New research on cannabis genetics suggests that incentives in the legal marijuana market—such as the desire for plants to mature faster and produce more cannabinoids for extraction—may be leading to a decline in biodiversity of the plant worldwide.

A graduate thesis published this month combines observations about genetic trends in cannabis with interviews with dozens of plant breeders to explain the factors behind what author Caleb Y. Chen, at California State Polytechnic University (Cal Poly) Humboldt, describes as “the bottlenecking of Cannabis genetics.”

The review notes that while humans have been selectively breeding the cannabis plant for thousands of years, breeders in what it refers to as the “post-prohibition” era have optimized for a handful of traits, such as a high proportion of flowers as opposed to stalks or leaves, maximum cannabinoid content, a “desirable suite” of aromatic terpenes and a reproducible chemical profile.

That hasn’t always aligned with connoisseur preferences, but it’s made economic and regulatory sense sense. Citing interviews with growers in a 2021 paper, Chen writes that “their preference for High THC content in cultivars ‘was due to state testing regulations and a misinformed consumer base, rather than grower partialities.’”

So-called genetic bottlenecking isn’t unique to cannabis, the paper acknowledges, but is a common occurrence among agricultural crops. Nevertheless, research indicates that wild cannabis varieties are effectively a thing of the past.

“Recent genetics studies of Cannabis collections continue to suggest that wild specimens of Cannabis have gone extinct and existing ‘wild’ cannabis plants are feral escapees of domesticates,” the paper says, noting that wind pollination and other factors have “eliminated wild specimens from the genepool.”

Wind pollination also threatens to “wipe out landrace populations with ‘contamination’ from pollen via modern hybrids, therefore further bottlenecking Cannabis genetic diversity on a global scale,” the research found. “This has been reported from Morocco but also in Jamaica, Mexico, Thailand…and even parts of India.”

“Even without the human aspect of added Prohibition, more so than other crops, genetic bottlenecking is a real and present problem for Cannabis,” it adds.

Read more at Marijuana Moment