PICTURE: Micropropagation could make growing cannabis a much easier task. view More

Photo credit: Jessica Lubell-Brand

As nurseries and garden centers fill up with plants for spring landscaping, home gardeners owe much to a technique called micropropagation, which has proven beneficial for many plants – and may soon be cannabis and thanks to the work of UConn researchers at the College of Agriculture, Health natural resources.

Micropropagation is a technique used to grow large numbers of new plants from fewer “parent” plants and obtain clones with the same predictable traits. However, the cannabis industry (Cannabis sativa) has been largely excluded from this beneficial technique as this type of plant is extremely difficult to micropagate.

UConn researchers – including Associate Professor Jessica Lubell-Brand, Ph.D. Student Lauren Kurtz and Professor Mark Brand from the Institute of Plant Science and Landscape Architecture have overcome some of the challenges of cannabis micropropagation from hemp. Their method was recently published in HortTechnology.

Currently, the commercial cannabis industry relies on other propagation techniques such as collecting seeds or taking carefully timed cuttings from “mother” plants. These methods require a lot of space and maintenance because in the event of a disease outbreak or plant death, multiple copies of each line of stem plants must be kept.

“Micropropagation produces many more clones than other methods. Since it is not seed-based, the clones are uniform and behave similarly to the mother plant. Plants derived from tissue culture also have the benefit of being disease-free. They often show an increased vitality, and you can grow a lot more in less space, “says Lubell-Brand.

Tissue culture plants rely on the breeder to take on nature’s role in maintaining the right balance between nutrients and growth hormones in the culture media, regulating temperature and light – everything. In some plants, micropropagation is easy to perform, with explants placed in the growth medium multiplying easily. For others, like cannabis, the process requires quite a bit of refining to ensure the production of large numbers of healthy plants.

“Cannabis doesn’t really want to be in tissue culture. This research tries a lot to find out what more the plant needs.” says Lubell-Brand.

Realizing the potential to meet the needs of the rapidly growing medical cannabis industry, researchers set out to answer that question and decipher the needs of cannabis in tissue culture. The process requires a lot of trial and error, explains Lubell-Brand.

“We start the culture with the tips of the shoots grown in the greenhouse. Then we subculture them and if we suspect that something is missing, for example that the plant is not getting what it needs in the media, we experiment with nutrients such as Calcium. Magnesium, Phosphorus, and Nitrogen to try to extend the length of time they grow in culture. “

According to Lubell-Brand, one of the problems with micropropagation of hemp is the hyperhydricity of the shoots: when the shoots become saturated with water, they become brittle and do not grow well.

Lubell-Brand explains that adjusting the media for the first six weeks in culture and using ventilated vessels to increase airflow has avoided hyperhydricity.

“In addition to generating large numbers of parent plant clones, micropagated plants are very likely to show increased vigor compared to traditional stem propagated plants,” she says.

In the medical cannabis industry, consistency and reliability in crops are in great demand, and micropropagation could deliver both. In order for producers to start using the micropropagation technique, some equipment is required, e.g. B. an autoclave and a laminar flow bank to ensure a sterile environment. However, for operations that already use tissue culture techniques, the equipment is the same, says Lubell-Brand.

Kurtz says the research was received with some excitement: “Tissue culture is not as well elaborated for cannabis in the literature. People are aware of the complications, problems and disadvantages, so people have been quite receptive to the newspaper.”

Research continues, according to Lubell-Brand, and Kurtz plans further studies to refine the process, such as determining the optimal time for roots to form and the length of time for shoots to remain in culture.

The strains the researchers are working with are cannabidol (CBD) strains, which lack psychoactive amounts of tetrahydrocannabinol (THC), but their micropropagation technique can also be applied to THC-dominant strains. Someday, perhaps not so far in the future, most of the cannabis could be micropaged using tissue culture, though improvements still need to be made, according to Lubell-Brand.

“Despite our best efforts, growing cannabis in tissue culture is still not easy. Now, however, we can propagate shoots and roots and move them from the laboratory to the greenhouse, which is progress.”

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