"Basal-derived cannabis explants should be used as the preferred tissue culture starting material"

"Cannabis has presented challenges in micropropagation, including high rates of hyperhydricity, low multiplication rates, and culture decline over time. For cannabis, little attention has been given to the potential impact of explant sources within the plant on subsequent growth and development in vitro. From other species, it is known that the explant source can have a significant impact on future development." Therefore, a study was performed by the University of Guelph to compare the growth and development of explants collected from various positions within the plant, ranging from the top to the bottom. "Explants derived from the basal portion of the plant had an acceptable multiplication rate throughout the experiment and produced cannabis plantlets with shorter but wider leaves, indicative of rejuvenation."

The researchers selected stem segments from a high-cannabinoid cultivar called Honey Banana. To study the effect of the explant's sources, stem segments with two nodes were selected from different parts of the greenhouse-grown mother plant, including the basal part, near-basal part, middle part, and apical part. 

Results 
The results showed that the explants derived from the basal and near-basal parts led to maximum plantlet height, number of nodes, and canopy surface area. "Our results also display that the explants derived from the basal and near-basal parts produced plantlets of higher quality, which shows that these types of explants have greater potential to produce more vigorous plantlets." The researchers explain that the endogenous balance of phytohormones in the explants obtained from the basal and near-basal parts of the mother plant contributes to the emergence of their juvenile characteristics. "Therefore, such explants have been reported as the best source of initial explants for in vitro rejuvenation practices. Moreover, such explants have better performance in tackling the adverse effects of somaclonal variations."

To read the complete study, go to www.mdpi.com