University of Minnesota researchers have validated a genetic test that can predict whether a cannabis plant will produce mostly CBD or THC – a tool that could help prevent farmers from cultivating hemp that violates federal and state laws.
The team studied three different cannabis varieties – from industrial hemp growers, samples from the National Institute on Drug Abuse, and wild cannabis (or ditch weed) – comparing genetic markers with the ratio of THC versus CBD. The team then verified that genetics were a good predictor of the ratio.
George Weiblen, who is a professor in the College of Biological Sciences and the science director & curator of plants at the Bell Museum whose laboratory led the study, said he hopes the technique “can assist in new seed certification for the hemp industry.”
“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.” – Weiblen in a statement
In the paper, published in the American Journal of Botany, the researchers argue that basing the definition of hemp on THC alone doesn’t match the biology and, instead, propose THC and CBD ratios.
The researchers also noted that finding THC-rich ditch weed plants is very rare, a 1 in 100 chance.
“The presence of more than one of the three cannabinoid classes in feral, industrial, and clinical populations renders the dichotomy between ‘hemp’ and ‘marijuana’ meaningless from a botanical perspective,” the study states. “The dichotomy between ‘hemp’ and ‘marijuana’ perpetuates culturally biased and pejorative assumptions about C. sativa that have hindered scientific investigation for nearly a century.”
The researchers argue that “a decolonized definition recognizing THC‐type, CBD‐type, intermediate‐type, and CBG‐type plants would be more accurate botanically and perhaps more practical as the use and regulation of C. sativa continues to expand and diversify.”