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Isolation, chemical modification and applications of flax cyclolinopeptides2013 June 1900 (has links)
Oil from flaxseed (Linum usitatisssimum L.) contains hydrophobic cyclic peptides or cyclolinopeptides (CLs) comprising eight or nine amino acids. These bioactive compounds have potential therapeutic applications and may be used as scaffolds for increased utility. Two steps were undertaken to increase the potential utility of these compounds. Initially multigram quantities of flax CLs were highly enriched from flax oil. Subsequently new synthetic procedures were developed for modification of the CLs through the methionine group (Met). Finally, the utility of the modified CLs was tested in a number of applications. CLs were recovered from a crude oil extract that contain five CLs (CLA, CLC, CLE, CLJ and CLK). Oxidation of this mixture reduced the complexity of the mix to just three CLA, CLJ and CLK. CLJ and CLK were enriched then characterized by NMR and MS-MS methods. CLs containing methionine sulfoxide groups (Mso), CLC and CLE were isolated from crude mixture then selectively reduced to afford Met containing analogs: CLB and CLE'. The Met of modified CLs was used as a point for attachment of tags and couplers for various applications. Cyclic peptide modification through Met groups has not been reported previously. Synthetic methods were devised to introduce activating functional groups such as -CN, -COOH, -OH and -NH2 to the sulfur atom of Met. The modified CL conjugates were characterized using spectrometric techniques including 1D and 2D NMR spectrometry, as well as mass spectrometry. After activation the CLs were covalently linked to molecules or materials of interest including fluorescence tags (coumarin), affinity chromatography media and bovine serum albumin (BSA) for production of polyclonal antibodies. Fluorescence studies were performed in methanol, ethanol, dimethylformamide and acetonitrile to study the solvent effect. CLs attached to solid affinity matrix showed specific binding to apolipoprotein A1 after incubation with chicken serum. These CLs also act as hapten and have been used to couple BSA to produce polyclonal antibodies. Met modification was a satisfactory approach to produce a range of useful peptide products where more conventional methods of molecule attachment are not available.
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Characterizing the Flax Core Collection for Earliness and Canopy Traits2013 April 1900 (has links)
Early maturity is an important objective for breeding flax adapted to the Western Canada. Crop canopy traits influence seed yield; however, studying its effects is challenging due to the complexity and limited knowledge of the genetics of this trait. The objectives of this research are : i) to characterize flax accessions from the Canadian gene bank collection for early flowering, maturity and canopy traits; ii) to identify SSR markers associated with plant branching and leaf area index (LAI); iii) to use Structural Equation Modeling (SEM) to identify canopy variables with significant effects on yield.
The flax core collection, consisting of approximately 381 accessions, was grown at the Kernen Crop Research Farm in 2010 and 2011. Additionally, 17 early and 17 late flowering accessions from the flax core collection were screened and their phenotypic responses in both growth chamber and field environments were measured. A large amount of phenotypic diversity was observed in long day and short day environments in these experiments. Some accessions appeared to be more photosensitive, while others were photoperiod insensitive.
The genetic control of canopy traits such as LAI and plant branching were studied using association mapping. Genotyping of the core collection was conducted using 375 SSR markers. Population structure analysis assigned the 381 flax accessions in the core collection into four distinct groups. Model comparison revealed that the mixed linear model reduced spurious marker trait associations. A total of 26 markers were identified to be significantly associated with plant branching and LAI.
The simultaneous examination of crop phenology and canopy traits to seed yield was performed using SEM analysis. The results indicated greater plant stand resulted in higher irradiance absorption and which resulted in greater seed yield. Days to flowering had a significant negative effect on seed yield and growing degree days to maturity had a significant effect on seed yield. Plant branching and plant height had a positive non-linear effect on seed yield. This study has provided several insights into molecular approaches and statistical methods to improve flax breeding.
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A framework for assessing the exchange costs in the flax fibre supply chainMelitz, Siea M. 22 July 2005 (has links)
Canada has been recognized as the largest exporter of flax seed in the world. Currently, very little flax straw is further processed, despite its potential as a value added product, with only about 7-10% of Canadian flax seed producers harvesting residual flax straw rather than burning the straw. A traditional use of flax straw has been for the production of fibre for the linen industry. Interest in flax fibre has been rekindled with the impetus to seek out bioproducts that replace non-renewal resources and provide value-added opportunities for agricultural producers. Flax fibre also has a range of potential uses in automotive parts, geotextiles, insulation material, etc. Despite this potential, the Canadian flax fibre sector remains largely underdeveloped, with fledgling supply chains and lack of investment in the necessary processing capacity. This paper develops a framework for analysing the relational exchanges at different stage of the supply chain to determine if the paucity in investment is the result of prohibitively high exchange costs.
A number of distinct stages in the flax fibre supply chain can be identified: farmers producing flax seed and/or straw; processors who extract the natural fibre from the straw; and manufacturers who use the fibre in their products. The paper develops a framework that draws together insights from Transaction Cost Economics, Agency Theory and Bargaining Theory. The role of institutions in facilitating quality measurement and providing participants with information is also considered. The theoretical framework identifies asset specificity, agency measurement costs, bargaining power and under-developed institutions as key factors in the development of the flax fibre sector. From the theoretical framework, a set of propositions is developed that examine the anticipated effect of these factors on vertical coordination in the sector.
The theoretical propositions are explored through a series of semi-structured interviews with parties at each stage of the supply chain (producers, fibre processors, final manufacturers), as well as with industry experts. Information from the interviews is used to identify the transaction characteristics and the institutional framework characterizing the flax fibre sector in Canada. This is analysed through a comparative case study approach with the flax fibre sector in Europe, and the wool fibre sector in New Zealand as an example of a fully developed and long-standing fibre sector. By also noting the different vertical coordination strategies that are present in these supply chains, a connection is drawn between the presence of certain transaction characteristics and the corresponding cost-minimizing exchange relationships. The case studies are used to investigate the propositions developed from the theoretical framework regarding the impact of transaction characteristics on the optimal vertical coordination strategy and the impediments to development and investment in the sector.
The propositions developed in the framework are verified to a great extent by the comparative case study. The uncertainty in the exchange environment regarding the future direction of the flax fibre industry and the high measurement costs due to the absent quality and grading regime in the Canadian flax fibre set the two industries apart from each other. Both of these dimensions impact the exchange costs of a transaction and subsequently, the extent to which the parties are closely coordinated. The case studies verify that using a framework to analyze transactions provides additional insights because of the joint consideration of several features of the transaction.
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Field plot conditions for the expression and selection of straw fibre concentration in oilseed flaxBurton, Alison Dana 30 August 2007 (has links)
In Canada, flax (<i>Linum usitatissimum</i> L.) is grown for its seed oil. However, a major disadvantage associated with growing oilseed flax is that the straw is difficult to incorporate into the soil after harvest. Instead, the majority of flax straw is burned in the field, increasing the workload for farmers, as well as creating air pollution. Agronomic concerns are also associated with burning, since it leaves fields vulnerable to wind and water erosion. A small market exists for Canadian flax straw for making high quality paper products and some plastic composites. However, fibre-based and fibre-using industries are growing world wide, and flax straw fibre is becoming an important product. Flax straw fibre concentration varies among cultivars and environments. Consistently high fibre concentrations are essential if the fibre in oilseed flax is to become an important product for Canadian farmers. This study assembled the agronomic information necessary to select for increased straw fibre concentration in the Crop Development Centre (CDC) Flax Breeding Program. Three experiments were conducted to determine: how seeding rate and row spacing effects straw fibre concentration, the effects of seeding date on straw fibre concentration, and how nitrogen fertilizer rates effects straw fibre concentration. Seeding in mid-May at either an 18 or 36 cm row spacing at a seeding rate of 30 or 45 kg/ha resulted in high straw fibre concentration without reducing other important oilseed characteristics such as seed yield, oil content and straw fibre yield. Nitrogen fertilizer did not have an effect on either straw fibre concentration or straw fibre yield.
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Effects of composite flours on quality and nutritional profile of flour tortillasGritsenko, Maria 16 January 2010 (has links)
Obesity, glucose intolerance or insulin resistance and elevated blood
pressure are now prevalent in the U.S. Increased intake of dietary fiber, omega-
3 fatty acids, and antioxidants may help prevent or manage these diseases.
Tortillas are now part of the American diet, and are excellent carriers of higher
amounts of fiber and other nutraceutical ingredients. This study was conducted
to determine the effects of incorporating nutraceutical ingredients (flaxseed,
sorghum bran, oat flour, buckwheat flour) on whole white wheat tortilla quality.
Tortillas were prepared using a hot-press, gas-fired oven and were evaluated for
physical properties, texture and shelf-stability.
Objective and subjective tests demonstrated that whole white wheat and
multigrain tortilla doughs were harder, rougher and less extensible than refined
flour tortilla dough. Multigrain flour tortillas were thinner, larger and more
translucent than the refined flour treatment. Incorporation of whole multigrain
flours affected color of the product, giving darker tortillas. Tortilla flexibility
decreased over time. After 16 days of storage rollability scores of tortillas
decreased drastically. The most pronounced decrease in tortilla flexibility was
observed for 5% sorghum bran, 10% buckwheat, and for the treatment prepared
with of 5% flax, 5% sorghum, 5% oat, 5% buckwheat. The flexibility loss was
higher for whole white wheat and multigrain tortillas than for the refined one
which was confirmed with objective and subjective tests. To extend shelf stability of whole multigrain tortillas various amounts of commercial hydrocolloid
and ?-amylase were added to the formulation. Tortillas with 75 ppm, 100 ppm of
?-amylase, 1% and 1.5% of gum retained their flexibility during 16 days of
storage. Consumer acceptability of the whole multigrain tortillas (5% flaxseed,
5% sorghum bran, 5% oat, 5% buckwheat) was compared with commercial
multigrain tortillas and whole white wheat flour tortillas using an untrained
sensory panel. The multigrain tortillas were liked by the panel as much as the
other samples. Prepared multigrain tortillas had improved nutritional value.
Each multigrain treatment contained at least 3 g of dietary fiber, 0.29 g of ?-
linolenic fatty acid, lignans and antioxidants. It makes possible to claim them as
a ?good source of dietary fiber? and ?an excellent source of ?-linolenic fatty acid?.
The formulations tested, together with future refinements, provide more options
to consumers seeking healthier alternatives to refined wheat flour tortillas.
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Genetic and Hormonal Regulation of Stem Vascular Tissue Development In Flax (Linum usitatissimum L.)McKenzie, Ryan Unknown Date
No description available.
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Quantification and risk assessment of seed-mediated gene flow with flax as a platform crop for bioproductsDexter, Jody Elaine Unknown Date
No description available.
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Barley and flax hull ingredients as functional foodsHao, Meili 22 September 2010 (has links)
The purpose of the research was to investigate the potential for converting agricultural by-products, barley hull and flaxseed hull as well as their co-extract, into value-added functional food ingredients.
Four varieties of barley hull and 3 types of flaxseed hull were hydrolyzed in calcium hydroxide solution in a water bath at 70°C for 4 hrs with shaking. The major phenolic compounds in barley hull, flaxseed hull and their co-extracts were identified by reversed phase high performance liquid chromatography (HPLC) coupled with photodiode array detection (PAD) and quadrupole - time of flight (Q-TOF) mass spectrometry (LC-MS). Ferulic acid, p-coumaric acid, vanillic acid and vanillin, and four ferulate dehydrodimers were detected in barley hull and their co-extracts. Quantitative analysis was conducted on the phenolic acids using the available standards. However, the phenolic compounds in flaxseed were found to be distinct from that of barley hull. Large amounts of secoisolariciresinol diglucoside (SDG), ferulic acid glucoside (FeAG), p-coumaric acid glucoside (CouAG) were found in flaxseed hull with minor content of caffeic acid glucoside (CAG) and flavonoids herbacitin glucoside (HDG), whereas the phytochemical profile of the co-extract was enriched by combining major phenolic compounds from both barley hull and flaxseed hull.The antioxidant activity of barley hull, flaxseed hull as well as their co-extract was evaluated using DPPH radical scavenging assay while total phenolic content was measured using the Folin-Ciocalteau method. After screening using chemical assays, the representative barley hull extract, flaxseed hull extract as well as their co-extract were tested for their intracellular antioxidant activity and the antiproliferative activity in PC-3 human prostate cancer cells. Both chemical assays and the cell culture assays indicated that barley and flaxseed hull had strong antioxidant activity and antiproliferative activity. Although the co-extract exhibited the strong antioxidant activity in the chemicals assay, it behaved differently in the cell culture assay, which may be attributed to the chemical and biological properties of the major phenolics in the co-extract.Following evaluation of the antioxidant activity and anticancer effect of barley hull extract, flaxseed hull extract as well as their co-extract, each type of extract was incorporated into Chinese steamed bread (CSB). The phytochemical profile of CSB was enriched by incorporating barley hull extract, flaxseed hull extract as well as their co-extract, which resulted in a significant enhancement in the antioxidant activity evaluated by DPPH and ORAC.
Therefore, barley hull, flaxseed hull and their co-extract are suggested as promising sources of functional food ingredients.
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Low Fruit Set, Pollen Limitation and the Roles of Birds and Insects in Pollination of Native New Zealand Plants.Greenfield, Cassandra Joyce January 2010 (has links)
Pollination and fruit set of four species of native New Zealand flowering plant species were examined through two field seasons. Bird exclusion, pollinator exclusion, natural and supplemental pollination treatments were initiated on individuals of Cordyline australis (Cabbage tree), Phormium tenax (Flax), Kunzea ericoides (Kanuka), and Pseudopanax arboreus (Five-finger). The species differed in the self-compatibility as well as in their floral syndrome. No species showed any evidence of pollen limitation, and two species. K. ericoides and P. arboreus set fruit from more than 70% of their flowers. The response of fruit set to treatment in C. australis varied from season to season, with birds appearing important to pollination in the first but not the second field season, while birds were important in pollination across both seasons for P. tenax. K. ericoides was resilient to treatment, setting high fruit set in every treatment, compared to P. arboreus which set high fruit set when pollinators had access, but low when all pollinators were excluded. No trends relating to fruit set or PLI and self-compatibility or floral syndrome were found. That there was no evidence of pollen limitation for any species, despite variation in fruit set from some treatments, indicates that these species are performing well and not at risk of decreased population size due to pollen limitation.
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Flowering Time Studies in Canadian Cultivars and 5-Azacytidine Mutants of Oilseed Flax (Linum usitatissimum L.)2015 January 1900 (has links)
Canada is a global leader in flax production, but flax acreage in Canada remains limited since flax is not well adapted to the northern Prairies. Therefore, breeding early-flowering and early maturing flax cultivars that are adapted to the climate of the northern Prairies is one of the major strategies to expand flax acreage in Canada. The objective of this project is to understand flowering time in flax and generate early flowering genotypes that are adapted to the continental climate of the Canadian Prairies.
This project examined photoperiod sensitivity in five Canadian flax cultivars (CDC Sorrel, CDC Bethune, Flanders, Prairie Thunder and Royal) and three M9 genotypes derived from 5-azacytidine (5-azaC) treatment (RE1, RE2 and RE3). To investigate how each cultivar or genotype responds to photoperiod changes, a reciprocal transfer experiment between long day and short day conditions was conducted. All cultivars and genotypes were photoperiod sensitive. However, the level of sensitivity and length of the sensitive phase varied among cultivars and genotypes. The five cultivars were more sensitive to photoperiod changes compared with the three mutant genotypes, while RE2, which was the earliest flowering genotype, was the least sensitive genotype.
This project, in addition, examined the expression pattern of ELF4 (EARLY FLOWERING 4), a specific flowering-related gene. This experiment was conducted with three Canadian flax cultivars (CDC Sorrel, CDC Bethune and Royal) and one 5-azaC mutant genotype (RE2). GAPDH (Glyceraldehyde 3-phosphate dehydrogenase) was used as a reference gene in RT-qPCR. Results of RT-qPCR demonstrated that CDC Sorrel and CDC Bethune had a similar expression pattern, while Royal and RE2 had a similar expression pattern.
This project also sought to generate early-flowering genotypes by treating CDC Sorrel with 5-azaC as well as to introgress the early-flowering trait from RE genotypes into CDC Sorrel via hybridization. Mutant populations (M2, M3, bulk M3) and hybrid populations (F2, F3, and bulk F3) were grown and evaluated for time to flowering, maturity and height under latitude (53° N) field conditions in 2012 and 2013. 5-azaC treatment did not induce significant differences in flowering or maturity in the CDC Sorrel background. However, the early flowering trait was successfully introgressed into CDC Sorrel background since selected progeny lines flowered significantly earlier than the later flowering CDC Sorrel parental line.
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