Researchers want to develop better forages that have more biomass, stress tolerance and altered leaf lipid content
The earliest form of genetic modification started thousands of years ago when ancient farmers experimented with selection of wild plants to make them better to eat.
“When you see a new trait it is because a genetic change has occurred,” said Stacy Singer, a biotechnologist and microbiologist at Agriculture Canada in Lethbridge.
Selection of the best plants resulted in better crops but it took a long time to make changes, she said at the Canadian Forage and Grassland Association annual meeting in Calgary held Nov. 14-15.
The trial and error process is speeded up when modern researchers study the alphabet of DNA that consists of four nucleotides known as A, C, T and G. These four proteins result in different traits. A genetic change is a mutation that occurred with the substitution of one nucleotide for another, deletions, insertions or rearrangements.
“These occur naturally all the time,” she said.
Many people associate genetic modification with transgenic techniques but there are a myriad of technologies to implement change at the cellular level. It is sometimes hard to differentiate between the man-made techniques and natural changes.
Genome editing is a new breeding technology and is like precision gene surgery. The CRISPR technique introduces a protein that acts as molecular scissors to cut a specific gene site. The plant cell repairs the cut, resulting in a small mutation. It can be indistinguishable from a natural change.
In the case of forages, most genetic work has been done with alfalfa and sainfoin.
Researchers like Singer want to grow more and better forages in a sustainable manner where plants have more biomass, stress tolerance and altered leaf lipid content.
They are looking for genes that are contributing to these desirable traits but it is a step by step process at the molecular level to develop new and improved germplasm. They need to examine thousands of plants and hope one will have the mutation they seek.
Better understanding of the alfalfa gene has emerged but researchers are most likely to focus on traits that are economically feasible, said Dan Undersander, retired forage specialist at the University of Wisconsin with connections to Forage Genetics International, which released Roundup Ready alfalfa.
Researchers have developed plants with improved herbicide, insect and disease resistance. Recently, they have identified defensins, a form of protein with tremendous potential for broad spectrum disease resistance.
“That can only be put in as a gene trait at this point but has tremendous potential to help us in our alfalfa plants and other crops,” he said.
A modified trait for leaf retention during hay harvesting is also sought.
“One of the major issues is leaf loss during harvesting. Will it ever become a GM trait? Probably not because we don’t think enough farmers would buy the seed to justify the cost of getting a clearance at this point,” he said.
The associated costs of getting government approval and producer acceptance may guide research directions.
“The clearance of Roundup Ready alfalfa in the United States cost $100 million. If we hadn’t had Monsanto behind it, it never would have happened,” Undersander said.
“If we hadn’t got the first GM trait, we would never have another GM trait.”
The cost of reduced lignin clearance was about $20 million and cost less because past research was included from the herbicide resistant trait.
Alfalfa research will probably continue with herbicide resistance, low lignin and bypass protein traits because these have value to the industry. No other traits will be pursued at this time.
Government regulations and acceptance of new traits differ around the world. For example, the CRISPR technique is not regulated in the United States, but it is regulated in Canada.
CRISPR products could be sold in the U.S. but there are not enough other markets to make it worthwhile.
A reluctance to move ahead could leave the forage sector at a disadvantage.
Corn breeders are developing CRISPR products and think they can recover the costs.
“Are we going to stay current with the competition or let corn go ahead and have traits that alfalfa doesn’t have,” Undersander said.