A University of Minnesota research team has validated a simple genetic test to predict whether a cannabis sativa plant will produce mostly CBD or THC.
The group studied three different varieties of plant to compare genetic markers with the ratio of THC versus CBD, and then verified that genetics were a good predictor of the ratio.
Depending on the THC level, cannabis plants are classified as hemp or marijuana. However, the researchers argue that a definition based on THC alone doesn’t match the biology. Instead, they propose using the ratio of THC to CBD to separate THC-type plants from CBD-type plants.
Research lead George Weiblen said: “We validated a simple genetic test that can predict whether a plant will produce mostly the CBD or THC molecule, using a variety of cannabis sativa plants.”
Understanding the genetic basis for CBD-type and THC-type plants has implications for the US Department of Agriculture and state industrial hemp programs. The opportunity to know that seeds are CBD-type prior to planting means they could be certified to guarantee consistency and quality.
Industrial hemp growers monitor cannabis sativa plants throughout the season and send samples off for chemical analysis, but THC levels peak at the plant’s maturity and can catch growers off guard. If the crop exceeds federal THC levels, the growers must destroy the crop. This makes growing industrial hemp much riskier than other crops.
“We hope this new test can assist in new seed certification for the hemp industry,” said Weiblen.
“For hemp to take off in Minnesota and elsewhere, there must be ways to assure growers they won’t have to destroy their crops at the end of the season.”
The research team, led by the Weiblen Lab, published their findings in the American Journal of Botany.