Researchers say this means that when high-CBD plants are grown to full maturity, farmers interested in producing hemp for CBD run the risk of their crop crossing over the federal, legal limit of 0.3% THC.
The researchers examined different types of cannabis, including drug-type varieties that produce large amounts of psychoactive tetrahydrocannabinol (THC). Plant breeding has increased the THC level to the point where it can account for up to a quarter of a plant’s total weight. The scientists found that breeding high-THC plants with hemp-type plants can swap a few genes and make a new plant that produces high levels of CBD instead.
“Over the past decade, we’ve seen a surge in demand for CBD and we wanted to better understand how plant breeders created high-CBD plants to meet rising demand,” said study co-author George Weiblen, who is a professor in the College of Biological Sciences (CBS) and the science director at the Bell Museum.
After assembling a complete genome from a new breed of cannabis, University of Minnesota and Sunrise Genetics researchers found that high-CBD “hemp” plants have a mostly marijuana genome.
Published in the journal New Phytologist, the researchers found that high-CBD plants inherit about 90% of their genes from drug-type cannabis and the rest from hemp. Traditionally, cannabis plants are split into two varieties: a drug-type grown for psychoactive or intoxicating properties (i.e., marijuana) and a hemp-type used to make industrial products like fiber.
“This poses a challenge, though,” said study co-author and CBS graduate CJ Schwartz of Sunrise Genetics. “The genes that allow for the production of CBD are also a bit ‘leaky.’ This can result in about 5% of the product ending up as THC instead of 100% CBD.”
“These high-CBD plants are genetically marijuana for the most part and they can’t be expected to meet the legal definition of industrial hemp in every situation,” said Weiblen. “This means that CBD products — such as flowers, extracts and edibles — that are labeled ‘hemp’ could be incorrectly labeled and falsely branded. Fiber hemp and products made from hemp seeds, however, are drug-free.”
Research into CBD is still ongoing, though scientists have identified at least 60 different molecular pathways through which it operates. It acts via various receptor-independent channels and binds to different receptors in the brain such as serotonin 5HT1A and TRPV1. More importantly, CBD is believed to be a powerful anti-anxiety and anti-inflammatory agent.
How to Grow High CBD Marijuana: It’s All About Genetics
In any case, here are three high-CBD marijuana strains that are ideal for home growers:
2 – CBD Critical Cure
There is no way to enable your cannabis plants to produce more CBD than is genetically possible. For example, there is nothing you can do to transform a high-THC strain such as Strawberry Cough into something like ACDC which has a 20:1 CBD to THC ratio.