AUTHOR=Rico Saleta , Garrido José , Sánchez Conchi , Ferreiro-Vera Carlos , Codesido Verónica , Vidal Nieves TITLE=A Temporary Immersion System to Improve Cannabis sativa Micropropagation JOURNAL=Frontiers in Plant Science VOLUME=Volume 13 - 2022 YEAR=2022 URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.895971 DOI=10.3389/fpls.2022.895971 ISSN=1664-462X ABSTRACT=The aim of this study was to propagate axillary shoots of Cannabis sativa L. using liquid medium in temporary immersion bioreactors. The effect of the frequency of the immersion (3 or 6 immersions per day), explant type (apical or basal sections), number of explants (8, 10 and 16 explants), mineral medium (MS ½ nitrates, β-A and β-H, all supplemented with 2 μM metatopoline), sucrose supplementation (2%, 0.5% and 0% sucrose), duration of culture (4 and 6 weeks) and bioreactor type (RITA® and Plantform™) were investigated. As a result, we propose a protocol for the micropropagation of Cannabis apical segments in RITA® or Plantform™ bioreactors. The explants (8 per RITA® and 24 per Plantform™) are immersed for 1 min 3 times per day in β-A medium supplemented with 2 μM metatopoline and 0.5% of sucrose and subcultured every four weeks. This is the first study using temporary immersion systems in Cannabis sativa production, and our results provide new opportunities for the mass propagation of this species.