Geneva (AFP)

Researchers say they discovered that cannabis was first cultivated by humans around 12,000 years ago in China, according to a study based on the analysis of genomes of plants from around the world.

The study, published Friday in the journal Science Advances, explains that the genomic history of the domestication of cannabis has not been sufficiently studied compared to other cultivated species, in large part because of legal restrictions.

The researchers therefore compiled 110 entire genomes spanning the entire spectrum of cannabis, ranging from wild plants, to historical cultivars (a variety of a plant species obtained artificially for cultivation), to modern hybrids used for hemp and drugs.

The study claims to have determined "the time and origin of domestication, post-domestication divergence patterns and current genetic diversity."

"Our genomic dating suggests that the earliest domesticated ancestors of the hemp and drug types diverged from basal cannabis" about 12,000 years ago, "indicating that the species had already been domesticated by the early Neolithic," according to this. study.

"Contrary to a widely accepted opinion, which associates cannabis with a center of crop domestication in Central Asia, our results are consistent with a single origin of domestication of cannabis sativa in East Asia, consistent with early archaeological evidence. ", also say the authors.

Cannabis has been used for millennia for textiles, as well as for its medicinal and psychotropic properties.

The evolution of the cannabis genome suggests that the plant has been cultivated for multiple purposes for several millennia, according to the same study.

Current varieties of hemp and drugs are believed to come from selective crops initiated around 4,000 years ago, optimized for the production of fiber or cannabinoids.

Breeding resulted in tall, unbranched hemp plants with more fiber in the main stem, and short, well-branched marijuana plants with more flowers, maximizing resin production.

The study was led by Luca Fumagalli from the University of Lausanne and involved scientists from Great Britain, China, India, Pakistan, Qatar and Switzerland.

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