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Flax is often considered a total utilization crop because of the potential to extract value from two distinct products - seeds and stem fibres. However, very little genetic information is available on flax fibre genetics in comparison to oil improvement studies. In order to gain a detailed understanding of genetic control of the fibre concentration and search for the possibilities of developing dual purpose flax lines using both seed oil and stem fibre, the following studies were initiated: The first study evaluated the fibre and oil-related traits in a recombinant inbred population derived from a cross between a fibre flax variety Viking and an oilseed flax genotype E1747 over multiple locations under western Canadian field conditions. The study confirmed the presence of a significant genotype by environment interaction (p < 0.01) for fibre concentration indicating selection for this trait will be challenging. However, a lack of significant correlation between fibre and oilseed characteristics in field trials was encouraging and strengthened the hypothesis that breeding dual purpose flax types for western Canada is possible. The study also identified potential recombinant inbred lines (RILs) with enhanced fibre concentration as well as oil characteristics for use in future breeding endeavors. The second study established an anatomical basis for further research into flax fibre improvement by studying differences between the stem anatomy of 14 diverse flax genotypes in the field and under controlled environments such as a growth chamber. The results from the study supported the use of controlled environments for the purpose of quick screening of high fibre containing genotypes, especially at the green capsule stage of plant growth. The results also indicated that it was possible to select high fibre oilseed flax lines based on anatomical markers such as average area of single fibre cells, total fibre area and fibre to stem area ratio. In the third study, 17 simple sequence repeat (SSR) and 2 cleaved amplified polymorphic sequences (CAPS) molecular markers were used to assess the extent of genetic variability in the Viking × E1747 RIL population. CAPS markers LuFAD3A and LuFAD3B had the highest marker trait association (p < 0.0001) with linoleic and linolenic acid concentration. SSR markers such as CV8824, 5B6 and LU32 were found to be associated with plant height, oil concentration and protein concentration respectively using single marker analysis and step wise regression analysis. The molecular study confirmed the importance of Viking × E1747 mapping population in identifying genes/ markers related to both fibre and oilseed related traits in flax. In the fourth study, global transcript profiling using cDNA - based microarrays was performed to identify differentially expressed fibre related transcripts between Viking and E1747. The largest group of transcripts (7 %) found more abundant in Viking relative to E1747 fell under the functional group of cell wall development using gene ontology (GO) analysis. Transcripts such as callose synthases, expansins, cytochrome P450, fasciclin-like arabino galactan proteins and β-galactosidases were highly abundant in Viking relative to E1747. The transcripts more abundant in E1747 relative to Viking were UDP – glucose glucosyltransferase, auxin repressed protein, ubiquitin conjugating enzyme, peroxidases and lipid transfer proteins. Quantitative real time PCR results confirmed the suitability of the microarray platform to accurately discriminate transcript profiles between the two diverse flax types. In conclusion, this research has provided a number of new insights into flax fibre genetics. This information lays the foundation for further genetic studies on flax bast fibres and will complement research on developing dual purpose flax varieties.

Grewia optiva är en utav många outnyttjade stjälkfibrer som skulle kunna bidra till ökandet utav de naturliga fiberalternativen. Fibern har idag inte så många användningsområden på grund utav dess hårda och styva uppbyggnad, vilket gör den svår att spinna till garn. På uppdrag av organisationen Bhartiya Gramotthan Sanstha (BGS) har i detta projekt en redan befintlig metod utvecklats för att förädla fibern. Vad som främst eftersöktes var nedbrytandet av pektin som är en av de faktorer som bidrar till fiberns hårda och styva struktur. I metoden användes biologiskt nedbrytbara enzym som katalysatorer. En fungerande metod skulle kunna öka användningsområdet hos stjälkfibrer generellt och öka möjligheten till användandet utav fler naturliga fibrer. Enzymet som har använts i metoden är ett pektatlyas EC 4.2.2.2 som katalyserar reaktionen som sker då pektinmolekyler klyvs. För att effektivisera processen adderades en komplexbildare, EDTA, som tidigare visat goda resultat för lin. Efter enzymbehandlingen skedde en viktreduktion av fibrerna samt förändring av deras utseende. I svepelektronmikroskop observerades förändring av ytstruktur samt separation mellan fiberbuntarna. Dessa parametrar är viktiga och har stor inverkan på spinnbarheten hos fibrer. I projektet har försök att spinna fibern gjorts men inte lyckats helt. Förändringen på ytstruktur och separation mellan fibrerna tyder dock på att behandlingen är ett steg i rätt riktning. / Grewia optiva is one of many unused bast fibres that could contribute to an increase of natural textile fibres on the industrial market. This fibre has to-day not as many applications due to its stiff and hard structure that makes the fibre difficult to spin into yarn. On behalf of the organisation Bhartiya Gramotthan Sanstha (BGS) has an existing method been developed to process the Grewia optiva fibre. The method is developed to break down substances like pectin that is responsi-ble for the hard and stiff structure of the fibre. Degradable biological en-zymes were used as catalyser in the method. With a functioning method like this the applications of bast fibres could increase and contribute to the use of more natural fibres. The enzyme used to catalyse the chemical reaction and the cleavage of pec-tin molecules in this method was a pectate lyase EC 4.2.2.2. In this method EDTA was used as a chelator to efficient the chemical process. EDTA has been used as a chelator in earlier reports and showed good results. After the enzymatic treatment a weight reduction of the fibre was notable. In SEM-analysis separation between fibres and changes on the fibre surfaces was observed. These parameters are important and affect the spinning capability of the fibre. To test the spinning capability of the enzyme treated fibre they were spun in a ring spinning system, unfortunately not successfully. The surface changes and the separation shows that the enzymatic treatment had occurred and indicates that the method has developed in the right direction.

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.