The world is going to need more food. One of the obvious paths toward resolving that issue is crafting versions of widely used crops that can better grow in harsh environments, and among the big crops that researchers have been looking at is wheat. The genetics of bread wheat have been under investigation for years now, but today a group of researchers is publishing a draft of the crop’s genome, which they say will provide the tools necessary to start planting better wheat.
A faster way to breed just the right wheat
“It’s a fairly important information resource for breeding,” Klaus Mayer, lead author of the paper, tells The Verge. Using the genome draft, Mayer says, will allow people who breed wheat “to speed up the breeding to adjust to challenges." That includes anything from resistance to pathogens to adapting to climate change.
This isn’t genetic modification though. Instead, breeders would test their seeds to see if they have the specific genes that they’re looking for, and then breed those seeds with other wheat until they get the perfect mixture. Effectively, it’s a modernized version of what humans have been doing for ages — selectively growing whatever crops work best. Now, it can just be done much more efficiently.
The opportunities that Mayer lists are broad because breeders don’t necessarily know how much is possible. Rather than modifying the crops to have a certain trait, breeders are in effect diving back in to the crop’s history, searching for traits that can exist in wheat but have been passed over by genetics in most modern strains.
There isn’t any one trait that’s the holy grail for growing wheat, though. Rather, breeders are broadly looking to increase the crop’s yield: improving the ratio of wheat that’s planted to wheat that’s ultimately harvested. But it can take activating one or more of many different traits to actually get there.
“This includes things like [resistance against] diseases, pest resistance, anything like that,” Kellye Eversole, executive director of the International Wheat Genome Sequencing Consortium (IWGSC), tells The Verge. "Also, things for droughts or too much water. It can be almost any aspect.”
"It takes a while to put it all together."
Eversole’s organization, the IWGSC, is responsible for the draft sequence that’s being described today by a paper in Science. It isn’t the very first draft of the bread wheat genome out there, but the consortium’s draft is supposed to more accurately describes where each gene is located, filling in significant limitations on an earlier version. In fact, Mayer himself was a corresponding author on the paper describing those earlier findings.
Publishing a draft of the wheat genome is a critical addition to researchers’ growing work on the genetics of plants. Together, wheat, corn, and rice make up the vast majority of grain crops grown in the world. A draft sequence for corn was published in 2008, and a draft for rice was published even longer ago, back in 2002.
It’s fair to suspect that these developments could have a big impact on the world’s food supply, should they pan out. In a separate paper published today in Science, researchers from the University of Minnesota write that finding improvements in a few specific regions and crops could actually allow farmers to meet the hunger needs of the earth’s growing population.
The paper also places a big focus on the actual yield of wheat, corn, and rice, as well as other leading crops. By improving their yield by 50 percent, it finds, enough calories would be generated to feed an additional 850 million people. Most likely, these gains would come in Africa, Asia, and Eastern Europe. The paper also notes that reducing the nitrogen and phosphorus usage in fertilizers for these crops would help to cull a major source of greenhouse gases.
It'll still take years to put together the right genes
It’s natural then to accept the IWGSC’s obviously high hopes for what will come next for wheat with the help of their draft. In fact, the consortium says that some breeders have already started using it. Those benefits, however, likely won’t be seen in the immediate future.
“It takes a while to put it all together,” says Steve Goff, the lead author on one of the 2002 papers describing the rice genome draft. “A conventional breeder doesn’t necessarily instantly know how to convert a genome into a molecular breeding program. There’s a big technology gap there that needs to be filled.”
Companies that think they can make a profit off of wheat will certainly help to fill it. That’s been the case with rice as well, though Goff notes that it’s difficult to say just how much of a difference the genome has made so far: because companies keep their work private, one can’t tell exactly what was done to achieve a certain strain.
And even though being able to reference a genome can allow breeders to skip years of work, it could still take upward of 10 years to get the right strain together. Eversole says her hope is for future versions of the genome to help bring that figure down to between three and five years. “We’re still at the beginning of molecular breeding,” Goff says, “but it seems to be working.”