Micropropagation aids in the efficient production of large quantities of plants while taking up less space and ensuring consistent quality. However, some plants are more difficult to micropropagate than others, and require innovative techniques to help them grow and thrive in tissue cultures. University of Connecticut researchers recently developed a system that tackles the challenges of micropropagating cannabis by avoiding hyperhydricity and fine-tuning cultures through trial and error.
Recognizing that cannabis shoots are prone to hyperhydricity, researchers used vessels with vented lids to increase airflow to hemp shoots during a 6-week initiation period, and also initiated in a medium containing increased agar. Researchers then sought to optimize shoot multiplication and extension, and extend the time the plants could grow in culture, by subculturing to media containing different levels of nutrients such as calcium, magnesium, phosphorus and nitrogen.
The team’s micropropagation system prevented hyperhydricity, and two shoot multiplication media with added mesos and vitamins showed greater shoot extension and leaf lamina development than the control and other media. One medium was found to double the rate of shoot multiplication for 12 weeks after the initiation period when further supplemented with ammonium nitrate. The results were published in HortTechnology.
“Despite all our efforts, it’s still not easy to grow cannabis in tissue culture. However, now we can multiply shoots, root shoots, and transition them from the lab to the greenhouse, which is a step forward,” said Jessica Lubell-Brant, an associate professor at UConn.
The growing medical cannabis industry could greatly benefit from micropropagation techniques, due to the consistency and reliability of the cloned plants produced. The UConn team plans to further refine the system to determine the optimal timing of rooting and length of time shoots can remain in culture.
Photo: Hemp cultures grown in vitro in an optimized medium with added mesos and vitamins. Credit: University of Connecticut