compared to seeds imbibed in water. Un-germinated seeds imbibed in ABA had lower GA4+7 compared to un-germinated seeds imbibed in water; however, the contents of GA4+7 were similar for germinated seeds imbibed in either water or ABA. Phaseic acid (PA) and dihydrophaseic acid (DPA) increased in seeds imbibed in either water, the saline solution or ABA, while they decreased in seeds imbibed in GA4+7. In addition, we found that ABA inhibited GA4 biosynthesis, whereas, GA had no effect on ABA biosynthesis, but altered the ABA catabolic pathway. <p> Gene expression profiles revealed that there are significant differences between un-germinated and germinated seeds. Seeds imbibed in water, GA4+7, a saline solution or ABA had different gene profiles. LEA genes, hormone-related genes, hydrolase-related genes and specific seed germination-related genes were identified and their expression profiles were finely associated with seed germination performance.

Winter canola (Brassica napus cv. Crystal) requires vernalization, exposure to chilling, to induce bolting and flowering. Since gibberellins (GAs) have been implicated in the regulation of stem elongation and reproductive development in numerous plants, the role of GAs in events induced by vernalization was investigated. Three classical approaches for studying GA physiology were taken. Plant growth regulators were applied and showed that: (i) GA application induced stem elongation but not flowering in nonvernalized plants and (ii) plant growth retardants that block GA biosynthesis prevented elongation and flowering in vernalized plants. Endogenous GAs were extracted from vernalized and nonvernalized shoot tips, chromatographically purified and quantified by gas chromatography-selected ion monitoring. GA1,3,8,19 and 20 concentrations were higher in the vernalized shoots following vernalization. Feeds of [3H]GA20 to vernalized and nonvernalized plants demonstrated higher rates of [3H]GA1 formation after vernalization, suggesting increased metabolism to the biologically active form. Collectively, these studies indicate a regulatory role of GAs in the control of stem elongation in winter canola, but the role of GAs in flowering was less clear. Vernalization apparently induces stem elongation by increasing GA synthesis and particularly the biosynthesis of GA1. / xii, 138 leaves : ill., ports. ; 28 cm.

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