Industrial hemp (Cannabis sativa) is a highly productive crop that is well suited to cultivation in Canada. To better understand the development of bast (phloem) fiber secondary walls and to facilitate reverse genetics screening for improved germplasm, I undertook two sets of microarray experiments. The first compared transcript expression in stem peels at three positions along the length of the stem. The second set of microarray experiments compared transcript expression in adjacent tissue layers along the radial axis of the stem. The transcripts that were enriched in fiber-producing tissues in both studies were consistent with a dynamic program of cell wall deposition. Detailed qRT-PCR analysis of specific lignification genes identified the best targets for reverse genetics. Finally, as a first step towards establishing a virally induced gene silencing (VIGS) system, I identified viruses that produced visual symptoms of infection, although qRT-PCR failed to confirm the infection / Plant Biology

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The current study focuses on the vascular cambium and the reiterative formation of phloem fiber bundles in cotton stems. The role of the TDIF-PXY-WOX pathway was examined in regulating cambial activity and the differentiation of phloem fibers. A study was conducted to identify and characterize the cotton WOX family genes, focusing on WOX4 and WOX14, aiming to identify and analyze their phylogenetic relationships, tissue-specific expression profiles, functional roles, and metabolic consequences. Through a sequence analysis of the Gossypium hirsutum genome, 42 cotton loci were identified as WOX family members. GhWOX4 exhibited a close homology to 7 loci, while GhWOX14 displayed homology with 8 loci. Tissue-specific expression analysis revealed prominent expression patterns of GhWOX4 and GhWOX14 in cotton internodes and roots, suggesting their involvement in vascular tissue development. Functional studies utilizing VIGS (virus-induced gene silencing) demonstrated that the knockdown of GhWOX4 and GhWOX14 resulted in a significant reduction in stem diameter and bast fiber production. This result suggests that secondary phloem fiber development is regulated by GhWOX4 and GhWOX14 genes in cotton. Additionally, the metabolic profiling of VIGS plants revealed significant alterations in amino acids, organic acids, and sugars, with implications for primary metabolic pathways. These findings suggest that GhWOX4 and GhWOX14 play pivotal roles in cotton plant development, including vascular tissue growth and phloem fiber production, and metabolic regulation.

Previous studies have shown favourable properties for papaya bast fibres, with a Young's modulus of up to 10 GPa and a tensile strength of up to 100 MPa. Because the fibres remain as residues on papaya plantations across the tropics in large quantities, their use in the making of green composites would seem to be worthy of consideration. This study aims to show that such composites can have very suitable mechanical properties, comparable to or even better than the common wood plastic composites (WPCs), and as such, represent a promising raw material for composites and a low-cost alternative to wood.

Made available in DSpace on 2015-04-17T14:49:24Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1076293 bytes, checksum: e93b44f17488b33d1721a995828d5ab1 (MD5) Previous issue date: 2013-02-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The flour obtained from the watermelon bast is a byproduct with important nutritional characteristics, which is being considered a promising alternative for the development of new products. The objectives of this work were to study the process of the production of the flour from the white part of watermelon and the development of new cookies source and rich in dietary fiber. The flour was obtained by convective drying using the following conditions: temperature of 60°C, process duration of 240 minutes and air velocity of 3.0 m/s, followed by milling, grinding and sieving processes. The physico-chemical compositions were determined for the raw material, the flour and the cookies. The cookies formulations used were three: control (CT), source of dietary fiber (F1) and rich in dietary fiber (F2). For the sensory evaluation, forty-eight untrained panelists received samples of these biscuits and performed the sensory tests of acceptability, using a 9 point hedonic scale. Data analysis was performed using analysis of variance (ANOVA), using the statistical software Assistat 7.4 beta. For the flour, it was found values of moisture (9.55%) and ash (9.97%) contents within the current legislation standards, and high value of dietary fiber (33.30%) and minerals. The cookies formulated presented lower moisture content, water activity and protein, and higher contents of carbohydrates and ash. Regarding the analysis of acceptability, formulations F1 and CT obtained scores ≥ 6, with the attributes of color and texture as the most relevant. The flour from the white part of watermelon can be considered a great alternative as an ingredient in baked goods. / A farinha da entrecasca de melancia é um subproduto com características nutricionais importantes, sendo uma alternativa promissora para o desenvolvimento de novos produtos. Os objetivos deste trabalho foram estudar o processo de produção da farinha da entrecasca de melancia e desenvolver novos biscoitos fonte e rico em fibra alimentar. A farinha foi obtida por secagem convectiva nas condições de temperatura de 60 °C, tempo de 240 minutos e velocidade do ar de 3,0 m/s, seguida das operações de trituração, moagem e peneiramento. Foram determinadas as composições físico-químicas, para a matéria-prima in natura, farinha e biscoitos. As formulações utilizadas para elaboração dos biscoitos foram três: controle (CT), fonte de fibras alimentares (F1) e rico em fibras alimentares (F2). Na avaliação sensorial, quarenta e oito provadores não treinados receberam amostras desses biscoitos e realizaram testes sensoriais de aceitação, utilizando escala hedônica de nove pontos. A análise dos dados foi realizada mediante análise de variância (Anova), utilizando-se o software estatístico Assistat 7.4 beta. Foram encontrados para a farinha valores de umidade (9,55%) e cinzas (9,97%) dentro dos padrões da legislação vigente, como também, alto valor de fibra alimentar (33,30%) e ainda de minerais. Os biscoitos formulados apresentaram menores valores de umidade, atividade de água e proteína, e maiores em cinzas e de carboidratos. Quanto à análise de aceitação, as formulações CT e F1 obtiveram escores ≥ 6, sendo os atributos de cor e textura como os de maior relevância. Portanto, a farinha da entrecasca de melancia pode ser considerada uma ótima alternativa como ingrediente de produtos de panificação.

Previous studies have shown favourable properties for papaya bast fibres, with a Young's modulus of up to 10 GPa and a tensile strength of up to 100 MPa. Because the fibres remain as residues on papaya plantations across the tropics in large quantities, their use in the making of green composites would seem to be worthy of consideration. This study aims to show that such composites can have very suitable mechanical properties, comparable to or even better than the common wood plastic composites (WPCs), and as such, represent a promising raw material for composites and a low-cost alternative to wood.

This study has its background in the EU directive, the ‘Single-Use Plastics Directive’. The directive was initiated due to the environmental impacts that the oceans suffer due to plastic waste. The directive presents the most common single-use products found as waste in the oceans, including wipes and cloths. In collaboration with Essity, a global hygiene and health company, this study aims to find a replacement fibre for the currently used polyester fibre in Essity’s industrial cleaning cloths. To this end, we have evaluated the applicability of an agricultural fibre in the aspects of processability and sustainability. A theoretical part including a literature study of agricultural fibres is combined with a practical experimental part to evaluate a manufactured prototype. The theoretical part includes a compilation of the relevant parameters per fibre and the experimental part consists of laboratory tests and a panel test. On this basis, it was concluded that the first agricultural fibre, hemp, did not function adequately in the process due to the variations in fibre length and coarseness. A solution to this problem may be pre-treatments of the fibres. The second fibre, flax, functioned well in the process and may then be considered applicable in the aspect of process. The applicability of an agricultural fibre is possible in industrial cleaning cloths, but the geographical location of cultivation, transport, the chemicals used and irrigation should also be taken into account in the aspects of sustainability. / Bakgrunden till denna studie är EU-direktivet, ‘Single-Use Plastics Directive’. Direktivet har sitt ursprung i de miljöproblem som våra hav lider av på grund av nedskräpningen medplastavfall. Direktivet redovisar de engångsartiklar som återfinns allra mest i haven idag, däribland rengöringsdukar. På förekommen anledningen ska därför denna studie i samarbete med Essity, ett globalt hygien- och hälsoföretag, undersöka möjligheten att ersätta den befintliga polyesterfibern i deras industriella rengöringsdukar. Studien har utvärderat möjligheten att använda en naturlig fiber med avseende på tillverkningsprocess och hållbarhet. För att möjliggöra en utvärdering av en tillverkad prototyp, så har en teoretisk del med en litteraturstudie i kombination med en praktisk experimentell del genomförts. Den teoretiska delen består av en sammanställning av relevanta parametrar för varje fiber och den experimentella delen består av laboratorietester och ett paneltest. Slutsatserna från ett förstaförsök var att hampafibrer inte fungerade i processen på grund av variationer i hampansfiberlängd och grovlek. Att göra en förbehandling skulle kunna vara lösningen. I det andraförsöket med linfibrer, visade det sig att linfibrer fungerar i processen och därför kan vara applicerbar med avseende på tillverkningsprocess. En naturlig fiber kan användas i industriella rengöringsdukar, ur ett hållbarhetsperspektiv är det viktigt att beakta den geografiska platsen för odling, transporter, användning av kemikalier och konstbevattning.

La fibra di canapa europea è l'unica fibra naturale con una certificazione di sostenibilità. La qualità della fibra è influenzata principalmente da genotipo, tecniche agronomiche, epoca di raccolta e metodo di macerazione. L'obiettivo principale della tesi è delineare le pratiche agronomiche e di post-raccolta per migliorare l'estrazione e la qualità della fibra, con particolare attenzione alla produzione di canapa multiuso ritardando la raccolta fino alla maturazione dei semi. Le prove di densità, fertilizzazione azotata e varietali sono state condotte in differenti ambienti Europei. La procedura di decorticazione standardizzata è stata confrontata con la linea longitudinale di estrazione della fibra per applicazioni di alto valore aggiunto. I test su bio-compositi di canapa sono stati effettuati con fibra pettinata per confrontarne le proprietà tra genotipi, epoca di raccolta e metodi di macerazione. I risultati di questa indagine suggeriscono che i) la densità di semina e la concimazione azotata ottimale sono tra 90-150 piante m-2 e 30-60 kg N ha-1; ii) le nuove varietà dallo stelo giallo presentano un'alta efficienza di decorticazione e una ridotta contaminazione da canapulo nella fibra, iii) la fibra di canapa, con proprietà comparabili a quelle del lino, si è dimostrata adatta per applicazioni in compositi di alto valore. / European hemp fibres are the only natural fibre with an established sustainability certification. Hemp fibre quality is affected by genotype, agronomic techniques, harvest time and retting method. The main objective of this thesis is to outline the agronomic and post-harvest practices for improved fibre extraction and fibre quality, with special attention to multipurpose hemp production delaying the harvest from the flowering stage until seed ripening is complete. Planting density and nitrogen fertilization trials and variety trials were conducted in contrasting environments in Europe. Stems were decorticated following a standardised procedure and longitudinal hemp line for textile and high-added values application was compared with lab-scaled decortication. Impregnated fibre bundle tests were carried out with hemp hackled fibre bundles to compare composites and back-calculated fibre properties between genotypes, harvest times and retting methods. Results of this investigation suggest that i) optimum plant density and nitrogen fertilization are between 90 and 150 plants m-2 and 30 and 60 Kg N ha-1 respectively; ii) new yellow stemmed varieties are characterized by high decortication efficiency and relative high cleanness of the extracted fibre and iii) long hemp fibre, having properties comparable to those of flax, proved to be suitable for high-tech composites applications.

The tradition of using naturally occurring plant fibers is still alive in Africa. In the Uíge province of northern Angola, bast fibers from Triumfetta cordifolia serve as the basis for everyday objects, such as baskets, mats, fishing nets, and traditional clothing. The fibers exhibit a Young’s modulus of 53.4 GPa and average tensile strength of 916.3 MPa, which are comparable to those of commercial kenaf fibers. These values indicate a high potential for use as a reinforcement in biocomposites. Based on this promising mechanical and physical profile of individual fibers, different biocomposites were produced with polylactide (PLA) as a matrix. The obtained composites were analyzed mechanically, physically, and visually. Unidirectionally arranged PLA/33% T. cordifolia composites with continuous fibers showed the highest Young’s modulus (10.79 GPa ± 1.52 GPa) and tensile strength (79.37 MPa ± 14.01 MPa). These composites were comparable to those of PLA/30% hemp composites (10.9 GPa and 82.9 MPa, respectively) and therefore have economic potential.

Biodiversity is a concurrent part of the nature inheritance. The human’s activity (development of cities, industry, agriculture, transport infrastructure, pollution, etc) is influencing the nature’s disbalance. Natural areas of habitats are on the way to disappear or their status is getting worse. There is a need for special means to ensure the protection of many species of fauna and flora and their natural habitats, because they are in danger of disappearing. The network “Natura 2000” has few goals: to cover the fragile and valuable natural habitats and species of particular importance for the conservation of biological diversity within the territory of EU and to guarantee sustained efforts to protect the most important areas properly. The main objective of the “Natura 2000” network is to ensure the survival of species that are threatened or rare throughout Europe. These legal EU documents ensure the creation of the above-mentioned European network of protected territories in public territories as well as in private lands. Economic and farming activities are restricted in these areas as a way to protect natural habitats types, rare animals as well as are plants habitats. That way the interests of land owners become quite different from the nature protectionists and the prohibitions of land or forest property rights. It is quite difficult to evaluate the economical loss while establishing some new protected areas in public and private lands. The evaluation is specific for... [to full text]