de Ronne, M.; Lapierre, E.; Torkamaneh, D.

Cannabis (Cannabis sativa L.), once shrouded in the shadows of prohibition, is now emerging as a versatile and promising plant species, riding the wave of recent legalization. This transformation has unlocked opportunities for both medical research and industry growth, propelling cannabis into the global spotlight. Yet, years of prohibition have hindered the cannabis research community, which is hugely undersized and suffers from a scarcity of understanding of cannabis genetics and how key traits are expressed or inherited. To bridge this gap, we conducted a comprehensive genome-wide association study (GWAS), using a panel of 176 drug-type cannabis accessions, curated to represent the Canadian legal market. This pioneering GWAS harnessed the power of high-density genotyping-by-sequencing (HD-GBS), resulting in an exhaustive catalog of 800K genetic variants. These variants served as the bedrock for a GWAS designed to dissect the genetic foundations of nine key traits. To identify the most robust markers associated with these traits, two sophisticated statistical methodologies were used (SUPER and BLINK), ultimately identifying 33 markers significantly associated with agronomic and morphological traits. These markers, several of which exert a substantial phenotypic impact, guided us to a rich trove of putative candidate genes that reside in high linkage-disequilibrium (LD) with the markers. Markers uncovered in this study hold enormous promise, poised to revolutionize molecular breeding for the development of enhanced cannabis varieties that can cater to an array of diverse needs. In doing so, they lay the solid foundation for a vibrant and innovative cannabis industry poised to reshape the future.