Towards the improvement of hemp (Cannabis sativa L.) for agriculture

Hemp (Cannabis sativa L.) is a multipurpose crop with numerous beneficial applications. The uses of hemp range from the pharmaceutical sector to the building materials industry. Meanwhile, the carbon sequestration potential of hemp makes it an ideal candidate for transitioning to a low-carbon economy. However, due to widespread legislative ban on hemp cultivation, and difficulties in hemp breeding, we currently lack high-yielding hemp cultivars with improved traits for specific end-uses. Here, I explored methods that can be used to improve hemp for agriculture and research. First, I developed an Agrobacterium tumefaciens-mediated transient genetic transformation protocol that can be utilised to study hemp genetics. I tested the protocol on a panel of five hemp cultivars, and achieved successful transformation in all five cultivars. Subsequently, I utilised this protocol to perform a protein localisation assay. Further, I explored the effects of phytohormones on hemp vegetative and reproductive traits, and evaluated their potential use as plant growth regulators. I investigated the effects of auxin, gibberellin, and their inhibitors, on plant height, time of branch initiation, biomass yield, flowering time, and sex expression, using the monoecious fibre cultivar ‘Felina 32’. Finally, I conducted the first characterisation the members of TCP transcription factor family in the Cannabis genome. I performed phylogenetic analysis, identified conserved domains and motifs in the CsTCP proteins, and explored the expression patterns of the CsTCP genes, and provides putative functions of agronomic relevance for several of the proteins. Together, the findings in this thesis advance our knowledge of key methods that can be used to improve hemp for agriculture and facilitate in-depth genetic hemp research.