A new University study on hemp and marijuana could pave the way for a drug-free industrial hemp plant.
The study identifies the genetic markers that differentiate hemp from marijuana and could have broader implications for the growing of industrial hemp and criminal cases involving marijuana distribution.
The technique, developed by University researchers George Weiblen and Shannon Datwyler,
has immediate applications in Europe and Canada, where it is illegal to grow marijuana but legal to grow hemp, Weiblen said.
In the United States, both marijuana and hemp are illegal to grow, but the research is useful in forensic science, and DNA fingerprints from the plants could be used to link marijuana growers to distributors, he said.
Weiblen said he became interested in the research after former Gov. Jesse Ventura formed a task force to assess the viability of hemp as an alternative crop for Minnesota farmers.
“A lot of things have changed since that task force made its recommendation,” Weiblen said. “In the current climate, the applications of this technology for the Drug Enforcement Administration seem more promising than the applications for the development of a drug-free industrial hemp plant.”
The research, published in the March issue of the Journal of Forensic Science, used three hemp populations and one marijuana population.
“This is a limited and preliminary sample, but what we have shown is that there is much genetic variation within the species Cannabis,” Weiblen said. “That information is useful for separating drug and nondrug plants.”
The researchers used DNA fingerprinting to identify differences in cultivars, or domesticated plant lines. Hemp and marijuana both belong to the species Cannabis sativa, but differ in levels of the psychoactive drug tetrahydrocannabinol or THC.
Weiblen said the research is important because it is the first to unequivocally demonstrate the genetic difference between hemp and marijuana. Previous methods were able to show chemical differences between the plants, but the new research uses genetic markers.
The researchers used a technique called amplified fragment length polymorphism, which generates about 100 more genetic markers per unit effort than other research techniques.
“At this time we have a long way to go before we see a current change in policy, but this kind of work is a step in that direction,” he said. “Clearly there is a problem separating marijuana from hemp.”
Weiblen said more research will be necessary to create a drug-free and recognizably distinct cannabis plant that can’t be confused with marijuana.
“It could be accomplished through traditional breeding or genetic engineering,” he said.
Ulrike Tschirner, an associate professor in the department of bio-based products, studies hemp and flax fiber as paper alternatives. Tschirner said paper companies are looking for alternative fibers as wood becomes more expensive and difficult to get. Hemp offers a very strong fiber that is longer than fibers in straw or corn.
“Hemp is a crop like a lot of other crops; the oil has value, and the fiber is very strong, but it can be used for a lot of different things,” she said. “Papermaking fiber is just one of them.”
By law, hemp products in the United States are imported. Bruce Benson, owner of Know Name Records in Dinkytown, which sells hemp products, said most of his items come from Europe. Benson said hemp is an “amazingly tough fiber,” and that clothing made from it lasts “forever.”
Benson said he thought it was unlikely that industrial hemp would be grown in the United States.
“Good luck in this country,” he said.
Vote Hemp, an organization that lobbies for the legalization of industrial hemp in the United States, is working with some U.S. states that want to grow the plant.
Eric Steenstra, Vote Hemp president, said the market for hemp products is expanding. Canadian farmers grew 25,000 acres of the plant in 2005, with a large percentage of goods being exported to the United States, he said.
“It doesn’t make any sense that American farmers wouldn’t be allowed to compete in the market,” he said.
Steenstra said the group was encouraged by the new research.
“It’s further evidence of the distinction between hemp and marijuana,” he said. “We continue to be frustrated with the fact that the federal government refuses to recognize the distinction.”