Unraveling the genetic diversity of Cannabis sativa L.: Phenotypic and molecular assessment, drivers of variation, and implications

Cannabis (Cannabis sativa L.) is a highly diverse species exhibiting significant phenotypic and genotypic variation. This review provides a comprehensive overview of current literature on cannabis genetic diversity. We begin by outlining key morphological and phenotypic traits -such as plant height, leaf morphology, flowering time, and cannabinoid composition- that are commonly used to distinguish between cultivars. We then explore genotypic diversity through molecular marker studies, including Simple Sequence Repeats, Single Nucleotide Polymorphism, and Next-Generation Sequencing approaches. These tools have significantly advanced our understanding of cannabis population structure and genetic relationships. The implications of genetic diversity studies are examined in several contexts, including the development of improved cultivars, the conservation of genetic resources, and the formulation of regulatory frameworks to ensure traceability and genetic integrity. Additionally, we investigate major factors influencing cannabis genetic diversity, such as domestication history, hybridization events, environmental pressures, and regulatory policies. By synthesizing recent findings, this review highlights the need to expand genetic research into underexplored regions like Africa, implement robust conservation strategies (e.g., seed banks) to preserve unique genetic resources, and adopt data-driven breeding approaches to enhance both agronomic traits and phytochemical profiles.