The Past, Present and Future of Cannabis sativa Tissue Culture

Abstract

The recent legalization of Cannabis sativa L. in many regions has revealed a need for effective propagation and biotechnologies for the species. Micropropagation affords researchers and producers methods to rapidly propagate insect/disease/virus free clonal plants, store germplasm, and forms the basis for other biotechnologies. Despite this need, research in the area is limited due to the long history or prohibitions and restrictions. Existing literature has multiple limitation: many publications use hemp as a proxy for drug-type Cannabis when it is well established that there is significant genotype specificity, studies using drug-type cultivars are predominantly op-timized using a single cultivar, most protocols have not been replicated by independent groups, and some attempts demonstrate a lack of reproducibility across genotypes. Due to culture decline and other problems the multiplication phase of micropropagation (stage 2) has not been fully developed in many reports. This review will provide a brief background on the history and botany of Cannabis as well as a comprehensive and critical summary of Cannabis tissue culture. Special attention will be paid to current challenges faced by researchers, the limitations of existing Cannabis micropropagation studies, and recent developments and future directions of Cannabis tissue culture technologies.

Comparative Restriction Enzyme Analysis of Methylation (CREAM) Reveals Methylome Variability Within a ClonalIn VitroCannabis Population

“…In order to reliably produce consistent extracts, it is critical that they are obtained from genetically stable plants grown under highly controlled conditions. Although cannabis is an outcrossing species with exceptionally high levels of within population variability, clonal propagation methods are relatively easy to use and are optimized to produce uniform populations (Monthony et al, 2021). As a result, in recent years, clonal propagation methods have emerged as the primary method for large-scale production of cannabis.…”

“…The compact setup of in vitro tissue culture allows for a higher density of plants, minimizing the floor area needed for maintaining mother plants. Importantly, the sterile nature of this technique enables the production of insect-, pathogen-, and virus-free propagules, reducing biotic pressures on the plants (Hesami et al, 2021;Monthony et al, 2021). Typically, it is expected that clones produced in vitro using tissue culture techniques will share the same genetics and thus express the same phenotypes.…”