Establishing robust tools for Cannabis propagation and variety improvement
Creators: name: Das, Rekhamani
Publisher: name: Southern Cross University
Year: 2024
Subjects: Cannabis
Micropropagation
Cannabis tissue culture
QTL mapping
GM cannabis
Agroinfiltration

description: The deregulation of Cannabis (Cannabis sativa L.) has renewed interest in Cannabis research for medicinal, recreational, and industrial purposes. The various Cannabis industries are still in their infancy and many standard practices relating to cultivation, genetic resource management and cultivar improvement have not been fully developed and optimized. This thesis aims to address these fundamental gaps through three research chapters: 1) investigating quantitative genetic approaches for trait development, 2) improving efficient micropropagation methodologies, and 3) developing transgene technologies to support research and development (R&amp;D).
description: The genetic control of complex traits like cannabinoid and terpene composition remains poorly understood. Two lines of contrasting cannabinoids and terpene profiles were selected from a diverse collection as parents to develop a quantitative trait loci (QTL) mapping population. The F2 population resulting from a selfed female F1 was phenotype in two environments and genotyped with a novel Cannabis fingerprinting platform. A total of 32 QTLs were identified, including two major QTL clusters, one for major cannabinoids on chromosome 7 and another for monoterpenes on chromosome 5. A candidate cannabinoid synthase and four candidate terpene synthases were identified within a 1 Mb region of the respective peak markers.
description: Cannabis is challenging to propagate sexually due to dioeciousness, heterozygosity and inbreeding depression. Conventional vegetative propagation via cuttings is associated with a lack of scalability and production inefficiencies. Micropropagation has the potential to overcome these challenges. However, while protocols for Cannabis tissue culture are available, issues with reproducibility and broad scale applicability continue to exist. Utilizing diverse Cannabis germplasm and commercial lines, the second study focused on enhancing the health and multiplication rate of Cannabis during the multiplication phase through the optimization of basal salt composition. Assessing the impact of hormones, calcium and nitrate on key factors such as height, health, vitrification, rooting, and multiplication rate, a medium that yielded optimal results was identified.
description: The creation of transgenic Cannabis remains an elusive milestone in Cannabis R&amp;D, hindered by the recalcitrant nature of Cannabis tissue towards transformation and regeneration. In the third study proof-of-concept for a novel transformation method based on vacuum infiltration of Agrobacterium tumefaciens was established. Successful transformation in floral tissue, trichomes, immature embryos and callus was demonstrated using a GUS reporter construct. Although regeneration of transgenic plant from transformed callus was not achieved, transformation of female reproductive organs might pave the way for a floral dip method for Cannabis. The tools developed here will benefit both the Cannabis research community and industry.