Botanists conduct first large-scale genetic study of marijuana, hemp

August 26, 2015, University of British Columbia
A study by Canadian researchers is providing a clearer picture of the evolutionary history and genetic organization of cannabis. Credit: Jonathan Page

A study by Canadian researchers is providing a clearer picture of the evolutionary history and genetic organization of cannabis, a step that could have agricultural, medical and legal implications for this valuable crop.

"Even though hemp and are important crops, knowledge about is lacking because of its status as a controlled drug," said Jonathan Page, a University of British Columbia botanist who co-led the first large-scale study of the of cannabis. The research was conducted together with Sean Myles, a population geneticist at Dalhousie University.

Researchers looked at the genotypes of 81 marijuana and 43 hemp samples. Using the DNA variants in the cannabis genome, they were able to search for relationships between different plants. They found that , which consist of three species (C. sativa, C. indica and C. ruderalis), are often incorrectly labeled.

Popular lore assigns different characteristics to marijuana plants. For example, Indica-type plants are believed to produce relaxing and sedative effects as opposed to more stimulating Sativa-type plants. The researchers found only a moderate correlation between the ancestry of marijuana strains reported by breeders and the ancestry inferred from their DNA. For example, a sample of Jamaican Lambs Bread, which is classified as C. sativa, was almost identical at a genetic level to a C. indica strain from Afghanistan.

"Cannabis breeders and growers often indicate the percentage of Sativa or Indica in a cannabis strain, but they are not very accurate," Page explained.

While hemp plants also go by the latin name C. sativa, researchers discovered that hemp showed a high amount of genetic separation from marijuana, likely due to the breeding of the for radically different uses.

Canada is a global leader in hemp production, with more than 80,000 acres devoted to seed and fibre production. A licence from Health Canada is required to grow marijuana for medical purposes, and there are now 25 licensed producers supplying about 21,000 Canadian patients. Understanding cannabis genetics and evolution could assist in better breeding efforts for both crops.

"The genetic difference between marijuana and has in many countries," said Page. "Right now, the genetic identity of a marijuana strain cannot be accurately determined by its name or reported ancestry. Ultimately we require a practical, accurate and more reliable classification system of this plant."

The findings were published today in PLOS ONE.

Explore further: Study explains why hemp and marijuana are different

More information: Sawler J, Stout JM, Gardner KM, Hudson D, Vidmar J, Butler L, et al. (2015) The Genetic Structure of Marijuana and Hemp. PLoS ONE 10(8): e0133292. doi:10.1371/journal.pone.0133292 . … journal.pone.0133292

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not rated yet Aug 26, 2015
It will end when all lobbying of the US government is made illegal, with something like a 3-5 year minimum jail term for each individual offense, consecutively served, no plea bargaining, no time off for good behavior. Both politician and corporate Representative to be serving time.

All funds for air time and banners, etc, all campaign funds for any federal election of any kind are to be paid for out of the public coffers, each representative bid has the same influence.

Fund given to politicians for campaigning to be made illegal, support of any kind out idea of the public coffer system made illegal, with a minimum 3-5 year jail term for each offense, to be served by political hopeful and the corporate offender alike.

This is largely the way it is done in other countries due to the problem of corporate fascism being the end result ----if it is not curbed.

Only then will you even begin to get the US government and system pried free of the influence of big pharma.
not rated yet Aug 26, 2015
As of 2014 the United States government recognized THC as a cancer killing agent. When will the oppressive hypocrisy end-

You are not going to cure any cancers with THC alone.

THC is marginally active as tumor suppressor, in fact CBD (cannabidiol, which is considered non-psychoactive) is slightly better at suppressing tumor. However, a combination of THC-CBD at low dosage, together with irradiation is considerably active at tumor suppression.

Wai Liu is a senior research fellow at St George's, University of London:
"Our results showed that the dose of irradiation we used had no dramatic effect on tumor growth, whereas CBD and THC administered together marginally reduced tumor progression. However, combining the cannabinoids with irradiation further impeded the rate at which tumor growth progressed"

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